TY - JOUR TI - Influences of adrenal secretions on testicular testosterone in the bovine AU - Welsh, T. H. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1981/// PY - 1981/// VL - 42 IS - 1 SP - 92 ER - TY - JOUR TI - INTERRELATIONSHIPS OF SERUM CORTICOSTEROIDS, LH, AND TESTOSTERONE IN MALE BOVINE AU - WELSH, TH AU - RANDEL, RD AU - JOHNSON, BH T2 - ARCHIVES OF ANDROLOGY AB - Temporal interrelationships of endogenous peripheral blood concentrations of corticosteriods (CS), luteinizing hormone (LH), and testosterone(T) were evaluate in bulls. Concentrations of CS, LH, and T were quantitated in blood samples collected at hourly intervals via jugular cannula from four bulls during a single 24-hr period in January and again in June. Alterations in hormone profile characteristics were noted within bulls between January and June. An increased number of LH peaks and increased area beneath entire 24-hr LH profile suggested that LH secretion was higher during the June sampling period than the January sampling period. However, no significant alteration in T secretion in June was observed. as number of T peaks and area under T peaks were essentially unchanged relative to January. An inconsistent relationship between secretion of LH and T was observed in June, with only 47% of LH peaks associated with elevations in concentration of T whereas in January 80% of LH peaks were associated with T peaks. A higher lag correlation over all bulls between concentration of LH at one hour and concentration of T at the subsequent hour for all such combinations throughout the 24-hr period (LAG-LHTCORR) in January (r = 0.45, p less than 0.001) than in June (r = 0.12, p less than 0.24) also indicated that the temporal relationship between LH and T changed between these two periods of time. Coincident with the area beneath entire 24-hr CS profile and the height of CS peaks were greater in June. Prolonged elevations in concentration of CS were observed to be coincident with basal concentrations of LH and T and a negative value was obtained for LAG-CSTCORR in June (r = -0.10) but not in January (r = 0.06). Results of this study indicate that the major effect of LH upon blood concentration if T in the bull is usually exerted within 1 hr of a LH surge. However, failure of some LH peaks to be followed by T peaks suggests that the secretion of LH and T in the bull may be subject to modulation by adrenocortical hormones and other intrinsic and extrinsic factors. DA - 1981/// PY - 1981/// DO - 10.3109/01485018108987354 VL - 6 IS - 2 SP - 141-150 SN - 0148-5016 ER - TY - JOUR TI - INFLUENCE OF ELECTROEJACULATION ON PERIPHERAL-BLOOD CONCENTRATIONS OF CORTICOSTEROIDS, PROGESTERONE, LH, AND TESTOSTERONE IN BULLS AU - WELSH, TH AU - JOHNSON, BH T2 - ARCHIVES OF ANDROLOGY AB - AbstractTemporal relationships among serum concentrations of corticosteroids (CS), luteinizing hormone (LH), progesterone (P), and testosterone (T) were examined in ten bulls exposed to the stress of electroejaculation (EE). Concentrations of CS and P increased concomitantly among bulls to peak levels by 15 min post-EE and then declined to pre-EE levels between 2 and 4 hr after EE. Total number of LH and T peaks decreased from 24 and 18, respectively, during the 12-hr pre-EE period to 11 and 14 during the 12-h post-EE period. Mean concentration of LH decreased after EE until 4 hr post-EE when episodic LH secretion resumed and concentrations of CS and P had declined to pre-EE levels. Similarly, mean concentration of T declined after EE and then increased 6–8 hr post-EE in response to resumption of LH secretion. The temporal associations of elevated concentrations of CS and P with basal LH and T before EE, absence of T response to endogenous LH peaks, and the temporary absence of episodic LH and T peaks after EE, suggest that endogenous adrenal steroids may modulate secretion of T in the bull.Key Words: LHTestosteroneCorticosteroidsProgesteroneAdrenalsTestisStressBulls DA - 1981/// PY - 1981/// DO - 10.3109/01485018108999313 VL - 7 IS - 3 SP - 245-250 SN - 0148-5016 ER - TY - JOUR TI - Evaluating fertility of dairy bulls using dairy herd improvement data AU - McCraw, R. L. