Genetic analyses of live-animal ultrasound and abattoir carcass traits in Australian Angus and Hereford cattle.

Reverter, Antônio; Johnston, David; Graser, H. U.; Wolcott, Matthew Lee; Upton, W

doi:10.2527/2000.7871786x

Cited by 117 publications

(165 citation statements)

References 18 publications

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“…Genetic correlations among live seedstock ultrasound and carcass traits have also been studied extensively in Australia (Reverter et al 2000). However, the seedstock bulls and heifers used in the Australian study were considerably older (approximately 490 d) than the bulls used in the present study.…”

Section: Correlations Among Live Bull and Steer Carcass Traitsmentioning

confidence: 77%

Genetic correlations among indicator traits for carcass composition measured in yearling beef bulls and finished feedlot steers

Bergen¹,

Miller²,

Wilton³

2005

Can. J. Anim. Sci.

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among indicator traits for carcass composition measured in yearling beef bulls and finished feedlot steers. Can. J. Anim. Sci. 85: 463-473. Genetic correlations were examined among 10 live growth and ultrasound traits measured in yearling beef bulls (n = 2172) and four carcass traits measured in crossbred finished feedlot steers (n = 1031). Heritabilities ranged from 0.13 (bull ultrasound longissimus muscle width) to 0.83 (yearling bull hip height). Genetic correlations indicated that selecting yearling bulls for increased growth rate and hip height would lead to higher carcass weight, increased longissimus muscle area and reduced levels of carcass marbling in steers. Bull ultrasound fat depth was positively associated with both carcass fat depth and marbling score. Most ultrasound longissimus muscle size measurements in bulls were positively associated with each other and with carcass longissimus muscle area in steers, but the magnitude of the genetic correlation with carcass measurements depended on the bull longissimus muscle size trait in question. This suggests that longissimus muscle shape in bulls may be related to carcass weight, fat and muscle traits in steers. Results confirm that while ultrasound is a valuable tool for the genetic improvement of carcass traits in beef cattle, genetic correlations between live bull ultrasound and steer carcass traits less then unity suggest that selection would benefit from multiple trait evaluations in situations where reliable carcass data are available. Les corrélations génétiques indiquent qu'en sélectionnant les bouvillons d'un an d'après un taux de croissance plus rapide et la hauteur aux hanches, on obtiendrait des carcasses plus lourdes, un longissimus d'une plus grande superficie et de la viande moins persillée. L'épaisseur du gras des bovins mesurée aux ultrasons présente une corrélation positive avec l'épaisseur du gras de la carcasse et le persillé. La plupart des mesures du longissimus obtenues aux ultrasons chez les bovins sont positivement corrélées les unes aux autres ainsi qu'avec la superficie de ce muscle dans la carcasse des bouvillons, mais l'importance de la corrélation génétique avec les mesures de la carcasse dépend du paramètre concerné des dimensions du longissimus chez l'animal adulte. On en déduit que la forme du muscle chez les bovins adultes pourrait dépendre de caractères régissant le poids de la carcasse, le gras et les muscles chez les bouvillons. Les résultats confirment que si l'analyse aux ultrasons a son utilité pour parvenir à une amélioration génétique des paramètres de la carcasse chez les bovins de boucherie, quand les corrélations génétiques entre les mesures prises sur l'animal vivant aux ultrasons et les paramètres de la carcasse des bouvillons ont une valeur inférieure à l'unité, la sélection profiterait d'une évaluation multifactorielle dans l'éventualité où on possède des données fiables sur la carcasse.

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Section: Correlations Among Live Bull and Steer Carcass Traitsmentioning

confidence: 77%

Genetic correlations among indicator traits for carcass composition measured in yearling beef bulls and finished feedlot steers

Bergen¹,

Miller²,

Wilton³

2005

Can. J. Anim. Sci.

