Abstract

Previous studies have reported that intestinal populations of Clostridium perfringens, the causative agent of necrotic enteritis (NE), are correlated with diets high in glycine. To establish a direct causative link, 3 trials were conducted to examine the effect of dietary glycine levels on gut populations of C. perfringens, α-toxin production, and NE lesion scores in broiler chickens.

In trials 1 and 2, 12 groups of 4 birds were fed 4 different ideal protein-balanced diets formulated to contain 0.75, 1.58, 3.04, or 4.21%, glycine from d 14 to 28 of age. In trial 3,24 groups of 4 birds were given 6 different ideal protein balanced diets formulated to contain 0.50, 0.75, 1.00, 1.50, 2.00, or 4.00%, glycine.

All birds were orally challenged with a broth culture of C. perfringens type A on d 1 and between d 14 and 21 of age and killed on d 28. The majority of birds showed clinical signs of NE with 4.16 to 8.33% mortality in the 3 trials. The highest mortality and intestinal lesion scores were observed in chickens receiving 3.04% glycine in trials 1 and 2, and 4.00%, glycine in trial 3.

Clostridium perfringens populations in the cecum varied quadratically with increasing dietary glycine, with the maximal response seen at 3.30, 3.89, and 3.51%, dietary glycine in trials 1, 2, and 3, respectively. Numbers of lactobacilli in cecum declined significantly (P < 0.05) with increasing levels of glycine. The results suggest that dietary glycine level has a significant effect on C. perfringens and lactobacilli populations and may be a predisposing factor for NE in broiler chickens.

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The study is published in Poultry Science 84:1875-1885, September 2005 edition

Source: Poultry Science - September 2005