Abstract:
Proc. Aust. Soc. Anim. Prod. Vol. 19 VARIATION OF CARCASS PARAMETERS IN BEEF FOR JAPAN D. L. HOPKINSAB ATasmanian Dept of Primary Industry, P.O. Box 180, Kings Meadows, Tas. 7249. BPresent Address: NSW Agriculture, P.O. Box 242, Cowra, N.S.W. 2794. With predictions that liberalisation of the Japanese beef market will result in an increased demand for high quality grain-fed beef (Morison 1990), it is important that the quality characteristics of our lot-fed beef are quantified. This knowledge, coupled with market research (Anon. 1990) is essential for Australia to capitalise on this expanding market. Carcass characteristics of 20 Angus lot-fed steers destined for the Japanese market were obtained. The steers came from 2 properties, 10 from each. They were lot-fed for 400 days, slaughtered and hot carcass weight and dentition recorded. After chilling for 24 h the carcasses were quartered between the 6th/7th ribs and the cross-sectional area of the M. longissimus thoracis et lumborum (LM) measured using the grid technique. Fat depth at the P8 site was measured. Marbling was assessed using colour photographs on a 12 point scale (1, no marbling to 12, very highly marbled) on the surface of the LM. Meat colour was assessed at the same site at least 20 minutes after quartering using silicon chips on a 9 point scale (1, very light red to 9, very dark red). Colour of the intermuscular fat adjacent to the LM was assessed using silicon chips on a 10 point scale (0, polar white to 9, creamy yellow). All steers had 2 permanent incisors. The carcasses had a mean (k s.d.) weight of 338 & 17.6 kg with a range of 308-372 kg. Mean LM area was 45 & 4.5 cm* and ranged from 39-58. The mean P8 fat depth was 20.7 + 0.88 mm with a range of 15-28 mm. Marbling scores ranged from 1 to 4 with a mean of 2.2 + 0.67. Meat colour scores ranged from 1 to 3 with a mean of 2.2 * 0.59. Fat colour scores ranged from 0 to 1,18 carcasses having scores of 0. The carcass weight and P8 fat depth for these steers were comparable to others slaughtered in Australia (Baud 1991) and broadly acceptable for the Japanese trade with 5 being overfat (based on a 12-22 mm specification). There was a degree of variation between animals for marbling but even those carcasses with scores of 3 or 4 would only be considered of moderate quality by the Japanese (A. Dunlop pers. comm.). This is consistent with the majority of carcasses produced in Australia for Japan. Both meat and fat colour were acceptable for this market; these are important considerations for Japanese consumers (Anon 1990). It is evident that to achieve maximum returns from lot-fed beef there is scope to improve the consistency of subcutaneous fat levels. ANON. (1990). Research Report, June, AMLRDUAMLC, Sydney, Australia. BAUD, S. (1991). Proc. Aust. Assoc. Anim. Breed. and Genetics 9: 216-23. MORISON, J. (1990). Aust. Rural Science Annual pp. 124-5. 94