Influence of LED light spectra and photoperiods on broiler breeders production, reproduction, blood metabolites, immunological response, and hepatic sterol regulatory element binding protein-1 (SREBP1) relative gene expression

Lighting is one of the important management factors affecting the health and welfare of birds. The objective of this study was to assess the effects of light-emitting diodes (LEDs) on production, reproduction, blood metabolites, immunology, and hepatic sterol regulatory element binding protein-1 (SREBP1) gene expression in broiler breeders. One-day-old Ross 308 female breeder chicks (n=100) were randomly assigned to 20 light-proof pens and reared under five lighting regimens, including green (GL) or white (WL) LED at two exposure photophases (8 or 12 hours) as a 2 ´ 2 factorial experiment plus a control group (incandescent lamp at 8L:16D duration; CON). The LED color affected the feed intake during the rearing period, being higher in white than in green light; however, green light resulted in more medium and large white follicles on the ovaries, higher mean corpuscular hemoglobin concentration, and plasma cholesterol level. In WL8 lighting, the relative weight of the bursa of Fabricius was higher (P≤0.05) than in CON birds. Plasma cholesterol level in GL12 was higher compared to CON. Conventional and WL12 regimens resulted in lower plasma alkaline phosphatase activity. Twelve hours of GL lighting resulted in higher eggshell weight and strength while it caused a small but significant decrease in egg shape index. Greater numbers of medium white (MWF) and large white (LWF) follicles were recorded in GL12 birds, and there were more small white follicles (SWF) in GL8 group (P≤0.05). The GL12 and CON lighting resulted in higher concentrations of WBC and Hb compared with WL. Hepatic expression of SREBP1 was higher in WL8 birds. The results indicated that green LED improved egg quality while white LED caused higher relative weight of bursa and hepatic SREBP1 expression, indicating the LED light may be beneficial to broiler breeder productivity. However, more studies are required to substantiate these findings.