TY - JOUR TI - Innate variability in sexual development irrespective of body fatness in gilts1 AU - Beltranena, E. AU - Aherne, F. X. AU - Foxcroft, G. R. T2 - Journal of Animal Science AB - To separate the effects of fatness from those of lean tissue growth on reproductive development, 52 gilts (33.2 kg, 75 d) had ad libitum access to a high-energy diet (HE; n = 31) or were fed restrictively a low-energy diet (approximately 80% of ad libitum; LE; n = 31) until 160 d of age. All HE and 15 LE gilts were then slaughtered; the 16 LE gilts that remained were then allowed ad libitum access to the low-energy diet until slaughter at 175 d (LER). Twelve littermate trios allocated across treatments were cannulated and bled during both unfed and fed states before slaughter. Gilts in the HE group were 8 kg heavier, 3.5 mm fatter (backfat), and consumed 14.9 MJ of DE more per day than gilts in the LE group at 160 d (hereafter P < .05); LER gilts were 7 kg heavier, 2.2 mm fatter, and consumed 21 MJ of DE more per day at 175 d than LE gilts at 160 d. Carcass fat was lower in LE gilts than in HE or LER gilts, but carcass lean was similar among groups. Treatment did not affect basal or episodic LH or growth hormone secretion, reproductive tract weight, follicular volume, or plasma or follicular fluid estradiol-17β. Postprandial plasma insulin was greater in LER than in HE or LE gilts, but plasma insulin-like growth factor I and urea nitrogen were similar among groups. Plasma nonesterified fatty acids and creatinine were greater in HE than in LE or LER gilts. These results suggest that when protein accretion rate is maximal, differences in fatness do not influence reproductive development in the prepubertal gilt. Irrespective of treatment, the only measured factor showing an association with ovarian development was the innate variability in episodic and basal LH secretion. DA - 1993/2/1/ PY - 1993/2/1/ DO - 10.2527/1993.712471x VL - 71 IS - 2 SP - 471-480 LA - en OP - SN - 0021-8812 1525-3163 UR - http://dx.doi.org/10.2527/1993.712471x DB - Crossref ER - TY - CONF TI - Studies on potassium-lysine interrelationship in broiler chicks AU - Shin, H.Y. AU - Han, I.K. AU - Kim, W. C2 - 1993/// C3 - Proceedings VII World Conference on Animal Production DA - 1993/// VL - 2 SP - 386–387 ER - TY - CONF TI - Effects of bacterial inoculation and propionic acid on fermentation quality, microbial population, and aerobic stability of ensiled high-moisture ear maize AU - Sebastian, S. AU - Phillip, L.E. AU - Fellner, V. AU - Idziak, E.S. T2 - 10th International Conference on Silage Research C2 - 1993/// CY - Dublin, Ireland DA - 1993/// PY - 1993/// ER - TY - JOUR TI - A comparison of the effects of a bacterial inoculum and propionic acid in preserving high moisture ear corn, and their subsequent impact on rumen fermentation, digestion and growth by beef cattle AU - Fellner, V. AU - Sebastian, S. AU - Phillip, L.E. T2 - Journal of Animal Science DA - 1993/// PY - 1993/// VL - 71 IS - Supplement 1 SP - 265 ER - TY - RPRT TI - Preservation of high-moisture ear corn (HMEC) with a bacterial inoculum and propionic acid, and its impact on rumen fermentation, digestion and growth by beef cattle AU - Fellner, V. AU - Phillip, L.E. AU - Sebastian, S. AU - Idziak, E.S. A3 - Department of Animal Science, McGill University DA - 1993/// PY - 1993/// M3 - Research Report PB - Department of Animal Science, McGill University ER - TY - RPRT TI - The use of a ventilator prevents the decrease in blood pH in sheep anesthetized for an extended period AU - Fellner, V. AU - Burchard, J.B. AU - Pika, J. AU - Phillip, L.E. A3 - Department of Animal Science, McGill University DA - 1993/// PY - 1993/// M3 - Research Report PB - Department of Animal Science, McGill University ER - TY - RPRT TI - Effects of bacterial inoculation and propionic acid on fermentation quality, microbial population and aerobic stability of ensiled high-moisture ear corn AU - Sebastian, S. AU - Phillip, L.E. AU - Fellner, V. AU - Idziak, E.S. A3 - Department of Animal Science, McGill University DA - 1993/// PY - 1993/// M3 - Research Report PB - Department of Animal Science, McGill University ER - TY - RPRT TI - Unique energy supplements for newborn piglets AU - Odle, J. AU - Lin, Xi AU - Wieland, T.M. AU - van Kempen, T.A.T.G. AU - Zijllstr, R. A3 - National Pork Producers Council DA - 1993/// PY - 1993/// M3 - Research Investment Report PB - National Pork Producers Council ER - TY - JOUR TI - Pig serum and milk insulin-like growth factor (IGF) binding proteins throughout lactation AU - Donovan, S.M. AU - McNeil, L.K. AU - Odle, J. AU - Jimenez-Flores, R. T2 - FASEB Journal DA - 1993/// PY - 1993/// VL - 7 SP - A643 ER - TY - JOUR TI - Maximum oxidation of 3-14C-(D)-(-)-β-hydroxybutyrate (BHBA) in 1-2-day-old-piglets AU - Tetrick, M.A. AU - Adams, S.H. AU - Odle, J. AU - Benevenga, N.J. T2 - FASEB Journal DA - 1993/// PY - 1993/// VL - 7 SP - A380 ER - TY - JOUR TI - Acetogenesis replaces ketogenesis during β-oxidation in neonatal pigs AU - Adams, S.H. AU - Lin, X. AU - Odle, J. AU - van Kempen, T.A.T.G. T2 - American Zoologist DA - 1993/// PY - 1993/// VL - 33 SP - 37A ER - TY - CONF TI - Role of EGF and IGF in the neonatal intestine: development of a piglet model AU - Donovan, S.M. AU - Zijlstra, R. AU - Odle, J. T2 - IV. International Symposium on Hormones and Growth Factors in Milk C2 - 1993/// CY - Slovakia DA - 1993/// PY - 1993/// ER - TY - MGZN TI - Nutrient allowances for swine AU - Easter, R.A. AU - Odle, J. AU - Hollis, G.R. AU - Baker, D.H. T2 - Feedstuffs DA - 1993/// PY - 1993/// VL - 65 SP - 38–44 ER - TY - RPRT TI - Unique energy supplements for newborn piglets AU - Odle, J. AU - Lin, X. AU - Wieland, T.M. AU - van Kempen, T.A.T.G. AU - Zijlstra, R. DA - 1993/// PY - 1993/// SP - 175–188 ER - TY - SOUND TI - Nutrition and neonatal survival AU - Odle, J. DA - 1993/// PY - 1993/// ER - TY - SOUND TI - Medium-chain fatty acid metabolism in neonatal pigs AU - Odle, J. DA - 1993/4/15/ PY - 1993/4/15/ ER - TY - SOUND TI - Carbohydrate sources for the neonate: Are there viable alternatives to lactose AU - Odle, J. DA - 1993/2/9/ PY - 1993/2/9/ ER - TY - SOUND TI - Research on medium-chain triglycerides AU - Odle, J. DA - 1993/1/20/ PY - 1993/1/20/ M3 - Radio interview ER - TY - SOUND TI - Toward Improved Newborn Piglet Survival AU - Odle, J. DA - 1993/6/17/ PY - 1993/6/17/ ER - TY - SOUND TI - Neonatal Growth Factors AU - Odle, J. DA - 1993/7/29/ PY - 1993/7/29/ ER - TY - SOUND TI - Medium-chain Triglycerides for Improving Piglet Survival AU - Odle, J. DA - 1993/9/14/ PY - 1993/9/14/ ER - TY - SOUND TI - Nutritional Attributes of Medium-chain Triglycerides AU - Odle, J. DA - 1993/9/16/ PY - 1993/9/16/ ER - TY - SOUND TI - Nutritional Factors Affecting Piglet Survivability AU - Odle, J. DA - 1993/10/6/ PY - 1993/10/6/ ER - TY - SOUND TI - Improving Neonatal Survival by Nutritional Means: Efforts that Enhance the Efficacy of Medium-chain Triglycerides AU - Odle, J. DA - 1993/12/1/ PY - 1993/12/1/ ER - TY - JOUR TI - Effect of emulsification on the oxidation of triacylglycerols containing [1-14C]-hexanoate or octanoate by newborn pigs AU - Odle, J. AU - Lin, X. AU - Wieland, T.M. AU - van Kempen, T.A.T.G. T2 - FASEB Journal DA - 1993/// PY - 1993/// VL - 7 SP - A883 ER - TY - JOUR TI - Does HMG-CoA synthase play a role in limitation of ketogenesis in neonatal pigs? AU - Adams, S.H. AU - Odle, J. T2 - FASEB Journal DA - 1993/// PY - 1993/// VL - 7 SP - A379 ER - TY - JOUR TI - Carnitine affects medium-chain fatty acid (MCFA) metabolism in newborn pigs AU - van Kempen, T.A.T.G. AU - Odle, J. T2 - FASEB Journal DA - 1993/// PY - 1993/// VL - 7 SP - A64 ER - TY - JOUR TI - Production of dicarboxylic acids (DCA) in newborn pigs infused with various medium-chain fatty acids AU - Lin, X. AU - van Kempen, T.A.T.G. AU - Odle, J. T2 - FASEB Journal DA - 1993/// PY - 1993/// VL - 7 SP - A384 ER - TY - JOUR TI - Restricted maximum likelihood estimation of variance components from field data for number of pigs born alive. AU - See, M.T. AU - Mabry, J.W. AU - Bertrand, J.K. T2 - Journal of animal science AB - Variance components for number of pigs born alive (NBA) were estimated from sow productivity field records collected by purebred breed associations. Data sets analyzed were as follows: Hampshire (n = 13,537), Landrace (n = 10,822), and Spotted (n = 3,949). Variance components for service sire, sire of sow, dam of sow, and residual effects on NBA (adjusted for parity) were estimated. The single-trait model included relationships between service sires, sires of sows, and dams of sows. The model was implemented using an expectation maximization (EM) REML algorithm. A sparse-matrix solver was also used. Heritability estimates for NBA were .13, .13, and .12 for Hampshire, Spotted, and Landrace, respectively. Estimates of maternal genetic (co)variances (m2) expressed