TY - JOUR TI - Enzymatic Degradation of Washwater solids AU - Fellner, V. AU - Belyea, R.L. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 IS - Supplement 1 SP - 246 ER - TY - THES TI - The interrelationship between vitamin A and E in absorption and transportation AU - Lin, Xi AU - Rong, Y. DA - 1990/// PY - 1990/// M3 - Ph.D. thesis, Part II ER - TY - THES TI - The interaction between vitamin A and E in the immune system of chicks AU - Lin, Xi AU - Rong, Y. DA - 1990/// PY - 1990/// M3 - Ph.D. thesis PB - Part I ER - TY - JOUR TI - Metabolism of medium- and long-chain fatty acids by isolated hepatocytes from small-for-gestational-age and appropriate-for-gestational-age piglets AU - Odle, J. AU - Benevenga, N.J. AU - Crenshaw, T.D. T2 - FASEB Journal DA - 1990/// PY - 1990/// VL - 4 SP - A658 ER - TY - RPRT TI - Do small for gestational age pigs need a different energy source than appropriate for gestational age pigs? AU - Benevenga, N.J. AU - Odle, J. AU - Crenshaw, T.D. A3 - University of Wisconsin-Madison DA - 1990/// PY - 1990/// SP - 1-3 PB - University of Wisconsin-Madison ER - TY - JOUR TI - Selection with the Animal Model Versus Selection Within Contemporary Groups for Swine AU - Mabry, J.W. AU - See, M.T. T2 - Journal of Dairy Science AB - Selection response for decreased days to 104.5 kg was compared in four sets of simulated pig populations.The four selection programs compared were: withinherd selection, one-half of boars tested, selection on phenotype within contemporary group (SI); within-herd selection, one-half of boars and all gilts tested, both selected on phenotype within contemporary group (S2); within-herd selection, one-half of boars and all gilts tested, selection on within-herd BLUP breeding value estimate (S3); and across-herd selection and AI, one-half of boars and all gilts tested, selection on across-herd BLUP breeding value estimates (S4).Selection was practiced for five generations in 10 herds with three farrowing groups of 20 sows each.With heritability =.35, after five generations, S1 resulted in a response of -14.9 d.The S2 program (testing gilts in addition to testing onehalf the boars) increased this response by 39.6%; S3 (using within-herd BLUP instead of contemporary group deviations) increased the response by another 16.3%; and S4 (using across-herd BLUP with AI) further increased the response to selection by another 37.6%.It appears then that testing of gilts, use of animal model estimates of genetic merit, and across-herd AI will result in a cumulative increase in genetic progress when compared with selection on phenotype within contemporary groups for swine. DA - 1990/// PY - 1990/// DO - 10.3168/jds.S0022-0302(90)78951-5 VL - 73 IS - 9 SP - 2657-2665 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0005383397&partnerID=MN8TOARS ER - TY - JOUR TI - SEX-RELATED DIFFERENCES IN THE CONTROL OF GONADOTROPIN CONCENTRATIONS IN NEONATAL PIGS AU - ZIECIK, AJ AU - ESBENSHADE, KL AU - HOWARD, HJ AU - BRITT, JH T2 - ANIMAL REPRODUCTION SCIENCE AB - Two experiments were conducted to examine gonadal regulation of gonadotropin secretion in male and female neonatal piglets. In the first experiment, a single i.p. injection of charcoal-treated porcine follicular fluid (pFF) lowered (P < 0.05) concentrations of plasma follicle-stimulating hormone (FSH) at 6 and 12 h after administration in 7-day-old intact male piglets, but failed to alter FSH in castrated male or intact female piglets. In the second experiment, administration of pFF twice daily from day 0 to 14 of life caused an increase in plasma FSH levels in intact males, but did not significantly alter FSH in females or in males castrated at birth. Plasma LH did not differ between male and female piglets, but FSH was significantly lower in males than in females. Castration of males at birth resulted in lower testosterone and estradiol-17β levels and resulted in a gradual increase in concentrations of FSH over the 14-day experimental period. Treatment of neonatal pigs with pFF altered concentrations of FSH in intact males, but not in intact females, indicating a divergence between the sexes in the postnatal control of FSH secretion. DA - 1990/9// PY - 1990/9// DO - 10.1016/0378-4320(90)90054-J VL - 23 IS - 2 SP - 123-133 SN - 0378-4320 ER - TY - JOUR TI - ONTOGENY OF THE GONADAL RECEPTOR FOR LUTEINIZING-HORMONE IN THE PIG AU - ZIECIK, AJ AU - ESBENSHADE, KL AU - HOWARD, HJ AU - BRITT, JH T2 - THERIOGENOLOGY AB - Homogenates of porcine ovaries and testes collected between 70 d post coitum and 42 d post partum were incubated with radiolabelled human chorionic gonadotropin (hCG) to determine the presence and relative amounts of luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptors. Specific binding of 125I-hCG to ovaries and testes occurred at all stages of fetal and postnatal development. Ovarian tissue possessed relatively low affinity, high capacity LH/hCG binding sites that were most numerous at Day 80 of gestation and decreased thereafter. In contrast, high affinity, low capacity LH/hCG binding sites were found in the testes. In males, the total number of LH/hCG binding sites remained stable until near term and then increased with age, but the number of sites per gram of testicular tissue did not change (P>0.05). In summary, differential binding of LH/hCG in gonadal tissue occurred in male and female piglets during pre- and post-natal periods, and this binding reflected the known differential pattern of development of the male and female gonad. DA - 1990/3// PY - 1990/3// DO - 10.1016/0093-691X(90)90535-2 VL - 33 IS - 3 SP - 583-589 SN - 0093-691X ER - TY - JOUR TI - Effect of rumen undegradable protein on lactational performance in cows fed low fiber diets AU - Zimmerman, C. A. AU - Rakes, A. H. AU - Daniel, T. E. AU - Hopkins, B. A. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 169 ER - TY - JOUR TI - Isolation, identification, and characterization of a feather-degrading bacterium AU - Williams, C. M. AU - Richter, C. S. AU - MacKenzie, J. M., Jr. AU - Shih, J. C. H. T2 - Applied and Environmental Microbiology DA - 1990/// PY - 1990/// VL - 56 IS - 6 SP - 1509 ER - TY - JOUR TI - Heifer viability and mortality rates as correlated responses to selection for milk yield in Randleigh Jerseys AU - Wilk, J. C. AU - McDaniel, B. T. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 139 ER - TY - JOUR TI - Evaluation of udder and teat traits and their relationship to selection for milk yield in Randleigh Jerseys AU - Wilk, J. C. AU - McDaniel, B. T. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 139 ER - TY - JOUR TI - PRODUCTION RESEARCH - PAST, PRESENT, AND FUTURE - A REVIEW AU - LEGATES, JE T2 - JOURNAL OF DAIRY SCIENCE AB - Abstract Dairy production research was in its infancy when the Hatch Act was passed in 1887. This source of continuing research funding stimulated matching support from the Agricultural Experiment Stations to develop a broad-based, yet scientifically sound, national research effort. Major advances in genetics and breeding, nutrition and feeding, reproduction and lactation, and management have resulted in a dairy industry that has attained a high degree of specialization and efficiency. Future research will depend heavily on a multidisciplinary approach. Equipment and instrumentation will require even higher investments than in the past. Federal funding for agricultural research already has been targeted for longer range fundamental inquiries. Hence, state and other research funding will be necessary for research at the interface between basic findings and their demonstrated usefulness. A host of unanswered questions continues in all areas of current dairy production research. New research tools and the advances in molecular biology bring a fresh perspective to approach difficult problem areas in genetics, reproduction, nutrition, lactation, and