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" The Effects of LED Lighting and the Identification of the AgRp Feeding Mechanism in Turkey Hens "
Bartz, Brooke Marie
Kwak, Thomas
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Latin Dissertation
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| Language of Document
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English
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| Record Number
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1106601
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TLpq2406470211
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| Main Entry
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Bartz, Brooke Marie
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Kwak, Thomas
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| Title & Author
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The Effects of LED Lighting and the Identification of the AgRp Feeding Mechanism in Turkey Hens\ Bartz, Brooke MarieKwak, Thomas
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| College
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North Carolina State University
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| Date
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2020
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| student score
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2020
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| Degree
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Ph.D.
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| Page No
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98
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| Abstract
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Lighting is an essential part of the physical environment and artificial light sources are imperative in the management of avian species reared in environmentally controlled facilities. Light emitting diodes (LED) as alternative light sources to incandescent or compact fluorescent bulbs have been researched in domestic poultry applications but has yet to be studied in commercial turkeys. As feed cost contributes up to two-thirds of the production cost in poultry, understanding mechanisms related to feed intake are important. Therefore, three trials were completed with the first two focused on LED light management in turkeys and the third to assess the expression of neuropeptides related to feed intake in four different strains of turkeys. Trial one and two were completed using a combination of farm-rated, commercially available LED lights in an environmental and ventilation-controlled facility and compared to natural light conditions. Welfare parameters were completed to analyze feather coverage, eye measurements, and hormone analysis. Performance parameters were completed by data collection and subsequent calculations. LED lights used in trial one were 5,000 Kelvin (K) LED or a combination of 5,000K + Red LED at a 12hL:12hD or 18hL:6hD and compared to naturally decreasing day-length (NAT) or NAT light plus 18hL:6hD 5,0000K LED under NAT ventilation. Elongation of the anterior-posterior distance (APD) of the eye was affected by to type of light used rather than daylength, which has been indicated as a major factor in previous studies. Infrared (IR) thermal imaging of the breast feathers measures a significantly higher level of heat signature, indicating a decrease in feather coverage in all 18hL:6hD regimens, regardless of bulb or ventilation type when compared to the NAT treatment. Triiodothyronine (T3) hormone analysis was added as a biological measurement of feather coverage status and was inconsistent with IR imaging indicating the addition of a behavioral analysis to properly assess feather coverage in turkeys. The NAT treatment had significantly lower BWG during the brooding phase, however, by 14 wk, all birds that were exposed to NAT light during the grow-out phase (9 – 14 wk; excluding 18hL:6hD 5,000K LED during brooding phase) had the highest BWG overall. Trial two included 5,000K or 2,700K LED in combination with 2 footcandle (fc) or 10 fc light intensities at a fixed 14hL:10hD lighting schedule and compared to natural light and ventilation treatment supplemented with 75W Incandescent bulbs to maintain daylength. Novelty interactions with novel objects were introduced at 7 wk. Spectral output within the same Kelvin temperature LED was significantly altered during bulb dimming to achieve desired fc intensity levels (2fc or 10fc) in this study. There was a significant interaction between intensity level and bulb color temperature as measured by APD elongation of the eye under low intensity, 5,000K LED at 9 wk. There were no differences in feather coverage or T3 measurements between treatments and there were no differences in the latency to approach unknown objects between treatments. Performance results were mixed with general increases in BWG in all LED treatments when compared to NAT lighting and environmental conditions. It was concluded that daylength had a larger impact on bird performance and well-being with some interactions occurring based on bulb color temperature. The regulation of feed intake involves multiple physiological systems and the expression of feed intake regulatory neuropeptides are located within the arcuate nucleus (ARC) of the hypothalamus. The focus of the third trial was to identify of the alpha-melanocortin hormone (α-MSH) inhibitory neuropeptide, agouti-related peptide (AgRP) by immunohistochemistry on four mid-ARC sections of four different genetic strains of turkeys. AgRP identification was achieved in all genetic strains and feed intake per pen was positively correlated with genetic strain.
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Animal sciences
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