as a proportion of the phenotypic variance were .05, .01, and .03 for Hampshire, Spotted, and Landrace, respectively. Results indicated that service sires account for 1 to 2% of the total variation for NBA. Genetic effects influencing NBA seem to be small in these data sets, but selection for increased NBA should be effective. DA - 1993/// PY - 1993/// DO - 10.2527/1993.71112905x VL - 71 IS - 11 SP - 2905-2909 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027691183&partnerID=MN8TOARS KW - PIGS KW - REML KW - VARIANCE COMPONENTS KW - LITTER SIZE ER - TY - JOUR TI - Development of an animal model for across-herd genetic evaluation of number born alive in swine. AU - Woodward, B.W. AU - Mabry, J.W. AU - See, M.T. AU - Bertrand, J.K. AU - Benyshek, L.L. T2 - Journal of animal science AB - An animal model and computer software were developed to conduct across-herd genetic evaluations using data from producers participating in the Sow Productivity Index program of the American Yorkshire Club. The final data set consisted of 61,596 litter records from 1986 to early 1990. The animal model included fixed contemporary group effects and random additive direct, service sire, permanent environmental, and residual effects. Additive genetic relationships among animals were included. A separate relationship matrix for service sires and their sires was also included. A data set similar to the Yorkshire field data was simulated to use in testing the animal model. The simulated data set consisted of 40 herds, each with 120 reproducing dams and either four or five sires. Six generations of simulated data were produced, resulting in 20,605 litter records. These records were then evaluated using the animal model for number of pigs born alive. Finally, correlations between the true breeding values from the simulation and the predicted breeding values were computed. The correlation between the 918 true and predicted sire breeding values was considerably lower for the animal model without a service sire effect than when it was included (.53 vs .74, respectively). However, the difference was cut in half (.66 vs .77) when only sires with greater than five daughter records were included. The high accuracy of the animal model with a random service sire effect indicates that the proposed model adequately accounts for the variation found in records for number of pigs born alive. DA - 1993/// PY - 1993/// DO - 10.2527/1993.7182040x VL - 71 IS - 8 SP - 2040-2046 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027647918&partnerID=MN8TOARS KW - PIGS KW - ANIMAL MODELS KW - REPRODUCTION ER - TY - JOUR TI - Medium-chain fatty acid oxidation in colostrum-deprived newborn piglets: Stimulative effect of L-carnitine supplementation AU - Van Kempen, T.A.T.G. AU - Odle, J. T2 - Journal of Nutrition DA - 1993/// PY - 1993/// VL - 123 IS - 9 SP - 1531-1537 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027220217&partnerID=MN8TOARS ER - TY - JOUR TI - Utilization of medium-chain triglycerides by neonatal pigs: effects of emulsification and dose delivered AU - Wieland, Teresa M. AU - Lin, Xi AU - Odle, Jack T2 - Journal of Animal Science AB - Four trials were conducted using 86, 24-h-old pigs to evaluate the utilization of medium-chain triglycerides (MCT). Effects of emulsification and amount of MCT fed were examined. After a 4-h period during which feed was withheld, pigs were force-fed MCT (containing 75% octanoate and 25% decanoate), marking time 0 of the experiment. Blood samples were obtained at 1 and 2 h for subsequent medium-chain fatty acid (MCFA) analysis. In Trials 1 (six pigs/treatment) and 2 (four pigs/treatment) the response to three emulsifying agents was compared to a nonemulsified (NE) control. Twenty milliliters of a 30% (vol/vol) emulsion of MCT or 6 mL of NE MCT was administered. Concentrations of MCFA at 1 h in pigs receiving a Tween 80 (polyoxy-ethylene [20] sorbitan monooleate) emulsion were 3- to 19-fold higher than concentrations in animals administered a gum arabic/gum tragacanth emulsion, a lecithin emulsion, or NE MCT. Trials 3 (eight pigs/treatment) and 4 (six pigs/treatment) were conducted to determine the plasma MCFA concentrations resulting from feeding increasing levels of NE (3, 6, 9, or 12 mL of MCT) or emulsified MCT oil (2, 4, 6, or 8 mL in a 30% Tween 80 emulsion). Plasma octanoate concentrations measured at 1 h increased linearly (P < .05) with increasing MCT dosage through 9 mL of NE and 6 mL of emulsified MCT. A transient narcosis was observed in 8 of 12 animals that received 6 or 8 mL of emulsified MCT and was most pronounced 1 to 2 h after feeding, which roughly corresponded to peak plasma MCFA concentrations.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/7/1/ PY - 1993/7/1/ DO - 10.2527/1993.7171863x VL - 71 IS - 7 SP - 1863-1868 LA - en OP - SN - 0021-8812 1525-3163 UR - http://dx.doi.org/10.2527/1993.7171863x DB - Crossref KW - PIGS KW - NEONATES KW - MEDIUM CHAIN TRIACYLGLYCEROLS KW - FATTY ACIDS KW - EMULSIFICATION KW - TOXICITY ER - TY - JOUR TI - Taurine utilization by cats AU - Odle, J. AU - Roach, M. AU - Baker, D.H. T2 - Journal of Nutrition DA - 1993/// PY - 1993/// VL - 123 IS - 11 SP - 1932-1933 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027485981&partnerID=MN8TOARS ER - TY - JOUR TI - Plasma beta-hydroxybutyrate after octanoate challenge: Attenuated ketogenic capacity in neonatal swine AU - Adams, S.H. AU - Odle, J. T2 - AM.J.PHYSIOL. DA - 1993/// PY - 1993/// VL - 265 IS - 4 part 2 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027674866&partnerID=MN8TOARS ER - TY - JOUR TI - Emulsification and fatty-acid chain length affect the utilization of medium-chain triglycerides by neonatal pigs AU - Wieland, Teresa M. AU - Lin, Xi AU - Odle, Jack T2 - Journal of Animal Science AB - Three experiments were conducted using 52 pigs between 22 and 35 h of birth to determine the effects of emulsification and fatty-acid chain length on utilization of medium-chain triglycerides (MCT). After a 4-h period during which feed was withheld, pigs were force-fed 6 mL of nonemulsified (NE) MCT or 20 mL of a 30% (vol/vol) Tween 80-(polyoxy-ethylene [20] sorbitan monooleate) MCT emulsion, marking time 0, and serial blood samples were drawn throughout 8 h for analysis of medium-chain fatty acid (MCFA) concentrations by HPLC. In Exp. 1, pigs received either NE or emulsified Tri-C4, -C5, -C6, or -C7. The emulsified treatments were discontinued due to deaths caused by coma resulting from high concentrations (up to 12 mM) of plasma MCFA. Concentrations in pigs fed emulsified MCT were 2.5-fold higher than those in pigs fed NE MCT. In pigs fed NE MCT, concentrations of even-chain-length MCFA were higher than those of odd-chain-length MCFA (P < .001), with a tendency for C6 to be higher than C4 (P < .1). In Exp. 2 and 3, pigs received an equimolar mixture of MCT in either emulsified or NE form. In Exp. 2, the mixture contained Tri-C4 through Tri-C7; whereas, in Exp. 3 the mixture contained Tri-C4, -C6, -C8, and -C10. A three-way interaction (emulsion x fatty acid x sample time; P < .05) was observed in both experiments.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/7/1/ PY - 1993/7/1/ DO - 10.2527/1993.7171869x VL - 71 IS - 7 SP - 1869-1874 LA - en OP - SN - 0021-8812 1525-3163 UR - http://dx.doi.org/10.2527/1993.7171869x DB - Crossref KW - PIGS KW - NEONATES KW - MEDIUM CHAIN TRIACYLGLYCEROLS KW - FATTY ACIDS KW - EMULSIFICATION KW - TOXICITY ER - TY - JOUR TI - EFFECT OF FRUCTOSE-INDUCED HYPOGLYCEMIA ON CESSATION OF MACROMOLECULAR TRANSPORT IN THE NEONATAL CALF AU - TYLER, H AU - RAMSEY, H T2 - JOURNAL OF DAIRY SCIENCE AB - Fructose was used as a hypoglycemic agent to determine whether availability of glucose during early life mediates the cessation of intestinal transport of Ig (closure).Either glucose or fructose (100 g in 2 L of electrolyte solution) was fed to calves deprived of colostrum at 3, 6, 9, 12, 15, 18, and 21 h postpartum.Colostrum (1 kg) was fed to all calves at 24, 36, and 48 h postpartum.Venous blood was sampled, and plasma was harvested, for the measurement of glucose, fructose, insulin, and IgG.During the first 24 h, means for plasma glucose from calves treated with glucose and fructose, respectively, were 282 and 24 mgldl.1be latter value reflects the degree of hypoglycemia induced by feeding fructose.During the same period, corresponding concentrations of plasma fructose were 4 and 230 mgldl.Plasma insulin concentrations for precolostra1 calves were 101 and 11 p.Ulml for calves treated with glucose and fructose, respectively.Peak IgG concentrations were extremely low for both groups of calves, indicating that intestinal transport of Ig had virtually ceased by the end of the 24-h treabnent period.Thus, fructoseinduced hypoglycemia had no effect on the time of intestinal closure in the newborn calf. DA - 1993/10// PY - 1993/10// DO - 