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“…Carcass weight and IMF were uncorrelated (0.00), even lower than that reported by Koots et al (1994b) for carcass weight and marbling score (0.15). The strongest genetic correlation for production traits was between the two measures of fatness: s.c. fat depth (P8) and IMF (0.36), which is higher than that reported in U.S. (Gregory et al, 1994), Japanese (Oikawa et al, 2000), and other Australian cattle (Reverter et al, 2000). The low correlation between these two measures of fatness indicates ample potential to select animals within breeds for improvements in both s.c. (not desirable) and i.m.…”

Section: Fat Distributionmentioning

confidence: 77%

Genetic variation in fatness and fatty acid composition of crossbred cattle1

Pitchford

Deland

Siebert

et al. 2002

Journal of Animal Science

130

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Mature Hereford cows (766) were mated to 97 sires from seven breeds (Jersey, Wagyu, Angus, Hereford, South Devon, Limousin, and Belgian Blue), resulting in 1,215 calves born over 4 yr (1994 to 1997). These cattle comprised Australia's "Southern Crossbreeding Project." Heifers were slaughtered at an average of 16 mo with hot standard carcass weight of 219 kg and 9 mm fat over the rump. Steers were slaughtered at an average of 23 mo with carcass weight of 319 kg and 13 mm fat over the rump. Meat and fat samples were taken from the carcass on the day after slaughter for subsequent laboratory analysis of i.m. fat content and fatty acid composition. Data were analyzed using uni-and bivariate animal models containing fixed effects of cohort, management group, birth month, and sire breed. March-born calves had fat with a 0.5°C lower melting point, 0.6% higher total monounsaturated fatty acids, and 0.7% higher fatty acid desaturation index than calves born in April. Steers born in 1997 were the only cohort finished on pasture, and they had much

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“…The objectives of this project were firstly to quantify the effect of different market weight endpoints and finishing regimes on the phenotypic expression of numerous animal, carcass, and meat quality traits for temperate and tropically adapted breeds; secondly, to estimate genetic parameters, including heritabilities and genetic and phenotypic correlations for animal, carcass, and meat quality traits in temperate and tropically adapted breeds; lastly, to determine the existence of genotype by environment interactions for all traits by considering the records on animals in different market weights and finishing regimes as separate traits. Preliminary results from this project have been published by Reverter et al (2000), Robinson et al (2001), and Johnston et al (2001).…”

Section: Introductionmentioning

confidence: 88%

Genetic and phenotypic characterisation of animal, carcass, and meat quality traits from temperate and tropically adapted beef breeds.

Johnston¹,

Reverter²,

Burrow³

et al. 2003

Aust. J. Agric. Res.

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Abstract. A total of 7622 cattle were measured for several weight and body composition traits in temperate and tropically adapted breeds. Traits included: liveweight, hip height, body fat score, muscle score, flight time, ultrasound scanned fatness, and eye muscle area. Measurements were taken at 3 stages during the project: post-weaning, start of finishing, and end of finishing (i.e. pre-slaughter). Animals were finished to 3 target market-weight end-points (220, 280, or 340 kg carcass weight), either on pasture or in a feedlot, and in 2 different geographic regions for tropically adapted breeds. These data were used to estimate genetic parameters for the traits at each stage, and also to estimate the effect of market weight and finishing regimes on the phenotypic and genetic expression of each trait measured at the end of finishing stage. Results showed, for all traits, that the magnitude of the phenotypic expression increased across the stages and market-weight end-points for the end of finishing measures. Feedlot finishing decreased the age at slaughter, and increased fatness and muscling compared with pasture-finished animals. Heritabilities ranged from 0.13 to 0.58, with subjectively scored traits generally being lower than objectively measured traits. Additive genetic variances generally increased with stage of measurement, and with increasing market weight. Genetic correlations of the same measure across stages or market weights were all close to unity. Additive genetic variances of the various traits were similar for feedlot versus pasture finish groups, and the genetic correlation between each measure for feedlot and pasture finish was generally greater than 0.80. The effect of finishing geographic region (i.e. temperate versus subtropical environments) for the tropically adapted breeds had little effect on the size of the additive genetic variances or genetic correlations between traits across geographic regions.The results imply that changing the production system had a significant impact on the phenotypic expression of growth and body composition traits but little effect on the underlying genetic expression and subsequent ranking of sires (i.e. no evidence of genotype by production environment interactions). Therefore, these live animal measures could be used as selection criteria in genetic evaluation programs and may also be genetically correlated with abattoir carcass and meat quality traits.

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Genetic analyses of live-animal ultrasound and abattoir carcass traits in Australian Angus and Hereford cattle.

Cited by 117 publications

References 18 publications

Genetic correlations among indicator traits for carcass composition measured in yearling beef bulls and finished feedlot steers

Genetic correlations among indicator traits for carcass composition measured in yearling beef bulls and finished feedlot steers

Genetic variation in fatness and fatty acid composition of crossbred cattle1

Genetic and phenotypic characterisation of animal, carcass, and meat quality traits from temperate and tropically adapted beef breeds.

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