Genetic parameters of ultrasound and computer tomography scan traits in Austrian meat sheep

Maximini, Lina; Brown, D. J.; Baumung, Roswitha; Fuerst-Waltl, Birgit

doi:10.1016/j.livsci.2012.03.007

Cited by 20 publications

(22 citation statements)

References 11 publications

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“…The estimates of genetic and phenotypic correlations between ultrasound traits and carcass traits are shown in Table 7. Genetic correlations between ultrasound measures of fat depth measured at the C site on live animals and the various carcass measures of fat depth were generally high (0.63 to 0.94), consistent with other reports where ultrasound fat depth was adjusted for live weight and measures of carcass fat depth were adjusted for carcass weight (Waldron et al, 1992;Greeff et al, 2008;Mortimer et al, 2010;Maximini et al, 2012;Brito et al, 2015;Einarsson et al, 2015). Genetic correlations between ultrasound EMD and carcass EMD and EMA were also high (0.82 to 0.99), although they were lower with carcass EMW (0.32 to 0.36), which confirms previous estimates (Greeff et al, 2008;Mortimer et al, 2010;Maximini et al, 2012).…”

Section: Wool Color and Visual Traits With Carcasssupporting

confidence: 89%

Genetic correlations between wool traits and carcass traits in Merino sheep

Mortimer¹,

Hatcher²,

Fogarty³

et al. 2017

Journal of Animal Science

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ABSTRACT:Genetic correlations between 29 wool production and quality traits and 14 whole carcass measures and carcass component traits were estimated from the Information Nucleus of 8 flocks managed across a range of Australian sheep production environments and genetically linked. Wool data were from over 5,000 Merino progeny born over 5 yr, whereas carcass data were from over 1,200 wether progeny of over 176 sires, slaughtered at about 21 kg carcass weight, on average. Wool traits included yearling and adult records for wool weight, fiber diameter, fiber diameter variation, staple strength, scoured color, and visual scores for breech and body wrinkle. Whole carcass measures included HCW, dressing percentage (DP), and various measures of fat depth and eye muscle dimensions. Carcass components were obtained by dissection, and lean meat yield (LMY) was predicted. Heritability estimates for whole carcass measures ranged from 0.12 ± 0.08 to 0.35 ± 0.10 and ranged from 0.17 ± 0.10 to 0.46 ± 0.10 for carcass dissection traits, with no evidence of important genotype × environment interactions. Genetic correlations indicated that selection for increased clean wool weight will result in reduced carcass fat (−0.17 to −0.34) and DP (−0.48 ± 0.15), with little effect on carcass muscle. Selection for lower fiber diameter will reduce HCW (−0.48 ± 0.15) as well as carcass fat (0.14 to 0.27) and muscle (0.21 to 0.50). There were high genetic correlations between live animal measures of fat and muscle depth and the carcass traits (generally greater than 0.5 in size). Selection to increase HCW (and DP) will result in sheep with fewer wrinkles on the body (−0.57 ± 0.10) and barer breeches (−0.74 ± 0.12, favorable), with minor deterioration in scoured wool color (reduced brightness and increased yellowness). Selection for reduced fat will also result in sheep with fewer body wrinkles (−0.42 to −0.79). Increasing LMY in Merinos through selection would result in a large reduction in carcass fat and DP (−0.66 to −0.84), with a smaller increase in carcass muscle and some increase in wool weight and wrinkles. Although no major antagonisms are apparent between the wool and carcass traits, developing selection indexes for dualpurpose wool and meat breeding objectives will require accurate estimates of genetic parameters to ensure that unfavorable relationships are suitably considered. The findings will aid development of dual-purpose wool and meat breeding objectives.

