Abstract:
Animal Production in Australia TRYPTOPHANE AS A LIMITING FACTOR FOR THE GROWTH OF PIGS FED MEAT MEAL AND WHEAT DIETS JANE LEIBHOLZ* Meat meal has been used as a major protein supplement for pig diets in Australia. The tryptophane content of meat meals varies from 2.0 to 4.9 g/kg (Leibholz 1979), while the recommended level of tryptophane in the diet of the 5 to 10 kg pig is 1.8 g/kg (National Research Council 1973). It has been previously shown that the supplementation of wheat diets with meat meal, in place of soyabean meal, reduced the performance of pigs (Evans and Leibholz 1979), and it was of interest to determine if this was due to the high calcium or low tryptophane content of meat meals. A diet was formulated from soft offal meat meal and wheat to meet the nutritional requirements of pigs. This was fed without further supplements (diet A) r with 66 g/kg limestone and 35 g/kg calcium dihydrogen phosphate (diet B), with 120 g/kg bone meal (diet C> or with 120 g/kg bone meal and 0.24 g/kg tryptophane (diet D). The diets were fed - libitum to 48 cross-bred pigs between 28 ad and 56 d of age. TABLE 1 The performance of pigs and chemical composition of the diets The performance of the pigs was significantly (P<O.O5) lower when they fed diet C than when fed the other diets. As the calcium contents of diets and D was similar, but the tryptophane content of diet C was less than that all other diets, it may be concluded that 1.5 g/kg tryptophane in the diets insufficient for pigs between 3 and 14 kg live weight. Calcium to 34 g/kg diets did not depress the performance of pigs. were B, C of is of the In conclusion, it may be suggested that tryptophane should be considered as a dietary supplement of wheat and meat meal diets for young pigs. EVANS, D.F. and JANE LEIBHOLZ, 4: (1979). Anim. Feed Sci. Technol. = 33. LEIBHOLZ, JANE. (1979). Anim. Feed Sci. Technol. 4: 53. NATIONAL RESEARCH COUNCIL. (1973). 'Nutrient RequiFements of Swine'. (National Academy of Science: Washington, D.C.), * Department of Animal Husbandry, University of Sydney, Camden, N.S.W. 2570. 507