scholarly journals 128 Relationship between anti-Mullerian hormone (AMH) and reproductive traits in ewes

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 73-73
Author(s):  
Mohan Acharya ◽  
Berlin Howell ◽  
Joan M Burke ◽  
Rick Rorie

Abstract Objective was to determine correlations between serum AMH and reproductive traits in ewes. Blood was collected at breeding from Katahdin ewes between 0.7 and 9 yr age in 2015 (n = 158) and 2017 (n = 233) for the analysis of serum AMH concentrations using different immunoassays (Equine and Ovine AMH in 2015 and Ovine AMH in 2017; AnshLab). Relationships between AMH and first exposure pregnancy rate (PR) to spring or fall breeding, number of lambs born to first lambing, age at first lambing (using lifetime records), and estimated breeding values (EBVs) for number of lambs born (NLB), number of lambs weaned (NLW), maternal weaning weight (MWT), weaning weight (WWT), and maternal index were determined. Correlations were determined using PROC CORR (SAS), and PROC GLM used with AMH or AMH quartile as dependent or independent variables, and season in models. Serum AMH or quartiles did not correlate with any reproductive trait. In 2017 but not 2015, AMH concentrations (P = 0.02) and quartiles (P = 0.04) were greater in ewes that became pregnant than nonpregnant ewes to first breeding. Ewes that were pregnant at a younger age had a higher WWT (P = 0.002), NLW (P = 0.04) and Index (P = 0.02), and more prolific ewes at first lambing had a higher NLB (P < 0.001), NLW (P < 0.001), and Index (P < 0.001), regardless of season of first breeding. Mean PR was -4.6 ± 3.8% and 68.4 ± 3.8% for spring and fall breeding (P < 0.001), resulting in older spring compared with fall bred ewes at first lambing (2.04 ± 0.08 vs. 1.52 ± 0.05 yr, P < 0.001). While AMH did not appear to consistently predict fertility in ewes, higher EBVs (NLB, NLW, Index) were associated with younger ewes and greater prolificacy at first lambing.

2006 ◽  
Vol 57 (6) ◽  
pp. 651 ◽  
Author(s):  
P. L. Greenwood ◽  
G. E. Gardner ◽  
R. S. Hegarty

This study examined influences of sire (n = 9) estimated breeding values (EBVs), sire-group (Muscle, Growth, and Control), and nutrition (low and high quality and availability pasture) from birth to slaughter at ~8 months of age on indices of muscle cellularity and transcriptional and translational capacity in 56 castrate lambs. Effects of nutritional systems to 8 months of age were greater, overall, than those due to EBVs or sire-group. Amount of DNA increased with increasing EBV for post-weaning eye muscle depth (PEMD or Muscle EBV) in longissimus but not in semimembranosus and semitendinosus muscles, while Muscle EBV also had an inverse association with concentration of DNA. Protein to DNA and RNA to DNA were related positively to Muscle EBV, the associations being strongest for the semitendinosus muscle. Post-weaning weight (PWWT or Growth) EBV correlated positively with the RNA to DNA ratio and, among high but not low nutrition lambs, was inversely related to concentration of muscle DNA, whereas post-weaning fat depth (PFAT or Fat) EBV was correlated positively with RNA concentration. Overall, the magnitude of effects of sire-group was less than for sire EBVs, presumably due to differing selection pressures for muscling, fatness, and growth. High nutrition lambs had more protein to DNA than low nutrition lambs in the longissimus and semitendinosus muscles, but not in the semimembranosus muscle. In low compared with high nutrition lambs, concentration of DNA was greater in the longissimus and semitendinosus muscles. Total amount of DNA was reduced by more in low compared with high nutrition in the longissimus and semimembranosus than in the semitendinosus, and amount of protein was reduced by more in low compared with high nutrition in the longissimus than in the other two muscles. We conclude that genetic selection for eye muscle depth in sheep has differing effects on cellular characteristics of the longissimus, semimembranosus, and semitendinosus muscles, and has greater effects on muscle cellular characteristics than genetic selection for post-weaning weight or fat depth.