management. Continuing increases in herd size will require heavy reliance on computer-assisted management tools in the future. DA - 1990/5// PY - 1990/5// DO - 10.3168/jds.S0022-0302(90)78802-9 VL - 73 IS - 5 SP - 1351-1361 SN - 0022-0302 ER - TY - JOUR TI - Genetic parameters for carcass traits in Hereford bulls AU - Lamb, M. A. AU - Robison, O. W. AU - Tess, M. W. T2 - Journal of Animal Science DA - 1990/// PY - 1990/// VL - 68 IS - 1 SP - 64 ER - TY - JOUR TI - EFFICIENCY OF FEED-UTILIZATION IN HOLSTEINS SELECTED FOR YIELD AU - LEGATES, JE T2 - JOURNAL OF DAIRY SCIENCE AB - Feed intakes were obtained for d 71 through d 120 postpartum for 36 first lactation selection and 32 control cows during the last 3 yr of a 16-yr selection experiment for FCM yield in Holsteins. The ration consisted of concentrates fed according to production, limited alfalfa hay, and ad libitum corn silage. The higher estimated net energy intake by selection cows was due primarily to their significantly higher silage intake. Grain intake was slightly higher for the selection animals, but the control animals had a slightly higher hay intake. Neither differences was statistically significant. Only small and statistically nonsignificant differences in BW and weight change were found between the two groups. Selection animals had a 7.6% advantage in gross efficiency for the 50-d trial. Selection for yield gave a desired correlated change in gross feed efficiency. DA - 1990/6// PY - 1990/6// DO - 10.3168/jds.S0022-0302(90)78821-2 VL - 73 IS - 6 SP - 1533-1536 SN - 0022-0302 ER - TY - JOUR TI - IONOPHORES AND NUTRIENT DIGESTION AND ABSORPTION IN RUMINANTS AU - SPEARS, JW T2 - JOURNAL OF NUTRITION AB - This paper reviews the effects of feeding ionophores on nutrient digestion and absorption. In cattle, monensin and lasalocid increase apparent digestible energy by an average of 2.0 percentage units. In sheep, responses in digestible energy to ionophore feeding have been more variable, and neither monensin nor lasalocid have, on average, affected digestible energy. The effect of ionophores on fiber digestibility appears to depend on diet composition and source of fiber because both increases and decreases in fiber digestibility have been associated with ionophore feeding. Lasalocid and monensin reduce the percentage of starch digested in the rumen and increase the quantity of starch digested in the intestine. However, total gastrointestinal tract digestion of starch has generally not been affected by ionophores. Apparent nitrogen digestibility has been increased by ionophore feeding in a number of animal species. Apparent absorption of magnesium, phosphorus, zinc and selenium has been increased by ionophore supplementation. Absorption of calcium, potassium and sodium has been inconsistently affected by ionophores. Possible mechanisms whereby ionophores may affect nutrient digestion and absorption are discussed. DA - 1990/6// PY - 1990/6// DO - 10.1093/jn/120.6.632 VL - 120 IS - 6 SP - 632-638 SN - 1541-6100 ER - TY - JOUR TI - Effects of energy supplementation on lamb production of Javanese Thin-Tail ewes AU - Reese, A. A. AU - Handayani, S. W. AU - Ginting, S. P. AU - Sinulingga, W. AU - Reese, G. R. AU - Johnson, W. L. T2 - Journal of Animal Science AB - A 3-yr study was conducted in North Sumatra, Indonesia, as part of an evaluation of the feasibility of integrating sheep and rubber production. The objective was to evaluate the effects of increasing energy supplementation on reproduction and other performance criteria of Javanese Thin-Tail sheep grazing volunteer forages under 8- and 14-yr-old rubber trees. The control group was unsupplemented. The medium group was supplemented with high-energy feeds at 1% of the flock body weight, with the low and high groups receiving 60% or 140% of the daily energy provided by the medium group diet. Supplements provided 1.2 g protein per kilogram BW. There were 158 lambs born to the 152 ewes in the 1st year of the study. Preweaning mortality rates of lambs were reduced (P < .01) with supplementation (45 vs 12, 3 and 12% for the control, low, medium and high groups, respectively). During the 3 yr, litter size was higher (P < .01) in the high group (1.33, 1.31 and 1.34 vs 1.71 for ewes on the four respective diets). Observed repeatability of litter size of individual ewes in all treatment groups for the first three parities was higher (P < .01) than would be expected if litter size were a random event. Of the lambs born in the 1st yr, kilograms of lamb weaned per ewe joined were 3.1, 7.8, 7.3 and 9.8. At prevailing prices, only the high supplement level was profitable compared to the control. For the high group, the added return from the sale of lambs born the 1st yr was 120% of the added cost of supplementing the ewes until all the lambs were weaned (15 mo). Response of sheep to the high level of energy supplementation, especially with regard to litter size, indicates that supplementing sheep grazing in rubber plantations at a high level can be profitable. DA - 1990/// PY - 1990/// DO - 10.2527/1990.6871827x VL - 68 IS - 7 SP - 1827 ER - TY - JOUR TI - VARIATION IN HERD FINANCIAL AND PRODUCTION VARIABLES OVER TIME AU - MCGILLIARD, ML AU - CONKLIN, VJ AU - JAMES, RE AU - KOHL, DM AU - BENSON, GA T2 - JOURNAL OF DAIRY SCIENCE AB - Abstract Financial and DHI records from 1978 to 1981 from 126 dairy herds in Virginia and North Carolina were used to determine relationships among production and financial variables within herd over time. Herds averaged 6779kg milk per cow and $369 net cash income per cow for 103 cows. Expenses were 82% of receipts. Herd effects accounted for more than 40% of the variation in both financial and production variables. Year effects were less than 10% for financial variables except total receipts and expenses and were negligible for most DHI variables. Correlations among financial and DHI variables were largest between herds and smaller within herd and year. A time series, cross-sectional analysis regressed net cash income and different types of expenses on DHIA variables within herd and year. Net cash income per additional kilogram of milk was $.22 at 5000 kg/cow per yr, decreasing to 0 at 8162kg. Net cash income per cow decreased $7.70 per .1 added services per conception and $3.20 per 1% increase in culling due to changes in expenses. Crop hectares per cow and cows per man influenced receipts and expenses equally. Hired labor and cash interest per cow increased as milk yield exceeded 6000kg per cow. Holding heifers open an additional month also increased interest by $4.80 per cow. Differences in relationships among and within herds indicate difficulty in attaining herd improvement demonstrated by financial and production averages for single years. DA - 1990/6// PY - 1990/6// DO - 10.3168/jds.S0022-0302(90)78820-0 VL - 73 IS - 6 SP - 1525-1532 SN - 0022-0302 ER - TY - JOUR TI - Survival rates and reasons for removal of cows injected with rBST AU - McDaniel, B. T. AU - Bell, W. E. AU - Fetrow, J. AU - Harrington, B. D. AU - Rehman, J. D. