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.

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 < 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 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.

scholarly journals Associations between reproductive and carcass traits in Nellore

2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4423
Author(s):  
Edson Junior Heitor de Paula ◽  
Elias Nunes Martins ◽  
Carlos Antônio Lopes de Oliveira ◽  
Cláudio De Ulhoa Magnabosco ◽  
Roberto Daniel Sainz ◽  
...  
Keyword(s):  
Genetic Parameters ◽  
Random Effect ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Muscle Area ◽  
Scrotal Circumference ◽  
Short Period ◽  
Fat Thickness ◽  
Heritability Estimates

The objective of this study was to estimate the genetic parameters and (co)variance of Nellore animals and to characterize the associations between these characteristics for the following carcass traits: weight (W), longissimus muscle area (LMA), rump fat thickness (RF) and fat thickness between the 12th and 13th ribs obtained by ultrasound (BF); also, the following reproductive traits: age at first calving (AFC), first calving interval (FCI), scrotal circumference at 450 and 550 days of age (SC450 and SC550). The genetic parameters were estimated by a single-trait and two traits animal model using Bayesian inference. The model used for all of the features included the genetic random effect and age as covariate assuming a quadratic effect. Additionally, sex, month and year of birth and management of creation and environmental effects identified were included for the carcass traits. For AFC, FCI and SC450 and SC550, we considered only the month and year of birth. The heritability estimates for all of the traits were higher in the two traits analysis, except for AFC and FCI, which showed 0.75 and 0.29, respectively, similar values in the single trait analysis. The two traits analyses resulted in heritability estimates for a posteriori for the features W, LMA, BF, RF, SC450 and SC550 of 0.49, 0.66, 0.74, 0.68 0.66 and 0.74, respectively, suggesting the possibility of genetic gains during a short period of time. The genetic correlations between AFC and carcass traits measured by ultrasound were close to zero. A similar trend was found for AFC, SC450 and SC550 days, indicating that the selection for these traits does not promote changes in AFC. High genetic correlations (0.92, 0.93 and 0.94) were observed between the characteristics LMA and W, BF and RF, and SC450 and SC550, respectively.

scholarly journals Associations between reproductive and carcass traits in Nellore

2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4423 ◽  
Author(s):  
Edson Junior Heitor de Paula ◽  
Elias Nunes Martins ◽  
Carlos Antônio Lopes de Oliveira ◽  
Cláudio De Ulhoa Magnabosco ◽  
Roberto Daniel Sainz ◽  
...  
Keyword(s):  
Genetic Parameters ◽  
Random Effect ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Muscle Area ◽  
Scrotal Circumference ◽  
Short Period ◽  
Fat Thickness ◽  
Heritability Estimates

<p>The objective of this study was to estimate the genetic parameters and (co)variance of Nellore animals and to characterize the associations between these characteristics for the following carcass traits: weight (W), longissimus muscle area (LMA), rump fat thickness (RF) and fat thickness between the 12th and 13th ribs obtained by ultrasound (BF); also, the following reproductive traits: age at first calving (AFC), first calving interval (FCI), scrotal circumference at 450 and 550 days of age (SC450 and SC550). The genetic parameters were estimated by a single-trait and two traits animal model using Bayesian inference. The model used for all of the features included the genetic random effect and age as covariate assuming a quadratic effect. Additionally, sex, month and year of birth and management of creation and environmental effects identified were included for the carcass traits. For AFC, FCI and SC450 and SC550, we considered only the month and year of birth. The heritability estimates for all of the traits were higher in the two traits analysis, except for AFC and FCI, which showed 0.75 and 0.29, respectively, similar values in the single trait analysis. The two traits analyses resulted in heritability estimates for a posteriori for the features W, LMA, BF, RF, SC450 and SC550 of 0.49, 0.66, 0.74, 0.68 0.66 and 0.74, respectively, suggesting the possibility of genetic gains during a short period of time. The genetic correlations between AFC and carcass traits measured by ultrasound were close to zero. A similar trend was found for AFC, SC450 and SC550 days, indicating that the selection for these traits does not promote changes in AFC. High genetic correlations (0.92, 0.93 and 0.94) were observed between the characteristics LMA and W, BF and RF, and SC450 and SC550, respectively.</p>

scholarly journals Short communication: Genetic parameters for post-weaning visual scores and reproductive traits in Suffolk sheep

