A comparison of 15 ram breeds for export lamb production 2. Proportions of export cuts and carcass class

Abstract

The proportions of cuts from 7885 lamb carcasses sired by 15 different ram breeds, reared on pasture at two locations over 10 years, were measured and examined for breed differences. Although highly significant breed differences were found, their magnitude was small reaching a largest difference between crosses of 1.22% for the leg and 1.26% for the loin compared at the same carcass weight. Compared at the same time of slaughter (age), the maximum differences between the progeny of different ram breeds were 1.02% for the leg and 1.06% for the loin. Wether lambs had a slightly higher proportion of forequarter cuts. Sire breed had a major effect on the proportion of lambs reaching the fatter P grade (class) with the meat breeds Southdown, Dorset Down, South Dorset Down, Hampshire, and South Suffolk sires producing 68-76% P carcasses and the wool breeds such as the English Leicester, Merino, Romney, and Lincoln producing 18-23% of P carcasses. Lambs sired by the Poll Dorset, Dorset Horn, Suffolk, Ryeland, Border Leicester, and Cheviot produced 49-62% P carcasses.

Características de carcaça de ovinos em crescimento alimentados com rações contendo farelo de babaçu

“…Essa semelhança está associada ao porte dos ovinos estudados, próximos ao dos Morada Nova. Kirton et al (1996) reportaram que também ocorrem pequenas variações nas proporções dos cortes quando são realizados no mesmo ponto anatômico.…”

Breed and maturity effects on Churra Galega Bragançana and Suffolk lamb carcass characteristics: Killing-out proportion and composition

“…No differences (P > 0.05) were found between breeds for loin and chump percentages. Kirton et al (1996), in a study with 15 different breeds, also found a higher percentage of leg in Suffolk lambs. These results seem to confirm the superiority of Suffolk breed to develop higher proportions of expensive joints.…”

Year effects on the carcass composition of lambs slaughtered over a 10 year period

“…Rams were sampled from the main sources representing the various breeds used in New Zealand and most rams were used for only one year with about 10% used for a second year at the other location to link the genetic results from this trial (Kirton et al 1995(Kirton et al , 1996 together. Their management and the composition data collected have been described previously (Kirton et al 1995(Kirton et al , 1996. All lambs were slaughtered at the same abattoir by mainly the same staff using the same slaughter and carcass dressing methods over the 10 years of the trial.…”

“…Carcass measurements were taken as described by Kirton et al (1995Kirton et al ( , 1996 and included longissimus muscle width (A), depth (B), and cross sectional area (eye muscle area) when sectioned between the loin and rack and the fat depth over the longissimus muscle (C) and over the rib (J) as described by Palsson (1939). Two subcutaneous fat depths (S1 and S2) were taken on the cut surface of the shoulder separated between the 5th and 6th ribs and two leg subcutaneous fat depths (LI and L2) were taken on the cut surface of the short leg removed by a cut between the last cervical and first lumbar vertebrae as described by Kirton et al ( 1995).…”

“…An interesting sidelight in Kirton et al (1995Kirton et al ( , 1996 was that the year (season) had an important effect on carcass composition, and in particular on fatness, even after statistical adjustment of variation among animals to the same carcass/body weight. This paper further explores these results.…”