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1981/// PY - 1981/// VL - 42 IS - 1 SP - 5 ER - TY - JOUR TI - EFFECTS OF EMBRYO TRANSFER ON GENETIC CHANGE IN DAIRY-CATTLE AU - MCDANIEL, BT AU - CASSELL, BG T2 - JOURNAL OF DAIRY SCIENCE AB - Impact of embryo transfer on rate of genetic gain was examined for a) development of bulls for progeny test, b) development of replacement females, and c) progeny testing of dams of bulls and replacement females.Increased selection intensity by embryo transfer potentially could improve genetic merit of bull dams by 17% when applied to production of sires for progeny test.Additional benefits would arise from increased availability of sisters to such bulls.Genetic merit of dams of replacement females increases more than genetic merit of dams of bulls with embryo transfer.However, current costs of embryo transfer limit its application to production of replacement females when increased yield is the sole source of added income.Increases in generation interval offset improvement in rate of genetic gain per generation from progeny testing females.Therefore, mass selection on own performance and pedigree produce a higher rate of genetic gain per year than progeny testing females.Application of embryo transfer to selection schemes for multiple traits may prove beneficial. DA - 1981/// PY - 1981/// DO - 10.3168/jds.S0022-0302(81)82873-1 VL - 64 IS - 12 SP - 2484-2492 SN - 0022-0302 ER - TY - JOUR TI - Effect of accelerated growth and fattening from early weaning to parturition on ewe reproduction and lactation AU - Umberger, S. H. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1981/// PY - 1981/// VL - 41 IS - 7 SP - 2406 ER - TY - JOUR TI - THE INFLUENCE OF MATERNAL EFFECTS ON THE EFFICIENCY OF SELECTION - A REVIEW AU - ROBISON, OW T2 - LIVESTOCK PRODUCTION SCIENCE AB - The experimental evidence concerning the existence and importance of maternal effects in beef cattle, dairy cattle and swine is reviewed. It is clear that maternal effects are important in all three species. Unless management programs and selection methods take maternal effects into consideration, selection efficiency will be reduced. Some suggestions are given for altering management programs to increase production and selection efficiency. On passe en revue les faits expérimentaux concernant l'existence et l'importance des effets maternels chez les bovins, les ovins et les pores. Il est clair que ces effets sont importants dans les trois espèces. Si les programmes de conduite des animaux et les méthodes de sélection ne les prennent pas en compte, l'efficacité de la sélection sera diminuée. On propose quelques modifications des programmes de conduite des animaux afin d'accroître l'efficacité de la production et de la sélection. Es wird über das experimentelle Ergebnis bezüglich des Vorhandenseins und der Bedeutung maternaler Effekte bei Fleisch- und Milchrindern und Schweinen berichtet. Es ist eindeutig, dass die maternalen Effekte für alle drei Tierarten bedeutsam sind. Wenn Managementprogramme und Selektionsmethoden die maternalen Effekte unberücksichtigt lassen, wird der Selektionserfolg reduziert sein. Es werden einige Anregungen für veränderte Managementprogramme gegeben mit dem Ziel, Produktion und Selektionserfolg zu erhöhen. DA - 1981/// PY - 1981/// DO - 10.1016/0301-6226(81)90016-6 VL - 8 IS - 2 SP - 121-137 SN - 0301-6226 ER - TY - JOUR TI - Some practical uses for progestins in livestock management AU - Brannen, L. R. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1981/// PY - 1981/// VL - 42 IS - 5 SP - 1766 ER - TY - JOUR TI - ESTIMATION OF DIRECT AND MATERNAL ADDITIVE AND HETEROTIC EFFECTS FROM CROSSBREEDING EXPERIMENTS IN ANIMALS AU - ROBISON, OW AU - MCDANIEL, BT AU - RINCON, EJ T2 - JOURNAL OF ANIMAL SCIENCE AB - A model is proposed for the estimation of genetic effects from crossbreeding data. Analyses of variance and appropriate F-tests allow estimation of the importance of various effects. Deviations from the model provide evidence about the existence of epistasis and(or) linkage effects. This procedure has three advantages over conventional analyses of crossbreeding data: (1) It is a less complex statistical procedure; (2) It provides a clearer understanding of the genetic components; (3) It allows prediction of breed crosses that were not included in the data set. This model was applied to data from the long-term