2018 ◽  
Vol 16 (1) ◽  
pp. e04SC01 ◽  
Author(s):  
Juliana V. Portes ◽  
Adriana L. Somavilla ◽  
André L. Grion ◽  
Laila T. Dias ◽  
Rodrigo A. Teixeira
Keyword(s):  
Genetic Correlation ◽  
Random Effect ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Direct Selection ◽  
Additive Genetic Effect ◽  
Genetic Progress ◽  
Scrotal Circumference ◽  
Heritability Estimates ◽  
Suffolk Sheep

          The aim of this study was to estimate the coefficients of heritability and genetic correlations among visual scores (conformation, CPW; precocity, PPW; musculature, MPW) and reproductive traits: age at first lambing (AFL) and scrotal circumference (SC) evaluated at 180 days of age in Suffolk lambs. In the statistical model only the additive genetic effect was considered as random effect. The heritability estimates by univariate analyses for CPW, PPW, MPW, AFL and SC were 0.08, 0.12, 0.09, 0.20 and 0.22, respectively. The genetic correlations among AFL and CPW, PPW, MPW were -0.26, 0.19, and 0.08, respectively. The genetic correlation among SC and CPW, PPW, MPW were, respectively, 0.54, 0.88 and 0.86, and between AFL and SC was 0.26. The direct selection for conformation, precocity and musculature at 180 days of age and age at first lambing will provide slow genetic progress due to low heritability estimates. It is possible to obtain genetic gain in sexual precocity through selection on scrotal circumference in Suffolk rams. The favorable genetic correlation among visual scores and SC and between CPW and AFL, indicated the possibility to gain in genetic progress for reproductive traits through indirect selection of the visual scores in Suffolk sheep.

scholarly journals Genetic parameters and genetic gains for reproductive traits of Arabi sheep

2015 ◽  
Vol 31 (1) ◽  
pp. 23-36 ◽  
Author(s):  
H. Roshanfekr ◽  
P. Berg ◽  
K. Mohammadi ◽  
Mirza Mohamadi
Keyword(s):  
Litter Size ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Least Square ◽  
Research Station ◽  
Environmental Correlations ◽  
Breeding Values ◽  
Litter Weight

The current study reports, for the first time, the genetic parameters and genetic, phenotypic and environmental correlations and trends of reproductive traits in Arabi sheep. Data were collected at Animal Science Research Station of Khuzestan Ramin Agricultural and Natural Resources University (ASRSKRANRU), south-west of Iran from 2001 to 2008. Litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), litter mean weight per lamb weaned (LMWLW), total litter weight at birth (TLWB) and total litter weight at weaning (TLWW) averaged 1.11 lambs, 1.01 lambs, 3.83 kg, 19.43 kg, 4.16 kg and 20.12 kg, respectively. Genetic parameters and correlations were estimated with univariate and bivariate models using restricted maximum likelihood, breeding values of animals were estimated with best linear unbiased prediction (BLUP) and genetic- and phenotypic trends by regression of ewes? average breeding values and phenotypic least square means on year of birth respectively. Random effects were fitted by additive direct genetic effects and permanent environment related to the ewe as well as service sire effects, in addition to fixed effects of ewe age at lambing and lambing year. Heritability estimates of 0.05, 0.02, 0.13, 0.12, 0.04, and 0.06, and repeatability estimates of 0.08, 0.06, 0.17, 0.16, 0.14 and 0.21 for the six traits, respectively. Genetic correlations between traits varied from ?0.82 to 0.94. Phenotypic correlations were lower, ranging from ?0.33 to 0.52. Estimated annual genetic progress was very low; ?0.003 lambs for LSW and 15 g for TLWW. Annual phenotypic trend was only significant for LSW being 0.007 lambs. The study concluded that indirect selection based on total litter weight at weaning could be efficient for the traits studied.

scholarly journals Genetic Analysis of Basic and Composite Reproduction Traits in Guilan Sheep

