Physiological responses and performance of broiler chickens offered olive leaf extract under a hot humid tropical climate

This study was designed to determine the effects of olive leaf extract (OLE) supplementation in the drinking water on growth performance, hematological parameters, plasma triiodothyronine and malondialdeyde, superoxide dismutase, and rectal temperature of broiler chickens under a hot-humid tropical climate. Two hundred and forty Arbor acre broiler chickens were used for this experiment and were allotted to four treatments comprising four replicates of 15 birds each. The birds were offered OLE per liter of water at various levels (0, 5, 10, or 15 mL) in a completely randomized design. Rectal temperature (RT), hematological indices, weight, weight gains, feed consumed, feed conversion ratio, and plasma triiodothyronine (T3) were the parameters measured. The results obtained showed that the plasma T3 of the birds offered 15 mL OLE was higher (P < 0.05) than those of the birds in the other treatment groups. Significant differences (P < 0.05) were observed in the feed intake (DFI), total feed intake (TFI), final weight (FW), total weight gain (TWG), and feed conversion ratio (FCR) among treatments. The DFI, TFI, FW, TWG, and FCR of broilers offered 15 mL OLE were significantly (P < 0.05) better than those offered the 10 mL and 5 mL levels. It was concluded that inclusion of 15 mL of OLE enhanced the performance of broiler chickens during the hot dry season