Genetics of early and lifetime annual reproductive performance in cows of two tropical beef genotypes in northern Australia

2014 ◽  
Vol 54 (1) ◽  
pp. 1 ◽  
Author(s):  
D. J. Johnston ◽  
S. A. Barwick ◽  
G. Fordyce ◽  
R. G. Holroyd ◽  
P. J. Williams ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Reproductive Tract ◽  
Production Systems ◽  
Comprehensive Evaluation ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Female Reproduction ◽  
Reproduction Traits ◽  
Beef Cattle Breeds ◽  
Calving Rate

Reproduction records from 2137 cows first mated at 2 years of age and recorded through to 8.5 years of age were used to study the genetics of early and lifetime reproductive performance from two genotypes (1020 Brahman and 1117 Tropical Composite) in tropical Australian production systems. Regular ultrasound scanning of the reproductive tract, coupled with full recording of mating, calving and weaning histories, allowed a comprehensive evaluation of a range of reproductive traits. Results showed components traits of early reproductive performance had moderate to high heritabilities, especially in Brahmans. The heritability of lactation anoestrous interval in 3-year-old cows was 0.51 ± 0.18 and 0.26 ± 0.11 for Brahman and Tropical Composite, respectively. Heritabilities of binary reproductive output traits (conception rate, pregnancy rate, calving rate and weaning rate) from first and second matings were generally moderate to high on the underlying scale. Estimates ranged from 0.15 to 0.69 in Brahman and 0.15 to 0.34 in Tropical Composite, but were considerably lower when expressed on the observed scale, particularly for those traits with high mean levels. Heritabilities of lifetime reproduction traits were low, with estimates of 0.11 ± 0.06 and 0.07 ± 0.06 for lifetime annual weaning rate in Brahman and Tropical Composite, respectively. Significant differences in mean reproductive performance were observed between the two genotypes, especially for traits associated with anoestrus in first-lactation cows. Genetic correlations between early-in-life reproductive measures and lifetime reproduction traits were moderate to high. Genetic correlations between lactation anoestrous interval and lifetime annual weaning rate were –0.62 ± 0.24 in Brahman and –0.87 ± 0.32 in Tropical Composite. The results emphasise the substantial opportunity that exists to genetically improve weaning rates in tropical beef cattle breeds by focusing recording and selection on early-in-life female reproduction traits, particularly in Brahman for traits associated with lactation anoestrus.

Genetic correlations of young bull reproductive traits and heifer puberty traits with female reproductive performance in two tropical beef genotypes in northern Australia

2014 ◽  
Vol 54 (1) ◽  
pp. 74 ◽  
Author(s):  
D. J. Johnston ◽  
N. J. Corbet ◽  
S. A. Barwick ◽  
M. L. Wolcott ◽  
R. G. Holroyd
Keyword(s):  
Reproductive Performance ◽  
Semen Quality ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Northern Australia ◽  
Female Reproduction ◽  
Young Bull ◽  
Scrotal Circumference ◽  
Reproduction Traits ◽  
Age At Puberty

Genetic correlations of young bull and heifer puberty traits with measures of early and lifetime female reproductive performance were estimated in two tropical beef cattle genotypes. Heifer age at puberty was highly (rg = –0.71 ± 0.11) and moderately (rg = –0.40 ± 0.20) genetically correlated with pregnancy rate at first annual mating (mating 1) and lifetime annual calving rate, respectively in Brahman (BRAH). In Tropical Composite (TCOMP), heifer age at puberty was highly correlated with reproductive outcomes from the first re-breed (mating 2), mainly due to its association with lactation anoestrous interval (rg = 0.72 ± 0.17). Scrotal circumference were correlated with heifer age at puberty (rg = –0.41 ± 0.11 at 12 months in BRAH; –0.30 ± 0.13 at 6 months in TCOMP) but correlations were lower with later female reproduction traits. Bull insulin-like growth factor-I was correlated with heifer age at puberty (rg = –0.56 ± 0.11 in BRAH; –0.43 ± 0.11 in TCOMP) and blood luteinising hormone concentration was moderately correlated with lactation anoestrous interval (rg = 0.59 ± 0.23) in TCOMP. Semen quality traits, including mass activity, motility and percent normal sperm were genetically correlated with lactation anoestrus and female lifetime female reproductive traits in both genotypes, but the magnitudes of the relationships differed with bull age at measurement. Preputial eversion and sheath scores were genetically associated with lifetime calving and weaning rates in both genotypes. Several of the early-in-life male and female measures examined were moderately to highly genetically correlated with early and lifetime female reproduction traits and may be useful as indirect selection criteria for improving female reproduction in tropical breeds in northern Australia.

