Evaluation of the growth performance and carcass characteristics of lambs produced in Quebec

Abstract

Hammell, K. L. and Laforest, J. P. 2000. Evaluation of the growth performance and carcass characteristics of lambs produced in Quebec. Can. J. Anim. Sci. 80: 25-33. Data for a total of approximately 1100 lambs tested in 12 trials from 1992 to 1995 in commercial lamb test stations in Quebec were used to determine the effect of sex, sire breed and genetic type on growth performance and carcass characteristics. Lambs were housed two to a pen and fed commercial diets. Maximum test length was 112 d. Lambs were slaughtered when their liveweight was approximately 47 ± 5 kg for the males and 43 ± 4 kg for the females. Feed intake and growth rate were measured during the test, and carcass measurements were taken at slaughter and at 24 h following slaughter. Feed intake was the average for the pen, while the growth and carcass measurements were taken individually. Males ate more per day, had better gain and were younger at slaughter than females. Females had more body fat and better carcass conformation scores than males. However, males did not have a greater loin muscle thickness compared to females. Lambs sired by Hampshire or Suffolk rams had superior growth performance and leaner carcasses than lambs sired by Dorset rams. However, Hampshire and Suffolk-sired lambs did not have a greater loin muscle thickness compared to Dorset-sired lambs. Analysis of different genetic types did not demonstrate a pronounced effect on lamb performance. No specific genetic composition was clearly superior to the others for the various variables studied. Genetic quality within a breed of sheep bought or kept for reproduction is as important as the choice of breed or the combination of breeds.

Effect of some factors on growth of lambs from crossing between the Improved Wallachian and East Friesian

“…With the exception of DG 1, higher daily gains were found in males in all cases. Similar findings were reported by Hammel and Laforest (2000), Dixit et al (2001), Fernandes et al (2001), Macit et al (2001), Abegaz et al (2002), and Matika et al (2003). However, it is necessary to state that the above-mentioned authors recorded higher daily gains in males in all intervals under study.…”

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

“…Although not significant, Suffolk lambs had higher corrected cold killing-out proportion. Our results seems to confirm the theory that meat breeds tend to have smaller killing-out proportions than dam breeds (Hammell & Laforest, 2000;Wood, MacFie, & Brown, 1983;Wylie, Chestnutt, & Kilpatrick, 1997), since CGB breed presents dam breed characteristics (Teixeira et al, 1996). The degree of maturity had no effect (P > 0.05) on killing-out proportions.…”

Influence of live weight, sex and type of birth on growth and slaughter characteristics in early weaned lambs

“…Faster growth (Table 4) was partly associated with higher LW at birth and the influence of sex hormones on growth rate of lambs (Selaive-Villarroel et al, 2008). Faster growth requires more nutrients and actually Hammell and Laforest (1999) found that male lambs consumed more dry feed than females and according to several authors (Butterfield, 1988;Santos et al, 2008) the higher content of fat in the body of the female lambs causes a lower growth rate, compared with the leaner males.…”