Value of conformation as an indicator of sheep carcass composition within and between breeds

Abstract

1981). Value of conformation as an indicator of sheep carcass composition within and between breeds.ABSTRACT Carcass evaluation data from two breed-comparison trials were used to examine the value of conformation as an indicator of carcass composition when used in addition to carcass weight and different measures of fatness. One trial involved 1478 crossbred lambs out of three ewe types by Border Leicester, Dorset Down, Ile-de-France, North Country Cheviot, Oxford Down, Southdown, Suffolk, Texel and Wensleydale sires. The other trial involved 920 crossbred lambs out of two dam types by Dorset Down, Ile-de-France, Oldenburg, Oxford Down, Suffolk and Texel sires. Each trial extended over 3 years.Conformation contributed little to the prediction of carcass lean percentage or proportion of lean in the higherpriced joints, although the additional precision was often significant at P<0-01. When conformation was used in association with dissected subcutaneous fat percentage, it was positively associated with carcass lean content; used with a visual assessment of external fat cover on a five-point scale, which provided a less effective control of fatness variation, it tended to be negatively related to carcass lean content.Conformation was slightly more valuable for the prediction of lean to bone ratio and m. longissimus depth. The addition of sire-breed effect to weight and fat class provided an important increase in the precision of prediction of percentage lean in carcass and lean to bone ratio. Texel progeny had higher lean to bone ratios and more lean in the carcass than progeny of other sire breeds, but they did not have sufficiently high conformation scores to clearly identify this advantage. H *»\ O -X rn M fTexel and Ile-de-France sires were not included in all 3 years.

Effects of genotype and plane of nutrition on growth and carcass characteristics of lambs from hill sheep systems

“…Although, in the current experiment, no overall effect of plane of nutrition on conformation was observed, when corrected to fat classification 3, there was a tendency (P , 0.1) for lambs fed the HP to have better carcass conformation. This shift towards better carcass conformation is due to increased carcass fat and tissue depth measurements as conformation is assessed on the basis of muscle and fat thickness in relation to skeletal size (Kempster et al, 1981).…”

Comparison of objective external carcass measurements and subjective conformation scores for prediction of lamb carcass quality

“…Horgan et al (1995), Wolf et al (1981) and Kempster et al (1981) found subjective conformation to be of limited value in predicting saleable and/or lean meat yield, in direct contrast to the work of Kirton et al (1992) and Jones et al (1993). An explanation for this discrepancy may be found in the populations of lambs evaluated in these studies: the more variance in lamb breed types and sizes used, the greater the value of subjective conformation score in predicting lean and/or saleable meat yield.…”

Composição tecidual, química e de ácidos graxos presentes em pernas de caprinos alimentados com dieta rica em farelo grosso de trigo

“…A relação músculo:osso, de acordo com Kempster et al (1981), é potencialmente a mais importante função de conTabela 3. Componentes da perna de caprinos em função dos níveis de inclusão do farelo grosso de trigo na dieta formação da carcaça.…”