10.3168/jds.S0022-0302(93)77641-9 VL - 76 IS - 10 SP - 3021-3025 SN - 0022-0302 KW - CALF KW - HYPOGLYCEMIA KW - IMMUNOGLOBULINS KW - IMMUNITY ER - TY - JOUR TI - The disposal of dead pigs: A review AU - Morrow, W. M. AU - Ferket, P. R. T2 - Swine Health and Production DA - 1993/// PY - 1993/// VL - 1 IS - 3 SP - 7 ER - TY - JOUR TI - Response of porcine granulosa cells isolated from primary and secondary follicles to FSH, 8-bromo-cAMP and epidermal growth factor in vitro AU - Morbeck, D. E. AU - Flowers, W. L. AU - Britt, J. H. T2 - Journal of Reproduction & Fertility AB - A cell culture system was developed to study the function of porcine granulosa cells from primary and secondary follicles. Primary follicles were isolated from 1- to 3-day-old pigs. Secondary follicles were isolated from 50- to 60-day-old pigs. Follicles were isolated after a digestion for 15 min with 0.25% trypsin followed by 15 min with 1000 U DNAase. Follicles were plated at 100 primary follicles or 30 secondary follicles per well in 48-well plates and cultured in media containing 10% fetal bovine serum (FBS). During initial plating, follicles attached to the plate and cells spread from the point of attachment. This resulted in monolayer cultures of granulosa cells from primary or secondary follicles. On day 4 of culture, media were replaced with 0.5 ml media containing one of the following treatments: control (media only); 10% FBS; 100 ng FSH; 2 mmol 8-bromo-cAMP l-1 or 50 ng epidermal growth factor (EGF). Media and cells were harvested on day 6, after 2 days of treatment. FBS and EGF increased DNA in granulosa cell cultures from primary or secondary follicles (P < 0.01). Treatment with 8-bromo-cAMP increased DNA in granulosa cell cultures from primary but not from secondary follicles (P < 0.05). Conversely, treatment with FSH increased DNA in granulosa cell cultures from secondary but not from primary follicles (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/// PY - 1993/// DO - 10.1530/jrf.0.0990577 VL - 99 IS - 2 SP - 577 ER - TY - JOUR TI - EVALUATION OF MATING SYSTEMS INVOLVING 5 BREEDS FOR INTEGRATED BEEF-PRODUCTION SYSTEMS .4. ACCOUNTING FOR VARIABILITY AND GENETIC TRENDS AU - LAMB, MA AU - TESS, MW AU - ROBISON, OW T2 - JOURNAL OF ANIMAL SCIENCE AB - Computer models were used to simulate integrated cow-calf-feedlot production systems. Angus (A), Charolais (C), Hereford (H), Limousin (L), and Simmental (S) purebreds and two- and three-breed rotational crossbreds were included. Models were deterministic and based on data reported primarily from the 1970s. Variation in carcass weights were determined to predict distributions of carcass weights and values for 272- to 318-kg carcasses. Data were updated to a 1984 base by increasing birth, weaning, yearling, and mature weights to account for genetic trends within breeds. Two slaughter end points were considered: 288-kg carcass weight and low Choice grade. At low Choice grade, accounting for variation in carcass weights around the 272- to 318-kg target weight increased the estimated efficiency of A and AH crosses (input costs/carcass value), whereas at the 288-kg end point, efficiency rankings among other breed combinations were relatively unchanged. Including genetic trends resulted in increased estimated efficiencies among breed combinations with previously underweight carcasses at low Choice (A and AH), measured either as input costs/carcass weight or lean weight values. Within breeds, accounting for genetic trends and variation for weights caused breeds to be ranked differently when evaluated at low Choice. DA - 1993/3// PY - 1993/3// DO - 10.2527/1993.713587x VL - 71 IS - 3 SP - 587-594 SN - 0021-8812 KW - BEEF CATTLE KW - CROSSBREEDING KW - SIMULATION KW - EFFICIENCY ER - TY - JOUR TI - The effects of the nucleocytoplasmic ratio and the state of nuclear and cytoplasmic differentiation on the development of cloned and recloned embryos of mice AU - Meng, L. AU - Markert, C. L. T2 - Journal of Reproduction and Development AB - Nucleocytoplasmic interactions in controlling mouse embryonic development were tested by transplanting nuclei into different cytoplasmic environments. The nucleocytoplasmic ratios in 2-and 4-cell stage embryo were altered by removing one nucleus from a fused 2-cell and three nuclei from a fused 4-cell embryo. Such embryos containing relatively increased amounts of cytoplasm develop normally but at a slower rate than control embryos.The effects of transplanting 4-cell donor nuclei to the cytoplasm of an enucleated fused 2-cell embryo led to successful in vitro development and also to term in six out of 67 reconstituted embryos. When the donor nucleus was from an 8-cell embryo, successful development in vitro was less frequent and none were carried to term. Cytoplasms from the 2-cell and 4-cell embryos were very similar in affecting further development, but cytoplasms of the oocyte failed to provide a suitable environment for further development. Most of the reconstituted embryos containing a nucleus from an 8-cell embryo and cytoplasms of 2 or 4-cell embryos compacted at the subsequent 4 cell or even at the 2-cell stage of development. Thus, an 8-cell nucleus produced compaction in cytoplasms from an earlier stage.To test for reprogramming of nuclei transferred into the cytoplasms of an earlier stage of development, the nuclei from 4-cell stage reconstituted embryos were transferred into the cytoplasms of 2-cell embryos. Of the 53 recloned embryos 36(67.9%), 15(28.3%), and 1(1.7%) developed to the 2-, 4-, and 8-cell stages, respectively. The percent cleavage of recloned 4-cell stage nuclei was much lower than in the original reconstituted embryos. However no significant difference in frequency of cleavage was found between recloned embryos and reconstituted embryos with nuclei obtained from the normal morula stage. Forty-one of the recloned embryos were transferred to the oviducts of recipient mice. Of these, 17 were recovered from the oviducts after 72 h and five then continued to develop in vitro to the morula stage. These results suggest that embryonic nuclei are not reprogrammed, even by retransfer into less differentiated cytoplasms obtained from enucleated, fused 2-cell embryos. DA - 1993/// PY - 1993/// DO - 10.1262/jrd.39.175 VL - 39 IS - 3 SP - 175 ER - TY - JOUR TI - OVULATORY AND ENDOCRINE RESPONSES AFTER ACTIVE IMMUNIZATION OF GILTS AGAINST A SYNTHETIC FRAGMENT OF BOVINE INHIBIN AU - KING, BF AU - BRITT, JH AU - ESBENSHADE, KL AU - FLOWERS, WL AU - SESTI, LAC AU - MARTIN, TL AU - IRELAND, JJ T2 - JOURNAL OF ANIMAL SCIENCE AB - The objective of this study was to determine whether neutralizing endogenous inhibin would affect ovulation rate and serum concentrations of FSH, LH, estradiol-17 beta, and progesterone in gilts. At wk 0, during their second postpubertal estrous cycle, gilts (195 +/- 2.4 d of age) were given a primary immunization against the 1-26 gly-tyr NH-terminal amino acid sequence of bovine inhibin-alpha conjugated to human alpha globulin (INH; n = 10) or against human alpha globulin alone (control; n = 10). The primary immunization mixed with Freund's complete adjuvant contained .915 mg of the inhibin peptide. Booster immunizations in Freund's incomplete adjuvant contained .3 and .183 mg of the inhibin peptide and were given at wk 8 and 12, respectively. Free, unconjugated inhibin was given to INH gilts at 16 wk. Blood samples for determination of hormones were collected every 4 h beginning on d 15 of the first estrous cycle beyond wk 16 (first cycle) and continuing until d 5 of the second estrous cycle following wk 16 (second cycle). Ovulation rate was estimated by laparoscopy during the second cycle. Antibody titers were estimated by determining the percentage of [125I]-INH bound by serum diluted 1:4,000. The antibody titers were 17 +/- 2, 22 +/- 3, and 9 +/- 1% at wk 9, 17, and 23 for INH gilts, respectively, and 0% at all times for control gilts. Duration of three consecutive estrous cycles terminating with the first experimental cycle did not differ between treatments (INH, 20.7 +/- .3 vs control, 20.4 +/- .3 d).