dairy crossbreeding project conducted at the Beltsville Agricultural Research Center. Breed additive genetic superiorities of Holsteins over Ayrshires and Brown Swiss were 759 and 857 kg for milk yield (P<.01), 555 and 556 kg for fat-corrected milk yield (P<.05) and —.30 and —.44 for fat percentage (P<.01), respectively. Differences between Brown Swiss and Ayrshires were small. The nonadditive genetic effects measured by regression on the expected percentage of heterozygotic loci were important for Brown Swiss × Holstein and Ayrshire × Holstein crosses. Complete Brown Swiss × Holstein heterozygosity resulted in increases of 341 kg in milk (P<.05), 16.2 kg in milk fat (P<.01) and 378 kg in fat-corrected milk (P<.05). For Ayrshire × Holstein crosses, the heterosis contributions for milk fat and fat-corrected milk (P<.05) were 13.6 and 299 kg, respectively. Holstein maternal contributions for production traits exceeded those for Ayrshires and Brown Swiss by 607 (P<.01) and 476 kg (P<.01) for milk yield, 16.9 (P<.05) and 12.1 kg (NS) for fat yield and 494 (P<.01) and 375 kg (P<.05) for fat-corrected milk yield, but were .17 (P<.05) and .15% (NS) lower for fat percentage. There was no evidence that epistasis and linkage contributed significantly to differences among breed groups. DA - 1981/// PY - 1981/// DO - 10.2527/jas1981.52144x VL - 52 IS - 1 SP - 44-50 SN - 0021-8812 ER - TY - JOUR TI - ROLE OF THE OVARY IN CONTROLLING LUTEINIZING-HORMONE, FOLLICLE-STIMULATING-HORMONE, AND PROLACTIN SECRETION DURING AND AFTER LACTATION IN PIGS AU - STEVENSON, JS AU - COX, NM AU - BRITT, JH T2 - BIOLOGY OF REPRODUCTION AB - Concentrations of LH, FSH, prolactin, estrogen, and progesterone were measured in blood samples collected at various intervals during and immediately following lactation to determine the role of the ovary in controlling gonadotropin and prolactin secretion and initiation of estrous cycles in the pig. Ten primiparous sows were ovariectomized (ovex, n = 5) or left intact (n = 5) 2 to 4 days after farrowing. Serum progesterone and estrogens in samples collected daily during lactation were not different between intact and ovex sows. Serum FSH increased immediately after ovariectomy and remained elevated during lactation, but LH concentrations were similar between ovex and intact sows. Both LH and FSH were higher during the last 2 weeks of lactation than during the first 3 weeks. On Days 10 and 20 of lactation, all sows received (i.v.) two challenges of gonadotropin releasing hormone (GnRH; 400 μg each) at 135 min intervals. Peak change (maximum value minus baseline) in FSH after GnRH was higher in ovex than in intact sows on both Days 10 and 20. Peak change in FSH in ovex sows was higher on Day 20 than on Day 10, but peak change in FSH in intact rows was similar between Days 10 and 20. Peak change in LH after GnRH was similar between ovex and intact sows. Peak change in LH after the second GnRH challenge on Day 10 was higher than that after each of the other three challenges. Although serum prolactin concentrations in selected samples collected on Days 10 and 20 were not significantly different between treatment groups, intact sows had consistently higher concentrations compared with ovex sows. Separation of four sows from their litters for 4 h during the last week of lactation resulted in a decline in serum prolactin, but prolactin increased fivefold within 15 min and tenfold during the second hour after piglets were replaced. In contrast, LH did not change prior to or after piglets were allowed to nurse. After weaning, concentrations of estrogens peaked during 24 h around onset of estrus prior to the preovulatory surge of LH and FSH. In ovex sows treated with estradiol-17β on Days 8, 9, and 10 after weaning, estrous behavior and LH and FSH responses were indistinguishable from those observed in intact sows at the postweaning estrus. Serum LH, FSH, and prolactin increased in response to estrogen, and duration of estrus was similar to that observed in intact sows. Results from these experiments indicate that 1) LH is low during lactation in both intact and ovex sows; 2) FSH increases following ovariectomy, presumably because of removing some ovarian inhibitor of FSH secretion; 3) prolactin, but not LH, changes acutely with