scholarly journals Genetic parameter and genetic trend estimates for reproductive traits in Wistar rats

2020 ◽  
Vol 72 (4) ◽  
pp. 1479-1486
Author(s):  
G. Taroco ◽  
J.T. Paiva ◽  
G.B. Mourão ◽  
J.B.S. Ferraz ◽  
E.C. Mattos ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Wistar Rats ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Wistar Rat ◽  
The Other ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Genetic Trends

ABSTRACT The aim of this study was to estimate genetic parameters and genetic trends for reproductive traits in Wistar rats. A total of 1,167 data records from 283 females over six generations of monogamous mating pairs was used. Heritability and genetic correlation were estimated through Bayesian inference and genetic trends were calculated by linear regression of breeding values over generations. Heritability estimates for litter size at birth (LS), calving interval (CI), pup mortality (PM) and maternal cannibalism (CAN) presented low magnitude, ranging from 0.01 to 0.13. CAN presented high and positive genetic correlation with LS and PM (0.77 and 0.78, respectively). On the other hand, all the other estimated genetic correlations were not significant. Genetic trend was positive for LS (+0.0900 pups per generation), and negative for PM and CAN (-1.0085 and -0.5217 pups per generation, respectively). For CI the genetic trend was not significant. It is recommended to increase selection intensity on dams in this Wistar rat population in order to accelerate the genetic progress.

scholarly journals Genetic parameters and trends for reproductive traits in Blanco Orejinegro cattle from Colombia

2021 ◽  
Vol 42 (4) ◽  
pp. 2523-2538
Author(s):  
Sindy Liliana Caivio-Nasner ◽  
◽  
Albeiro López-Herrera ◽  
Luis Gabriel González-Herrera ◽  
Juan Carlos Rincón Flórez ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
Genetic Parameters ◽  
Environmental Influence ◽  
Cattle Breed ◽  
Heritability Estimate ◽  
Reproductive Traits ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Estimated Breeding Values ◽  
Genetic Trends

The Colombian creole cattle breed Blanco Orejinegro (BON) is an important zoogenetic resource, but there is little knowledge about the genetic parameters and trends of its reproductive traits. Therefore, the aim of this study was to estimate parameters for the reproductive traits calving interval (CI), age at first calving (AFC), gestation duration (GD) and genetic trends for CI in the BON breed. Genealogy information from 7,799 animals was used, and employing the MTDFREML program, the components of the variance, heritability (h2), repeatability (rep), and estimated breeding values (EBV) for CI (n=3308), AFC (n=729), and GD (n=306) were estimated, in addition to the inbreeding coefficient (F) of the population. Genetic trends were established through linear regression using R software. Finally, the animals were classified as inbred (F > 0) and noninbred (F=0), and the effect of inbreeding on reproductive performance was established through a generalized linear model using the R program. An average F value of 4.41%±0.06 was observed. The h2 for CI was 0.11±0.03 with a rep of 0.15±0.04; for AFC, h2 was 0.00±0.05; and for GD, h2 was 0.00±0.08. The genetic trend for CI was -0.01 days/year. Finally, for CI, inbreeding depression was evident; this trait increased when inbreeding increased. These results indicate an important environmental influence on reproductive traits. The heritability estimate for CI suggests that little genetic progress could be achieved through selection. The evidence of inbreeding depression raises the need to control inbreeding to conserve this genetic resource.

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 of reproductive traits in Tunisian Holsteins

2016 ◽  
Vol 59 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Hafedh Ben Zaabza ◽  
Abderrahmen Ben Gara ◽  
Hedi Hammami ◽  
Borni Jemmali ◽  
Mohamed Amine Ferchichi ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Parameter Estimates ◽  
Calving Interval ◽  
Cattle Herds ◽  
Correlation Estimate ◽  
Fertility Traits

