Publication: Effects of age at slaughter and sire genotype on fatness, muscularity, and the quality of meat from ram lambs born to Romney ewes
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Coadvisor
Graduate program
Undergraduate course
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Publisher
Sir Publishing
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Article
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Acesso restrito
Abstract
Ram lambs (n = 356) born to Romney ewes and sired by a range of straightbred or crossbred sires were evaluated for carcass composition and, for a subsample (n = 236), some meat quality characteristics over a period of 4 years. Within each year, 2 to 4 sire genotypes, including Romney controls, were evaluated at 2 slaughter ages (5-9 months and 10-11 months). Weight-adjusted carcass length was greater for lambs with some East Friesian or Finn genes, but no differences were found in dressing-out percent. At a constant carcass weight, carcass fatness (fat depths and leg dissectible fat) was lower in lambs with East Friesian, Texel, or Finn genes. Meat yield at a constant weight tended to be greatest in sire groups that were least fat, and M:B ratio in the femur region was highest in lambs with Texel genes and, to a lesser extent, those with Poll Dorset genes. Leg muscularity in the femur region generally paralleled differences in M:B, except in a comparison of East Friesian-cross and Romney lambs where the former had lower muscularity but slightly better M:B. Lambs slaughtered at the older age for each year had longer and leaner carcasses at the same weight, possibly because they had been taken part way through a winter or because of slower growth rates leading up to slaughter. Meat quality characteristics differed little between the genotype groups, but for 2 of 3 years, meat from the semimembranosus muscle of lambs in the older slaughter lot was significantly tougher.
Description
Keywords
lamb fatness, carcass muscularity, meat tenderness, sheep breeds
Language
English
Citation
New Zealand Journal of Agricultural Research. Wellington: Sir Publishing, v. 45, n. 2, p. 77-86, 2002.
