The Effect of Limiting the Time of Feed Access during the Growing Phase on the Performance of Broilers

This study was carried out to investigate the effect of feed restriction during the first week of the grower period on the performance, intestinal morphology, and some blood parameters of broilers. Seventy five one-day-old Ross 308 male broilers were used in a completely randomized design with 3 treatments, the control group and groups with feed restriction program at the first week of the grower phase for 6 or 12 hours (6HR or 12HR). In the grower phase, the 12HR program reduced feed intake and daily weight gain. The feed conversion ratio during the grower phase decreased by feed restriction. In the finisher phase and whole the experimental period, no difference was observed in the performance traits. Serum cholesterol levels decreased in the 12HR group compared to the HR group. Serum malondialdehyde levels decreased in both groups with dietary restriction compared with the control group. The aspartate transaminase activity was higher in the 12HR group than in the 6HR group. In the duodenum, a significant decrease in the height of the villi was observed due to feed restriction. The lowest crypt depth at the duodenum was also observed in the 12HR group. The ratio of villi height to crypt depth in the duodenum was lower in the 12HR group than in the other two groups. In the jejunum, the highest villi height was recorded in the 12HR, control, and 6hr groups. In the ileum, like in the jejunum, the highest height of villi was observed in the 12HR group, and the difference with the control group was significant. The diameter of villi in the Ileum was also not affected by feed restrictions. The depth of the crypt increased due to feed restriction. The results of this study suggest that 6 hours of dietary restriction in the first week of the grower period did not affect the production traits of broilers and 12 hours of dietary restriction in the mentioned period, although reduced feed intake and growth in the grower period, at the end of rearing period sufficient compensatory growth occurred. On the other hand, it seems that the 12-hour diet restriction in the first week of growth has positive effects on the morphology of the small intestine by increasing the absorption surface and also has a positive effect on the peroxidative state of the body, which needs further research.