Abstract. Multi-trait Bayesian procedure was used to estimate genetic parameters for reproductive traits in Tunisian Holstein cows. A total of 31 348 lactations of the calving years 2005 to 2012 were analyzed. Fertility traits were the calving interval (CI), days open (DO), days to first insemination (DFI), days from first insemination to conception (FIC), and number of inseminations per conception (NI). Posterior means of heritabilities of CI, DO, DFI, FIC, and NI were 0.047, 0.03, 0.025, 0.024, and 0.069, respectively. Posterior means of repeatabilities of the same respective traits were 0.106, 0.094, 0.051, 0.036, and 0.17. Genetic correlations among female fertility traits were also computed. Calving interval and DO had the highest genetic correlation estimate (0.85) because they have overlapping genetic meanings. The lowest genetic correlation estimate (−0.25) was found between DFI and NI. Genetic parameter estimates are low and are even lower than those reported in most literature, implying that more focus should be put upon improving the management of reproduction in dairy cattle herds in Tunisia.

scholarly journals Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Parameter Estimates ◽  
Sampling Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

Genetic parameter estimations and genomic insights for teat and udder structure in young and mature Canadian Angus cows

2021 ◽  
Author(s):  
K Devani ◽  
J J Crowley ◽  
G Plastow ◽  
K Orsel ◽  
T S Valente
Keyword(s):  
Animal Model ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Age Groups ◽  
Morbidity And Mortality ◽  
Parameter Estimations ◽  
Angus Cattle ◽  
Genetic Evaluations

Abstract Poor teat and udder structure, frequently associated with older cows, impact cow production and health, as well as calf morbidity and mortality. However, producer culling, for reasons including age, production, feed availability, and beef markets, creates a bias in teat and udder scores assessed and submitted to the Canadian Angus Association for genetic evaluations towards improved mammary structure. In addition, due to the infancy of the reporting program, repeated scores are rare. Prior to adoption of genetic evaluations for teat and udder scores in Canadian Angus cattle, it is imperative to verify that teat and udder scores from young cows are the same trait as teat and udder scores estimated on mature cows. Genetic parameters for teat and udder scores from all cows (n=4,192), and then from young cows (parity 1 and 2) and from mature cows (parity ≥ 4) were estimated using a single trait animal model. Genetic correlations for the traits between the two cow age groups were estimated using a two-trait animal model. Estimates of heritability (PSD) were 0.32 (0.07) and 0.45 (0.07) for young teat and udder score, and 0.27 (0.07) and 0.31 (0.07) for mature teat and udder score, respectively. Genetic correlation (PSD) between the young and mature traits was 0.87 (0.13) for teat score and 0.40 (0.17) for udder score. GWAS were used to further explore the genetic and biological commonalities and differences between the two groups. Although there were no genes in common for the two udder scores, 12 genes overlapped for teat score in the two cow age groups. Interestingly, there were also 23 genes in common between teat and udder scores in mature cows. Based on these findings, it is recommended that producers collect teat and udder score on their cow herd annually.

Genetic parameter estimates (full sib and half sib analysis) of fertility and hatchability in two strains of Rhode Island chickens

2021 ◽  
Vol 38 (1) ◽  
pp. 14-22
Author(s):  
M. Orunmuyi ◽  
I. A. Adeyinka ◽  
O.O Oni
Keyword(s):  
Rhode Island ◽  
Additive Genetic Variance ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Parameter Estimates ◽  
Phenotypic Correlations ◽  
Poultry Breeding ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

A study was conducted to estimate the genetic parameters of fertility and hatchability in two strains of Rhode Island Red (RIR) Chickens denoted as Strain A and Strain B respectively using the full-sib (sire +dam variance) and maternal half-sib (dam variance) components. The birds were obtained from the selected populations of RIR Chickens kept at the poultry breeding programme of National Animal Production Research Institute, Shika, Zaria, Nigeria. Settable eggs were collected from mating 28 cocks to 252 hens in a ratio of 1cock:9 hens from each strain. Eggs were pedigreed according to sire and dam. Results showed that values obtained for number of egg set (EGGSET), number of fertile eggs (NFERT), number of hatched chicks (NHATCH), percentage of chicks hatched from total eggs set (PHATCH) and percentage of chicks hatched from fertile eggs (PHATCHBL) were all higher in strain A than strain B. Heritability estimates obtained from the full-sib and maternal half-sib analysis ranged from medium to high for the two strains (0.24-0.96). The maternal half sib estimates were higher (0.40-0.96) than the estimates obtained from full sibs (0.24- 0.48). Genetic and phenotypic correlations obtained for both strains were positive and similar regardless of method of estimation. Genetic correlations between EGGSET and PFERT were low in strain A using both full-sib and maternal half-sib analyses (0.09-0.14). Phenotypic correlations between EGGSET and PFERT, PHATCH and PHATCHBL were also low in both strains and regardless of method of analyses. Moderate to high heritability estimates suggest that genetic improvement can be obtained by selection of these reproductive traits. The full-sib analysis for estimating heritability will be preferred since it is assumed that only additive genetic variance contributes to the covariance between family members.