2017 ◽  
Vol 17 (1) ◽  
pp. 105-116 ◽  
Author(s):  
Bahareh Eteqadi ◽  
Navid Ghavi Hossein-Zadeh ◽  
Abdol Ahad Shadparvar
Keyword(s):  
Litter Size ◽  
Fixed Effects ◽  
Production Efficiency ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Meat Production ◽  
Environmental Correlations ◽  
Litter Weight ◽  
The North

Abstract The objective of the present study was to estimate genetic parameters for reproductive traits in Guilan sheep. Data were comprised of 14,534 records of lambs from 136 sires and 2,021 dams which were collected during 1994 to 2011 by the Agriculture Organization of Guilan Province in the north of Iran. The basic reproductive traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), and litter mean weight per lamb weaned (LMWLW). The composite reproductive traits were total litter weight at birth per ewe lambing (TLWB) and total litter weight at weaning per ewe lambing (TLWW). The general linear model procedure of SAS was used for determining the fixed effects which had significant effect on the traits under study. The flock-year-season of lambing had significant effect on studied traits (P<0.01). The genetic parameters were estimated with repeatability animal model using restricted maximum likelihood (REML) procedure of the Wombat program. Direct heritability estimates were 0.00, 0.00, 0.01, 0.01, and 0.03 for LSB, LSW, LMWLW, TLWB, and TLWW, respectively, and corresponding repeatabilities were 0.2, 0.00006, 0.01, 0.972 and 0.034, respectively. Genetic correlation estimates between traits ranged from -0.99 for LSB-LSW to 0.99 for LMWLW-TLWW. Phenotypic correlations ranged from -0.09 for LSB-TLWB to 0.98 for LMWLW-TLWW and environmental correlations ranged from -0.03 for LSW-TLWW to 0.98 for LMWLW-TLWW. The results showed that strong positive genetic correlations of LMWLB and LMWLW with other traits may improve meat production efficiency in Guilan sheep. The low estimates of heritability and repeatability obtained for ewe productivity traits indicate that selection based on the ewe’s own performance may result in slow genetic improvement.

127 Antibody Response as an Indicator Trait for Improved Reproductive Performance During a PRRSV Outbreak: Genetic Correlations of S/P Ratio with Reproductive Traits in Landrace and Duroc Sows

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 19-20
Author(s):  
Felipe Hickmann ◽  
José Braccini Neto ◽  
Luke M Kramer ◽  
Kent A Gray ◽  
Yijian Huang ◽  
...  
Keyword(s):  
Antibody Response ◽  
Reproductive Performance ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Respiratory Syndrome Virus ◽  
Potential Indicator ◽  
Host Genetic ◽  
Heritability Estimates ◽  
Terminal Sire ◽  
Indicator Trait

Abstract Previous studies proposed the use of antibody response to Porcine Reproductive and Respiratory Syndrome virus (PRRSV), measured as sample-to-positive (S/P) ratio, as a potential indicator trait to improve the reproductive performance of PRRSV-infected Landrace sows. However, this indicator trait has not yet been validated in Landrace sows or evaluated in a terminal sire line, such as Duroc. The main objective of this work was to perform host-genetic analyses of S/P ratio and reproductive traits during a PRRSV outbreak in maternal and terminal breeds. The data consisted of 690 Duroc and 541 Landrace multiparous sows (1.9±1.2 and 2.3±1.5, respectively) with S/P ratio collected at approximately 54 days after the predicted beginning of the outbreak. Of these, 644 Duroc and 528 Landrace sows also had reproductive data recorded during the PRRSV outbreak comprising number of piglets born alive (NBA), stillborn piglets (NSB), mummified piglets (NBM), number born dead (NBD; sum of NSB and NBM), total number born (TNB; sum of NBA and NBD), and number weaned (NW). All animals had genotype data on ~30K SNPs common across both breeds. Heritability estimates (± standard error) of S/P ratio during the PRRSV outbreak were moderate, with 0.33±0.06 for Duroc and 0.28±0.07 for Landrace. Reproductive traits during the PRRSV outbreak had overall low heritability estimates (≤0.18). Favorable genetic correlations of S/P ratio with NBA (0.65±0.33), in accordance with previous studies, and NBD (-0.33±0.28) were observed for Landrace sows only. Estimates of genetic correlation with other traits were -0.21±0.30 (NBM), -0.12±0.29 (NSB), 0.10±0.38 (NW), and 0.54±1.29 (TNB) for Landrace. For Duroc, these estimates were weaker: -0.33±0.40 (NBA), 0.26±0.27 (NBA), and 0.28±0.30 (NW), with convergence issues for mortality traits. These results further support the use of S/P ratio as an indicator trait for improved reproductive performance during a PRRSV outbreak in Landrace sows.

