Effect of enzymolytic soybean meal supplementation on performance, nitrogen excretion, serum biochemical parameters...

The objective of this study was to investigate the effect of supplementation with enzymolytic soybean meal (ESBM) on broilers fed low crude protein (CP) diets.

A total of 360 one-day-old broilers were randomly assigned to six treatments with 6 replicates per treatment and 10 chicks per replicate for a period of 42 days. Chicks were fed a basal standard high-CP diet as a positive control (PC), a low-CP diet (reducing 10 g/kg CP from the PC) as a negative control (NC), or an NC + 0.5%, 1.0%, 1.5%, or 2.0% ESBM diet.

Compared to chicks fed the PC, chicks fed the NC had a decreased body weight gain (BWG, p<0.05) from 1 to 42 days, but supplementation with 2.0% ESBM restored BWG (p<0.05) and even linearly improved the feed conversion rate (FCR, p<0.05). Digestibility of CP and ether extract was increased (p<0.05) in chicks fed a 1.0% ESBM diet compared to the PC. With increasing levels of ESBM, nitrogen (N) excretion decreased (p<0.05). The addition of ESBM to the diet did not affect (p>0.05) serum concentrations of total protein, albumin and total cholesterol but led to a descending trend in triglycerides and an ascending trend in calcium and urea N at 42 days (p<0.10). There were no differences (p>0.05) in villus height (VH), crypt depth (CD), and VH/CD (V/C) of the duodenum and jejunum between the PC and NC at both 21 days and 42 days, while increasing dietary ESBM levels linearly (p<0.05) decreased CD and increased V/C of the duodenum and jejunum at both 21 days and 42 days.

The findings indicated that ESBM could be used in broiler low-CP diets to improve production performance, decrease N excretion, and enhance intestinal health.