The effect of protease pre-treatment of raw or micronized soyabean meal on the growth performance and carcass composition of liquid fed grower and finisher pigs.

Abstract

19A The effect of protease pre_treatment of raw or micronized soyabean meal on the growth performance and carcass composition of liquid_fed grower and finisher pigs J.D. Beal and P.H. Brooks University of Plymouth, Seale Hayne Faculty, Newton Abbot, Devon TQ12 6NQ, UK J.Beal@plymouth.ac.uk Laboratory studies demonstrated that protease treatment significantly (P<0.001) increased the in vitro nitrogen digestibility of raw soyabean meal (RSB) and micronized soyabean meal (MSB) (Beal et al.1998). This indicates that there is potential for improving the nutritional value of these protein sources with exogenous proteases. The objective of this study was to determine if these increases in vitro were reflected in pig performance. Thirty two Lar ge White x (Lar ge White x Landrace) pigs 12 _13 weeks old weighing 28.7 � 2.7 kg were randomly allocated to one of four dietary treatments according to a 2 x 2 factorial design. Factor 1 was soyabean meal that was raw (R) or micronized (M). Factor 2 was the presence (+) or the absence (_) of 20000 units g/N of protease P3 (Finnfeeds International Ltd). Soyabean meal was pre_treated by steeping (1feed:3 water) for 24 h at 20oC in the presence or absence of P3, prior to the addition of a cereal based diet and water (DM as fed 22.5 g/kg). The diets provided 14 MJ DE/kg with 0.71 g lysine/MJ DE (up to 50 kg), and 13.5 MJ DE/kg with 0.67 g lysine/MJ DE (50 kg to slaughter). The pigs were fed individually twice daily on restricted intake to give a DE intake of 2.02 MJ/d per kgW0.63. Weekly liveweight, daily DM feed intake, empty carcass weight, and lean: fat ratio were recorded. A significant ( P< 0.001) improvement in all measures of growth was observed with pigs fed MSB diets compared with pigs fed RSB diets. There were no significant differences in overall growth due to enzyme pre_treatment. However, with pigs fed RSB diets a significant improvement in average daily gain (ADG), from 0.515 to 0.606 kg/pig, and FCR (from 3.512 to 3.042) was observed due to enzyme treatment in the finisher period. There were no significant differences in killout percent. Lean: fat was significantly (P<0.05) increased by 0.423 � 0.158 in pigs fed R+ compared to R_. Enzyme addition had no significant effect on the time taken to reach slaughter weight in pigs fed RSB diets but this was significantly (P<0.05) reduced by 4 � 1.86 days in pigs fed M+ compared with M_. Although there were no significant differences in growth performance due to enzyme treatment in either the RSB or MSB diets there was a consistent trend towards improvement, which may have led to pigs on diet M+ attaining slaughter weight in less time than pigs on diet M_. The significant improvement in lean tissue deposition in the pigs fed diet R+ suggests that these pigs were better able to utilise raw soya protein than pigs fed diet R_. Beal, J.D., Brooks, P.H. and Schulze, H. (1998). The effect of pre_treatment with different proteases on the in vitro digestibility of nitrogen in raw soyabean and four differently processed full fat soyabean meals. Proceedings of the 49th Meeting of the European Association of Animal Production, Warsaw. Abstract No. 264. Table 1 Perfor mance of pigs fed raw (R) or micronized (M) soyabean meal pre_treated with 0 (_) or 20 000 units/g N (+) of P3 protease. Diet R+ ADFI kg/pig ADG kg/pig FCR 1.45 0.50 2.99 R_ 1.48 0.47 3.24 M+ 1.65 0.80 2.05 M_ 1.63 0.76 2.15 SED 0.023 0.023 0.125 Recent Advances in Animal Nutrition in Australia, Volume 13 (2001)