scholarly journals Genetic parameters and efficiency of early selection for half rotation-aged growth and form traits in Pinus taeda in China

2013 ◽  
Vol 62 (1-6) ◽  
pp. 277-284 ◽  
Author(s):  
Huixiao Yang ◽  
Tianyi Liu ◽  
Chunxin Liu ◽  
Jinbang Wang ◽  
Kaer Chen ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Early Selection ◽  
Direct Selection ◽  
Individual Tree ◽  
Stem Straightness ◽  
Selection For ◽  
Heritability Estimates

Abstract Genetic parameters for height (H), diameter at breast height (DBH), stem straightness (STR), and under crown clear bole height (CH) of loblolly pine (Pinus taeda L.) were estimated for 255 families (209 open pollinated (OP) and 46 controlled pollinated (CP) families) using a family model and an individual tree model at age 1, 2, 3, 5, 11, and 15 years. Heritability estimates for growth traits of individual trees at age 11 years were the highest (0.17-0.78), and those at age 15 years were the lowest (0.05-0.74). Heritability estimates for DBH, STR, and CH were lower than those for H. Genetic correlations between H and DBH were generally strongly positive, attained a maximum values at age 2 to 3, and declined slightly thereafter. The genetic correlations between CH at age 11 and both H and DBH at different ages were moderate. Age-age genetic correlations for growth traits were moderate to high (0.56-0.91) at age 5 for half-rotation age (15 years), indicating the opportunity exists for early selection. Indirect selection from the age 5 to 11 years for H and DBH could be expected to produce gains of over 50% and 35% respectively, for these two ages, relative to direct selection at age 15. Efficiencies of early selection for H and DBH indicated that growth at maturity could be improved by early selection.

Genetic parameters for reproductive performance of breeding cows and carcass traits of fattening animals in Japanese Black (Wagyu) cattle

2004 ◽  
Vol 78 (2) ◽  
pp. 195-201 ◽  
Author(s):  
K. Oyama ◽  
T. Katsuta ◽  
K. Anada ◽  
F. Mukai
Keyword(s):  
Reproductive Performance ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Reproductive Traits ◽  
Gestation Length ◽  
Marbling Score ◽  
Selection For

AbstractReproductive performance is receiving increased attention from beef cattle producers. There are concerns that intensive selection for carcass traits might reduce the reproductive performance of females. Genetic parameters among six carcass traits and, age at first calving (AFC), gestation length (GL), days open (DO) and calving interval (CI) under year-round artificial insemination were estimated. Reproductive traits were extracted from 174005 calving records of Japanese Black cows and were analysed with 31364 carcass records. The restricted maximum likelihood procedure under animal models was used to estimate the parameters. Heritabilities of AFC, GL, DO and CI were estimated to be 0.20, 0.40, 0.05 and 0.05, respectively, and those of carcass traits were higher, ranging from 0.38 to 0.56. Genetic correlations of CI with AFC and GL were 0.25 and 0.16, respectively, while no relationship was observed between AFC and GL. Correlations among carcass traits were generally favourable and a slightly negative estimate was obtained between subcutaneous fat thickness and marbling score. Genetic correlations for AFC were -0.27 with carcass weight and -0.24 with marbling score. In contrast, GL, DO and CI were genetically independent of carcass traits. Genetic relationships between reproductive and carcass traits were generally low, and therefore serious antagonism was not observed. The results suggested that selection for carcass traits would not compromise genetic progress in reproductive traits.

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