Breed and sex differences in muscle distribution in equally mature sheep

Abstract

Sheep from the Soay, Southdown, Finnish Landrace and Oxford Down breeds were serially slaughtered at 40, 52, 64 and 76% of their estimated mature body weight. Breed and sex comparisons of muscle distribution were made at these degrees of maturity. Comparisons were based on 12 individual muscles obtained from the prime retail joints. Together, these 12 muscles represented about 41 % of total weight of muscle in the carcass. Highly significant breed and sex differences in the weight of individual muscles were obtained, but these differences were greatly reduced when values were expressed as a percentage of total muscle weight. On a percentage basis, there were significant changes with stage of maturity in only three of the muscles studied, although most individual muscles showed an initial percentage decrease with increasing maturity (from 40 to 52%) but almost no change thereafter. Significant breed differences in muscle distribution were found. The individual muscles examined, when combined, comprised 40-8, 43-4, 40-5 and 39-8 % of total muscle weight respectively in the Soay, Southdown, Finnish Landrace and Oxford Down. No breed was significantly above average for every individual muscle, but the Southdown had the highest percentage in 6 out of 12 and might therefore be said to have had the most preferred muscle distribution. For most muscles examined, the percentage was slightly higher for females than for males, with totals for all 12 muscles of 41-9 and 40-4% respectively.

A comparison between 15 ram breeds for export lamb production 1. Liveweights, body components, carcass measurements, and composition

“…The larger eye muscle areas in the Southdown cross lambs at a set carcass weight may be a reflection of the fact that this breed has been shown to have a slightly higher proportion of longissimus muscle to total muscle in comparisons where this breed was included (Taylor et al 1980;Thonney et al 1987). This muscle comprised 9.6% of muscle in the Southdown lambs and 7.7% in the Finn lambs.…”

Breed and sex differences in equally mature sheep and goats 3. Muscle weight distribution

“…The slaughter procedure is described in Taylor et al (1980) and Thonney, Taylor, Murray and McClelland (1987b). The left side of the carcass was separated into four joints, namely shoulder, rib, loin and hindleg (gigot).…”

Evaluation des différences génétiques dans l'importance et la répartition du tissu musculaire, entre 25 et 150 jours, sur des agneaux Romanov, Berrichon x Romanov, Texel x Romanov, Lacaune x Romanov, Charmois x Romanov

“…Le croisement industriel est une pratique courante pour la production d'agneaux de boucherie .Il peut avoir une influence sur la croissance, le farmat et la qualité des carcasses (conformation, composition (FouRiE et al, 1970 ;JURY et al, 1977) (McCLEr.LnND et al, 1976 ;T AYLOR et al, 1980). La division de la musculature de la carcasse pour l'étude de la r6par-tition du tissu musculaire est aussi plus ou moins fine : étude de muscles individuels (JURY et al, 1977 ;T AYLOR et al, 1980), partition de la musculature en 9 régions anatomiques par regroupement de muscles individuels (JURY et al, 1977 ;T HOMPSON et al, 1979 b) ou en cinq régions par découpe de la carcasse avant dissection (SE EBECK , 1968 Except for muscles of the distal part of the pelvic limb (H,), relative growth coefficients are homogenous among breeds (H 2 or H 3 ) within the range of weights studied.…”

“…La division de la musculature de la carcasse pour l'étude de la r6par-tition du tissu musculaire est aussi plus ou moins fine : étude de muscles individuels (JURY et al, 1977 ;T AYLOR et al, 1980), partition de la musculature en 9 régions anatomiques par regroupement de muscles individuels (JURY et al, 1977 ;T HOMPSON et al, 1979 b) ou en cinq régions par découpe de la carcasse avant dissection (SE EBECK , 1968 Except for muscles of the distal part of the pelvic limb (H,), relative growth coefficients are homogenous among breeds (H 2 or H 3 ) within the range of weights studied. At the same carcass weight, Berrichon X Romanov crossbreeds have least muscle and Charmois X Romanov crossbreeds have most muscle, respectively 95.9 and 101.1 when comparing them to Romanov lambs (100).…”