Lamb carcase weight and fatness in New South Wales

Abstract

Proc. Amt. Sot. Anim. Prod. 1994 Vol. 20 LAMB CARCASE WEIGHT AND FATNESS IN NEW SOUTH WALES D.G. HALL, J.E. MORGAN and M.A. ANDERSON NSW Agriculture, PO Box 242, Cowra, N.S.W. 2794 In recent years there has been an emphasis on decreasing the fat level and increasing the carcase weight of Australian lambs because of changing domestic consumer requirements and the development of export markets. Consequently there needs to be a consistent supply of large, lean lambs (McLaughlin 1992). There is limited data available on the proportion of lamb carcases with different weight and fat specifications. The installation since 1992 of automated equipment which records carcase weights and measurements of GR (total tissue depth 110 mm from the mid line of the carcase over the 12th rib) by AUS-MEAT fat probes has allowed this data to be collected. This paper reports the proportion of lambs of various specifications from 2 NSW domestic abattoirs in 1992-93. Data were combined for all lambs slaughtered each month from July 1992 to June 1993 at Hastings (Port Macquarie, a third of the lambs) and Cowra Abattoirs. These abattoirs together represented 14% of the NSW lamb kill over the period. The carcases from Hastings were trimmed to AUS-MEAT standards while those from Cowra had kidneys, fat and skirt in. Ninety percent of the probe GR measurements (M. Anderson pers. comm.) were usually within 2 mm of the manual measurement. Overall 4.4% of lambs (Table 1) met Elite specifications (carcase > 22 kg, GR 6 to 15 mm) with a range of 2.9% in June and up to 5.4% in April. The percentages for lambs which met Trim lamb requirements (carcase > 18 kg, GR 6 to 15 mm) were 41.5 overall and from 34.9 in June to 47.1 in April. These percentages compare with less than 1% Elite and about 10% meeting Trim lamb requirements from 2 Tasmanian abattoirs in 1989-90 (Hopkins and Pirlot 1993) and an estimate of about 1% Elite lambs in Victoria in 1989-90 (McLauglin 1992). Based on these data it is apparent that the supply of suitable lambs is unlikely to limit adoption of the Australian Meat & Live-stock Corporation domestic Trim lamb program, although the data gives no indication of the breeds represented or the destination of the carcases. Data is also needed from other states and from export abattoirs. Table 1. Percentage of lambs with various carcase weight (kg) and GR (mm, tissue depth 110 mm from the mid-line of the carcase over the 12th rib) specifications and the total number (1000%) of lambs measured each month at Cowra and Hastings Abattoirs, 1992-93 We thank the operators of Cowra and Hastings Abattoirs for the supply of these data. Financial assistance was provided by the Meat Research Corporation. HOPKINS, D.L. and PIRLOT, K.L. (1993). Proceedings Australian Meat Industry Research Conference, Gold Coast, Session 3A, pp. l-3. MCLAUGHLIN, J.W. (1992). Proc. Amt. Sot. Anim. Prod. 19: 173-5. 356