(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/4// PY - 1993/4// DO - 10.2527/1993.714975x VL - 71 IS - 4 SP - 975-982 SN - 0021-8812 KW - PIGS KW - INHIBIN KW - IMMUNIZATION KW - OVULATION KW - OVARIES KW - REPRODUCTIVE HORMONES ER - TY - JOUR TI - CHANGES IN SERUM SOMATOTROPIN, SOMATOTROPIN MESSENGER-RNA, AND SERUM AND FOLLICULAR INSULIN-LIKE GROWTH FACTOR-I IN RESPONSE TO FEED RESTRICTION IN COWS ACTIVELY IMMUNIZED AGAINST GROWTH HORMONE-RELEASING FACTOR AU - KIRBY, CJ AU - ARMSTRONG, JD AU - HUFF, BG AU - STANKO, RL AU - HARVEY, RW AU - HEIMER, EP AU - CAMPBELL, RM T2 - JOURNAL OF ANIMAL SCIENCE AB - Cyclic cows immunized against growth hormone-releasing factor (GRFi, n = 19), human serum albumin (HSAi, n = 10), or not immunized (CON, n = 18) were used to investigate the effects of feed restriction on serum and pituitary somatotropin (ST), pituitary ST mRNA, and serum and follicular IGF-I. Cows were either fed 2.7 kg/d cottonseed hulls (R) or given ad libitum access to feed (AL) for 15 d. Ovaries bearing the largest follicle and pituitaries were collected on d 14, at 44 to 45 h after injection of prostaglandin F2 alpha. Data from CON and HSAi cows were similar; thus, data were combined (represented as CON). Serum ST (nanograms/milliliter) on d 13 was greater (P < .09) in CON-R (5.3) than in CON-AL (3.9), whereas ST in GRFi-AL (1.1) and GRFi-R (1.1; pooled SE = .4) were similar. Hemipituitary weight (grams) and ST mRNA (arbitrary units) were greater (P < .05) in CON (1.5 +/- .1 and 135 +/- 25) than in GRFi (1.0 +/- .1 and 90 +/- 18) cows. Across immunization, ST mRNA and pituitary ST concentration (mg/100 mg of tissue), respectively, were greater (P < .06) in R (152 +/- 22 and 22.5 +/- 1.9) than in AL (73 +/- 16 and 17.3 +/- 1.8) cows. Immunization and diet decreased (P < .05) serum IGF-I (nanograms/milliliter) on d 13 (CON, 176 +/- 7 vs GRFi, 42 +/- 8; AL, 120 +/- 7 vs R, 98 +/- 8). Concentrations of IGF-I in follicular fluid (FFL) from the largest follicle were lower in GRFi (29 +/- 3) than in CON (102 +/- 6) cows; however, IGF-I in FFL was similar in AL (70 +/- 9) and R (71 +/- 10) cows. In conclusion, GRFi decreased serum ST and IGF-I, and decreased ST mRNA. Feed restriction increased serum ST and ST mRNA, and decreased serum IGF-I. Although feed restriction and GRFi decreased serum IGF-I, concentrations of IGF-I in FFL were decreased only by GRFi. DA - 1993/11// PY - 1993/11// DO - 10.2527/1993.71113033x VL - 71 IS - 11 SP - 3033-3042 SN - 0021-8812 KW - SOMATOTROPIN KW - IGF-I KW - OVARIES KW - FEED RESTRICTION ER - TY - JOUR TI - EFFECT OF COPPER LEVEL AND SOURCE (COPPER LYSINE VS COPPER-SULFATE) ON COPPER STATUS, PERFORMANCE, AND IMMUNE-RESPONSE IN GROWING STEERS FED DIETS WITH OR WITHOUT SUPPLEMENTAL MOLYBDENUM AND SULFUR AU - WARD, JD AU - SPEARS, JW AU - KEGLEY, EB T2 - JOURNAL OF ANIMAL SCIENCE AB - One hundred twenty-six crossbred steers (218 kg initial BW) were used to determine the availability of Cu from copper lysine (CuLys) relative to CuSO4. Steers were assigned to pens (four replicates per treatment) based on BW and initial plasma Cu concentration and fed a corn silage-based diet supplemented with 0 or 5 ppm of Cu from either CuSO4 or CuLys. Half of the steers in each treatment were supplemented with 5 ppm of Mo and .2% S. Molybdenum and S supplementation increased (P < .10) growth rate during the first 21 d. Steers receiving CuSO4 gained more during the first 21 d than did control steers (P < .10) and steers receiving CuLys (P < .01). Growth, feed efficiency, and feed intake were not affected over the entire 98-d trial. Molybdenum and S supplementation decreased (P < .05) plasma Cu concentrations. Plasma Cu concentration was not affected by Cu source. Humoral immune response to ovalbumin was measured on d 7 and 77. Dietary treatment did not affect antibody production at either time. Cell-mediated immunity was measured in vivo on d 7 and 77 using phytohemagglutinin. In vivo cell reactivity was not affected by treatment on d 7 but was reduced (P < .10) by Mo and S supplementation on d 77. In vitro cell reactivity was measured on d 98 using a lymphocyte blastogenesis assay. Unstimulated lymphocytes from steers supplemented with Mo and S had lower (P < .10) uptakes of [3H]thymidine. There were no differences among treatments when lymphocytes were stimulated with pokeweed mitogen or phytohemagglutinin.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/10// PY - 1993/10// DO - 10.2527/1993.71102748x VL - 71 IS - 10 SP - 2748-2755 SN - 0021-8812 KW - COPPER KW - MOLYBDENUM KW - STEERS KW - IMMUNE RESPONSE KW - PERFORMANCE ER - TY - JOUR TI - COMPARISON OF COPPER LYSINE AND COPPER-SULFATE AS COPPER SOURCES FOR RUMINANTS USING IN-VITRO METHODS AU - WARD, JD AU - SPEARS, JW T2 - JOURNAL OF DAIRY SCIENCE AB - Two in vitro experiments were conducted to estimate the availability of Cu from Cu Lys compared with Cu from CuSO4. In experiment 1, a 24-h ruminal fermentation (alpha-cellulose substrate) containing either .1% added S or 2% added urea was performed with 4, 12, or 96 ppm of added Cu as either Cu Lys or CuSO4. Soluble Cu was measured at the end of the 24-h incubation, and concentrations were higher for Cu Lys with added urea (1.16 vs. .45 ppm), but no differences existed between sources of added S. In Experiment 2, 20 ppm of Cu added as either Cu Lys or CuSO4 with and without the addition of 10 ppm of Mo and .75% S were used in an vitro study designed to simulate digesta passage through the ruminant. A 24-h ruminal fermentation (orchardgrass substrate) was followed by a 2-h digestion in pepsin and HCl (pH 2.3) and then a 2-h digestion in NaHCO3 and pancreatin (pH 6.6). Soluble Cu concentrations were analyzed after each step. Molybdenum and S addition decreased soluble Cu after ruminal fermentation and tended to decrease soluble Cu concentrations after digestion of pancreatin and NaHCO3. The source of Cu did not affect soluble Cu concentrations. Results suggest that Cu from Cu Lys and CuSO4 behave similarly in the digestive tract of ruminants. DA - 1993/10// PY - 1993/10// DO - 10.3168/jds.S0022-0302(93)77638-9 VL - 76 IS - 10 SP - 2994-2998 SN - 0022-0302 KW - COPPER KW - LYSINE KW - RUMINANTS ER - TY - JOUR TI - Relationship of secretion of GnRH in vitro to changes in pituitary concentrations of LH and FSH and serum concentrations of LH during lactation in sows AU - Sesti, L. A. C. AU - Britt, J. H. T2 - Journal of Reproduction & Fertility AB - The objectives of this study were (1) to determine whether release of GnRH in vitro was related to concentrations of LH and FSH in serum and pituitaries and to oestradiol in serum of sows at mid- or late lactation, and (2) to determine whether weaning at mid-lactation changes concentrations of these hormones from values expected at mid-lactation to values expected at late lactation. Multiparous crossbred sows were killed on day 14 (n = 5) or day 28 (n = 5) of lactation or on day 14 post partum after litters had been weaned on day 10 (n = 5). Blood samples were taken every 6 h for 4 days before sows were killed, and the preoptic suprachiasmatic area, medial basal hypothalamus, stalk median eminence, anterior pituitary and ovaries were collected at slaughter. Sows killed on day 14 after having their litters weaned on day 10 had more (P < 0.01) preovulatory follicles (> 6 mm in diameter) than lactating sows killed on day 14 or 28 (7.0 +/- 1.2 versus 0.2 +/- 0.1 and 1.5 +/- 0.8, respectively). Concentrations of LH, FSH and oestradiol in serum during 90 h before slaughter were greater (P < 0.05) in weaned sows and lactating sows killed on day 28 than in lactating sows killed on day 14 (LH: 0.72 +/- 0.3 and 0.68 +/- 0.3 versus 0.45 +/- 0.2 ng ml-1; FSH: 39.3 +/- 2.7 and 57.3 +/- 4.0 versus 28.8 +/- 1.6 ng ml-1; oestradiol: 10.9 +/- 1.6 and 5.6 +/- 0.7 versus 2.7 +/- 0.2 pg ml-1, respectively).(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/// PY - 1993/// DO - 10.1530/jrf.0.0980393 VL - 98 IS - 2 SP - 393 ER - TY - JOUR TI - INFLUENCE OF STAGE OF LACTATION, EXOGENOUS LUTEINIZING-HORMONE-RELEASING HORMONE, AND SUCKLING ON ESTRUS, POSITIVE FEEDBACK OF LUTEINIZING-HORMONE, AND OVULATION IN SOWS TREATED WITH ESTROGEN AU - SESTI, LAC AU - BRITT, JH T2 - JOURNAL OF ANIMAL SCIENCE AB - The overall objective of this study was to investigate the LH response and occurrence of estrus and ovulation in sows treated with estradiol benzoate (EB) at mid- (d 14) or late (d 28) lactation. Experiment 1 tested the hypothesis that hourly pulses of LHRH given to sows treated with EB would cause a greater proportion to exhibit LH surges. Sows (n = 32) at mid- or late lactation were given (i.m.) corn oil (CO) or EB (10 micrograms/kg BW) at 0 h and no pulses or hourly pulses (100 ng/pulse) of the LHRH agonist des-Gly10,[D-ALA6]-LHRH ethylamide (LHRH-A) from 54 to 96 h, the anticipated period of positive feedback of LH. Blood samples for determination of estradiol-17 beta (E2) and LH were collected every 6 h from -12 to 120 h from sows treated with EB. Estrus was checked daily with a mature boar, and ovulation was assessed by measuring progesterone in blood 1 wk after estrus induced by EB or 2 wk after weaning at 34 +/- 1.4 d postpartum. Lactational estrus occurred in 0 of 16 and 15 of 16 sows given CO and EB, respectively; however, no sow ovulated in response to EB. Concentrations of LH were lower (P < .01) during mid- than during late lactation, and LHRH-A pulses had no effect on secretion of LH and E2. The LH concentrations during the pretreatment (-12 to 0 h), negative feedback (6 to 54 h), and positive feedback (60 to 96 h) periods at mid-lactation (.32 +/- .03, .22 +/- .01, and .54 +/- .08 ng/mL, respectively) differed (P < .01) from values at late lactation (.80 +/- .06, .49 +/- .02, and 1.47 +/- .17, respectively). Preovulatory-like surges of LH occurred in one of eight (peak 2.1 ng/mL) and seven of eight (peak 2.9 +/- 1 ng/mL) sows given EB at mid- and late lactation, respectively. Experiment 2 tested the hypothesis that the hypothalamus and pituitary of sows weaned 96 h before they were given EB would show a greater responsiveness than those weaned and given EB simultaneously. Sows (n = 16) at mid- or late lactation were treated with EB (10 micrograms/kg BW; i.m.), and one-half of the sows were suckled until the moment of EB treatment, whereas the other half had their litters weaned 96 h before treatment with EB.