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 159 ER - TY - JOUR TI - Regulation of digestive function in domestic livestock: Intestinal absorption and exocrine secretions AU - Jones, E. E. T2 - Journal of Animal Science AB - Journal Article Regulation of digestive function in domestic livestock: intestinal absorption and exocrine secretions Get access E. E. Jones E. E. Jones 3North Carolina State University Raleigh 27695-7621 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Animal Science, Volume 68, Issue 9, September 1990, Pages 2995–2996, https://doi.org/10.2527/1990.6892995x Published: 01 September 1990 Article history Received: 16 June 1989 Accepted: 14 December 1989 Published: 01 September 1990 DA - 1990/// PY - 1990/// DO - 10.2527/1990.6892995x VL - 68 IS - 9 SP - 2995 ER - TY - JOUR TI - Glucose, glutamine and inorganic phosphate in early development of the pig embryo in vitro AU - Petters, R. M. AU - Johnson, B. H. AU - Reed, M. L. AU - Archibong, A. E. T2 - Journal of Reproduction & Fertility AB - Summary. Pig embryos at the 1- or 2-cell stage (before the 'block' to development in vitro) were cultured in 8 different media derived from Krebs'–Ringer–bicarbonate medium. A 2 × 2 × 2 factorial arrangement was used for the treatments, with glucose, glutamine and phosphate being the major effects tested. Embryos were obtained from sows approximately 44–48 h after the observation of oestrus, with the majority being at the 1-cell stage. Embryos from each female were randomly assigned to each treatment. After in-vitro culture, all embryos were scored for the stage of development attained and stained to determine final cell number. Significant effects were evident due to female, glucose, glutamine, a phosphate × glucose interaction and a glutamine × glucose interaction. None of the media components tested was inhibitory to embryo development. The greatest development (45–60% morula or blastocyst) was achieved with glucose and glutamine (both alone and in combination) in the media, demonstrating that an amino acid can serve as the sole energy source for complete preimplantation embryonic development in vitro. Keywords: embryo; pig; in vitro culture; glutamine; glucose; phosphate DA - 1990/// PY - 1990/// DO - 10.1530/jrf.0.0890269 VL - 89 IS - 1 SP - 269 ER - TY - JOUR TI - GENETIC-CONTROL OF SURVIVAL OF FROZEN MOUSE EMBRYOS AU - POMP, D AU - EISEN, EJ T2 - BIOLOGY OF REPRODUCTION AB - Lines of mice selected for increased litter size (L+), increased body weight (W+), or randomly (K) were used to study genetic variation in embryo cryosurvival in response to standard cryopreservation protocols. A total of 60528-cell embryos from 400 females were used in two studies. In Study 1, embryos from L+, W+, and K were frozen by slow-cool and ultrarapid (direct-plunge) methods to evaluate effects of selection on cryosurvival and genotype × freezing method interaction. Post-thaw survival (PTS) was measured as percentage of recovered embryos developing in vitro to blastocyst per donor female. Nonfrozen control embryos developed similarly for each line. Within slow-cool freezing, lines differed (W+ > K, W+ = L+, L+ = K; p < 0.05); no differences were observed within the ultrarapid freezing. However, line × method interaction effects on PTS were not significant. In Study 2, reciprocal crosses were made between L+ and K and between W+ and K. Hybrid and pure line embryos were frozen by slow-cooling. Control embryos developed similarly for all genotypes. Selection lines did not differ for overall PTS. However, hybrid embryos from L+ dams were superior to those from K dams (84 vs. 61%; p < .001). No overall embryo heterosis was observed. Differences were not significant among embryo genotypes or treatments for cell number or in vivo survival. These results demonstrate significant correlated responses in embryo post-thaw cryosurvival due to selection, and implicate both maternal and embryonic genomes as controlling mouse embryo cryosurvival. DA - 1990/// PY - 1990/// DO - 10.1095/biolreprod42.5.775 VL - 42 IS - 5-6 SP - 775-786 SN - 1529-7268 ER - TY - JOUR TI - Factors affecting response to recombinant bovine somatotropin AU - McDaniel, B. T. AU - Fetrow, J. AU - Harrington, B. D. AU - Bell, W. E. AU - Rehman, J. D. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 159 ER - TY - JOUR TI - Influence of footing surface on mounting and other sexual behaviors of estrual Holstein cows AU - Vailes, L. D. AU - Britt, J. H. T2 - Journal of Animal Science AB - Seven ovariectomized Holstein cows, treated sequentially with progesterone and estradiol benzoate to induce estrus, were used to determine whether cows showed a preference for mounting and displaying other sexual behaviors toward estrual or nonestrual cows tied on dirt or concrete surfaces. Preference tests were conducted in a test area that consisted of equal-sized concrete and dirt surfaces; two cows, designated A and B, were tied on the two surfaces, one on either side. Cows A and B were treated so that on each of four test days both were estrual, only A was estrual, only B was estrual or neither A nor B were estrual. On each test day, five estrual test cows were introduced individually into the test area for two 30-min test periods. During the first test period, tied cow A was on concrete and tied cow B was on dirt, but during the second test period, their positions were switched. Test cows were able to move freely from surface to surface and to interact with tied cow A or B. Estrual test cows spent 21.6 ± 1.4 min of each 30-min test period on dirt, regardless of the estrual status of the cow tied on concrete or dirt. Mounting activity was 3- to 15-fold greater on dirt than on concrete when there was an estrual cow tied on dirt, regardless of the estrual status of the cow on concrete. Mounting activity was fourfold greater on concrete than on dirt when there was a tied estrual cow on concrete and a tied nonestrual cow on dirt.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1990/// PY - 1990/// DO - 10.2527/1990.6882333x VL - 68 IS - 8 SP - 2333 ER - TY - JOUR TI - Incorporation of nickel into ruminal factor F430 as affected by monensin and formate AU - Oscar, T. P. AU - Spears, J. W. T2 - Journal of Animal Science AB - A mixed culture of ruminal microorganisms was used to demonstrate that nickel (Ni) is incorporated into factor F430 and to determine the effects of monensin and formate on incorporation of Ni into factor F430. Ruminal microorganisms obtained from a semicontinuous culture were grown for 24 h in the presence of 63Ni and a 2 x 2 factorial arrangement of monensin (0 to 5 micrograms/ml) and formate (0 to 20 mM) treatments. Factor F430 was isolated and purified from the cultures by QAE-Sephadex A-25 column chromatography. The purified preparation contained 63Ni and exhibited a peak in absorbance at 430 nm. Methane production was decreased (P less than .01) 45% by monensin but was increased (P less than .01) 1.8-fold by formate. However, incorporation of 63Ni into factor F430, which is ubiquitous in methanogens and not found in other bacteria, did not parallel changes in methane production. Incorporation of 63Ni into factor F430 was decreased (P less than .01) 55% by monensin but was not affected (P greater than .05) by formate. In addition to its use for synthesis of urease and hydrogenase, Ni is involved in ruminal fermentation as a component of factor430. DA - 1990/// PY - 1990/// DO - 10.2527/1990.6851400x VL - 68 IS - 5 SP - 1400 ER - TY - JOUR TI - Diet quality, tiller dynamics and total nonstructural carbohydrates in flaccidgrass (Pennisetum flaccidum Griseb) under three defoliation regimes AU - Villalobos Morales, J. L. