Abstract:
Animal Production in Australia Vol. 15 EFFECT OF DIETARY TRYPSIN INHIBITOR LEVEL ON PERFORMANCE OF PIGS WEANED AT 20 DAYS AND 33 DAYS OF AGE R.R. CARTER*,D.F. EVANS** and B. CULLIS*** Soybeans contain a heat labile trypsin inhibitor which interferes with the utilization of its protein. Solvent extracted soybean meal compared with unheated soybeans resulted in highly significant differences in growth rate and feed conversion ratios in favour of soybean meal in pigs weighing 12kg (Yen et al.1977). The response in pigs weaned at 20 days compared with 33 days of age to increasing dietary concentrations of soybean trypsin inhibitor was investigated. Eight diets were prepared containing 598g/kg ground wheat, 360g/kg soybean and 42g/kg mineral-vitamin premix. Varying the ratio of un-heated soybeans and extruded soybeans resulted in dietary trypsin inhibitor concentrations of from 1.4 trypsin inhibitor units (AOCS, 1982>/mg diet to 16.2 TIU/mg diet. Sixteen pens I each of seven mixed sex pigs were used, eight pens with pigs weaned at 20 days weighing 5.62 2 0.57kg and eight pens with pigs weaned at 33 days weighing 8.34 k 0.99kg. Each diet was allocated to one pen of younger pigs and one pen of older pigs and fed ad lib for 14 days. Pigs weaned at younger, lighter pigs Toquantifythe effect relation ARGR = a + 6 trypsin inhibitor and 33 days consumed more feed with greater daily gains than the at each level of dietary trypsin inhibitor concentration. of dietary trypsin inhibitor concentration on ARGR, the log x was fitted to each age group where x is units of a and 6 are parameters to be estimated. TABLE 2 Estimates of regression coefficients deviation (x105 = 224) is less than the average SEM (x105 = 233). Based on wheatsoy diets with a trypsin inhibitor concentration range of 1.4 to 16.2, estimates of weight gain can be obtained for pigs within the age and liveweight range used in this experiment. AMERICAN OIL CHEMISTS' SOCIETY (1982) 'The Official and Tentative Methods of the American Oil Chemists' Society'. Ed. R.O. Walker (American Oil Chemists' Society). YEN, J.T., JENSEN, A-H. and SIMON, J. (1977). J. Nutr. .u:156. *Bayer Aust. Ltd., Veterinary Division, 47-67 Wilson St., Botany, N.S.W. **Wonga Projects Ltd., P-0. Box 50, Young, N.S.W. ***Siromath Pty. Ltd., 71 York St., Sydney, N.S.W. 663
