Collagen in two muscles of sheep selected for weight as yearlings

Abstract

Collagen concentration and solubility were examined in the semimembranosus and biceps femoris muscles of Romney lambs from the Hight line, a line selected for nine generations on the basis of high body weight at 1 year old. Lambs from the Control (CON) and high body weight (HBW) lines were slaughtered at five ages (0, 42, 70, 274, 365 days). In the semimembranosus muscle, there was no evidence of concentration or solubility differences between the lines at any age, but there was a subtle sex by age interaction, possibly because of increased collagen synthesis in males at puberty. In the biceps femoris muscle, collagen concentration was 14% higher in the HBW line, but there was no difference in solubility. The semimembranosus muscle was shear-tested after cooking to give an objective measure of tenderness. Selection line did not affect shear force. With the semimembranosus muscle, collagen solubility was a better predictor of shear force than collagen concentration, confirming previous work on this muscle. Although the biceps femoris muscle was not shear-tested, it is argued that the higher collagen concentration in the HBW line would cause only a minimal decrease in tenderness. The concentration and the solubility of collagen in A92064 the semimembranosus muscle were significant predictors of the same characteristics in the biceps femoris muscle, a finding that could be useful in a breeding programme.

Proteomic Profile of M. longissimus thoracis from Commercial Lambs Reared in Different Forage Systems

“…Collagen alpha-3 (VI) chain is a stromal protein in connective tissue, which is the only protein that had greater abundance in loins from wether lambs than ewe lambs in the current study. Similar results were reported by Monteschio et al [32] where both soluble collagen and total collagen content were greater in loins from wether lambs than ewe lambs, likely due to the increased collagen synthesis in males at puberty [33]. Hopkins et al [34] reported that measurement of collagen concentration did not explain the variation in shear force and sensory tenderness observed in the meat from lambs.…”

COMPARISON OF MUSCLE COMPOSITION AND MEAT QUALITY TRAITS IN DIVERSE COMMERCIAL LAMB TYPES1

“…In the particular case of the milk-fed lambs (types 4 and 7), the high muscle collagen content could also have been a consequence of their early stage of development. In sheep, Young et al (1993a) found that muscle collagen content was maximal at birth, was then reduced by half within 1.5 months of age and then remained stable at older ages up to one year. A similar shift has also been observed in cattle between birth and the age of 8 months onwards (Boccard et al 1979).…”

“…Usually breed effects can be explained by differences in maturity at slaughter and the consequent stage of fat tissue development (Vesely and Peters 1966;Bray 1988;Dransfield et al 1990;Dufey and Wirz 1995a;SaAudo et al 1998). As animal age increases, lamb meat exhibits a more intense color, lower tenderness and a stronger flavor (Jeremiah et al 1971;Bruwer et al 1987;Bray 1988;SchUnfeldt et al 1993;Young et al 1993a). Both feeding level and type of feed influence the amount and the composition of lamb tissue lipids, and consequently meat flavor (Sink and Caporaso 1977;Young et al 1998;Fisher et al 2000).…”

Effects of age at slaughter and sire genotype on fatness, muscularity, and the quality of meat from ram lambs born to Romney ewes

“…Jeremiah et al (1998), for example, concluded that sensory tenderness scores declined and WB shear values increased with increasing lamb age up to 15 months. Other studies have also indicated that the tenderness of lamb may decrease within the first 15 months (Jeremiah et al 1971;Purchas et al 1979;Devine et al 1993;Young et al 1993b;Carson et al 1999) Further research needs to be done using a range of muscles and cooking conditions to determine whether it would be commercially advantageous to subdivide lamb into age classes if the classes could be shown to differ in palatability characteristics such as tenderness.…”