scholarly journals Prevalence and breeding values of elbow dysplasia in the Estrela mountain dog

2013 ◽  
Vol 58 (No. 9) ◽  
pp. 484-490 ◽  
Author(s):  
S. Alves-Pimenta ◽  
B. Colaco ◽  
AM Silvestre ◽  
MM Ginja
Keyword(s):  
Hip Dysplasia ◽  
Mass Selection ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Breeding Values ◽  
Elbow Dysplasia ◽  
Low Mass ◽  
The Mean ◽  
Dog Breed ◽  
Genetic Trends

The aims of this study were to determine the prevalence and heritability of elbow dysplasia in the Estrela mountain dog breed, to investigate genetic trends over the last 20 years (1990–2009) and to evaluate the association of individual records with breeding values. The elbows of 351 Estrela mountain dogs were examined using the flexed mediolateral radiographic view and evaluated using the International Elbow Working Group scoring system. Heritability and breeding values were estimated using a linear model. Elbow Dysplasia was found in 16.5% (59/351) of the dogs; males (27%, 34/127) were more affected than females (11%, 24/224) (P < 0.05). The heritability was very low (0.065) and the genetic trend showed a slight positive slope with an improvement in 2004 and 2005. The mean breeding values in elbow dysplasia grades were different but the overlap among grades was very pronounced. The prevalence and heritability of elbow dysplasia in the breed are thus low. Mass selection using individual phenotypes may not be effective. Elbow dysplasia genetic trends are similar to trends for hip dysplasia and passive hip laxity, so the use of selection against hip dysplasia may also result in genetic progress for elbow dysplasia.  

Genetic correlations and trends for traits of economic importance in dairy buffalo

2020 ◽  
Vol 60 (4) ◽  
pp. 492 ◽  
Author(s):  
Ranielle Nogueira da Silva Vilela ◽  
Thomaz Marques Sena ◽  
Rusbel Raul Aspilcueta-Borquis ◽  
Leonardo de Oliveira Seno ◽  
Francisco Ribeiro de Araujo Neto ◽  
...  
Keyword(s):  
Milk Fat ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Milk Quality ◽  
Calving Interval ◽  
Age At First Calving ◽  
Productive Traits ◽  
Dairy Buffalo ◽  
Genetic Trends ◽  
Low Magnitude

Context The planning and execution of selection programs requires estimates of the genetic correlations between traits. As genetic change is achieved for a given trait, it is important to consider possible genetic changes for other traits. Understanding the magnitude and direction of genetic correlations can assist in selection decisions. Aims The aim of the present study was to estimate the genetic correlations of reproductive traits with productive traits and with percentages of fat and protein in the milk of dairy buffalo. Additionally, genetic trends were estimated for the traits under study over the years. Methods Data from 11530 complete lactations of 3431 female buffalo were used. The following traits were analysed: milk, fat and protein yields; percentages of fat and protein; age at first calving; and calving interval. The (co)variance components were estimated by Bayesian inference in multi-trait analyses, considering a linear animal model. To calculate the genetic trends, the average annual genetic values were regressed on the year of birth. Key results The means of genetic correlations estimated between reproductive (age at first calving and calving interval) and productive (milk, fat and protein yields) traits were positive, but of moderate to low magnitude. The association between the reproductive and milk quality (fat and protein percentages) traits were negative and of low magnitude. Genetic trends for the productive traits were positive (5.25 ± 0.63, 0.15 ± 0.034 and 0.09 ± 0.038 kg/year for milk, fat and protein yields respectively). Genetic trends for the reproductive traits of age at first calving and calving interval increased by 0.47 ± 0.09 and 0.48 ± 0.10 days/year respectively. In terms of milk quality, however, the percentages of fat and protein decreased by 0.016 ± 0.003 and 0.011 ± 0.001%/year respectively. Conclusions Genetic gains in productive traits may elevate the number of days at first calving and extend the calving interval, in addition to leading to the production of milk of lower quality. Implications The use of a multi-trait selection index is an alternative, as it combines information from different sources, such that an optimal selection criterion can be achieved over time by virtue of its emphasis on appropriate weighting for all traits.