Reproductive performance and genetic parameters for Australian Dorset Sheep

1994 ◽  
Vol 45 (2) ◽  
pp. 427 ◽  
Author(s):  
LD Brash ◽  
NM Fogarty ◽  
AR Gilmour
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Genetic Improvement ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Reproductive Rate ◽  
Parameter Estimates ◽  
Reproduction Traits ◽  
Component Traits ◽  
Lamb Survival

Reproductive performance of ewes in a large Dorset stud flock is reported. The data included 2488 ewes with 10016 joining records over 25 years. Average performance for reproductive traits were: fertility 92%, litter size 1.31, neonatal lamb survival 91%, lamb survival to weaning 85%, with overall lambs born 1.20 and lambs weaned 1.02 per ewe joined. Differences between breeds (Poll Dorset and Dorset Horn), season of birth (spring and autumn) and season of joining (spring and autumn) were significant for most reproduction traits. Linear and quadratic regressions for age of ewe at joining were highly significant for all traits (P < 0.001) with maximum performance between three and six years of age. Estimates of heritability for ewe reproductive traits were: 0.062 � 0-02 for number of lambs born and 0.04 � 0.01 for number of lambs weaned per ewe joined, and component traits, 0.02 �0 -01 for fertility, 0 08 � 0 -02 for litter size and 0.00 � 0.01 for lamb survival. Estimates of repeatability were less than 0.14 for all the reproduction traits, which resulted in substantially higher predicted heritabilities when repeated records were used. Heritability estimates for average ewe lifetime performance, with approximately four records, were 0.08 � 0 06 for lambs born, 0.12 � 0.05 for lambs weaned, 0.08 � 0.04 for fertility, 0.l9 � 0 -04 for litter size and zero for lamb survival. The genetic correlations between litter size and lambs born and weaned were close to unity, whereas those for fertility were lower and declined from lambs born (0.6l � 0.22) to lambs weaned (0-45 � 0.30). The estimated heritability for ewe longevity, defined as the number of years the ewe remained in the breeding flock, was 0.00 � 0.03. The potential for genetic improvement in reproductive rate is discussed in relation to other reports in the literature and in the context of the roles of the Dorset breed in the Australian lamb industry. Increased reproductive rate in Dorset flocks impacts on stud profitability and the rate of genetic improvement from selection for other traits such as liveweight. The parameter estimates derived will be used in compiling breed-specific parameter sets for genetic evaluation in LAMBPLAN.

Phenotypic and genetic parameters for reproductive performance in a synthetic line of sheep

1981 ◽  
Vol 96 (1) ◽  
pp. 107-113 ◽  
Author(s):  
T. G. Martin ◽  
D. Nicholson ◽  
C. Smith ◽  
D. I. Sales
Keyword(s):  
Reproductive Performance ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Direct Selection ◽  
Sex Distribution ◽  
Regression Methods ◽  
Litter Weight ◽  
Heritability Estimates ◽  
Synthetic Line

SUMMARYData on 902 ewes (1755 records) bom over 7 years in the synthetic ABRO Dam Line were analysed by least squares. Reproductive traits of the ewe were not affected by whether she was a single or a twin or by the age of her dam. Ewe age had major effects on all reproductive traits. Litter weight traits were affected by the sex distribution and the age of the litter when weighed.Heritability estimates, both by half sib and regression methods, were low for litter size, low to moderate for litter weights, and higher for ewe and fleece weights. Genetic correlations among the litter-weight traits were high. Together with the heritability estimates, they indicated that selection on litter weight at birth (and perhaps other traits) might give a greater change in total litter weight at weaning, the main measure of ewe productivity and the objective in improvement, than would direct selection.