2016 ◽  
Vol 32 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Dragomir Lukac ◽  
Vitomir Vidovic ◽  
Teodora Vasiljevic ◽  
Oliver Stankovic

The aim of this study was to estimate the genetic parameters and breeding values for reproduction traits of Landrace sows in the first three parities by Animal model. Records of 2238 first parity; 2125 second parity and 1872 third parity Landrace sows farrowing between 2007 and 2012 were included in the analysis. The traits included in the analyses were total pigs born (TB), number of pigs born alive (NBA), number of pigs weaned (NW) and litter weaning weight (LW) in the parities. The genetic parameters were estimated using a multivariate analyses Animal model using REML procedure. Estimates of heritability for TB were 0.03, 0.05 and 0.18, for NBA were 0.04, 0.02 and 0.17, for NW were 0.08, 0.08 and 0.01 and for LW were 0.09, 0.11 and 0.03 for parities 1 to 3. Genetic and phenotypic variance were increased from the first to the third parity. Between the majorities of studied reproductive traits were the recorded positive genetic and phenotypic correlations, except between LW and other analyzed properties where they recorded a high correlation negative in third parity. Means of estimated breeding values of reproductive traits from first parity to third parity was indecreased.


2010 ◽  
Vol 53 (1) ◽  
pp. 26-36 ◽  
Author(s):  
S. Bene ◽  
I. Füller ◽  
A. Fördős ◽  
F. Szabó

Abstract. Weaning weight, preweaning daily gain and 205-day weight of Hungarian Fleckvieh calves (n=8 929, bulls =4 539, heifers =4 390) born from 232 sires between 1980 and 2003 were examined. Variance, covariance components and heritability values and correlation coefficients were estimated. The effect of the maternal permanent environment on genetic parameters and breeding values were examined. Two animal models were used for breeding value estimation. The direct heritability (hd2) of weaning weight, preweaning daily gain and 205-day weight was between 0.37 and 0.42. The maternal heritability (hm2) of these traits was 0.06 and 0.07. The direct-maternal correlations (rdm) were medium and negative −0.52 and −0.74. Contribution of the maternal heritability and maternal permanent environment to phenotype is smaller than that of direct heritabilities (hm2+c2< hd2). The ratio of the variance of maternal permanent environment in the phenotypic variance (c2) changed from 3 to 6 %. Estimated breeding values changed whether the permanent environmental effect of dam wasn’t taken into consideration but the rank of the animals was not modified. The genetic value for weaning results of Hungarian Fleckvieh population has increased since 1997.


2011 ◽  
Vol 50 (No. 1) ◽  
pp. 1-6 ◽  
Author(s):  
P. Strapák ◽  
J. Candrák ◽  
J. Aumann

The correlations between longevity, functional longevity, stayability and selected milk, reproductive and type traits were estimated; it was done on the basis of estimated breeding values for longevity, functional longevity, dairy traits, reproductive traits and stayability rates at the age of 60, 72, 84, and 96 months. The correlation between breeding values for longevity and functional longevity was 0.69. The correlations between longevity and stayability at 60, 72, 84, and 96 months of age were around 0.75 (from 0.73 to 0.76) whereas the correlation with stayability at 48 months was considerably lower (0.64). The breeding values for dairy traits showed a positive relationship with longevity (from 0.37 to 0.46) and a slightly negative correlation with breeding values for functional longevity (from &ndash;0.10 to &ndash;0.20). A low relationship was found between longevity and reproductive traits. Between the type traits and longevity traits only the conformation score for the form (0.18) and for the udder showed a positive correlation (0.24). The correlation between the form and functional longevity remained approximately on the same level whereas the correlation with the main udder score decreased to 0.08, which indicated a positive relationship between milk traits and udder scores. &nbsp;


2021 ◽  
Vol 99 (2) ◽  
Author(s):  
Jorge Hidalgo ◽  
Daniela Lourenco ◽  
Shogo Tsuruta ◽  
Yutaka Masuda ◽  
Stephen Miller ◽  
...  

