Abstract:
Proc. Aust. Soc. Anim. Prod. (1978) 12: 150 SOYBEAN MEAL IN THE DIETS OF EARLY-WEANED PIGS R.H. WILSON*, L.R. DOBB* and JANE LEIBHOLZ* Soybean meal (SBM) has been used as a protein source for early-weaned pigs by many workers (see Lucas and Lodge 1961), but the performance of young pigs up to about 4 weeks of age is reduced as the percentage of protein from SBM is increased at the expense of milk protein (Zamora, Schmidt and Veum 1975). The present experiment was designed to study the possibility of including SBM in the diets of pigs between 5 and 28 d of age. Thirty-two male pigs were weaned at 5 d age and reared in tiered cages in a controlled environment room. They were fed ad. lib. pelleted diets in which the protein from SBM amounted to 0, 25, 50 and 75% of the total dietary protein. SBM replaced milk protein in iso-nitrogenous and isocaloric diets with lysine and methionine added to maintain similar levels in all diets. Growth rates (ADG) and feed conversions (FCR) were measured from 728 d age and the apparent digestibility of dry matter (DM) and nitrogen (N) determined from lo-15 and 17-22 d age. The results are given in the v table. TABLE 1. Performance of young pigs fed increasing levels of SBM.* The weight gain of the pigs between 7 and 28 d of age decreased linearly as the SBM content of the diets increased while feed conversion ratios were increased as the levels of SBM in the diets increased, There was no significant difference in the apparent digestibility of DM and N with age of the pigs over the two collection periods and the means of the two periods for each diet is given in the table. Greater apparent digestibilities of DM and N were obtained on diets containing all milk and 25% of the protein from SBM than the diets with higher SBM inclusions. It may be concluded that the ,inclusion of SBM in the diets of pigs between 7 and 28 d of age results in a reduction of performance. LUCAS, I.A.M. and LODGE, G,A, (1961). 'The Nutrition of the Young Pig'lb Technical Communication No. 22. (Commonwealth Bureau of Animal Nutrition: Scotland). 41:331. ZAMORA, R.G-, SCHMIDT, M.K. and VEUM, T,L. (1975). J. Anim. Sci. C (Abst. 340)' * Department of Animal Husbandry, University of Sydney, Camden, NSW 2570. t Present address: Watsons Foods Pty. Ltd., P.O. Box 539,' Freemantle, W.A. 6160, 150.