Age-related effect of high-frequency LED lighting in laying hens on biochemical, enzymatical, and electrolytes variables

Authors: Olanrewaju, Hammed; Evans, Jeffrey - Jeff; Collier, Stephanie; Purswell, Joseph - Jody; BRANTON, SCOTT - Retired ARS Employee

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2023
Publication Date: 9/1/2023
Citation: Olanrewaju, H.A., Evans, J.D., Collier, S.D., Purswell, J.L., Branton, S.L. 2023. Age-related effect of high-frequency LED lighting in laying hens on biochemical, enzymatical, and electrolytes variables. Journal of Applied Poultry Research. 32:3. https://doi.org/10.1016/j.japr.2023.100351.
DOI: https://doi.org/10.1016/j.japr.2023.100351

Interpretive Summary: The poultry industry is quickly increasing the efficiency of producing animal proteins which are commonly consumed by humans including eggs and meats. Advances include improved genetics and nutrition as well as changes in environmental management. In the past five decades, consumption of poultry eggs and meat has increased significantly, and this trend is expected to continue in the future due to the relative price-competitiveness compared to other animal protein products. However, concern among the public regarding animal well-being in food production systems continues to grow. There is a public perception that increased production efficiency takes a toll on the well-being of the animal. As the demand for animal protein products rises, increasing poultry production and production efficiencies will be critical to the continued viability of the U.S. poultry and livestock industries. To date, high frequency photostimulation has only been evaluated in laying hens through proprietary testing by the manufacturers. No evaluation has been conducted by independent scientists. Therefore, this study investigated the blood plasma biochemical, enzymatical, and electrolytes parameters of laying hens reared under conventional lights and a novel high-frequency photostimulation system developed to improve growth and maximize egg production without compromising the welfare of laying hens. Most of these blood parameters in this study are indicators of health and systemic homeostasis. In each trial of 2 trials, we evaluated the age-related effect of high frequency LED lighting and their interaction if any on selected Biochemical, Enzymatical, and Electrolytes Variables in laying hens to ensure their health and welfare. Results show that only UA was affected by treatments, but age had significant effects on most examined variables. Plasma corticosterone and glucose were not affected by feeder space and age, indicating absence of physiological stress. All these changes are still within the normal body homeostasis and physiological ranges of this species. Plasma corticosterone was not affected by treatments and week of age, indicating absence of physiological stress. The results contribute to our knowledge of prototype LED light on blood physiological variables in layer hens, which does not negatively affect layer hens’ welfare. It was concluded that the prototype LED lighting system examined in this study along with appropriate environmental management may be suitable to improve growth and maximize egg production without compromising the welfare of laying hens.

Technical Abstract: A novel lighting system using high frequency differential photostimulation developed for layer chickens was assessed for its effects on physiological response. In each of the 2 trials, a total of 320 10-week-old layer pullets were randomly allocated to 16 groups with 20 birds/group. Birds were weighed and randomly assigned to each of four cage banks in each of four rooms. Experimental treatments included the prototype LED lighting system and conventional 2700K LED bulbs. Photoperiod for the prototype system was 24L:0D per the manufacturer’s recommendations and photoperiod for the conventional system followed the Hy-Line Management Guide. Blood samples (3 ml) were collected from the brachial wing vein into heparinized syringes within 45 s after birds were caught from 8 randomly selected birds per room for a total of 32 birds at each blood sampling day of placement, prior to point of lay, and at the termination of the study for a total of 96 birds. Plasma was separated from blood samples by centrifugation and used to determine the concentration of biochemical parameters and enzyme activities using an ACE-AXCEL automatic analyzer. Also, estradiol, follicle stimulating hormone, corticosterone, melatonin, T3, and T4 levels using Tosoh A1A-360 automatic analyzer. Results show that only uric acid (UA) and estradiol were affected by treatments. However, woa had significant effects on most examined variables. Plasma corticosterone was not affected by treatments and woa, indicating absence of physiological stress. In conclusion, using high-frequency LED lighting in layer hen houses does not negatively affect layer hens’ welfare.