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1990/// PY - 1990/// VL - 51 IS - 4 SP - 1566 ER - TY - JOUR TI - Changes in ruminal and fecal particle weight distribution of steers fed coastal bermudagrass hay at four levels AU - Luginbuhl, J. M. AU - Pond, K. R. AU - Burns, J. C. T2 - Journal of Animal Science AB - Samples of digesta from the ruminal upper strata (RUS) and feces (F) were taken from four ruminally cannulated steers fed Coastal bermudagrass hay (78% NDF) in the long form to evaluate the effects of feeding level and time postfeeding on particle breakdown. The experimental design was a 4 x 4 Latin square with 18-d periods. Treatments based on previous intakes were set at 50, 70, 90 and 110% (3.1, 4.4, 5.5 and 6.7 kg/d, respectively) of feed consumed per animal and fed at 12-h intervals. Samples were taken at 2, 6 and 12h postfeeding and wet-sieved. Dry matter weight distribution of total recovered particles was used to partition RUS and F digesta among percentages of large (greater than 4.0 mm), medium (greater than 4.0 and less than or equal to 1.0 mm), small (less than 1.0 and greater than or eual to .125 mm) and fine (less than .125 and greater than or equal to .0027 mm) particles. With increasing feeding level, the percentage of medium RUS particles increased linearly (P less than .02), whereas the percentage of fine RUS particles decreased linearly (P less than .01). Increased time postfeeding resulted in a linear decrease in the percentage of large RUS particles (P less than .01), a linear increase in the percentage of small RUS particles (P less than .01) and in a quadratic increase in the percentage of fine RUS particles (P less than .01). Percentage of medium RUS particles remained unchanged. Increasing feeding level resulted in linear increases in mean RUS (P less than .01) and F (P less than .02) particle sizes. Percentages of RUS and F material passing through a 1.0-mm sieve averaged 52.8 and 88.8%, respectively. Animal-to-animal variation in proportions of RUS and mixed reticuloruminal particles was not entirely removed by rumination and was still reflected in the percentages of F particles. Factors such as particle entrapment in the fiber mat, reticular sedimentation, changes in specific gravity, swelling and hydration capacity, reticuloruminal motility and amount of digesta exiting per contraction appear to be more important than particle size reduction in the regulation of the passage of digesta from the reticulorumen. DA - 1990/// PY - 1990/// DO - 10.2527/1990.6892864x VL - 68 IS - 9 SP - 2864 ER - TY - JOUR TI - THE EFFECT OF AGE ON THE RHYTHMIC CONTRACTIONS OF THE RAT SMALL-INTESTINE AU - CARUOLO, EV T2 - LABORATORY ANIMALS AB - In vivo and in vitro rates of intestinal rhythmic contractions were measured in the same rats varying in age from very young to the senescent. Two rat strains, three small intestine locations, and six ages were compared. Contraction rates determined in vivo and in vitro were similar. Rhythmic contractions at all ages were fasted in the duodenum, slower in the jejunum, and slowest in the ileum. Contractions at 10 days of age were significantly slower than at all other ages; otherwise no systematic age-associated difference in contractions was demonstrated in either strain. Several factors were suggested as possibly influencing the developmental aspects of contraction rate and, therefore, their potential involvement in the early post natal period was suggested. It appears that old age does not influence the rate at which rhythmic contractions occur in the small intestine of the rat, and very possibly, these results are applicable to other species including humans. DA - 1990/7// PY - 1990/7// DO - 10.1258/002367790780866164 VL - 24 IS - 3 SP - 207-212 SN - 0023-6772 ER - TY - JOUR TI - Optimum time between mammary contractions AU - Caruolo, E. V. AU - Vreeland, C. E. AU - Dickey, D. A. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 202 ER - TY - JOUR TI - OPIOID CONTROL OF GROWTH-HORMONE IN THE SUCKLED SOW IS PRIMARILY MEDIATED THROUGH GROWTH-HORMONE RELEASING-FACTOR AU - ARMSTRONG, JD AU - ESBENSHADE, KL AU - COFFEY, MT AU - HEIMER, E AU - CAMPBELL, R AU - MOWLES, T AU - FELIX, A T2 - DOMESTIC ANIMAL ENDOCRINOLOGY AB - Endogenous opioid peptides mediate the effect of suckling on LH and PRL in the domestic pig. However, the role of opioids in modulating GH during lactation in swine is not known. Primiparous sows that had been immunized against GRF(1–29) conjugated to human serum albumin (GRF-HSA, n = 5) or HSA (n = 4) were used to determine changes in GH after naloxone. Treatments were imposed in all sows on day 21 of lactation when antibody titers were 9100 ± 1629. All sows received (i.v.) naloxone (0.25 mg/kg) or saline (0.0125 ml/kg) at 15 min intervals for 165 min. Active immunization against GRF-HSA during lactation decreased (P < 0.05) mean concentration (4.8 ± 0.2 vs 2.6 ± 0.1 ng/ml) and frequency (1.5 ± 0.3 vs 0.4 ± 0.2 peaks/4 hr). Concentrations of LH and PRL were similar in GRF-HSA and HSA immunized sows. Naloxone suppressed (P < 0.05) GH in all sows. In HSA sows, naloxone abolished episodic release of GH and decreased average, but not basal, concentrations of GH. In sows immunized against GRF-HSA, naloxone decreased (P < 0.05) average and basal GH but failed to decrease frequency of GH release. Naloxone failed to alter frequency of LH release. Concentrations of PRL decreased (P < 0.05) after naloxone in all sows. In conclusion, immunization against GRF-HSA blocked most of the effect of lactation on GH. Blocking opioid receptors with naloxone decreased GH and PRL in all sows. In contrast to previous findings naloxone had no effect on LH. Opioids alter concentrations of GH through a GRF dependent and GRF independent pathway. DA - 1990/4// PY - 1990/4// DO - 10.1016/0739-7240(90)90025-U VL - 7 IS - 2 SP - 191-198 SN - 0739-7240 ER - TY - JOUR TI - MILK TEMPERATURE IN THE CLAW PIECE OF THE MILKING MACHINE AND MAMMARY SURFACE-TEMPERATURE ARE PREDICTORS OF INTERNAL MAMMARY TEMPERATURE IN GOATS AU - CARUOLO, EV AU - JARMAN, RF AU - DICKEY, DA T2 - JOURNAL OF VETERINARY MEDICINE SERIES A-PHYSIOLOGY PATHOLOGY CLINICAL MEDICINE AB - Mammary internal and surface temperatures and milk temperature were correlated using five lactating goats. Internal mammary temperature was estimated using temperature-sensitive transmitters placed deep within the parenchyma of each mammary half. External mammary temperature was estimated using infrared thermography of four mammary skin sites: T1, teat end; T2, teat base; G1, about 20 mm above the teat base; and G2, about 20 mm ventral to the base of the gland deep to the thigh. The thermistor bead used for estimating milk temperature was placed in the claw piece where the short milk tube of the liner attaches. This placement minimized cooling effects of milk contact surfaces. The overall correlations of milk temperature with mammary temperatures ranged from 0.45 to 0.64. Correlations among the six paired values for the four external sites ranged from 0.76 to 0.92. Milk and surface temperatures, milking time, and milk weight were employed in various combinations as covariables; these were calculated within animal, within half. Milk temperature was the single most important predictor of internal mammary temperature in all models. Milk temperature alone or combined with covariables can be used to predict internal mammary temperature. DA - 1990/2// PY - 1990/2// DO - 10.1111/j.1439-0442.1990.tb00876.x VL - 37 IS - 1 SP - 61-67 SN - 0931-184X ER - TY - JOUR TI - LONG-TERM SWINE LAGOON EFFLUENT APPLICATIONS ON COASTAL BERMUDAGRASS .1. YIELD, QUALITY, AND ELEMENT REMOVAL AU - BURNS, JC AU - KING, LD AU - WESTERMAN, PW T2 - JOURNAL OF ENVIRONMENTAL QUALITY AB - Abstract Swine ( Sus scrofa domesticus ) confinement systems that use anaerobic lagoons for waste collection in the humid regions require effluent removal during the year. Land area adjacent to the hog facility frequently becomes the site for continuous effluent distribution. The objective of this experiment was to determine the effect of long‐term application of swine lagoon effluent to ‘Coastal’ bermudagrass [ Cynodon dactylon (L.) Pers.] on dry matter yield, stand persistence, and nutrient concentration and removal. Effluent loading rates of low (L), medium (M), and high (H) approximating 335, 670, and 1340 kg of N ha −1 yr −1 , respectively, were evaluated for 11 yr beginning in 1973 through 1983. The experiment was a randomized complete block with three replicates. Dry matter yields in Year 11 were altered by effluent loading rates with greater production from the M (19.0 Mg ha −1 ) or H (19.6 Mg ha −1 ) compared with the L (13.1 Mg ha −1 ). Although fluxes in stands occurred, they recovered completely as indicated by these yields. Higher concentrations of N, P, K, Mg, Cl, and Zn were present in forage in 1983 compared with 1973. Calcium was unchanged and Cu, Fe, and Na were less. In vitro dry matter disappearance of the forage was similar among loading rates (0.634) in 1983 and greater than in 1973 (0.553). Concentrations of NO 3 ‐N were higher in 1978 (1.14 g kg −1 ) compared with 1973 (0.87 g kg −1 ), but highest concentrations occurred in 1983 (1.57 g kg −1 ). By 1983, NO 3 ‐N concentrations of forages from the H loading rate approached or exceeded the toxic threshold in all summer harvests. Only the H loading (1340 kg ha −1 ) caused unstable stands and eventually produced forage that had NO 3 ‐N concentrations potentially toxic if fed as the sole ration to ruminants. Further, it resulted in disproportionally greater quantities of elements—especially N, P, K, Cl, and Na—that remained in the soil environment to become potential soil and soil‐water pollutants. DA - 1990/// PY - 1990/// DO - 10.2134/jeq1990.00472425001900040019x VL - 19 IS - 4 SP - 749-756 SN - 0047-2425 ER - TY - JOUR TI - Effect of fructose-induced hypoglycemia on cessation of intestinal transport of immunoglobulins in newborn calves AU - Tyler, H. D. AU - Ramsey, H. A. