Effects of meal-time feeding and protein restriction on walking ability and some bone and carcass properties in broilers

Effect of different feed restriction regimens on performance, behaviors, blood cortisol, and carcass parameters of growing Sasso broilers

The aim of this study was to evaluate the effect of different feed restriction regimens on performance, behavioral patterns, blood cortisol, and carcass parameters in Sasso broilers. Sixty healthy 1-day-old unsexed Sasso chicks were randomly assigned to three groups (20 chicks per group) and each group was divided into 4 replicates with 5 chicks each based on feed restriction program during the rearing period (60 days). The first group (G1) is control in which birds were fed ad libitum had free access to feed (no restriction). The second group (G2) was subjected to temporary feed restriction at the first 2 weeks as birds had access to feed for 12 h only after that they had free access to feed until the end of the experimental period. The third one (G3) was subjected to continuous feed restriction as birds had free access to feed for 12 h only throughout the rearing periods. During the study period, growth performance and behavioral patterns were estimated. At the end of the study, blood samples for cortisol testing were taken. Three birds from each group were slaughtered at the end of the study to see how the feed restriction affected carcass parameters. Feed restriction had a substantial impact (P ≤ 0.05) on final body weight and carcass parameters. Feed restriction elevated blood cortisol significantly (P = 0.004). Feed restriction showed a significant impact on some behaviors as feeding, stretching, preening, and aggression. Overall, different feed restriction programs had a wide effect on growth performance, behaviors, cortisol concentration, and carcass parameters of Sasso broilers.

Assessment of growth performance, immune responses, serum metabolites, and prevalence of leg weakness in broiler chicks submitted to early-age water restriction

The objective of this study was to evaluate the effects of two methods of early-age water restriction on performance, some immune responses, serum metabolites, and prevalence of leg weakness in broiler chicks. One-hundred-eighty-seven-day-old chicks (Ross 308) were allocated to three treatments with four replicates based on a completely randomized design. Treatments included the control group, where birds had free access to water, and water-restricted groups, where access to water was limited to three 2-h periods (WRT1) or a 12-h period (WRT2) per day from days 7 to 17. Chicks in the control group were significantly heavier (P < 0.05) at 17 and 46 days of age compared to the restricted birds. In the WRT2 group, feed intake decreased significantly over the 17- to 28-day period while feed conversion ratio was poorer during water restriction (P < 0.05). Antibody titers against Newcastle and SRBC were higher (P < 0.05) for chicks with ad libitum access to water. Birds in the restricted groups exhibited a higher heterophil to lymphocyte ratio compared to the control group (P < 0.05). The treatments had no significant impact on serum metabolites including protein, triglyceride, total cholesterol, high-density lipoprotein and low-density lipoprotein cholesterols, calcium, and phosphorus concentrations. Walking ability, tibial dyschondroplasia, foot pad, hock burn, and valgus/varus angulation were not significantly influenced by water restriction. In conclusion, the current results indicate that early-age water restriction negatively influenced productive traits and immunological responses of broiler chicks and failed to have any favorable impacts on leg health.