Genetic parameters for tropical beef cattle in northern Australia: a review

1993 ◽  
Vol 44 (2) ◽  
pp. 179 ◽  
Author(s):  
GP Davis
Keyword(s):  
Genetic Parameters ◽  
Production Systems ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Genetic Correlations ◽  
Environmental Stresses ◽  
Northern Australia ◽  
Weighted Mean ◽  
Weaning Weight ◽  
Reproduction Traits

This paper reviews published estimates of genetic parameters for traits of growth, reproduction and resistance to environmental stresses for Bos indicus and Zebu derived breeds in northern Australia. Most published estimates of heritabilities for growth and reproduction traits were higher for tropically adapted breeds in northern Australia than for Bos taurus breeds in temperate Australia. Weighted mean estimates of heritabilities for the direct component of weaning weight were 39% for the Brahman breed and 30% for Zebu-derived breeds in northern Australia compared with 13% for Bos taurus breeds in temperate areas of Australia. Mean estimates for the maternal component of weaning weight were 5, 24 and 13% respectively. Mean heritabilities for yearling and 550 day weights for Zebu derived breeds in northern Australia (24 and 25%) were similar to those for Bos taurus breeds in temperate areas, though estimates for Brahmans were higher (39 and 39%). Published estimates of heritabilities of later weights (700 and 900 days), which are most relevant to northern Australian production systems, were rare but averaged between 32 and 45% for Zebu-derived breeds and Brahmans. Weighted mean heritability for female calving success was 14% and for realised bull fertility was 5%. Published estimates of heritabilities of scrota1 circumference averaged 31%, and testosterone response to GNRH stimulation was 52%. Heritabilities of resistance to various environmental stresses were all moderate with weighted means between 20 and 34%. Genetic correlations between growth, reproduction and resistance to environmental stresses are also reviewed. There appears to be predictable variation in estimates of parameters between breeds in different environments which is related to level of resistance to environmental stresses, and this is likely to affect the prediction of breeding values for cattle in northern Australia.

scholarly journals Host Genetics of Response to Porcine Reproductive and Respiratory Syndrome in Sows: Reproductive Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Felipe M. W. Hickmann ◽  
José Braccini Neto ◽  
Luke M. Kramer ◽  
Yijian Huang ◽  
Kent A. Gray ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Additive Genetic Variance ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
The Other ◽  
Nucleotide Polymorphisms ◽  
Host Genetics ◽  
Other Hand ◽  
Selection For ◽  
Heritability Estimates

Porcine Reproductive and Respiratory Syndrome (PRRS) is historically the most economically important swine disease worldwide that severely affects the reproductive performance of sows. However, little is still known about the genetic basis of reproductive performance in purebred herds during a PRRS outbreak through the comparison of maternal and terminal breeds. Thus, the objective of this work was to explore the host genetics of response to PRRS in purebred sows from two breeds. Reproductive data included 2546 Duroc and 2522 Landrace litters from 894 and 813 purebred sows, respectively, which had high-density genotype data available (29,799 single nucleotide polymorphisms; SNPs). The data were split into pre-PRRS, PRRS, and post-PRRS phases based on standardized farrow-year-week estimates. Heritability estimates for reproductive traits were low to moderate (≤0.20) for Duroc and Landrace across PRRS phases. On the other hand, genetic correlations of reproductive traits between PRRS phases were overall moderate to high for both breeds. Several associations between MARC0034894, a candidate SNP for response to PRRS, with reproductive performance were identified (P-value &lt; 0.05). Genomic analyses detected few QTL for reproductive performance across all phases, most explaining a small percentage of the additive genetic variance (≤8.2%, averaging 2.1%), indicating that these traits are highly polygenic. None of the identified QTL within a breed and trait overlapped between PRRS phases. Overall, our results indicate that Duroc sows are phenotypically more resilient to PRRS than Landrace sows, with a similar return to PRRS-free performance between breeds for most reproductive traits. Genomic prediction results indicate that genomic selection for improved reproductive performance under a PRRS outbreak is possible, especially in Landrace sows, by training markers using data from PRRS-challenged sows. On the other hand, the high genetic correlations with reproductive traits between PRRS phases suggest that selection for improved reproductive performance in a clean environment could improve performance during PRRS, but with limited efficiency due to their low heritability estimates. Thus, we hypothesize that an indicator trait that could be indirectly selected to increase the response to selection for these traits would be desirable and would also improve the reproductive performance of sows during a PRRS outbreak.