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 219 ER - TY - JOUR TI - Effect of feeding thyrotropin-releasing hormone to lactating sows AU - Cabell, S. B. AU - Esbenshade, K. L. T2 - Journal of Animal Science AB - Two experiments were conducted to assess the effects of feeding thyrotropin-releasing hormone (TRH) during lactation on sows. In Exp. 1, sows were fed 0, 1, 10, 100 or 1,000 mg TRH on d 10.8 +/- .4 (mean +/- SE) after parturition. Blood samples were taken from sows every 30 min from -2 h to 8 h and at 10, 12 and 18 h from feeding. Consumption of 100 or 1,000 mg TRH increased mean serum concentrations of thyroxine (T4; P less than .001), 1,000 mg TRH increased growth hormone (GH; P less than .06) and 100 or 1,000 mg TRH increased prolactin (PRL; P less than .01), but insulin (INS; P greater than .10) was unaffected by TRH. Serum concentrations of T4 were elevated within 2 to 4 h after feeding TRH and remained elevated for 12 to 18 h. Concentrations of GH and PRL began to increase immediately after feeding 100 or 1,000 mg TRH and remained elevated for 6 and 8 h, respectively. In Exp. 2, sows were fed 0 or 200 mg TRH from d 111 of gestation to weaning at 27.1 +/- .3 d of lactation. Consumption of TRH elevated concentrations of T4 at all stages of lactation and increased respiration rate on d 10 and d 20, heart rate on d 20, and milk production on d 20 of lactation. Consumption of TRH did not influence number of pigs born, number born alive, survival rate during lactation, sow body weight, heartgirth, backfat depth, feed disappearance, or milk production on d 10 of lactation. Piglets nursing sows fed TRH were similar in weight to piglets nursing sows not fed TRH on d 0 and 5 of lactation, but they were heavier on d 10 (P less than .07), 15 (P less than .001), 20 (P less than .001) and 27 (P less than .0001). Sows fed TRH took longer (P less than .001) to return to estrus after weaning than control sows. Results indicated that feeding TRH elevated T4, GH and PRL and that feeding TRH for the duration of lactation increased milk production on d 20 of lactation and increased weaning weights, but it delayed estrus after weaning. DA - 1990/// PY - 1990/// DO - 10.2527/1990.68124292x VL - 68 IS - 12 SP - 4292 ER - TY - JOUR TI - Air leakage and milk flow influence milk temperature AU - Caruolo, E. V. AU - Vreeland, C. E. AU - Dickey, D. A. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 202 ER - TY - JOUR TI - Active immunization of pigs against growth hormone-releasing factor: Effect on concentrations of growth hormone and insulin-like growth factor 1 AU - Armstrong, J. D. AU - Esbenshade, K. L. AU - Johnson, J. L. AU - Coffey, M. T. AU - Heimer, E. AU - Campbell, R. M. AU - Mowles, T. AU - Felix, A. T2 - Journal of Animal Science AB - Cyclic gilts (96 ± 1 kg) were used to determine the effect of active immunization against growth hormone-releasing factor GRF(l-29)-NH2 on concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Gilts were immunized against GRF conjugated to human serum albumin (GRF-HSA, n = 5) or HS A alone at 180 d of age (wk 0). Booster doses were administered at wk 9 and 13. Seven days after the second booster (wk 14), blood samples were collected at 15-min intervals for 6 h before feeding and 30, 60, 120, 180 and 240 min after feeding. Eight days after the second booster, all gilts were administered a GRF analog, [desNH2Tyr1,Alal5]-GRF(l-29)-NH2, followed by an opioid agonist, FK33-824. Blood samples were collected at 15-min intervals from -30 to 240 min after injection. Immunization against GRF-HSA resulted in antibody titers, expressed as dilution required to bind 50% of [125I]GRF, ranging from 1:11,000 to 1:60,000 (wk 11 and 14); binding was not detectable or was less than 50% at 1:100 in HS A gilts (P < .05). Episodic release of GH was abolished by immunization against GRF-HSA (P < .05). Mean GH was decreased (P < .07), but basal GH concentrations were not altered (P > .15) by immunization against GRF-HSA. Serum concentrations of IGF-1 were similar at wk 0, but concentrations were lower in GRF-HSA than in HSA gilts (P < .05) at wk 14.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1990/// PY - 1990/// DO - 10.2527/1990.682427x VL - 68 IS - 2 SP - 427 ER - TY - JOUR TI - The effect of human growth hormone-releasing factor or porcine somatotropin on serum hormones and metabolites, growth performance and carcass traits in swine AU - Johnson, J. L. AU - Coffey, M. T. AU - Esbenshade, K. L. AU - Schricker, B. R. AU - Pilkington, D. H. T2 - Journal of Animal Science AB - Forty barrows (77.9 +/- 5.5 kg BW) were allotted to one of five treatment groups to examine the effects of various doses of human growth hormone-releasing factor (1-44)NH2 (hGRF) or porcine somatotropin (pST) administered twice daily on serum hormones and metabolites, performance and carcass traits. Barrows were injected s.c. with either a placebo, 10 micrograms hGRF.kg BW-1.12 h-1, 20 micrograms hGRF.kg BW-1.12 h-1, 20 micrograms pST.kg BW-1.12 h-1 or 40 micrograms pST.kg BW-1.12 h-1 for a 36-d growth trial. Blood samples were collected from 13 barrows at intervals for 360 min after injection on d 21. Compared with the placebo, 10 micrograms hGRF.kg-1.12 h-1 increased (P less than .01) serum pST and insulin and decreased (P less than .001) urea N. Injecting 20 micrograms hGRF/kg.12 h-1 elevated (P less than .001) serum pST, insulin and insulin-like growth factor-I (IGF-I) but lowered (P less than .001) urea N. Exogenous pST increased (P less than .001) serum pST, insulin, IGF-I and glucose but decreased (P less than .001) urea N. Growth rate tended to increase, and feed intake and feed/gain decreased, in a dose-related manner in response to hGRF. Also, pigs receiving 10 or 20 micrograms hGRF.kg-1.12 h-1 had reduced (P less than .1) backfat and increased (P less than .1) loineye area and percentage lean in the ham compared with pigs receiving the placebo. At equal doses, pST elicited more dramatic improvements in performance and carcass criteria than did hGRF.