suckling or weaning; and 4) surges in LH, FSH, and prolactin at estrus are induced by estrogen whether of endogenous (intact sows) or exogenous (ovex sows) origin. DA - 1981/// PY - 1981/// DO - 10.1095/biolreprod24.2.341 VL - 24 IS - 2 SP - 341-353 SN - 0006-3363 ER - TY - JOUR TI - Predicting selection response for total litter weight AU - Eisen, E. J. T2 - Journal of Animal Breeding and Genetics AB - Zeitschrift für Tierzüchtung und ZüchtungsbiologieVolume 98, Issue 1-4 p. 55-76 Predicting selection response for total litter weight1 E.J. Eisen, Corresponding Author Institute of Animal Genetics, University of Edinburgh, Edinburgh, Scotland and Department of Animal Science, North Carolina State University, Raleigh, North Carolina, U.S.A. On leave at the Institute of Animal Genetics, West Mains Road, Edinburgh EH9 3JN, Scotland. Supported, in part, by an Underwood Fund Fellowship, Agricultural Research Council, and an Edinburgh University Biological Fellowship in the Department of Genetics.Department of Animal Science, North Carolina State University, Raleigh, North Carolina 27650, USASearch for more papers by this author E.J. Eisen, Corresponding Author Institute of Animal Genetics, University of Edinburgh, Edinburgh, Scotland and Department of Animal Science, North Carolina State University, Raleigh, North Carolina, U.S.A. On leave at the Institute of Animal Genetics, West Mains Road, Edinburgh EH9 3JN, Scotland. Supported, in part, by an Underwood Fund Fellowship, Agricultural Research Council, and an Edinburgh University Biological Fellowship in the Department of Genetics.Department of Animal Science, North Carolina State University, Raleigh, North Carolina 27650, USASearch for more papers by this author First published: January‐December 1981 https://doi.org/10.1111/j.1439-0388.1981.tb00329.xCitations: 8 1 Paper No. 6367 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh. 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 onEmailFacebookTwitterLinked InRedditWechat Citing Literature Volume98, Issue1-4January‐December 1981Pages 55-76 RelatedInformation DA - 1981/// PY - 1981/// DO - 10.1111/j.1439-0388.1981.tb00329.x VL - 98 IS - 1 SP - 54 ER - TY - JOUR TI - INTERVAL TO ESTRUS IN SOWS AND PERFORMANCE OF PIGS AFTER ALTERATION OF LITTER SIZE DURING LATE LACTATION AU - STEVENSON, JS AU - BRITT, JH T2 - JOURNAL OF ANIMAL SCIENCE AB - The effects of altering litter size during the 5 days before weaning on interval to estrus of sows and postweaning performance of pigs were examined. Litters averaged 8.3 ± .7 pigs from parturition until 5 days before weaning. Litters were then adjusted so that sows (five per group) nursed small- (three pigs), average- (eight pigs) or large-sized (13 to 14 pigs) litters during the last 5 days of lactation. Weaning occurred 27.4 ± .7 days postpartum. Interval from weaning to estrus (days) and duration of estrus (hours) for sows that weaned small-, average- and large-sized litters averaged 1.1 ± .4 and 38 ± 4, 4.1 ± .4 and 60 ± 4, and 4.0 ± .4 and 61 ± 4, respectively. Interval to estrus and to ovulation and duration of estrus were decreased (P<.01) in sows that nursed only three pigs before weaning. Pigs weaned from foster sows weighed less (P<.05) at weaning than pigs weaned from their dams. However, by 3 weeks after weaning, body weights were similar. Body weight at weaning and at 3 weeks postweaning and average daily gains during the 3 weeks after weaning were similar for pigs weaned from small-, average- and large-sized litters. Reducing the litter size before weaning resulted in earlier postweaning estrus and ovulation and had no adverse effects on the performance of weanling pigs. DA - 1981/// PY - 1981/// DO - 10.2527/jas1981.531177x VL - 53 IS - 1 SP - 177-181 SN - 1525-3163 ER - TY - JOUR TI - Correlated responses in male reproductive traits in mice selected for litter size and body weight AU - Eisen, E. J. AU - Johnson, B. H. T2 - Genetics DA - 1981/// PY - 1981/// VL - 99 IS - 3 SP - 513 ER - TY - JOUR TI - Control of anterior pituitary and ovarian hormone secretion and manifestation of estrus during and after lactation in the pig AU - Stevenson, J. S. T2 - Dissertation Abstracts International. B, Sciences and Engineering DA - 1981/// PY - 1981/// VL - 41 IS - 12 SP - 4410 ER -