Abstract The stability of genomic evaluations depends on the amount of data and population parameters. When the dataset is large enough to estimate the value of nearly all independent chromosome segments (~10K in American Angus cattle), the accuracy and persistency of breeding values will be high. The objective of this study was to investigate changes in estimated breeding values (EBV) and genomic EBV (GEBV) across monthly evaluations for 1 yr in a large genotyped population of beef cattle. The American Angus data used included 8.2 million records for birth weight, 8.9 for weaning weight, and 4.4 for postweaning gain. A total of 10.1 million animals born until December 2017 had pedigree information, and 484,074 were genotyped. A truncated dataset included animals born until December 2016. To mimic a scenario with monthly evaluations, 2017 data were added 1 mo at a time to estimate EBV using best linear unbiased prediction (BLUP) and GEBV using single-step genomic BLUP with the algorithm for proven and young (APY) with core group fixed for 1 yr or updated monthly. Predictions from monthly evaluations in 2017 were contrasted with the predictions of the evaluation in December 2016 or the previous month for all genotyped animals born until December 2016 with or without their own phenotypes or progeny phenotypes. Changes in EBV and GEBV were similar across traits, and only results for weaning weight are presented. Correlations between evaluations from December 2016 and the 12 consecutive evaluations were ≥0.97 for EBV and ≥0.99 for GEBV. Average absolute changes for EBV were about two times smaller than for GEBV, except for animals with new progeny phenotypes (≤0.12 and ≤0.11 additive genetic SD [SDa] for EBV and GEBV). The maximum absolute changes for EBV (≤2.95 SDa) were greater than for GEBV (≤1.59 SDa). The average(maximum) absolute GEBV changes for young animals from December 2016 to January and December 2017 ranged from 0.05(0.25) to 0.10(0.53) SDa. Corresponding ranges for animals with new progeny phenotypes were from 0.05(0.88) to 0.11(1.59) SDa for GEBV changes. The average absolute change in EBV(GEBV) from December 2016 to December 2017 for sires with ≤50 progeny phenotypes was 0.26(0.14) and for sires with &gt;50 progeny phenotypes was 0.25(0.16) SDa. Updating the core group in APY without adding data created an average absolute change of 0.07 SDa in GEBV. Genomic evaluations in large genotyped populations are as stable and persistent as the traditional genetic evaluations, with less extreme changes.


2021 ◽  
Vol 13 ◽  
pp. 81-87
Author(s):  
D. V. Uza

An analysis of some reproductive perfor­mance traits was carried out for the period 1983 to 1985, in a herd of 168 Santa Gertrudis beef cattle imported from Okla­homa, U.S.A. in 1981 into lkyogen cattle ranch in Nigeria. Three calf crops were obtained during the period. Mean pregnancy rate and calving percentage were 63.24 and 55.72% respectively; with pregnancy rate increasing from 54.23 to 70,41% while calving percentage increased from 48.42 to 61.11% during the period. Mean calf mortality rate of 40.83% was high and increased from 36.34 to 45.15%. Mean adult mortality rate was 5.68% of which 16.99% was recorded in the first year of introduction but this declined sharply to 0O2% in the next two years. Mean weaning rate was 50.08% and this declined from 55.71 to 44.32% during the period under study. Mean birth weight, weaning weight and calving interval were 27.8 t 0.29 kg, 174 ± 4.6kg and 451 days respectively It was concluded that with the exception of weaning weight, the reproductive traits of the imported Santta Gertrudis cattle reported in this study were not superior to those of the predominant indigenous cattle breeds of Nigeria. The implications of these results in the beef cattle industry of Nigeria are discussed.


2020 ◽  
Vol 72 (5) ◽  
pp. 1874-1880
Author(s):  
R.Z. Vaz ◽  
J.F.P. Lobato ◽  
J. Restle ◽  
V.G.D. Conceição ◽  
O.G.L. Ferreira ◽  
...  

ABSTRACT The objective of this study was to evaluate, for two years, the performance of 124 female and 105 male Braford calves born during the first and second halves of the same calving season and the effects of birth period on the development of males until slaughter, as yearlings, and of females until calving, after having mated at 13-15 months of age. Early-born females were heavier than those born late at weaning (119.3 vs 109.9kg; P<0.05), at the start of the breeding season (275.0 vs 263.0kg; P<0.05), and at the end of the breeding season (300.0 vs 289.5kg; P<0.05), in addition to being more fertile (70 vs 50% pregnancy rate). There was no difference (P>0.05) in the development of males born early in relation to those born late, except for weaning weight, which was higher in the former. Steers born early were ready for slaughter at a younger age (459.6 vs 490.1 days; P<0.05), and both groups (early- and late-born) had a body condition classified as fat (4.21 points). In intensive production systems, both male and female calves perform better if they are born during the first half of the calving season.


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