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1990/// PY - 1990/// DO - 10.2527/1990.68103204x VL - 68 IS - 10 SP - 3204 ER - TY - JOUR TI - PARTHENOGENETIC ACTIVATION OF MOUSE AND PIG OOCYTES MATURED INVITRO AU - DIDION, BA AU - MARTIN, MJ AU - MARKERT, CL T2 - THERIOGENOLOGY AB - The objective of this study was to determine if mouse and pig oocytes matured in vitro undergo parthenogenetic activation following exposure to various activation stimuli. Cumulus-intact, germinal vesicle-stage mouse oocytes (n = 151) were collected from pregnant mare serum gonadotropin primed mice and incubated overnight in Brinster's medium. This culture system allowed an 85% maturation to Metaphase II. Pig oocytes (n = 242) were gathered from ovaries collected at an abbattoir and incubated in vitro for 48 h to allow maturation to occur (51% maturation to Metaphase II). Following maturation, mouse and pig oocytes were exposed to various activation stimuli. Mouse oocytes were treated with medium containing ethanol (7%), electricity (85 V, 30 us, one time), or medium; then they were incubated for 6 to 8 h to allow for activation. Pig oocytes were treated with medium containing ethanol (10%), electricity (85 V, 30 us once or twice), ethanol followed by electricity, or medium then incubated for 18 h to allow for activation. A portion of the mouse and pig oocytes were fixed immediately after maturation to serve as a control. The nuclear status of the oocytes was examined after staining with Hoechst 33342. Chi-square procedures were used to analyze the data. The proportion of mouse oocytes which underwent activation was higher (P<0.01) for ethanol and electricity than for the medium (22, 30 and 0%, respectively). The proportion of pig oocytes which underwent activation was higher (P<0.05) for two current exposures (14%) and ethanol followed by current (16%) than for the medium (0%). There was no evidence of spontaneous activation occurring in mouse or pig oocytes during the maturation period. Most of the activated mouse oocytes contained a single haploid pronucleus, as evidenced by two polar bodies and one pronucleus. In contrast, most of the activated pig oocytes were diploid parthenotes, as evidenced by one polar body and one pronucleus. The results show that a portion of in vitro matured mouse and pig oocytes undergo parthenogenetic activation following exposure to activation stimuli. DA - 1990/6// PY - 1990/6// DO - 10.1016/0093-691X(90)90035-R VL - 33 IS - 6 SP - 1165-1175 SN - 0093-691X ER - TY - JOUR TI - Observations on the cooling and cryopreservation of pig oocytes at the germinal vesicle stage AU - Didion, B. A. AU - Pomp, D. AU - Martin, M. J. AU - Homanics, G. E. AU - Markert, C. L. T2 - Journal of Animal Science AB - This study examined the viability of pig oocytes at the germinal vesicle stage following cooling or cryopreservation. Cumulus-intact oocytes (n = 641) were collected from slaughterhouse pig ovaries and used in two experiments. In Exp. I the viability of 1) control, 2) cryoprotectant control (CC, 1.5 M glycerol/.5 M sucrose), 3) cooled (0 degrees C) and 4) cryopreserved (-196 degrees C) oocytes was assessed after no incubation or a 24-h incubation. Survivability was judged by morphological appearance, trypan blue exclusion and fluorescein diacetate staining. Survival rate of control oocytes (90%; based primarily on morphological appearance of the cumulus) incubated 0 h was greater (P less than .05) than that of all other groups, whereas survival rate of -196 degrees C oocytes (57%) was less (P less than .05) than that of all other groups. However, vital staining of 0 degrees C and -196 degrees C oocytes showed 0% survival rate as evidenced by trypan blue uptake and lack of fluorescence. The cumulus cells surrounding oocytes that were stored at 0 degrees C or -196 degrees C survived freezing as evidenced by trypan blue exclusion and intense fluorescence. Similar differences among treatment groups were found for oocytes incubated 24 h. Exp. 2 examined the temperature at which oocytes became sensitive to cooling. Oocyte death occurred when oocytes were cooled to 15 degrees C or lower. These results demonstrate that pig oocytes at the germinal vesicle stage did not survive cooling to 15 degrees C or below. When assessing the viability of cryopreserved cumulus enclosed oocytes it is important to use vital stains in conjunction with morphological appearance. DA - 1990/// PY - 1990/// DO - 10.2527/1990.6892803x VL - 68 IS - 9 SP - 2803 ER - TY - JOUR TI - EFFECT OF GROWTH HORMONE-RELEASING FACTOR (1-44)NH2 ADMINISTRATION ON SOMATOTROPIN IN PIGS AU - JOHNSON, JL AU - COFFEY, MT AU - ESBENSHADE, KL AU - SCHRICKER, BR T2 - CANADIAN JOURNAL OF ANIMAL SCIENCE AB - Two experiments were conducted to examine the dose response and optimum pattern of subcutaneous (s.c.) administration of human growth hormone-releasing factor [hGRF (1–44)NH 2 ]on serum somatotropin (ST) in barrows. In exp. 1, 10 barrows (79.9 ± 3.3 kg) were used in a replicated 5 × 5 Latin square and blood samples were collected for 300 min from a single injection of hGRF. Injecting 0, 1, 10, 40 or 100 μg hGRF kg −1 resulted in dose related increase (P < 0.01) in peak concentrations of pST (3.93, 4.41, 10.61, 16.01 and 23.56 ng mL −1 ), and area under the ST response curve (AUC) (565.4, 546.2, 757.5, 1048.0 and 1314.0 ng min mL −1 , respectively). The 40 μg kg −1 dose resulted in a higher (P < 0.05) peak pST and AUC than 0 or 1 μg hGRF kg −1 . Peak concentration and AUC were greater (P < 0.05) for the 100 μg hGRF kg −1 dose compared with the 0, 1 and 10 μg hGRF kg −1 doses, but there was no difference between the 40 and 100 μg kg −1 doses. In exp. 2, eight barrows (85.4 ± 8.0 kg) were used in a replicated 4 × 4 Latin square to examine the relationship between pattern of hGRF administration and serum ST. Blood samples were collected −15, 0 and 15 min from initiation of administration and then hourly for 24 h. Treatments were designed to deliver 160 μg hGRF kg −1 every 24 h and were administered as 40 μg kg −1 injected four times daily, 80 μg kg −1 injected twice daily or by continuous s.c. infusion. There was no difference (P > 0.10) between treatments for peak ST concentration, AUC or area above the ST baseline. These data indicated a dose response to s.c. hGRF injections and ST in barrows. Further, ST response was not altered by the pattern of s.c. administration when barrows received 160 μg hGRF kg −1 daily by either 4 or 2 discrete injections or by continuous infusion. Key words: Swine, somatotropin, growth hormone-releasing factor DA - 1990/9// PY - 1990/9// DO - 10.4141/cjas90-098 VL - 70 IS - 3 SP - 785-793 SN - 0008-3984 ER - TY - JOUR TI - Cholinergic manipulation of digestive function in ruminants and other domestic livestock: A review AU - Croom, W. J. AU - Froetschel, M. A. AU - Hagler, W. M. T2 - Journal of Animal Science AB - Exocrine secretions in the digestive tract of domestic livestock are controlled by a combination of neural and endocrine inputs. The parasympathetic domain of the autonomic nervous system is responsible for efferent signals that regulate most exocrine secretory processes. Exocrine tissues possess cholinergic muscarinic receptor subtypes that are different from those found in brain, heart and muscle tissues. Cholinergic stimulation of specific muscarinic receptor subtypes has enhanced secretions of the salivary glands and pancreas. These changes in output of exocrine glands can alter digestive function that may benefit production of cattle and swine. DA - 1990/// PY - 1990/// DO - 10.2527/1990.6893023x VL - 68 IS - 9 SP - 3023 ER - TY - JOUR TI - EFFECTS OF PROTEIN SUPPLEMENTATION AND PARASYMPATHETIC STIMULATION WITH SLAFRAMINE ON UTILIZATION OF LOW QUALITY ROUGHAGE FED TO GOATS AND SHEEP AU - GASKINS, HR AU - CROOM, WJ AU - VANEYS, JE AU - JOHNSON, WL AU - HAGLER, WM T2 - SMALL RUMINANT RESEARCH AB - Eighteen Angora goats (average BW 14 kg) and 18 Barbados Blackbelly X Dorset sheep (average BW 24 kg), all wethers, were fed chopped coastal bermudagrass hay (84% neutral detergent fiber (NDF), 6% crude protein (CP)) ad libitum and offered only alfalfa hay or cottonseed meal as protein supplement during an 84-day feeding trial. From day 28, animals received daily injections of physiological saline with or without the parasympathomimetric slaframine (SF) at 30 μg kg−1 BW. Digestibility and digesta kinetics measurements were made during a 7-day fecal collection period. Goats had lower (P< 0.05) intakes of DM, NDF and CP than sheep. There were no differences in digestibility of DM, NDF or CO