Progress 10/01/20 to 09/30/21
Outputs
Target Audience:Industry and academic scientists in poultry welfare and production. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One graduate student has performed this research. One Ph.D. student was added to this project on July 14, 2020 and has assisted with behavior observation, data analysis, and sampling of birds in initial trials. How have the results been disseminated to communities of interest?Results were presented at international conference meeting (International Poultry Scientific Forum) and published at scientific journals. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
In collaboration with Tyson Food Inc., all experiment trials were conducted in the Tyson broiler research farm. Environmental light affects behavior and brain plasticity in birds. Studies aim to evaluate welfare and production factors of broilers in the different lighting programs and enrichment hut. In each trial, day old Cobb 700 chicks were placed in four commercial broiler houses. In trial 1, variable intensity lighting (VL) house has lower feed conversion ratio (FCR) than 5 lux (5L), 20 lux (20L) and natural light (NL) house at Day 56. Number of lame induced culled birds in VL house was about 21%, 21%, and 25% lower than those of 5L, 20L, and NL house, respectively. Mortality of VL house was about 2.0%, 0.7%, and 3.2% lower than 5L, 20L, and NL house, respectively. In trial 3, VL house has the lowest FCR among the treatments at day 49. Number of lame induced culled birds in VL house was about 34%, 36%, and 50% lower than those of 5L, 20L, and NL house, respectively. Mortality of VL house was about 8% and 24% lower than 5L, and NL house, respectively. In trial 1, number of dust-bathing holes in NL house was expectedly higher compared to those in 5L and 20L houses in all three time points, 9, 16 and 23 days of age. In VL house at day 9, number of dust-bathing holes was significantly higher compared to those of NL house as well as 5L and 20L houses (p<0.05). The significant higher numbers of dust-bathing holes in the VL houses were observed at 16 and 23 days of age compared to 5L and 20L houses. In trial 3, number of dust-bathing holes at 23 days of age in NL house was higher than those in 5L and 20L houses. In VL house, number of dust-bathing holes was significantly higher compared to those of NL houses as well as 5L and 20L houses (p<0.05). This result indicates that voluntary natural behavior, dust-bathing, of birds was stimulated by VL program in the commercial broiler house. Number of zones where are over 35% moisture was lowest in VL house and highest in 20L house among the houses. At day 35 and 42, footpad dermatitis was evaluated and VL house had lower score than other houses. In trial 2, four enrichment treatments (control, negative control, 1xHut, and 3xHut) were tested. In VL house, the number of lame induced culled birds in 3xHut treated section was lower than control, 1xHut and negative control. Based on this observation and dustbathing behaviors of each treatment, trial 4 was redesigned. In trial 4, effects of enrichment 3xHut on the lameness and mortality were tested. The number of lame induced culled birds was significantly decreased by enrichment 3xHut (p<0.05) in the VL house. In the VL house, the leg problem caused culled birds were reduced 20 birds in each section (4800/section) by enrichment 3xHut compare to control. Total 88 birds were saved by enrichment 3xHut per house per flock (19,200). In trial 5, FCR of VL houses was about 3.5% lower than 20L houses at 55 days of age. Number of lame induced culled birds in VL house_3xHut sections was about 10.2% lower than lame birds of 20L house_3xHut sections. Mortality of VL house_3xHut sections was about 14.9% lower than 20L house_3xHut sections. At the 42 days of age, expression of tryptophan hydroxylase 2 (TPH2: rate-limiting enzyme of 5-HT biosynthesis) in dorsal raphe nucleus (DRN) and ventral tegmental area (VTA) of VL birds was significantly lower compared to 5L and 20L birds (p<0.05), but not significantly different with that of NL birds (p>0.05), suggesting the balanced central serotonergic homeostasis in VL treated birds. VTA- tyrosine hydroxylase (TH: rate-limiting enzyme of dopamine biosynthesis) expression in 5L birds was significantly higher than those of 20L, NL and VL birds (p<0.05), suggesting the high stress-susceptibility of 5L birds. VTA- BDNF (brain-derived neurotrophic factor) expression of NL birds was 2.5 fold higher than those of 5L, 20L and VL birds (p<0.05), and VL birds showed the lowest level of BDNF expression (p<0.05), suggesting the chronic social defeat stress in NL birds compared to 5L, 20L and VL birds. Lower VTA- GR (glucocorticoid receptor) expression in 20L and VL birds indicates lower stress in birds compared to NL and 5L birds (p<0.05). Results of welfare related brain activity indicate the beneficial effects of VL lighting program on broiler welfare in commercial broiler houses. Taken together, these studies provide an insight into environmental factors that could be responsible for broiler's voluntary natural behavior, leg health, and production factor FCR. Environment optimization using VL lighting program and enrichment hut have beneficial effects on the broiler's welfare as well as the economic gains of broiler industry by improving feed efficiency.
Publications
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Progress 07/15/20 to 09/30/20
Outputs
Target Audience:Industrial and academic scientists in Poultry Welfare and Production. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A PhD graduate student was joined to this project at July 14th, 2020, and had assisted with behavior observation, analysis of data, and sampling of birds in the first trial. How have the results been disseminated to communities of interest?Results will be presented at international conference meeting (International Poultry Scientific forum IPSF 2021). What do you plan to do during the next reporting period to accomplish the goals?Variable light intensity study and enrichment study will be finished at commercial broiler house and sampling for assay will be accomplished.
Impacts
What was accomplished under these goals?
During the project period, from July to Sep 2020, Trial 1 was performed to determine effects of variable intensity lighting (VL) and natural lighting (NL) program on welfare behavior and gait score of commercially housed broilers. In trial 1, VL house had lower feed conversion ratio (FCR) than 5L, 20L and NL house at Day 56. Number of lame birds in VL house was lower than lame birds of 5L, 20L, and NL house. Mortality of VL house was lower than 5L, 20L, and NL house. Trial 2 was initiated to investigate the effect of enrichment hut on bird behavior, gait score in the different lighting programs.
Publications
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