scholarly journals Genetic Variation and Correlation among Resin Yield, Growth, and Morphologic Traits of Pinus massoniana

2013 ◽  
Vol 62 (1-6) ◽  
pp. 38-43 ◽  
Author(s):  
Qinghua Liu ◽  
Zhichun Zhou ◽  
Huihua Fan ◽  
Yurong Liu
Keyword(s):  
Genetic Correlation ◽  
Genetic Correlations ◽  
Tree Height ◽  
Pinus Massoniana ◽  
The Other ◽  
Breeding Programs ◽  
Family Effects ◽  
Breast Height ◽  
Sib Families ◽  
The Individual

AbstractIn breeding programs, the variations and relationships among main traits need to be understood to develop selection and breeding strategies. Resin is considered as one of most important non-timber production of P. massoniana which can privides terpenes used in the chemical industry. The present study assessed the genetic variations in growth, morphologic traits, and resin yield, as well as the phenotypic and genetic correlations between these traits of 45 half-sib families of eight-year-old Pinus massoniana trees. All traits show highly significant family effects. The individual heritability for diameter at breast height (DBH) was the highest (hi2=0.55). Heritabilities for resin yield, tree height, crown depth, and the height to the live crown were slightly lower than DBH, ranging from 0.32 to 0.45. The other traits were under weak genetic control and heritabilities ranged from 0.17 to 0.20. All growth and morphologic traits were significantly correlated genetically with resin yield. Number of living branches had the highest genetic correlation with resin yield (rg=0.99), followed by DBH and number of living whorls (rg=0.73 and 0.70). Only a moderate positive genetic correlation with resin yield was found with the other traits (rg=0.47-0.57), except for height under the living branches (rg=-0.45). The results of this study indicate that both resin yield and growth can be improved simultaneously in the next generation. Of the traits assessed DBH was the optimum trait for indirectly selecting high-yielding resin trees.

Within-farm estimates of genetic and phenotypic parameters for growth and reproductive traits for red deer

1993 ◽  
Vol 57 (1) ◽  
pp. 153-159 ◽  
Author(s):  
C. McManus
Keyword(s):  
Birth Weight ◽  
Maximum Likelihood ◽  
Eastern Europe ◽  
Red Deer ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
The Other ◽  
The United Kingdom ◽  
Terminal Sire

AbstractGenetic and phenotypic parameters were estimated for farmed red deer on eight farms distributed throughout the United Kingdom. Genetic parameters were estimated using restricted maximum likelihood (REML) analysis. Heritabilities for date of calving were low on seven of the eight farms (< 0–05), while repeatabilities were low to moderate (0·06 to 0·37). Heritabilities of all weights tended to be moderate to high on most farms (0·31 to 0·49; 0·22 to 0·89; 0·33 to 0·48; 0·37 to 0·45 and 0·37 to 0·90 for birth weight, weaning weight, mid-winter weight, turn-out weight and other weights respectively). The exception was farm 8 for which heritability estimates were very low (<0·08). This is attributed to inbreeding effects on this farm. Phenotypic and genetic correlations between post-weaning traits tended to be high, indicating selection at any stage of growth will be expected to lead to an increased growth at the other stages. Animals whose bloodlines originated in the forests of Eastern Europe (Yugoslavia, Hungary, Germany) were heavier at all stages indicating their usefulness as ‘terminal sire’ breeds. Hinds of mainland ‘European’ parentage also tended to calve earlier.

Sign in / Sign up

Export Citation Format

Share Document