scholarly journals The superiority of multi-trait models with genotype-by-environment interactions in a limited number of environments for genomic prediction in pigs

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hailiang Song ◽  
Qin Zhang ◽  
Xiangdong Ding
Keyword(s):  
Genomic Prediction ◽  
Production Systems ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Reference Population ◽  
Linear Unbiased Prediction ◽  
Genotype By Environment ◽  
Best Linear Unbiased ◽  
Effect Estimation ◽  
Two Populations

Abstract Background Different production systems and climates could lead to genotype-by-environment (G × E) interactions between populations, and the inclusion of G × E interactions is becoming essential in breeding decisions. The objective of this study was to investigate the performance of multi-trait models in genomic prediction in a limited number of environments with G × E interactions. Results In total, 2,688 and 1,384 individuals with growth and reproduction phenotypes, respectively, from two Yorkshire pig populations with similar genetic backgrounds were genotyped with the PorcineSNP80 panel. Single- and multi-trait models with genomic best linear unbiased prediction (GBLUP) and BayesC π were implemented to investigate their genomic prediction abilities with 20 replicates of five-fold cross-validation. Our results regarding between-environment genetic correlations of growth and reproductive traits (ranging from 0.618 to 0.723) indicated the existence of G × E interactions between these two Yorkshire pig populations. For single-trait models, genomic prediction with GBLUP was only 1.1% more accurate on average in the combined population than in single populations, and no significant improvements were obtained by BayesC π for most traits. In addition, single-trait models with either GBLUP or BayesC π produced greater bias for the combined population than for single populations. However, multi-trait models with GBLUP and BayesC π better accommodated G × E interactions, yielding 2.2% – 3.8% and 1.0% – 2.5% higher prediction accuracies for growth and reproductive traits, respectively, compared to those for single-trait models of single populations and the combined population. The multi-trait models also yielded lower bias and larger gains in the case of a small reference population. The smaller improvement in prediction accuracy and larger bias obtained by the single-trait models in the combined population was mainly due to the low consistency of linkage disequilibrium between the two populations, which also caused the BayesC π method to always produce the largest standard error in marker effect estimation for the combined population. Conclusions In conclusion, our findings confirmed that directly combining populations to enlarge the reference population is not efficient in improving the accuracy of genomic prediction in the presence of G × E interactions, while multi-trait models perform better in a limited number of environments with G × E interactions.

Genetic studies on growth, reproduction and wool productiontraits in Harnali sheep

2016 ◽  
Author(s):  
SPACE Lalit ◽  
Z. S. Malik ◽  
D. S. Dalal ◽  
C. S. Patil ◽  
S. P. Dahiya
Keyword(s):  
Body Weight ◽  
Growth Traits ◽  
Additive Genetic Variance ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Reproductive Traits ◽  
Phenotypic Correlation ◽  
Reproduction Traits ◽  
Heritability Estimates ◽  
Fleece Weight

