Use of a hydroalcoholic extract of Salix alba L. bark powder in diets of broilers exposed to high heat stress
A study was conducted to determine the effects of dietary hydroalcoholic willow bark extract powder (HWE) supplemented to broilers (14–42 days old) that were exposed to heat stress, on the performance, serum biochemical parameters, liver oxidative status and caecal microflora. The feeding trial was conducted on 120 Cobb 500 broilers (14 days old), assigned to three treatments (T0, T25, and T50), each treatment consisting of eight replicates (five chicks per replicate). The broilers were housed in an experimental hall at a 32 °C constant temperature and 23 hours light regimen. Unlike the dietary control treatment (T0), the experimental treatments were supplemented with 25 g HWE powder/100 kg diet (T25), and 50 g HWE powder 100 kg diet (T50), respectively. Dietary HWE powder did not affect the broilers’ performance significantly (14–42 days). A significantly lower amount of malondialdehyde was noticed in the liver of broilers from T25 and T50 treatments in comparison with broilers from T0. Also, the serum cholesterol, triglycerides and alanine aminotransferase were significantly lower in broilers fed with T50, compared with those fed with T0. At 35 and at 42 days, the broilers from T25 and T50 recorded a significantly lower number of E. coli and staphylococci and a higher number of lactobacilli in the caecum than those of T0. It could be concluded that supplementation of dietary HWE powder reduced some of the adverse effects of heat stress, the most effective being the level of 50 g/100 kg diet.
Keywords: biochemical parameters, caecal microflora, high temperature, liver oxidative status