Genetic analysis of weight, fat and muscle depth in growing lambs using random regression models

Fischer, T. M.; Werf, J. H. J. van der; Banks, Robert; Ball, Alexander; Gilmour, AR

doi:10.1079/asc200511

Cited by 7 publications

(4 citation statements)

References 17 publications

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“…Growth traits. Consistent with literature estimates, body weight traits were all moderately to strongly correlated (0.46 ± 0.04 to 0.89 ± 0.01; Table 5), with weights measured at closer ages having stronger phenotypic and genetic correlations than those measured at more distant ages (Fischer et al, 2006;Ingham et al, 2007;Huisman and Brown, 2008;Boareki, 2017). Positive genetic correlations between WWT, PWWT, and WTUS (0.82 ± 0.06 to 0.89 ± 0.01; Table 5) were favorable, as selection for these traits would be expected to increase production efficiency.…”

Section: Genetic Correlationssupporting

confidence: 84%

A genetic evaluation of growth, ultrasound, and carcass traits at alternative slaughter endpoints in crossbred heavy lambs1

Massender

Brito

Cánovas

et al. 2018

Journal of Animal Science

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Genetic parameters were estimated for growth, ultrasound, and carcass traits in a Canadian crossbred heavy lamb population. Traits analyzed included birth, weaning, post-weaning, and ultrasound scanning weights; pre-and post-weaning average daily gain; ultrasonically measured eye muscle and fat depths; hot carcass weight; fat depth at the GR site (110 mm from the midline on the 12th rib); carcass conformation scores; saleable meat yield; price grid value; and total carcass value. The impact of three alternative slaughter endpoints (slaughter age, carcass weight, and carcass fatness) on genetic parameter estimates was also evaluated. In general, carcass traits were found to be moderately heritable, with heritability estimates ranging from 0.17 ± 0.02 for hot carcass weight at a constant slaughter age to 0.34 ± 0.02 for average carcass conformation score at a constant carcass weight. Heritability estimates were similar when observations were adjusted to alternative slaughter endpoints, but for some traits, phenotypic variance and genetic correlation estimates differed. Genetic correlations between carcass

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Section: Genetic Correlationssupporting

confidence: 84%

A genetic evaluation of growth, ultrasound, and carcass traits at alternative slaughter endpoints in crossbred heavy lambs1

Massender

Brito

Cánovas

et al. 2018

Journal of Animal Science

View full text Add to dashboard Cite

show abstract

“…Regarded to genetic correlations in this study, the results confirm what has been observed by other authors (Fischer et al, 2004(Fischer et al, , 2006Lambe et al;Sarmento et al, in press), that genetic correlations among weights at subsequent ages, close together, are high, tending to unity and the weights at younger ages are not under the same genetic control than those taken in later life.…”

Section: Resultssupporting

confidence: 80%

Genetic evaluation of partial growth trajectory of Santa Inês breed using random regression models