Data on growth, reproduction and wool traits of 1603 Harnali sheep maintained at Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar over a period of 22 years (1992-2013) were utilized for genetic analysis. The overall least squares mean for birth weight (BW), weaning weight (WW), six month body weight (SMW), age at first lambing (AFL), weight at lambing (WL), average lambing interval (ALI), greasy fleece weight (GFW), staple length (SL) and Fibre diameter (FD) were estimated as 3.35±0.02 kg, 12.41±0.08 kg, 16.30±0.12 kg, 707.05±2.07 days, 26.91±0.10 kg and 402.85±2.40 days, 1.62±0.02 kg, 5.65±0.03 cm and 25.85±0.07 μ, respectively. The effect of year of birth, sex of lamb and dam's weight at lambing were significant for all growth traits. The effect of year of birth and dam's weight at lambing were significant for all reproduction traits and GFW. No definite trend was observed over the years for body weights and reproductive traits. The effect of sex was significant for early growth traits. The heritability estimates were moderate for all the growth traits with high genetic correlations of BW and WW with SMW. Reproduction traits had lower estimates of heritability which indicated presence of lower additive genetic variance for these traits. Heritability estimates for studied wool traits were moderate to high. Positive genetic and phenotypic correlation of BW and WW with six month body weight and grease fleece weight indicated that selection for six month body weight would increase body weight and grease fleece weight.

Seasonal reproductive performance of crossbred ewes in intensive lamb-production systems

2014 ◽  
Vol 54 (6) ◽  
pp. 791 ◽  
Author(s):  
N. M. Fogarty ◽  
J. G. Mulholland
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Fixed Effects ◽  
Mixed Model ◽  
Production Systems ◽  
Random Effect ◽  
Seasonal Effect ◽  
Wagga Wagga ◽  
Reproduction Traits ◽  
Season Interaction

The lambing performance of 1179 crossbred ewes with 5540 joining records in three seasons (autumn, winter and spring) at two sites (Cowra and Wagga Wagga) was evaluated in three lamb-production systems (spring joining with autumn backup matings at both locations, with accelerated lambing at Cowra or annual autumn joining at Wagga Wagga) over 4 years. Two genotypes of ewes, Border Leicester × Merino (BLM) and Hyfer (Dorset × Merino composite), were used at both sites, with natural matings to Dorset, Suffolk or Hyfer rams. The following five traits were analysed separately at each site to evaluate ewe lambing performance: fertility, litter size, lambs born (per ewe joined), lambs weaned (per ewe joined) and weight of lamb weaned (per ewe joined). The mixed model included fixed effects for season of joining, ewe breed, ram group, ewe prejoining weight (spline) and their interactions, with ewe fitted as a random effect. The autumn (February) joinings had higher ewe fertility, litter size and overall lamb production than did joinings in spring (October and November), with winter (June) being intermediate. At the autumn joinings, the BLM ewes had higher fertility, lambs weaned and weight of lamb weaned than did the Hyfer ewes, although this was reversed at the spring joinings, causing significant season × ewe breed interactions. While litter size was larger in the autumn than in the spring for both breeds there was a much smaller seasonal effect among the Hyfer than BLM ewes. Prejoining ewe weight had a significant effect on all reproduction traits, with generally a curvilinear response with increasing weight. The interactions of weight with season × ewe breed were significant (P < 0.001) for all traits at Cowra and most traits at Wagga Wagga. Ram group was significant (P < 0.05) for most traits, with ewes joined to Hyfer rams having higher fertility than those joined to Suffolk. and with Dorset rams being intermediate. At Wagga Wagga, this was the case for spring joinings, but there was no difference between the ram groups in autumn, causing a significant ram × season interaction (P < 0.001). Ewe repeatability ranged from 0.15 to 0.25 for all traits. Using suitable breeds or genotypes, together with optimising management, could improve out-of-season lamb production.

scholarly journals Genetic analysis of reproductive characteristics in Iran-Black sheep

2020 ◽  
Vol 42 ◽  
pp. e47380
Author(s):  
Hasan Baneh ◽  
Javad Ahmadpanah ◽  
Yahya Mohammadi
Keyword(s):  
Reproductive Performance ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Environmental Correlations ◽  
Black Sheep ◽  
Litter Weight ◽  
Breeding Station ◽  
Reproduction Traits ◽  
Using Data ◽  
Size At Birth