(ABSTRACT TRUNCATED AT 400 WORDS) DA - 1993/4// PY - 1993/4// DO - 10.2527/1993.714989x VL - 71 IS - 4 SP - 989-998 SN - 1525-3163 KW - SOWS KW - LACTATION KW - ESTROGENS KW - ESTRUS KW - LH KW - LHRH ER - TY - JOUR TI - EFFECTS OF PREGNANT MARE SERUM GONADOTROPIN ON REPRODUCTION IN 4 GENOTYPES OF GILTS AU - LUBRITZ, DL AU - EISEN, EJ AU - ROBISON, OW T2 - JOURNAL OF ANIMAL BREEDING AND GENETICS AB - Summary Effects of PMSG and genotype on various measures of reproductive efficiency were investigated. Prenatal data were obtained at 40 d of gestation from 96 gilts representing four genotypes. Data on Duroc (D), Yorkshire (Y), Synthetic (Large White × Landrace) (SYN), and Crossbred Duroc × Yorkshire (XB) gilts were collected from January, 1990 through May, 1991. Litter size (LS) data were collected from 482 farrowings of siblings. Treatment with exogenous hormones significantly increased number of corpora lutea (CL), number of embryos (EN), ovum wastage, (OVWS) and embryo length (ELG). Breed group differences (P < .05) were detected for natural ovulation rate, hormone‐induced ovulation rate, CL, OVWS, ELG, embryo weight, ovum success, uterine length, ovary weight, range and variance of within‐litter embryo weight (RWT and VWT), and litter size born alive. Natural ovulation rates for D, Y, SYN and XB were 10.46 ± 1.61, 12.64 ± 1.41, 14.10 ± .99 and 10.90 ± 1.47, and hormone‐induced ovulation rates were 15.00 ± 1.53, 17.69 ± 1.40, 19.43 ± 1.17 and 12.19 ± 1.43, respectively. Range and variance of within‐litter embryo length were not affected by either treatment or genotype. Increases in RWT and VWT observed in D and XB gilts after PMSG treatment did not adversely affect embryo survival to 40 d gestation. Significant genetic differences existed for litter size at birth. The PMSG treatment and interactions with PMSG were not significant for litter size born alive. Breed groups seem to differ for CL and EN in response to PMSG but only Yorkshire showed any response in LS (P < .10). Although PMSG increased ovulation rate in siblings by 4.06 ova and number of embryos at 40 d gestation by 1.87 compared with control gilts, there were no differences in litter size born alive due to PMSG treatment. The increase in ovulation rate and number of embryos generated by PMSG seems to be negated by fetal losses occurring both before and after 40 d of gestation. Zusammenfassung Einflüsse von Stutenserum‐Gonadotropin (PMSG) auf Reproduktionsmerkmale von vier Genotypen bei Jungsauen Einflüsse von PMSG und Genotyp auf verschiedene Merkmale der Reproduktion wurden untersucht. Daten wurden am 40. Trächtigkeitstag von 96 Jungsauen von vier Genotypen‐Duroc (D), Yorkshire (Y), Synthetik (Edelschwein × Landrasse (SYN)) und Kreuzungen‐Duroc × Yorkshire (XB) zwischen Januar 1990 und Mai 1991 erhoben. Wurfgröße (LS) wurden von 492 Würfen von Geschwistertieren erhoben. Behandlung mit exogenem Hormon steigert signifikant die Zahl der Gelbkörper (CL), Zahl der Embryonen (EN), Ovarverlust (OVWS) und Embryolänge (ELG). Differenzen zwischen Genotypen wurden für natürliche und hormoninduzierte Ovulationsrate, CL, OVWS, ELG, Embryogewicht, Embryoerfolg, Gebärmutterlänge, Ovargewicht, Streuungsbereich und Varianz des Embryogewichtes von Wurfgeschwistern (RWT und VWT) und Zahl lebendgeborener Ferkel erhoben. Die natürlichen Ovulationsraten für D, Y, SYN und XB waren 10,46 ± 1,61, 12,64 ± 1,41, 14,10 ± 0,99 und 10,90 ± 1,47, und die hormoninduzierten 15,00 ± 1,53, 17,69 ± 1,40, 19,43 ± 1,17 und 12,19 ± 1,43. Streuungsbereich und Varianz zwischen Embryonenlänge eines Wurfes wurden weder durch Behandlung noch Genotyp tangiert. Steigerungen in RWT und VWT in D und XB Jungsauen nach Hormonbehandlung hat Embryoüberleben bis 40 Tage nicht beeinträchtigt. Signifikante genetische Unterschiede existieren zwischen Wurfgröße bei Geburt. Hormonbehandlungen und Interaktionen mit Genotypen waren für die Wurfgröße nicht signifikant. Rassengruppen scheinen für CL und EN im Hinblick auf Hormonbehandlung sich zu unterscheiden, aber nur Yorkshire zeigten Reaktion bei LS (P < .1). Obwohl das Hormon die Ovulationsrate um 4,06 Eier und Zahl der Embryonen bei 40 Tagen um 1,87 gegenüber Kontrollsauen vergrößerte, verblieben keine Unterschiede in Wurf größe. Die Steigerung der Ovulationsrate und Zahl der Embryonen nach Hormonbehandlung scheint durch Fötalverluste vor und nach 40 Tagen Trächtigkeit eliminiert zu werden. DA - 1993/10// PY - 1993/10// DO - 10.1111/j.1439-0388.1993.tb00749.x VL - 110 IS - 5 SP - 363-373 SN - 1439-0388 ER - TY - JOUR TI - AGONIST-INDUCED RELEASE OF GONADOTROPIN-RELEASING-HORMONE, LUTEINIZING-HORMONE, AND FOLLICLE-STIMULATING-HORMONE AND THEIR ASSOCIATIONS WITH BASAL SECRETION OF LUTEINIZING-HORMONE AND FOLLICLE-STIMULATING-HORMONE THROUGHOUT LACTATION IN SOWS AU - SESTI, LAC AU - BRITT, JH T2 - BIOLOGY OF REPRODUCTION AB - Our working hypothesis was that the normal increase in basal secretion of LH and FSH during lactation in sows is paralleled by an increase in readily releasable pools of GnRH, LH, and FSH. Sows fitted with indwelling catheters and nursing 9-11 piglets were sampled on Days 1, 7, 14, and 21 (primiparous sows; n = 10; experiment 1) or Days 7 and 21 (multiparous sows; n = 10; experiment 2) of lactation. On each day, blood was collected at 10-min intervals for 2 h before one member of a pair of sows was infused (i.v.) with saline (n = 5) and the other with the neuroexcitatory amino acid N-methyl-DL-aspartic acid (NMA; 10 mg/kg b.w.) to measure readily releasable GnRH as estimated by LH release. Two hours later, each sow that had received saline was given GnRH (100 micrograms, i.v.) for estimation of releasable pools of pituitary LH and FSH. Responses to NMA and GnRH were estimated by area under the curve (ng.ml-1.min) of serum LH profiles for 1 h (NMA group) or 2 h (GnRH group) after treatment. Basal LH secretion in primiparous sows decreased from Day 1 to Day 7 and then returned to Day 1 values by Day 21. Similarly, in multiparous sows, basal LH was lower on Day 7 than on Day 21. Basal FSH secretion increased linearly as lactation progressed in primiparous and multiparous sows.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/8// PY - 1993/8// DO - 10.1095/biolreprod49.2.332 VL - 49 IS - 2 SP - 332-339 SN - 1529-7268 ER - TY - JOUR TI - TROPICAL PASTURE HAY UTILIZATION WITH SLAFRAMINE AND COTTONSEED MEAL - RUMINAL CHARACTERISTICS AND DIGESTA PASSAGE IN WETHERS AU - BIRD, AR AU - CROOM, WJ AU - BAILEY, JV AU - OSULLIVAN, BM AU - HAGLER, WM AU - GORDON, GLR AU - MARTIN, PR T2 - JOURNAL OF ANIMAL SCIENCE AB - Sixteen mature, ruminally cannulated wethers (average BW = 41 +/- 1 kg) were fed a low-quality hay diet with or without a cottonseed meal (CSM) supplement and the parasympathomimetic agonist slaframine (SF). Treatments were basal diet (Mitchell grass hay, 4.8% CP, 46.8% ADF) available on an ad libitum basis, basal diet plus SF (8 micrograms/kg BW, 2 x daily i.m. injection), basal diet plus CSM (41.0% CP; 100 g/d), or basal diet plus SF and CSM. Treatments were arranged as a 2 x 2 factorial within a replicated 4 x 4 Latin square with 20-d periods followed by a 10-d adjustment during which only the basal diet was fed. All measurements were performed within the final 10 d of each period. Slaframine increased salivary flow by 10 to 35% (P < .07), ruminal fluid dilution rate by 8 to 11% (P < .10), and pH by 3 to 4% (P < .001). A twofold increase (P < .05) in ruminal cellulolytic bacteria numbers occurred in SF-treated wethers. Despite these SF-induced changes in the ruminal environment, whole-tract apparent nutrient digestibility, N and mineral balance, and ruminal VFA concentrations were not changed. Cottonseed meal increased forage intake by 34 to 54% (P < .001) and DM digestibility by 30% (P < .001). Cottonseed meal supplementation of a Mitchell grass hay diet improved nutritional status and attenuated live weight loss. DA - 1993/6// PY - 1993/6// DO - 10.2527/1993.7161634x VL - 71 IS - 6 SP - 1634-1640 SN - 1525-3163 KW - PARASYMPATHOMIMETICS KW - COTTONSEED MEAL KW - FORAGE KW - SHEEP ER - TY - JOUR TI - In vitro and in vivo immunological measurements in growing lambs fed diets