Effects Of Arginine On The Growth 'Performance, Hormones, Digestive Organ Development And Intestinal Morphology In The Early Growth Stage Of Layer Chickens

The objective of this study was to investigate the effects of arginine on the growth performance, hormones, digestive organ development and intestinal morphology of chicks of laying hens. A total of three hundred 1-d-old male Lohmann Brown chicks were randomly assigned to five groups, each with six replicate sets of 10 birds. The five groups were fed different diets containing 1.19, 1.44, 1.69, 1.94 or 2.19% arginine from 1 d to 42 d of age. The results showed that dietary levels of arginine had a significant effect on body weight at 14, 28 and 42 d (p < .05). The insulin-like growth factor-I (IGF-I) concentration in serum was significantly increased with increasing levels of dietary arginine (p < .05). With the increase in dietary arginine, chicks had a higher relative liver weight (p < .05). Levels of 1.94 and 2.19% dietary arginine had a more positive effect on the length (p < .05) and relative weight of the small intestine (p < .05), respectively. The morphology of the duodenal mucosa and the villus height of the ileum in chicks were significantly affected by the dietary arginine levels (p < .05). This study suggested that 1.44% dietary arginine provided the maximum body weight of layer chickens during their early development by increasing the villus height in both the duodenum and ileum, whereas 2.19% dietary arginine inhibited the growth of the chicks via a shorter villus height in the intestinal mucosa and excessive serum IGF-I.