Effect of increased ventilation during feeding on broiler breeder biochemical, enzymatical, and electrolytes parameters

Breeders exhibit increased heat stress during and after meal feeding, thus increasing ventilation during and immediately post‐feeding may result in improved productivity and health as well as minimizing physiological stress. This study investigated the effect of increased ventilation during feeding on broiler breeder biochemical, enzymatical, and electrolytes parameters. A total of 288 breeder pullets were obtained from a commercial farm at 21 weeks of age (woa) and assigned to 12 pens (24 birds/pen). Each pen was equipped with two tube feeders, nipple drinkers, fresh pine shaving, and LED lighting. Temperature and lighting were adjusted according to primary breeder recommendations. Feed was provided by a commercial feed mill and meal fed once daily, while water was available ad libitum . Feed was presented at 0730 each day concurrently with the beginning of the photoperiod. Treatments included still air (S, negative control), conventional ventilation with no cool‐down (C, positive control), and variable air speed to mimic a cool‐down ventilation program during and immediately post‐feeding (V). Air speed in the V treatment wind tunnel was increased for three hours to offset the increase in metabolic heat production due to feeding and nesting activity, before returning to the baseline ventilation rate. Three sentinel birds in each pen were identified for physiological monitoring at the beginning of the study. On d 21 (start of treatments), 63 (midpoint), and 105 (end of the treatment period), blood samples (3 mL) were collected between 0800 and 0900 h from the brachial wing vein from each of the three sentinel birds into heparinized syringes within 45 s after birds were caught. The collected blood samples were centrifuged to separate the plasma and used to determine the electrolytes levels, concentration of biochemical (ALB, TBILI, BUN, CREAT, TP, UA, CHOL, LDL‐C, HDL, TRIG, GLUC) parameters and enzyme (ALT, ALP, AMYL, AST, CK, GGT, LDH, LIP) activities using an ACE‐AXCEL automatic analyzer. Results show that ALT, BUN, GLUC, and LDL‐C were affected by treatments. However, woa had significant effects on most examined variables along with few interactions. Plasma CORT was not affected by treatments and time, indicating absence of physiological stress. The results are in broad agreement with those reported in the literature and contribute to our knowledge of increasing ventilation during and immediately post‐feeding on blood metabolites variation in broiler breeders.