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Effect of Natuzyme supplementation on broiler performance in deficient standardized ileal threonine diets
S. Khalaji, M. Zaghari*, and M. Shivazad, University of Tehran, Karaj, Iran.
The objective of this study was to determine the effects of Natuzyme supplemention on broiler performance in a threonine deficient diet. Day-old male broiler chicks were randomly assigned to 20 battery cage pens in a completely randomized block design and grown to 6 wk of age. Birds were fed dietary treatments from 1 to 42 d of age. The 6 treatments were basal diets containing 0.56 and 0.46% standardized ileal threonine (SID Thr) in starter and grower periods, respectively. Treatments 2 to 6 were the basal diets supplemented with 0.1, 0.2, 0.3, 0.4 and 0.5 g/kg Natuzyme. Body weight and feed intake of birds were recorded at 28 and 42 d of age. Supplementing diets with Natuzyme significantly (P<0.001) improved feed conversion ratio (FCR) at 28 and 42 d of age. The effect of Natuzyme on body weight was significant (P<0.05) at 28 d of age but it had no effect on body weight at 42 d of age. In vivo lymphoproliferation against the Phytohemagglutinin-P (PHA-P) at 36 d of age significantly (P<0.05) increased with supplementation of Natuzyme. There were no significant differences in breast, thigh and abdominal fat at 42 d of age. These results showed that Natuzyme improved the efficiency of broilers fed a low threonine diet during the starter period. |