deficient, marginal or adequate in zinc AU - Droke, E. A. AU - Spears, J. W. T2 - Journal of Nutritional Immunology AB - Abstract Semi-purified diets, severely deficient (basal diet, 3.7 mg Zn/kg of diet), marginally deficient (basal diet + 5 mg Zn/kg of diet) or adequate (basal diet + 40 mg Zn/kg of diet) in zinc (Zn), were used to determine the effect of dietary Zn on humoral and cell-mediated immune responses in growing lambs. Dry matter intake, daily gain, serum alkaline phosphatase activity and serum Zn were lower for severely deficient lambs. The total number of peripheral blood leukocytes and an in vivo response to phytohemagglutinin were not affected by treatment. Severe Zn deficiency resulted in a lower percentage of lymphocytes and higher percentage of neutrophils in peripheral blood. Lymphocyte blastogenesis, measured by [3H]thymidine incorporation into peripheral blood lymphocytes, was lower when lymphocytes from severely deficient lambs were incubated with concentrations of phytohemagglutinin that were suboptimal for maximum proliferation. Blastogenesis was higher when lymphocytes from severely deficient lambs were incubated with a pokeweed mitogen concentration that was in excess of that needed for maximum proliferation. Immunoglobulin G titers, in response to lysozyme injection, were unaffected by dietary Zn. Severe Zn deficiency affected feed intake, weight gain, the percentages of peripheral blood leukocytes and in vitro lymphocyte blastogenesis to concentrations of mitogens that were not optimal for maximum pro-liferation. However, marginally deficient lambs were not different from Zn adequate lambs, indicating a dietary Zn level of 8.7 mg Zn/kg of diet was adequate for the parameters measured. DA - 1993/// PY - 1993/// DO - 10.1300/j053v02n01_08 VL - 2 IS - 1 SP - 71 ER - TY - JOUR TI - INFLUENCE OF DIETARY ZINC AND DEXAMETHASONE ON IMMUNE-RESPONSES AND RESISTANCE TO PASTUERELLA-HEMOLYTICA CHALLENGE IN GROWING LAMBS AU - DROKE, EA AU - SPEARS, JW AU - BROWN, TT AU - QURESHI, MA T2 - NUTRITION RESEARCH AB - Stress may suppress immune responses and increase susceptibility to bacterial pneumonia in lambs of marginal zinc (Zn) status to a greater extent than that of Zn adequate lambs. Lambs were fed diets deficient (basal diet deficient in Zn; 5.5 mg Zn/kg of diet), marginal (basal diet + 5 mg Zn/kg of diet) or adequate in Zn (basal diet + 40 mg Zn/kg of diet). Serum Zn was lower with decreasing dietary Zn by d 58. In Period 1 to simulate stress, lambs were injected i.m. with 0.2 mg dexamethasone (DEX)/kg every 24 h for 3 d. Lymphocyte blastogenesis, antibody titers following administration of chick RBCs and an in vivo response to phytohemagglutinin were not affected by dietary Zn. In Period 2, lambs were administered DEX for 3 d followed by intratracheal inoculation with 1 × 108 cfu of Pasteurella hemolytica. Clinical signs of pneumonia were not apparent in any of the lambs 72 h after inoculation. Adrenal weights were higher for deficient lambs when compared to marginal lambs. Adrenal weights for deficient and marginal lambs were not different from Zn adequate lambs. Adrenal, thymus and spleen zinc concentrations, and thymus and spleen weights were not affected by dietary Zn. These results indicate that dexamethasone did not suppress immune responses or increase susceptibility to bacterial pneumonia in lambs fed inadequate dietary Zn to a greater extent than that of lambs fed adequate dietary Zn. DA - 1993/10// PY - 1993/10// DO - 10.1016/s0271-5317(05)80745-6 VL - 13 IS - 10 SP - 1213-1226 SN - 0271-5317 KW - ZINC DEFICIENCY KW - LAMBS KW - DEXAMETHASONE KW - PASTEURELLA-HEMOLYTICA KW - IMMUNITY ER - TY - JOUR TI - FEEDLOT PERFORMANCE, CARCASS CHARACTERISTICS, HORMONES, AND METABOLITES IN STEERS ACTIVELY IMMUNIZED AGAINST GROWTH HORMONE-RELEASING FACTOR AU - HARVEY, RW AU - ARMSTRONG, JD AU - HEIMER, EP AU - CAMPBELL, RM T2 - JOURNAL OF ANIMAL SCIENCE AB - Large-framed Simmental and Charolais steers were actively immunized against growth hormone-releasing factor (GRF) to evaluate the effect on growth, carcass characteristics (especially intramuscular fat deposition), and concentrations of somatotropin (ST) and IGF-I. Primary immunizations of 1.5 mg of GRF-(1-29)-Gly-Gly-Cys-NH2 conjugated to 1.5 mg of human serum albumin (GRFi, n = 12) or 1.5 mg of human serum albumin (HSAi, n = 12) were given at approximately 10 mo of age. Booster immunizations of .5 mg of the appropriate antigen were given at d 49 and 125. Weights of steers administered GRFi were less (P < .05) than those given HSAi at 126 d (34.6 kg) or at 262 d (48.2 kg) after treatment. Carcass weights were 28.2 kg less (P < .01) for GRFi than for HSAi steers. Dry matter intake was not affected by immunization treatment, whereas feed efficiency was reduced in GRFi steers. Marbling scores were higher (P < .05) for HSAi than for GRFi steers but similar percentages (83.3) of both treatments graded Low Choice or higher. Rib sections of GRFi steers contained more fat (31.2 vs 25.0%) and less lean (63.3 vs 68.4%) than those of HSAi steers (P < .05). A breed x treatment interaction was observed for percentage of fat within the trimmed longissimus muscle (P < .05); percentage of fat was similar for Charolais and Simmental steers when immunized against HSAi but was higher for Simmental than for Charolais when immunized against GRFi.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/11// PY - 1993/11// DO - 10.2527/1993.71112853x VL - 71 IS - 11 SP - 2853-2859 SN - 0021-8812 KW - IMMUNIZATION KW - GHRF KW - CATTLE KW - GROWTH KW - CARCASS COMPOSITION ER - TY - JOUR TI - Ensiling characteristics and utilization of switchgrass preserved as silage AU - Burns, J. C. AU - Fisher, D. S. AU - Pond, K. R. T2 - Postharvest Biology and Technology AB - Switchgrass (Panicum virgatum L.) harvested at several maturities was readily ensiled when either directly cut and stored at a dry matter (DM) concentration of about 250 g kg−1 or wilted and stored at a DM concentration of about 350 g kg−1. Silage pH ranged from 4.6 to 5.1 for all treatments with acetic and lactic acids predominating. Acetic acid concentrations in the direct cut silage was double the concentrations in the wilted silage while lactic acid concentrations were similar. Forage at ensiling was high in cell walls (694 to 743 g kg−1) and low in crude protein (53 to 63 g kg−1). Silage was stable when either direct cut or wilted and well preserved when air was excluded. Forage artificially-dried (hay) or when ensiled (direct cut or wilted) did not alter DM intake (kg 100−1 kg body weight) which averaged 1.48 for the late boot stage and 1.41 when fully mature. Apparent digestion coefficients for DM and cell wall constituents of fully headed switchgrass showed no difference when preserved as hay or silage. Digestion coefficients from wilted silage were lower, however, than from direct cut silage for DM, crude protein, neutral detergent fiber, acid detergent fiber and cellulose. These results indicate that switchgrass can be preserved through fermentation with best results from immediate ensiling and subsequently utilized as silage in animal production systems. DA - 1993/// PY - 1993/// DO - 10.1016/0925-5214(93)90015-u VL - 3 IS - 4 SP - 349 ER - TY - JOUR TI - EFFECT OF INSULIN-INDUCED HYPOGLYCEMIA ON CESSATION OF MACROMOLECULAR TRANSPORT IN THE NEONATAL CALF AU - TYLER, H AU - RAMSEY, H T2 - JOURNAL OF DAIRY SCIENCE AB - The effect of hypoglycemia on the absorption of colostral Ig was studied in 12 neonatal calves.Hypoglycemic calves received 1 cc (100 units) of insulin at birth; control calves received 1 cc of saline.Two dietary regimens were imposed; colostrum was fed at birth or at 24 h.Glucose, insulin, and IgG were measured in venous blood.Insulin induced decreases in circulating glucose in insulin-treated calves from 12 to 42 h postnatally; insulin concentrations were significantly higher from 12 through 24 h.Concentrations of glucose also were decreased in calves deprived of initial colostrum compared with those fed at birth over the same period, although insulin concentrations were not different.Time of closure was delayed in insulintreated calves relative to saline-treated calves (40 and 29 h, respectively) and in calves deprived of initial colostrum relative to those fed at birth (45 and 23 h, respectively).Glucose availability may influence timing of closure in the calf, although the decreased rate of absorption of IgG in hypoglycemic calves• prevents them from realizing any benefit in peak IgG concentrations higher than those of their nonnoglycemic counterparts. DA - 1993/9// PY - 1993/9// DO - 10.3168/jds.s0022-0302(93)77610-9 VL - 76 IS - 9 SP - 2736-2741 SN - 0022-0302 KW - CALF KW - HYPOGLYCEMIA KW - IMMUNOGLOBULINS KW - NEWBORN ER - TY - JOUR TI - EFFECT OF FEED RESTRICTION ON SERUM SOMATOTROPIN, INSULIN-LIKE GROWTH FACTOR-I-(IGF-I) AND IGF BINDING-PROTEINS