between species. Protein supplementation increased digestibility of DM (P< 0.05), NDF (P< 0.10), and CP (P< 0.01) without affecting intake. No differences were due to type of supplement in intake and digestibility. SF depressed (P< 0.05) intake of DM, NDF and CP and tended (P<0.10) to lower DM and CP digestibility. Protein supplementation increased (P<0.05) and SF decreased (P< 0.01) weight gain. Animals receiving protein supplement lost less body weight (BW) after SF treatment than those receiving no supplement. Goats and sheep apparently utilized low quality roughages differently but responded similarly to protein supplementation. SF was not effective in altering ruminal liquid dilution rate or enhancing nutrient digestibility in goats and sheep fed high fiber diets. DA - 1990/10// PY - 1990/10// DO - 10.1016/0921-4488(90)90051-7 VL - 3 IS - 6 SP - 561-573 SN - 0921-4488 ER - TY - JOUR TI - ANIMAL-MODEL ESTIMATES OF CYTOPLASMIC LINE CONSTANTS FOR YIELD IN HOLSTEINS AU - FAUST, MA AU - ROBISON, OW AU - MCDANIEL, BT T2 - JOURNAL OF ANIMAL BREEDING AND GENETICS-ZEITSCHRIFT FUR TIERZUCHTUNG UND ZUCHTUNGSBIOLOGIE AB - Journal of Animal Breeding and GeneticsVolume 107, Issue 1-6 p. 401-410 Animal model estimates of cytoplasmic line constants for yield in Holsteins1 M. A. Faust, M. A. Faust Department of Animal Science, North Carolina State University, Raleigh, USASearch for more papers by this authorDr. O. W. Robison, Corresponding Author Dr. O. W. Robison Department of Animal Science, North Carolina State University, Raleigh, USAAnimal Science Department. P.O. Box 7621, N.C. State University, Raleigh, NC 27695-7621, USASearch for more papers by this authorB. T. McDaniel, B. T. McDaniel Department of Animal Science, North Carolina State University, Raleigh, USASearch for more papers by this author M. A. Faust, M. A. Faust Department of Animal Science, North Carolina State University, Raleigh, USASearch for more papers by this authorDr. O. W. Robison, Corresponding Author Dr. O. W. Robison Department of Animal Science, North Carolina State University, Raleigh, USAAnimal Science Department. P.O. Box 7621, N.C. State University, Raleigh, NC 27695-7621, USASearch for more papers by this authorB. T. McDaniel, B. T. McDaniel Department of Animal Science, North Carolina State University, Raleigh, USASearch for more papers by this author First published: January‐December 1990 https://doi.org/10.1111/j.1439-0388.1990.tb00051.xCitations: 8 1 Research supported by the North Carolina Agricultural Research Service, Raleigh 27695-7601 and the national Association of Animal Breeders. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume107, Issue1-6January‐December 1990Pages 401-410 RelatedInformation DA - 1990/12// PY - 1990/12// DO - 10.1111/j.1439-0388.1990.tb00051.x VL - 107 IS - 6 SP - 401-410 SN - 0931-2668 ER - TY - JOUR TI - Prostaglandin F-2alpha causes regression of an HCG-induced corpus luteum before day 5 of its lifespan in cattle AU - Howard, H. J. AU - Britt, J. H. T2 - Journal of Reproduction & Fertility AB - The experimental objective was to evaluate how a spontaneously formed corpus luteum (CL) differed in its response to prostaglandin (PG) F-2 alpha, given during the first 5 days after ovulation, from a CL induced during dioestrus with hCG. Sixteen Holstein heifers were used during each of 2 consecutive oestrous cycles. During the first cycle (sham cycle), heifers were given no PGF-2 alpha (control) or PGF-2 alpha (25 mg, i.m.) on Day 2, 4 or 6 (oestrus = Day 0). During the second cycle (hCG-treated cycle), heifers were given hCG (5000 i.u., i.m.) on Day 10, followed by no PGF-2 alpha (control) or PGF-2 alpha on Day 12, 14 or 16, corresponding to 2, 4 or 6 days after the ovulatory dose of hCG. A new ovulation was induced in 13 of 16 heifers given hCG on Day 10. Luteolysis did not occur immediately in heifers given PGF-2 alpha on Day 2 or 4 during the sham cycle, but concentration of progesterone in serum during the remainder of the cycle was lower in heifers given PGF-2 alpha on Day 4 than in sham controls or heifers given PGF-2 alpha on Day 2 (P less than 0.05). Luteolysis occurred immediately in heifers given PGF-2 alpha on Day 6 of the sham cycle or on Day 12, 14 or 16 of the hCG-treated cycle, with concentration of progesterone in serum decreasing to less than 1 ng/ml within 2 days.(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1990/// PY - 1990/// DO - 10.1530/jrf.0.0900245 VL - 90 IS - 1 SP - 245 ER - TY - JOUR TI - Mechanisms of extended corpus luteum function in dairy cattle treated with human chorionic gonadotropin or infused continuously with oxytocin AU - Howard, H. J. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1990/// PY - 1990/// VL - 51 IS - 2 SP - 607 ER - TY - JOUR TI - Extension of oestrous cycles and prolonged secretion of progesterone in non-pregnant cattle infused continuously with oxytocin AU - Howard, H. J. AU - Morbeck, D. E. AU - Britt, J. H. T2 - Journal of Reproduction & Fertility AB - Summary. The experimental objective was to evaluate how continuous infusion of oxytocin during the anticipated period of luteolysis in cattle would influence secretion of progesterone, oestradiol and 13,14-dihydro-15-keto-prostaglandin F-2α (PGFM). In Exp. I, 6 non-lactating Holstein cows were infused with saline or oxytocin (20 IU/h, i.v.) from Day 13 to Day 20 of an oestrous cycle in a cross-over experimental design (Day 0 = oestrus). During saline cycles, concentrations of progesterone decreased from 11·0 ± 2·0 ng/ml on Day 14 to 2·0 ± 1·3 ng/ml on Day 23; however, during oxytocin cycles, luteolysis was delayed and progesterone secretion remained near 11 ng/ml until after Day 22 (P < 0·05). Interoestrous interval was 1·6 days longer in oxytocin than in saline cycles (P = 0·07). Baseline PGFM and amplitude and frequency of PGFM peaks in blood samples collected hourly on Day 18 did not differ between saline and oxytocin cycles. In Exp. II, 7 non-lactating Holstein cows were infused with saline or oxytocin from Day 13 to Day 25 after oestrus in a cross-over experimental design. Secretion of progesterone decreased from 6·8 ± 0·7 ng/ml on Day 16 to <2 ng/ml on Day 22 of saline cycles; however, during oxytocin cycles, luteolysis did not occur until after Day 25 (P < 0·05). Interoestrous interval was 5·9 days longer for oxytocin than for saline cycles (P < 0·05). In blood samples taken every 2 h from Day 17 to Day 23, PGFM peak amplitude was higher (P < 0·05) in saline (142·1 ± 25·1 pg/ml) than in oxytocin cycles (109·8 ± 15·2 pg/ml). Nevertheless, pulsatile secretion of PGFM was detected during 6 of 7 oxytocin cycles. In both experiments, the anticipated rise in serum oestradiol concentrations before oestrus, around Days 18-20, was observed during saline cycles, but during oxytocin cycles, concentrations of oestradiol remained at basal levels until after oxytocin infusion was discontinued. We concluded that continuous infusion of oxytocin caused extended oestrous cycles, prolonged the secretion of progesterone, and reduced the amplitude of PGFM pulses. Moreover, when oxytocin was infused, pulsatile secretion of PGFM was not abolished, but oestrogen secretion did not increase until oxytocin infusion stopped. Keywords: corpus luteum; prostaglandin; progesterone; oxytocin; cow DA - 1990/// PY - 1990/// DO - 10.1530/jrf.0.0900493 VL - 90 IS - 2 SP - 493 ER - TY - JOUR TI - Effects of intraperitoneal infusion of L-leucine, L-isoleucine, L-valine, and L-arginine of alleviation of milk fat depression in early lactation Holstein dairy cows AU - Hopkins, B. A. AU - Rakes, A. H. AU - Daniel, T. E. AU - Zimmerman, C. A. AU - Croom, W. J., Jr. T2 - Journal of Dairy Science DA - 1990/// PY - 1990/// VL - 73 SP - 171 ER - TY - JOUR TI - Subclinical ammonia toxicity in steers: Effects on hepatic and portal-drained visceral flux of metabolites and regulatory hormones AU - Fernandez, J. M. AU - Croom, W. J. AU - Tate, L. P. AU - Johnson, A. D. T2 - Journal of Animal Science AB - Four calves (avg wt 161 kg) were surgically fitted with indwelling catheters in the femoral artery and femoral, portal, hepatic and mesenteric veins to study the effects of subclinical ammonia toxicity on portal-drained viscera (PDV) and hepatic (HEP) net flux of key metabolites and pancreatic hormones. Hyperammonemia was induced via administration of ammonium chloride (NH4Cl; 12 mumol.kg BW-1.min-1) via the femoral vein catheter for 240 min; infusions were preceded (PRE) and followed (POST) by 60- and 180-min control periods, respectively. Blood samples were obtained from the arterial catheters, and portal and hepatic vein catheters. Net flux rates were calculated by multiplying venoarterial differences by blood flow. Arterial plasma ammonia N peaked (P less than .01) at 327 micrograms/dl; hepatic ammonia extraction increased (P less than .01) from 10 to 23% during NH4Cl infusion. Arterial plasma glucose concentrations increased (P less than .05) during NH4Cl infusion (90.5 vs 82.6 mg/dl) concomitant with trends toward a reduction in net HEP glucose output. Portal-drained visceral release of insulin did not increase (P greater than .10) during NH4Cl infusion despite the steady rise in circulating glucose concentration; however, cessation of NH4Cl infusion resulted in a 109% increase (P less than .05) in PDV insulin release at +60 min POST. Plasma L-lactate, nonesterified fatty acids, urea N and glucagon concentrations and net fluxes were variable throughout the experiment. Results tend to indicate that hyperammonemia reduced hepatic glucose output and glucose-mediated pancreatic insulin release. DA - 1990/// PY - 1990/// DO - 10.2527/1990.6861726x VL - 68 IS - 6 SP - 1726 ER - TY - JOUR TI - Replicate differences in lines of mice selected for body composition AU - Eisen, E. J. AU - Pomp, D. T2 - Genome AB - Replicate differences were studied in lines of mice selected at 12 weeks of age for high (HF1, HF2) or low (LF1, LF2) right epididymal fat pad weight as a percentage of body weight (%EFP); for high (HL1, HL2) or low (LL1, LL2) hind carcass weight as a percentage of body weight (%HC); and randomly (RC1, RC2). Correlated traits were subcutaneous fat pad weight as a percentage of body weight (%SFP), water weight in hind carcass as a percentage of hind carcass weight (%WAT), body weights at 3, 6, and 12 weeks of age, and 3- to 6-week weight gain. Individual and maternal effects contributed to significant genetic drift for selected and correlated traits. No evidence indicated that drift was greater in selection treatments than in controls. Significant heterosis in replicate crosses within selection treatments was found for %HC in HL, LL, and LF and for %EFP in HF. Heterosis was insignificant in crosses of control replicates. Divergence in parental lines and replicate crosses was similar, indicating that differences in heterosis between high and low lines were small relative to divergence. Asymmetry tended to be greater between replicate crosses and parental lines, because selected replicates have greater average heterosis than control replicates. Multivariate discriminant function and Mahalanobis distance analysis of selected traits showed that divergence between replicates within selection treatments was much less than among selection treatments.Key words: selection, genetic drift, body composition, mice. DA - 1990/// PY - 1990/// DO - 10.1139/g90-045 VL - 33 IS - 2 SP - 294 ER - TY - JOUR TI - Regulation and action of gonadotropins in pigs AU - Esbenshade, K. L. AU - Ziecik, A. J. AU - Britt, J. H. T2 - Journal of Reproduction & Fertility DA - 1990/// PY - 1990/// SP - 19 ER - TY - JOUR TI - ENCAPSULATION OF PORCINE SPERMATOZOA IN POLYLYSINE MICROSPHERES AU - ESBENSHADE, KL AU - NEBEL, RL T2 - THERIOGENOLOGY AB - Three experiments were conducted to examine the effects of incubating porcine spermatozoa in concentrated samples, to determine the viability of sperm encapsulated in microspheres and to evaluate the potential of microencapsulating porcine spermatozoa for use in artificial insemination. In Experiment 1, sperm incubated at 4, 15, 20 or 37 degrees C and at concentrations of 7.5, 15, 30, 60 or 120 x 10(6) sperm/ml lost motility over a 16-h incubation period. Sperm motility was significantly lower at 4 degrees C than at 15, 20 or 37 degrees C and was significantly higher in more concentrated samples. In Experiment 2, sperm were encapsulated in poly-lysine microspheres at concentrations of 30, 60 or 120 x 10(6) sperm/ml and incubated in vitro at 4, 15 or 20 degrees C. Unencapsulated samples were incubated at similar concentrations and temperatures and served as controls. Motility and percentage of sperm with intact acrosomes were estimated at 2, 4, 8 and 16 h of incubation. The procedure of encapsulation did not affect sperm motility or acrosomal morphology; however, there was an accelerated loss of motility in encapsulated samples. There were no differences in acrosomal morphology between the two groups across time. In Experiment 3, sperm were encapsulated at a concentration of 120 x 10(6) sperm/ml and 20 ml of capsules were inseminated into estrous sows. Uterine contents were flushed at 3, 6 and 24 h after insemination and examined for capsules. Capsules containing motile sperm were recovered from sows at 3 and 6 h, but not at 24 h. These results demonstrate that porcine spermatozoa can be encapsulated in microspheres and that these capsules can be inseminated into estrous females, but the sperm undergo an accelerated loss of motility in vitro and in vivo. DA - 1990/2// PY - 1990/2// DO - 10.1016/0093-691X(90)90507-P VL - 33 IS - 2 SP - 499-508 SN - 0093-691X ER - TY - JOUR TI - Correlated responses in body composition based on selection for different indicator traits in mice AU - Eisen, E. J. AU - Coffey, M. T. T2 - Journal of Animal Science AB - Correlated responses in whole-body composition were determined in 12-wk-old male mice from replicate lines selected for 12 generations for high (HF) or low (LF) epididymal fat pad weight as a percentage of body weight (EPID) and high (HL) or low (LL) hind carcass weight as a percentage of body weight. The HF and LF lines diverged (P less than .01) in body fat percentage (FAT) and subcutaneous depot fat by 93 and 71%, respectively, of the control line (RC) mean. EPID increased (P less than .01) proportionately more than FAT in the HF line; EPID decreased (P less than .01) proportionately less than FAT in LF. Protein, fat and water as a percentage of empty body weight showed negative correlated responses (P less than .01) due to selection for EPID, but lean body mass, body weight and body length had positive correlated responses (P less than .01). Correlated responses of fat-free protein and ash percentage were minor. Correlated responses in HL and LL were the mirror images of those in HF and LF, but they generally were of smaller magnitude. The results indicate that, although there are high positive genetic correlations between fat depots in mice, local control of lipogenesis and(or) lipolysis exists at different sites of fat deposition. Further, the lack of correlated responses in fat-free percentage of protein (and percentage of ash) suggests that additive genetic variances are low for these traits and(or) the genetic correlations of these traits with the selection criteria are low. DA - 1990/// PY - 1990/// DO - 10.2527/1990.68113557x VL - 68 IS - 11 SP - 3557 ER - TY - PAT TI - Method of degrading keratinaceous material and bacteria useful therefore AU - Shih, J. C. H. AU - Williams, C. M. C2 - 1990/// DA - 1990/// PY - 1990/// ER - TY - PAT TI - Feather-lysate, a hydrolyzed feather feed ingredient and animal feeds containing the same AU - Shih, J. C. H. AU - Williams, C. M. C2 - 1990/// DA - 1990/// PY - 1990/// ER -