This experiment was to investigate the effects of dynamic segmentation of interval nutrient supply phase feeding on the growth performance, carcass characteristics, immune organs indexes and intestinal morphology of broilers. A total of 320 one-day-old broilers were randomly assigned into 4 feeding treatments, which included 4 interval nutrient supply phases as follows. Treatment A: a nutrient supply standard was used for every 14 d. Treatment B: a nutrient supply standard was used for every 7 d. Treatment C: a nutrient supply standard was used for every 3.5 d except that one nutrient supply standard was used for d 1 to 7. Treatment D: a nutrient supply standard was used for every 3.5 d including d 1 to 7. Each treatment was represented by 8 replicates with 10 broilers per replicate. The trial lasted for 42 days. Throughout the 42 d trial period, treatment A showed significantly higher average daily gain than treatments B and C (P < 0.05). The feed:gain ratio of treatment A was significantly lower than those of treatments C and D (P < 0.05). On d 28 and 42, body weight of broilers in treatment A was much higher than those of treatments B and C (P < 0.05). The slaughter rate of treatment A was significantly higher than that of treatment B (P < 0.05). Eviscerated percentage of treatment A was significantly higher than those of treatment B and D (P < 0.05). There were no significant differences among 4 treatments in immune organs indexes (P > 0.05). The crypt depth of duodenum was significantly greater in treatments A and B than in treatment C on day 42 (P < 0.05). Meanwhile, the ratio of villus height to crypt depth (V:C ratio) of treatment D was significantly higher than that of treatment A (P < 0.05). No significant differences were found between treatments C and D in growth performance, carcass performance, immune organs indexes and intestinal structure (P > 0.05). In conclusion, this study revealed that the growth and carcass performance of broilers is the best for 14 days segmentation phase feeding, and 3.5 days segmentation interval phase feeding can promote small intestinal development of broilers. Dynamic segmentation of dietary supply fails to affect the immune function of broilers.
Keywords: Broilers; Immune organ index; Intestine; Performance; Phase feeding.