IN CYCLIC HEIFERS ACTIVELY IMMUNIZED AGAINST GROWTH-HORMONE RELEASING-FACTOR AU - ARMSTRONG, JD AU - COHICK, WS AU - HARVEY, RW AU - HEIMER, EP AU - CAMPBELL, RM T2 - DOMESTIC ANIMAL ENDOCRINOLOGY AB - Feed restriction often increases serum somatotropin (ST) and decreases insulin-like growth factor-I (IGF-I) in ruminants; however, the mechanisms responsible for this change in ST and IGF-I are not well defined. We investigated the effects of feed restriction on serum ST, IGF-I, IGF binding proteins (IGFBP), insulin and nonesterified fatty acids (NEFA) in cyclic Angus and Charolais heifers (n = 15) previously immunized against growth hormone releasing factor (GRFi) or human serum albumin (HSAi). Cows were fed a concentrate diet ad libitum (AL) or were restricted to 2 kg cotton seed hulls (R) for 4 d. Each heifer received each dietary treatment in a single reversal design. As anticipated, GRFi decreased ST, IGF-I and insulin (P < .05). In addition, GRFi decreased serum IGFBP-3 (P < .01), but increased IGFBP-2 (P < .01). Feed restriction resulted in an increase in serum ST in HSAi, but not in GRFi heifers. Regardless of immunization treatment, feed restriction decreased serum IGF-I and insulin, and increased NEFA (P < .01). In conclusion, the increase in serum ST levels observed during feed restriction was blocked by active immunization against GRF. However, feed restriction resulted in decreased serum IGF-I in GRFi heifers in spite of initial low levels of IGF-I (due to GRFi). Although GRFi decreased levels of IGFBP-3 and increased levels of IGFBP-2, feed restriction for 4 d did not alter serum IGFBP. DA - 1993/10// PY - 1993/10// DO - 10.1016/0739-7240(93)90035-A VL - 10 IS - 4 SP - 315-324 SN - 0739-7240 ER - TY - JOUR TI - DIETARY ZINC AFFECTS SERUM CONCENTRATIONS OF INSULIN AND INSULIN-LIKE GROWTH FACTOR-I IN GROWING LAMBS AU - DROKE, EA AU - SPEARS, JW AU - ARMSTRONG, JD AU - KEGLEY, EB AU - SIMPSON, RB T2 - JOURNAL OF NUTRITION AB - Glucose tolerance and concentrations of insulin, somatotropin, insulin-like growth factor-I and cortisol were evaluated in lambs deficient, marginal or adequate in zinc. There were three treatments: 1) deficient (basal diet deficient in zinc; 3.7 mg zinc/kg diet); 2) marginal (basal diet + 5 mg zinc/kg diet); and 3) adequate (basal diet + 40 mg zinc/kg diet). Lambs fed the zinc-deficient diet had lower (P < 0.05) serum insulin concentrations 1 h after feeding compared with those fed the marginal diet, whereas the concentrations in lambs fed the adequate diet were intermediate. Dietary zinc did not affect plasma glucose or serum somatotropin before or after feeding or intravenous glucose administration. A growth hormone-releasing factor analog was given to evaluate concentrations of somatotropin. Serum somatotropin in response to growth hormone-releasing factor analog tended to be higher (P = 0.20) in deficient and marginal lambs when compared with adequate lambs. Serum insulin-like growth factor-I was lower (P < 0.05) in deficient lambs than in marginal or adequate lambs. Cortisol concentrations were not affected (P > 0.05) by zinc status. Severe zinc deficiency altered circulating concentrations of insulin, insulin-like growth factor-I and somatotropin, whereas a marginal deficiency had no effect in growing lambs DA - 1993/1// PY - 1993/1// DO - 10.1093/jn/123.1.13 VL - 123 IS - 1 SP - 13-19 SN - 0022-3166 KW - ZINC KW - INSULIN KW - SOMATOTROPIN KW - INSULIN-LIKE GROWTH FACTOR-I KW - LAMBS ER - TY - JOUR TI - MANIPULATION OF GASTROINTESTINAL NUTRIENT DELIVERY IN LIVESTOCK AU - CROOM, WJ AU - BIRD, AR AU - BLACK, BL AU - MCBRIDE, BW T2 - JOURNAL OF DAIRY SCIENCE AB - Discussed herein are the constraints of nutrient delivery from the gastrointestinal tract that are placed on postabsorptive synthetic processes in highly selected strains of domestic livestock or livestock treated with growth promotants exogenously or via transgenic manipulation. Emphasis is placed on the discussion of recent advances in the knowledge of the regulation and manipulation of digestion and the absorption by the intestinal epithelium. Slaframine, a muscarinic exocrine secretagogue with a high affinity for the gastrointestinal tract, and epidermal growth factor may have practical potential for the manipulation of digestion and absorption, respectively. Special consideration is given to energetic considerations that must accompany any manipulation of gastrointestinal function. Down-regulation and up-regulation of mechanisms must be equally considered as this area is explored further. DA - 1993/7// PY - 1993/7// DO - 10.3168/jds.S0022-0302(93)77546-3 VL - 76 IS - 7 SP - 2112-2124 SN - 0022-0302 KW - GASTROINTESTINAL TRACT KW - DIGESTION KW - ABSORPTION KW - LIVESTOCK ER - TY - JOUR TI - INTEGRATED SYSTEMS-ANALYSIS OF SOW REPLACEMENT RATES IN A HIERARCHICAL SWINE BREEDING STRUCTURE AU - FAUST, MA AU - ROBISON, OW AU - TESS, MW T2 - JOURNAL OF ANIMAL SCIENCE AB - Sow replacement rates in a three-tiered breeding structure were investigated for a 10-yr planning horizon using a stochastic life-cycle swine production model. Market hogs were produced in a three-breed static crossing program and marketed on a liveweight basis. Growth and reproductive traits of individual pigs were simulated using genetic, environmental, and economic parameters. Sows were culled after a maximum of 1, 5, or 10 parities. Systems were defined by maximum sow age at culling and included combinations of 1- and 5-parity nucleus and 1-, 5-, and 10-parity multiplier and commercial tiers. Economic response to index selection was considerable for all culling alternatives with yearly increases in system profits ranging from $1.06 to 1.44 for each commercial hog marketed. When sows were culled after one parity in nucleus, multiplier, and commercial tiers, respectively (1,1,1), annual changes in net returns and all cost measures were 40 to 50% larger than responses in systems with lower sow replacement rates. Based on 10-yr averages for net returns, systems with low multiplier- and commercial-level replacement rates were more profitable than systems with higher replacement rates. The most profitable system (5,10,10) differed from the least profitable system (1,1,1) by more than $10 per pig, but when the (1,1,1) system was excluded, the range was only $3 per pig. The system with lowest replacement rates supported 3,388 more multiplier and 34,151 more commercial sows from a 750-sow nucleus level than the (1,1,1) system. Output from the two extremes differed by > 664,000 commercial market hogs sold.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/11// PY - 1993/11// DO - 10.2527/1993.71112885x VL - 71 IS - 11 SP - 2885-2890 SN - 0021-8812 KW - PIGS KW - BREEDING PROGRAMS KW - REPLACEMENT RATE KW - ECONOMICS KW - SIMULATION ER - TY - JOUR TI - HERITABILITIES OF MEASURES OF HOOVES AND THEIR RELATION TO OTHER TRAITS OF HOLSTEINS AU - CHOI, YS AU - MCDANIEL, BT T2 - JOURNAL OF DAIRY SCIENCE AB - Abstract Genetic and phenotypic variations of hoof measurements were related to milk and fat yields, days open from calving to conception, and survival to various ages. Data were from 5551 measures in the first four lactations of 2972 Holstein cows in six herds over 15 yr. Estimates of heritabilities for hoof angles by multivariate REML averaged .18 but ranged from .03 to .39 by lactation. Similar averages for hoof lengths were .25 (range .08 to .53) and .07 (range .02 to .16) for heel depth. Hoof lengths had the highest phenotypic relationships with milk or fat yields and days open. Hoof angles of the first lactation were positively related to survival rates to various ages. For the second lactation, hoof lengths were the only useful predictors of survival. Days open, survival rate, and increase in age-adjusted milk yield from first to second lactation were favorably related to higher hoof angles and shorter hoof lengths. Within a lactation, higher angles and shorter lengths were undesirable for increased milk or fat yields. Genetic correlations of milk and fat yields with hoof angles were generally negative, but those for length were mostly positive. Genetically, days open decreased as hoof angle increased; some differences occurred among lactations. Longer hooves and deeper heels were positively related genetically to days open. Genetic correlations of hoof angles and heel depth with survival were positive, but those with hoof length tended to be negative. DA - 1993/7// PY - 1993/7// DO - 10.3168/jds.S0022-0302(93)77532-3 VL - 76 IS - 7 SP - 1989-1993 SN - 0022-0302 KW - FOOT ANGLE KW - LONGEVITY KW - DAYS OPEN KW - HERITABILITY ER - TY - JOUR TI - GENETIC AND ECONOMIC-ANALYSES OF SOW REPLACEMENT RATES IN THE COMMERCIAL TIER OF A HIERARCHICAL SWINE BREEDING STRUCTURE AU - FAUST, MA AU - ROBISON, OW AU - TESS, MW T2 - JOURNAL OF ANIMAL SCIENCE AB - Commercial-level sow replacement rates were investigated for a 10-yr