Skip to main content
ARS Home » Southeast Area » Mississippi State, Mississippi » Poultry Research » Research » Publications at this Location » Publication #343112
Title: Effects of light ingress through ventilation fan apertures on selected blood variables of male broilers

Author
item Olanrewaju, Hammed
item Purswell, Joseph - Jody
item Collier, Stephanie
item Branton, Scott

Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2017
Publication Date: 8/25/2017
Citation: Olanrewaju, H.A., Purswell, J.L., Collier, S.D., Branton, S.L. 2017. Effects of light ingress through ventilation fan apertures on selected blood variables of male broilers. International Journal of Poultry Science. 16(8):288-295.

Interpretive Summary: Lighting programs for broiler production are formulated to provide some control over growth trajectory and minimize adverse behaviors. However, the lighting environment within a modern solid-walled broiler house can vary with construction practices (fan placement, evaporative pad length, interior reflectivity) as well as environmental control methods (tunnel vs. perimeter ventilation) and may alter the effectiveness of the prescribed lighting program. Increasing broiler house size and ventilation capacity have resulted in increased light ingress through ventilation system components. Light ingress may alter the effective photoperiod for broiler chickens and create local increases light intensity. We evaluated the effects of light ingress through ventilation fan apertures on selected blood variables of male broilers reared to 63 days of age. Selected blood plasma biochemistry, enzyme activities, and electrolyte levels were evaluated. The results showed that in comparison to broilers exposed to a C light intensity of 2.5 lx, broilers exposed to V lighting that mimicked areas near tunnel fans, had significantly lower levels of pH, Ca2+, K+, and higher levels of angap, which were within physiological acid-base ranges. Also, treatments only lower CK activity, but age have significant contributor effects on most selected variables. Moreover, blood glucose and plasma corticosterone concentrations were not affected by treatment, suggesting an absence of physiological stress and an uncompromising welfare of the birds. Hence, it is suggested that there may be a need to mitigate light ingress through ventilation system components to improve live performance of broilers.

Technical Abstract: Increasing broiler house size and ventilation capacity have resulted in increased light ingress through ventilation system component apertures. The effective photoperiod for broilers may create local increases in light intensity, which may also impact broiler’ body homeostasis. The objective of this study was to determine the influence of aperture light ingress in grow-out houses on selected blood variables of male broilers reared to 63 days of age. Sixty male broiler chicks were randomly distributed to each of 16 environmentally-controlled rooms (960 total birds). Birds were provided a diet formulated to meet or exceed NRC recommendations with feed and water provided ad libitum. The two treatments consisted of a constant (C) light intensity at 2.5 lx at 16L: 8D based on prescriptive intensities in typical heavy broiler lighting programs, and a variable (V) light intensity and photoperiod program that was based on field measurements near tunnel fans in a solid walled broiler house. The lighting program to 35 d was identical for both treatments and the treatments were initiated at 36 d. Blood samples were collected from the wing brachial vein of 6 birds per room on d 35 (before treatments) and 63, which were then analyzed immediately for whole blood physiological variables. Selected blood plasma biochemistry, enzyme activities, and electrolyte levels were evaluated. The results showed that in comparison to broilers exposed to a C light intensity of 2.5 lx, broilers exposed to V lighting that mimicked areas near tunnel fans, had significantly lower levels of pH, Ca2+, K+, CK, and higher levels of angap, which were within physiological acid-base ranges. Also, age have significant contributor effects on most selected variables. In addition, blood glucose and plasma corticosterone concentrations were not affected by treatment, suggesting an absence of physiological stress and an uncompromising welfare of the birds. Hence, it is suggested that there may be a need to mitigate light ingress through ventilation system components to improve live performance of broilers.