Effect of Stocking Density and Dietary Antimicrobial Inclusion of Male Broilers Grown to 35 Days of Age Part 1: Biochemical and Enzymatical Variables
Abstract
Objective: This study investigated the effects of recommended stocking densities and dietary antimicrobial inclusion of male broilers grown to 35 days of age on selected hemato biochemical and enzymatical variables. Materials and Methods: In each study, a total of 1024 1-day-old Ross×Ross 708 male chicks were randomly distributed into 32 pens based on 4 assigned stocking density treatments. The treatments consisted of 4 densities (27, 29, 33, 39 kg m–2) and 2 diets (AGP+, ABF) arranged in a 4 × 2 factorial with eight replicates. Conventional (antimicrobial-growth-promoters, AGP+) and antibiotic free (ABF) diets were equally assigned to each pen with feed and water provided ad libitum. Blood samples were collected from the brachial wing vein of 3 birds per pen on d 15, 28 and 35. The collected blood samples were centrifuged to separate the plasma and used to determine the concentration of biochemical parameters and enzyme activities using an ACE-AXCEL automatic analyzer. Results: Results show that only uric acid (UA) was affected by stocking density. However, in comparison to broilers fed the ABF diet, broilers with AGP+ had higher significant (p<0.05) effects on albumin (ALB), total protein (TP), alkaline phosphatase (ALP), Gamma-glutamyl transferase (GGT), Ca2+ and K+ along with lower total bilirubin (TBILI). The results are in broad agreement with those reported in the literature and contribute to our knowledge of blood metabolites and homeostatic variation in developing male broilers. Conclusion: The results indicating that stocking densities up to 39 kg m–2 with appropriate environmental management regardless of antimicrobial addition in the diets may be suitable for both poultry integrators and contract growers to enhance broilers production efficiency without compromising the welfare of broilers grown to 35 days of age.
Keywords:
Antimicrobial, biochem-enzyme, broilers, stocking-density, welfareArticle Metrics
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