planning horizon using a stochastic life-cycle swine production model. A three-tiered breeding structure was modeled for the production of market hogs in a three-breed static crossing scheme. Growth and reproductive traits of individual pigs were simulated using genetic, environmental, and economic parameters. Culling was after a maximum of 1, 5, or 10 parities in commercial levels within 1- and 5-parity nucleus and 1-, 5-, and 10-parity multiplier combinations. Yearly changes and average phenotypic levels were computed for pig and sow performance and economic measures. For growth traits, greater commercial level response was for systems with higher sow replacement rates, 110 to 115% of lowest response. Phenotypic changes in net returns ranged from $.85 to 1.01·pig−1·yr−1. Average growth performances were highest for systems with greatest genetic trend. Highest kilograms·sow−1·year−1 finished was for 10-parity commercial alternatives. System differences in total costs and returns per pig resulted primarily from differences in replacement costs. Removal of the gilt system from analyses often reduced ranges among systems for economic measures by more than 70%. Systems with the lowest commercial replacement rates were most profitable. Within these systems, those with higher genetic change had highest net returns. For high replacement rates, no more than 175% of market value could be paid for gilts, but with lower sow replacement rates commercial units could justify as much as 450%. DA - 1993/6// PY - 1993/6// DO - 10.2527/1993.7161400x VL - 71 IS - 6 SP - 1400-1406 SN - 0021-8812 KW - PIGS KW - BREEDING PROGRAMS KW - GENETIC GAIN KW - ECONOMICS KW - SIMULATION ER - TY - JOUR TI - Enhancement of sow reproductive performance by beta-carotene or vitamin A AU - Coffey, M. T. AU - Britt, J. H. T2 - Journal of Animal Science AB - Two experiments were conducted at separate commercial farms. In Exp. 1, all primiparous sows and an equal number of multiparous sows weaned each week were randomly assigned to one of four treatment groups. Treatments consisted of one i.m. injection on the day of weaning of 0, 50, 100, or 200 mg of β-carotene. Sows were checked for estrus with boars once daily and mated at first estrus after weaning. A sample of sows (n = 100) was selected for determination of plasma β-carotene and vitamin A. Blood samples were obtained from another group (n = 120) 14 d after injection to determine plasma progesterone. In Exp. 2, treatments consisted of i.m. injection of 200 mg of β-carotene, 50,000 IU of vitamin A, or vehicle on the day of weaning, on the day of mating, and on d 7 after mating. In both experiments, the sow diet was supplemented with 11,000 IU/kg of vitamin A. In Exp. 1, there was no effect of dose of β-carotene on the interval from weaning to estrus or on the repeat service rate. There was a dose × parity interaction on the number of pigs born dead (P < .01) and born alive (P < .10), because treatment with β-carotene did not affect reproduction in primiparous sows, but litters subsequently farrowed by multiparous sows had more pigs born alive and fewer pigs born dead. There was a dose × day interaction (P < .05) on plasma β-carotene; β-carotene was elevated on d 6 and 13 after injection.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1993/// PY - 1993/// DO - 10.2527/1993.7151198x VL - 71 IS - 5 SP - 1198 ER - TY - JOUR TI - EFFECTS OF THE PERIPUBERTAL REARING ENVIRONMENT ON ENDOCRINE AND BEHAVIORAL-RESPONSES TO ESTROUS FEMALE EXPOSURE IN THE MATURE BULL AU - BORG, KE AU - ESBENSHADE, KL AU - JOHNSON, BH T2 - APPLIED ANIMAL BEHAVIOUR SCIENCE AB - The objective of this study was to determine the impact of the peri-pubertal rearing environment upon subsequent endocrine and behavioural responses of the bulls to oestrous female exposure. Thirty Angus bulls were allotted to one of three rearing environments at 10–11 months of age: on pasture (male contact only, CON); on pasture with male contact and female contact for 2 h at 28-day intervals (female-exposed treatment, EXP); or penned individually which restricted direct physical contact with other animals (IND). Environmental conditions were maintained for 8 months after which bulls were observed during a single 30-min exposure to an oestrous female with concurrent blood sampling. Significantly elevated serum cortisol concentrations were a result of the female contact period in CON, EXP and IND bulls. Detectable increases in growth hormone were evident during oestrous female exposure in IND bulls (P<0.01). This observation was absent in CON and EXP bulls. Increased mean testosterone levels were measured subsequent to the period of female exposure in all bulls. Of the behavioural events recorded, only the elapsed time to first mounting was different between environmental rearing groups. The CON bulls were slower to initiate mounting than EXP and IND bulls (P<0.07). These results suggest that the rearing environment, at or near the time of puberty, can alter subsequent endocrine responses during mating with little or no effect on behavioural parameters during the post-pubertal period of the bull. DA - 1993/1// PY - 1993/1// DO - 10.1016/0168-1591(93)90140-K VL - 35 IS - 3 SP - 245-253 SN - 0168-1591 ER - TY - JOUR TI - MULTITRAIT RESTRICTED AND DESIRED GAINS SELECTION INDEXES DESIGNED TO CHANGE GROWTH AND BODY-COMPOSITION IN MICE AU - EISEN, EJ T2 - JOURNAL OF ANIMAL BREEDING AND GENETICS-ZEITSCHRIFT FUR TIERZUCHTUNG UND ZUCHTUNGSBIOLOGIE AB - Summary Effectiveness of restricted and desired gains index selection to change growth and body composition was tested in mice. Replicate lines were selected within full‐sib families as follows: RI, restricted index to increase 12‐week body weight (BW) and hind carcass weight (HC) with no change in right epididymal fat pad weight (EF); DG, desired gains index to increase BW and HC and decrease EF and right subcutaneous fat pad weight (SF) in designated proportions; RS, random selection. Realized heritabilities of index units, converted to an individual basis, were 0.65 ± 0.17 in RI and 0.50 ± 0.23 in DG, which exceeded the respective base population estimates of 0.32 ± 0.11 and 0.37 ±0.11, calculated as twice the regression of son on sire. Realized genetic correlation between the two selection index units of 0.87 ± 0.12 was not significantly different from the base population estimate of 0.91 ± 0.21. Realized correlated responses in component traits of the indices did not agree closely with expectation. Possible explanations for these discrepancies include genetic drift, weak selection intensity, discrepancies between estimated and true genetic parameters and changes in genetic parameters due to selection. Antagonistic selection for multiple traits may magnify the importance of these factors. Zusammenfassung Restringierte und erwünschte genetische Fortschritte zur Veränderung von Wachstum und Körperzusammensetzung von Mäusen Die Wirksamkeit restraingierter und erwünschter Fortschritt‐Indexselektionsveränderung von Wachstum und Körpergewicht wurde bei Mäusen geprüft. Wiederholungslinien wurden innerhalb Vollgeschwisterfamilien folgendermaßen selektiert: RI, restringierter Index zur Steigerung des 12‐Wochengewichtes (BW), Schlachtkörperhälfte (HC) ohne Änderung des rechten Nebenhodenfettgewichts (EF); TG, erwünschter Zuchtfortschrittindex zur Steigerung von BW und HC und Verminderung von EF des rechten subkutanen Fettanteils (SF) in erwünschten Verhältnissen; RS Zufallsselektion. Realisierte Heritabilitätswerte im Index, auf individuelle Basis umgerechnet, waren 0,65 ±0,17 bei RI und 0,50 ± 0,23 bei DG, die die diesbezüglichen Basispopulationsschätzungen von 0,23 ±0,11 und 0,37 ±0,11 übertrafen. Diese wurden als die doppelte Regression von Sohn auf Vatertier berechnet. Realisierte genetische Korrelationen zwischen den zwei Selektionsindexeinheiten von 0,87 unterschieden sich nicht signifikant vom Basispopulationswert 0,91 ± 0,21. Realisierte korrelierte Selektion‐sreaktionen in den Teilmerkmalen der Indices haben mit den Erwartungswerten nicht gut übereingestimmt. Mögliche Erklärung für diese Abweichung beinhalten genetische Drift, schwache Selektionsintensität, Nichtübereinstimmung zwischen geschätzten und wahren genetischen Parametern und Veränderungen in diesen durch Selektion. Antagonistische Selektion für mehrere Merkmale könnte die Bedeutung dieser Faktoren steigern. DA - 1993/3// PY - 1993/3// DO - 10.1111/j.1439-0388.1993.tb00713.x VL - 110 IS - 1 SP - 13-29 SN - 0931-2668 ER - TY - JOUR TI - EFFECT OF GENETIC BACKGROUND ON GROWTH OF MICE HEMIZYGOTIC FOR WILD-TYPE OR DWARF MUTATED BOVINE GROWTH-HORMONE TRANSGENES AU - EISEN, EJ AU - FORTMAN, M AU - CHEN, WY AU - KOPCHICK, JJ T2 - THEORETICAL AND APPLIED GENETICS DA - 1993/10// PY - 1993/10// DO - 10.1007/bf00223760 VL - 87 IS - 1-2 SP - 161-169 SN - 0040-5752 KW - GROWTH HORMONE KW - MICE KW - TRANSGENE KW - GROWTH ER -