INFLUENCE OF ASCORBIC ACID ON PHYSIOLOGICAL INDICES OF BROILER CHICKEN DURING DRY SEASON

Abstract

The study evaluated the physiological response of broiler birds to different levels of Ascorbic Acid (AA) supplementation during the dry season. 320 one-day-old Ross 308 broiler chicks were allotted randomly to four dietary treatments groups T1 (Control), T2 (50), T3 (100) and T4 (150 mg AA/kg diet) in a completely randomized design. The experiment lasted for 8 weeks during which data on growth parameters, body morphometry, haematology, serum biochemistry and other physiological parameters were collected. Findings from the study revealed that, body weight gain and feed intake were highest in T4, indicating that AA significantly (p<0.05) elicited improvement in the growth performance parameters. Collagen synthesis of AA was also observed as there was an improved (p<0.05) thigh and shank lengths in birds exposed to AA. Haematological analysis indicated that, AA induced erythropoiesis as evidenced by significant (p<0.05) increase in red blood cell counts from T1 (15.12 x 10⁶cell/μL) to T4 (27.57 x 10⁶cell/μL), with a decrease in physiological leukocytosis often related to tissue damage by heat. The AA proved non-hepatotoxic as serum biochemical indices were within safe ranges. By week 8, there was a significant reduction (p<0.05) in rectal temperatures from 42.37 ⁰C in the control group to 40.01 ⁰C in T4. Significant reduction in respiratory rates were observed with birds in T1 having 59.59 breadth/min, while those T4 had 53.41 breadth/min suggesting that AA induced lower thermal polypnea and inhibition of respiratory alkalosis. Conclusively, incorporation of AA up to 150 mg/kg efficiently reduced the adverse effects of thermal stress, while maintaining homeothermy and promoting the overall performance and welfare of broiler chickens during the hot season.