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Section: Wool Color and Visual Traits With Carcasssupporting

confidence: 89%

Genetic correlations between wool traits and carcass traits in Merino sheep

Mortimer¹,

Hatcher²,

Fogarty³

et al. 2017

Journal of Animal Science

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“…In agreement with our finding (0.26), Maximini et al (2012) Maxa et al (2007) (100 days of age), respectively. Our results were well in line with the published results for direct heritability (0.23) of MD, whereas the estimated maternal heritability (0.24) of this study was much higher than estimates given in the literature.…”

Section: Discussionsupporting

confidence: 94%

Bayesian inference of genetic parameters for ultrasound scanning traits of Kivircik lambs

Cemal

Karaman

Fırat

et al. 2017

Animal

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Ultrasound scanning traits have been adapted in selection programs in many countries to improve carcass traits for lean meat production. As the genetic parameters of the traits interested are important for breeding programs, the estimation of these parameters was aimed at the present investigation. The estimated parameters were direct and maternal heritability as well as genetic correlations between the studied traits. The traits were backfat thickness (BFT), skin + backfat thickness (SBFT), eye muscle depth (MD) and live weights at the day of scanning (LW). The breed investigated was Kivircik, which has a high quality of meat. Six different multi-trait animal models were fitted to determine the most suitable model for the data using Bayesian approach. Based on deviance information criterion, a model that includes direct additive genetic effects, maternal additive genetic effects, direct maternal genetic covariance and maternal permanent environmental effects revealed to be the most appropriate for the data, and therefore, inferences were built on the results of that model. The direct heritability estimates for BFT, SBFT, MD and LW were 0.26, 0.26, 0.23 and 0.09, whereas the maternal heritability estimates were 0.27, 0.27, 0.24 and 0.20, respectively. Negative genetic correlations were obtained between direct and maternal effects for BFT, SBFT and MD. Both direct and maternal genetic correlations between traits were favorable, whereas BFT-MD and SBFT-MD had negligible direct genetic correlation. The highest direct and maternal genetic correlations were between BFT and SBFT (0.39) and between MD and LW (0.48), respectively. Our results, in general, indicated that maternal effects should be accounted for in estimation of genetic parameters of ultrasound scanning traits in Kivircik lambs, and SBFT can be used as a selection criterion to improve BFT.

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“…The low genetic correlation between UMD and UFD fell within the diverse results for other breeds (e.g. Maxa et al 2007, Maximini et al 2012, Safari et al 2005. Studies on Icelandic sheep have also shown both negative (Thorsteinsson & Eythórsdóttir 1998, Thorsteinsson et al 1994) and positive (Einarsson et al 2015) genetic correlation.…”

Section: Genetic Parameterssupporting

confidence: 51%

“…Maximini et al 2012, Safari et al 2005. Studies on Icelandic sheep have shown similar or higher heritability (Einarsson et al 2015, Thorsteinsson & Eythórsdóttir 1998, Thorsteinsson et al 1994.…”

Section: Genetic Parametersmentioning

confidence: 99%

Sources of bias, genetic trend and changes in genetic correlation in carcass and ultrasound traits in the icelandic sheep population

Eiríksson¹,

Sigurdsson²

2017

IAS

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Genetic parameters for carcass conformation, carcass fat, ultrasound eye muscle depth and ultrasound fat depth over eye muscle were estimated with data from Icelandic farms during three periods, 2001-2003, 2006-2008 and 2011-2013. Heritability ranged from 0.30 to 0.42. Genetic correlation between carcass conformation and carcass fat was 0.41, 0.29 and 0.26 in 2001-2003, 2006-2008 and 2011-2013, respectively.Breeding values based on carcass scoring records of 5,796,474 lambs in 2000-2013 were estimated with a bivariate model and compared to the results of a multitrait model, including 715,771 ultrasound records. The genetic merit of rams for carcass conformation was underestimated in the bivariate analysis in the cases where many offspring were kept for replacement. Applying the multitrait model reduced this bias and gave more accurate results for both traits.The genetic trend was -0.05 and 0.08 genetic standard deviations per year for carcass fat and carcass conformation, respectively, in the period 2000-2013.

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Genetic parameters of ultrasound and computer tomography scan traits in Austrian meat sheep

Cited by 20 publications

References 11 publications

Genetic correlations between wool traits and carcass traits in Merino sheep

Genetic correlations between wool traits and carcass traits in Merino sheep

Bayesian inference of genetic parameters for ultrasound scanning traits of Kivircik lambs

Sources of bias, genetic trend and changes in genetic correlation in carcass and ultrasound traits in the icelandic sheep population

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