In vivo assessment of urease activity test for its utility in identifying excess heating in soybean meal

Abstract

A biological trial was conducted to study the influence of soybean meal quality as assessed in terms of urease activity on commercial broiler chicken. Two lots of soybean meal (SBM), 1 showing (SBM1) normal urease activity (42.6% CP and 18.4% CF) and the other (SBM2) showing no urease activity (51.5% CP and 7.3% CF) were fed with or without lysine supplementation (0.9 and 0.8% in starter and finisher phases respectively) to a total of 120 chicks with 6 replicates of 5 chicks for each diet on iso-caloric and iso-nitrogenous basis. Body weight of broi ler chickens was not influenced by the sources of SBM and lysine supplementation depressed body weight in the group fed SBM2. Feed intake was low and feed conversion efficiency was better with SBM2. Lysine supplementation to 8BM2-diet depressed feed intake. The digestibility of DM in the birds fed SBM1 with lysine was lower than in other groups. Calcium retention decreased in the group fed 8BM2, which was partially alleviated with lysine supplementation. Retention of P, serum protein concentration, HI titre to ND virus, ready to cook yield and weights of gizzard, liver, giblet and spleen were not influenced by the sources of SBM and lysine, whereas weights of bursa and abdominal fat were higher in the group fed SBM2. It was concluded that urease activity test may not be a reliable tool for identifying excess heating in soybean meal.