|MILLER, W. - Animal Ophthalmology Clinic|
|MASLIN, W - Mississippi State University|
|Purswell, Joseph - Jody|
Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2015
Publication Date: 5/20/2015
Citation: Olanrewaju, H.A., Miller, W.W., Maslin, W.R., Collier, S.D., Purswell, J.L., Branton, S.L. 2015. Influence of photoperiod, light intensity, and their interaction on health indices of modern broilers grown to heavy weights. International Journal of Poultry Science. 14(4):183-190.
Interpretive Summary: Modern commercial poultry facilities are using different light/dark (photoperiod) and dim light to optimize production performance and minimize the incidence of skin scratches associated with higher illuminance and activity. However, the effects of these lighting programs on broiler visual abilities, general health and their involvement in the welfare of broilers grown to heavy weights (> 3.0 kg) under environmentally controlled conditions still need more studies. In 2 trials, ocular health and general health assessments were performed. The data indicate that regular/intermittent photoperiod and long/continuous equally improved broiler welfare indices compared with short/non-intermittent photoperiod where food pad lesion quality decreased with decreasing photoperiod. This study shows the positive impact on profits to commercial poultry facilities that are using low lighting environment to reduce energy utilization, hyperactivity, and pecking damage Regular/intermittent photoperiod versus a long/continuous photoperiod will save energy utilization thereby reducing the total cost of production without compromising the welfare of the broilers grown to heavy weights.
Technical Abstract: The effects of photoperiod, light-intensity, and their interaction on health indices of broiler chickens grown to heavy weights under environmentally controlled conditions were evaluated in 2 trials. In each trial, 540 1 d old Ross × Ross 708 chicks were randomly distributed into 9 environmentally controlled chambers (30 male and 30 female chicks/chamber), provided 23L:1D with 20 lx of intensity from placement to 7 d, and then subjected to the following treatments. The treatments consisted of 3 photoperiod (long/continuous [23L:1D] from d 8 - d 56; regular/intermittent [2L:2D], and short/non-intermittent [8L:16D] from d 8 - d 48 and 23L:1D from d 49 - d 56, respectively) and exposure to 3 light intensities (10, 5.0 and 0.5 lx) from d 8 through d 56 at 50% RH. All birds were fed the same diet. Feed and water were provided ad libitum. Ocular health and general health assessments were performed on d 42 and 49, respectively, while foot pad score was evaluated on d 56 of age. There were only significant effects of photoperiod on live BW and eye weight, but no differences on ocular weight relative to BW. Food pad lesions quality was significantly decreased with decreasing in photoperiod. There were no differences among treatments on ocular assessments, gait scoring test or tonic immobility responses, suggesting that these treatments did not compromise welfare of the birds. These results indicate that long/continuous and regular/intermittent photoperiods equally improved broiler performance compared with short/non-intermittent photoperiod and no significant effect of light intensity treatments was observed in this study.