Location: Livestock Behavior Research
Project Number: 5020-32000-013-36-I
Project Type: Interagency Reimbursable Agreement
Start Date: May 15, 2017
End Date: May 14, 2021
The aim of the work is to develop a novel method to safeguard hen welfare by preventing osteoporosis. We hypothesize that a Bacillus subtilis probiotic formulation dietary supplementation will 1) reduce inflammation-induced skeletal damage via regulating intestinal and systemic immunity; 2) enhance the function of the central serotonergic system in regulating skeletal health; 3) reduce osteoporosis in laying hens by enhanced bone remodeling, and 4) improve hen livability and egg production. Supporting objectives are: to examine 1) probiotic-increased bone formation; 2) the reduction of osteoporosis and its correlation with probiotic-induced long-lasting neurobiological plasticity; and 3) the effects of probiotic on mortality and egg production.
Two trials, each lasting to when hens are 80 weeks of age, will be initiated in January of 2017 and February 2019, respectively. For each trial, a most popular commercial layer strain will be used in this study (n=480) randomly divided into 2 treatments: control hens and probiotic fed hens. Upon hatching, the female chicks will be randomly assigned to 20-bird floor pens in 12 replicates per treatment for 80 weeks under standard management. Mortality and egg production (beginning at week 20) will be recorded daily; active behaviors (walking, standing, and eating) will be recorded at 5 week intervals; and brain, bone, and blood samples will be collected at 20, 40, and 80 wk (n=12 birds/treatment/time). Samples will be analyzed for serotonin and its receptors, interleukin(IL)-2 and IL-6 (pro-inflammatory cytokines), IL-10 (anti- inflammatory cytokine), skeletal health (microarchitectural deterioration, facture, and bone mineral density and content), biomarkers and factors regulating functions of osteoclasts and osteoblasts (osteocalcin, type-I collagen, fibroblast growth factors, alkaline phosphatase, thyroid hormone, parathyroid hormone, and leptin), and eggshell quality (mineral content and thickness). Skeletal health, behavior, neuroendocrine function, and production will be compared between treatments.