Performance, egg quality and some blood biochemical parameters in laying hens exposed to chronic heat stress affected by feed rationing

Abstract

This study was performed to investigate the effects of feed rationing on laying performance, egg quality and some blood biochemical parameters in laying hens exposed to chronic heat stress. A total of 640 (Lohmann LSL-Lite White egg layers, 50 weeks of age) were placed into the cages as 4 feeding rationing treatments with 4 replicates (n = 40 hens/cage). The dietary treatment groups were assigned as control feeding (ad-libitum, CF), daily once morning feeding (102 g feed, DMF), daily once evening feeding (102 g feed, DEF), daily twice feeding (morning and evening 51 g feed, DTF). The egg production was the highest in DMF and DEF groups during the experimental period. Higher egg weight was observed in CF (62.8 g) and DMF (61.1 g) between 51-55 weeks, also egg weight was the highest in CF (63.2 g, P<0.05) between 56-60 weeks. The best feed conversion rate was observed in the DTF group (1.66 between 51-55 weeks and 1.80 between 56-60 weeks of age, P<0.01). At 60 weeks of age, the highest level of total cholesterol, AST, ALT, and H/Lratio were higher in the control group. It could be concluded that feed rationing could be beneficial to alleviate the negative impacts of heat stress on laying performance, egg quality and stress level of hens in comparison with ad-libitum feeding.