This study was conducted to estimate genetic parameters and trends for reproduction traits using data collected at the breeding station of Iran-Black sheep during 1980 to 2004. The traits included in the analyses were litter size at birth (LSB) and weaning (LSW) and litter mean weight per lamb born (LMWLB) and weaned (LMWLW) as basic traits, and total litter weight at birth (TLWB) and weaning (TLWW) as composite traits. Direct heritability estimates for LSB, TLWB, LMWLB, LSW, TLWW and LMWLW were 0.11, 0.07, 0.33, 0.08, 0.09 and 0.11, respectively. The permanent environmental effects had significant impact on all traits and ranged from 0.05 to 0.16. Effect of service sire was highly significant (p < 0.01) for all traits except LMWLW. Estimates of genetic correlations ranged from -0.76 (LSB-LMWLB) to 0.98 (LSB-LSW). Phenotypic and environmental correlations were generally lower than those of genetic correlations. Environmental correlations ranged from -0.55 (LSW-LMWLW) to 0.99 (LSB-LSW). Also, the estimated correlation for the effect of service sire ranged from -0.77 (LMWLB-TLWW) to 0.96 (LSB-LSW and LSB-TLWW). The results suggest that selection based on TLWB could be more effective than the other traits to enhance reproductive performance in Iran-Black ewes.

Variation in reproduction and production of Poll Dorset ewes

1994 ◽  
Vol 45 (2) ◽  
pp. 415 ◽  
Author(s):  
DG Hall ◽  
AR Gilmour ◽  
NM Fogarty
Keyword(s):  
Litter Size ◽  
Environmental Effects ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Late Summer ◽  
Reproductive History ◽  
Reproduction Traits ◽  
Lamb Survival ◽  
Fleece Weight ◽  
One Year

Poll Dorset ewes were joined to Booroola Merino (n = 22) or Trangie Fertility Merino (n = 26) rams in single sire joinings during late summer/autumn of 1978, 1979, 1980 and 1981. Rams were changed each year and there were 1678 individual ewe joinings. A maximum of 527 ewes were used in any one year, and they represented 14 studs and varied in age, reproductive history and liveweight. The traits, litter size, maternal lamb survival, lambs weaned per ewe lambing and weight of lamb weaned per ewe lambing (kg at 100 days) were analysed for the effect of year, stud, age, lambs born and ewe liveweight. Litter size averaged 1-37, maternal lamb survival 0.70, and number of lambs weaned per ewe was 0.94. There were large variations in the reproductive traits due to year and stud and lesser effects due to age. Each extra kilogram of ewe liveweight at joining increased litter size by 0.012 and weight of lamb weaned by 0.39 kg, but had no significant effect on maternal lamb survival or number of lambs weaned. Multiple-bearing ewes weaned 0.72 more lambs and 16 - 2 kg more lamb weight than single-bearing ewes. Lamb survival was similar for singleand multiple-bearing ewes. Greasy fleece weight averaged 2.2 kg ewe-' and single bearing ewes produced 0.19 kg/ewe more than multiple-bearing ewes. Dystocia caused 53% and starvation/mismothering/exposure caused 23% of lamb deaths; the proportion of deaths due to starvation/mismothering/exposure increased with increasing ewe joining liveweight. The large variation between studs in reproductive performance partly reflected genetic differences between Poll Dorset flocks which could be exploited. Estimates of heritabilities ranged from 0.06 to 0.14 � 0.10 for the reproductive traits and were 0.10 � 0.12 for ewe liveweight and 0.16 � 0.20 for greasy fleece weight. However much of the between stud variation may also have arisen from early environmental effects. Estimates of repeatability ranged from 0.06 to 0.l5 � 0 05 for reproduction traits and were 0.44 � 0.06 for ewe liveweight at joining and 0.56 � 0.08 for greasy fleece weight.

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