2010

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-It was evaluated data set of 19,303 weight records of Santa Inês sheep in order to evaluate distinct polynomial functions with different order for better adjustements of fixed and random regressions of growth trajectory and to estimate (co)variances components and genetic parameters of this trajectory. Fixed effects used in analysis were contemporary group, sex and birth type. Ordinary and Legendre polynomials, ranging from two to four orders, were evaluated for fixed regression of average growth trajectory. Legendre and quadratic b-spline functions, ranging from three to four orders, were evaluated for random regressions. Legendre polynomials of order fourth were suitable to fit random regression, while ordinary polynomials of third order were the best for fixed trajectory. Direct heritabilities on days 1, 50, 150, 250 and 411 were 0.24, 0.12, 0.44, 0.84, and 0.96, respectively, while maternal heritabilities for the same ages were 0.24, 0.19, 0.09, 0.02, and 0.01, respectively. Genetic correlations among weights in subsequent ages were high, tending to unity, and there were negative correlations between weights at early ages and weights at late ages. It is possible to modify the growth trajectory by selection with the observed genetic variability. Genetic control of weights at initial ages is not the same in late ages. So, selection of animals for slaughter in early age must be different from that of replacement animals.Key Words: β-spline functions, genetic correlation, heritability, Legendre polynomials, ordinary polynomials Avaliação genética de parte da trajetória de crescimento em ovinos da raça Santa Inês utilizando modelos de regressão aleatória .303 registros de peso de ovinos da raça Santa Inês com os objetivos de avaliar funções polinomiais com diferentes ordens para melhor ajuste das regressões fixas e aleatórias da trajetória de crescimento e estimar os componentes de covariância e os parâmetros genéticos desta trajetória. Os efeitos fixos utilizados nas análises foram grupo de contemporâneos, sexo e tipo de nascimento. Para ajuste da regressão fixa da trajetória média de crescimento, foram avaliados polinômios ordinários e de Legendre com ordens variando de 2 a 4. Para as regressões aleatórias, foram avaliadas as funções de Legendre e β-spline quadrática, com ordens variando de 3 a 4. As funções com polinômios de Legendre de quarta ordem foram adequadas para ajustar a parte aleatória, enquanto os polinômios ordinários de terceira ordem foram melhores para ajustar a parte fixa. As herdabilidades diretas nos dias 1, 50, 150, 250 e 411 foram de 0,24; 0,12; 0,44; 0,84; e 0,96, respectivamente, enquanto as herdabilidades maternas nessas idades foram de 0,24; 0,19; 0,09; 0,02 e 0,01. As correlações genéticas entre pesos em idades subsequentes foram elevadas, tendendo à unidade, e houve correlações negativas entre pesos tomados em idades mais jovens e aqueles tomados em idades mais avançadas. A variabilidade genética observada permite alterar a trajetória de crescimento por meio de seleção. O co...

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“…52-0 . 77 for TBLM (Nguyen et al, 1998 ;Hanisch et al, 2004;Hsu et al, 2005;Fischer & Van der Werf, 2006). Interestingly, TBFM and TBLM are highly correlated, phenotypically and genetically (Gray & Bauer, 1991 ;Zhao et al, 2006), suggesting that they may share common genetic factors.…”

Section: Introductionmentioning

confidence: 97%

Bivariate genome linkage analysis suggests pleiotropic effects on chromosomes 20p and 3p for body fat mass and lean mass

et al. 2008

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Total body fat mass (TBFM) and total body lean mass (TBLM) are the major components of the human body. Although these highly correlated phenotypic traits are frequently used to characterize obesity, the specific shared genetic factors that influence both traits remain largely unknown. Our study was aimed at identifying common quantitative trait loci (QTLs) contributing to both TBFM and TBLM. We performed a whole genome-linkage scan study in a large sample of 3255 subjects from 420 Caucasian pedigrees. Bivariate linkage analysis was carried out in both the entire sample and gender-specific subsamples. Several potentially important genomic regions that may harbour QTLs important for TBFM and TBLM were identified. For example, 20p12-11 achieved a LOD score of 2.04 in the entire sample and, in the male subsample, two genomic regions, 20p12 (LOD=2.08) and 3p26-25 (LOD=1.92), showed suggestive linkage. In addition, two-point linkage analyses for chromosome X showed suggestive linkages on Xp22 in the entire sample (LOD=2.14) and significant linkage on Xp22 in the female subsample (LOD=3.05). Complete pleiotropy was suggested for 20p12 and 3p26-25 in males. Our results suggest that QTLs on chromosomes 20p12, 3p26-25 and Xp22 may jointly influence TBFM and TBLM. Further fine mapping and gene identification studies for these pleiotropic effects are needed.

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Genetic analysis of weight, fat and muscle depth in growing lambs using random regression models

Cited by 7 publications

References 17 publications

A genetic evaluation of growth, ultrasound, and carcass traits at alternative slaughter endpoints in crossbred heavy lambs1

A genetic evaluation of growth, ultrasound, and carcass traits at alternative slaughter endpoints in crossbred heavy lambs1

Genetic evaluation of partial growth trajectory of Santa Inês breed using random regression models

Bivariate genome linkage analysis suggests pleiotropic effects on chromosomes 20p and 3p for body fat mass and lean mass

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