A comparison of lamb growth rate and lean carcass gain within and among farm flocks

K.G. Geenty, C.B. Dyson; G.H. Scales and C. Ward

Canterbury Agriculture and Science Centre Ministry of Agriculture and Fisheries, Lincoln; Ministry of Agriculture and Fisheries, Christchurch and Waitaki International Ltd, Christchurch

Proceedings of the New Zealand Society of Animal Production. 1987, 47: 99-100

Lines of 40 ram lambs of a variety of breeds from 22 farms in Canterbury, and initially weighing between 32 and 40 kg live weight, were assembled on a farm and compared for growth rate and lean carcass gain during 12 weeks. High quality legume dominant pastures were used and changes in carcass measurements obtained from samples of lambs slaughtered at the start and end of the trial.

Average growth rates and rates of lean carcass gain among lines ranged from 143 to 252 g/d and 27 to 53 g/d respectively. Lines of specialist meat and short-wool breeds (Suffolk-cross, Perendale and Dorset) had higher average gains than long-wool breeds (Corriedale, Coopworth and Romney). The long-wool breeds showed greater variation in fat measurement GR (S.D. ± 4.07 mm) than specialist meat and short-wool breeds (S.D. ± 3.25 mm) at the final slaughter when carcass weights ranged from 22 to 27 kg among lines and around 70% of all carcasses graded trimmer or overfat.

Keywords: NZSAPAB; Sheep; lamb growth; carcass qualities; sheep breeds

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Last Updated 03-05-1997