Use of a hydroalcoholic extract of Salix alba L. bark powder in diets of broilers exposed to high heat stress

Abstract

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.

Influence of Dietary Supplementation of Salix alba Bark on Performance, Oxidative Stress Parameters in Liver and Gut Microflora of Broilers

“…For example, in a study conducted on rabbits [9] it was reported that a higher dose of Salix alba extract (120 mg/kg diet) was more effective than the lower dose (60 mg/kg diet). Similar results were found on heat-stressed broilers [4] when willow bark extract was used (50 g/100 kg diet). The explanation for this result may be that SAB acts in a dose-dependent mode, an idea highlighted by other researchers [9,26].…”

“…Our results show that the dietary SAB powder is able to reduce the lipid peroxidation in chickens. In the literature, there were recorded decreases in liver malonaldehyde content for broilers fed dietary hydroalcoholic extract of willow bark powder (0.025% and 0.05%, respectively) compared to those fed the conventional diet under heat stress conditions [4]. This property of Salix bark is probably attributed to its high antioxidant content, scavenging free radicals, and consequently diminishing the oxidative stress.…”

“…It seems like lactobacilli are sensitive to SAB action even at a low dose of inclusion in broiler diet. There were many studies proving the antibacterial effect of Salix alba both in vitro and in vivo [4,7,10,11]. Among in vivo studies, only a few of them were conducted on broilers.…”

“…This trend is particularly important since the administration of antibiotics as growth promoters has been forbidden. In recent years, many plants containing phenolic compounds have gained considerable interest for reducing oxidative stress both in vitro and in vivo studies [1,3,4].…”

“…In a study on humans, it was concluded that willow bark is able to increase the activity of antioxidant enzymes and consequently counteract oxidative reactions [12]. Some authors noticed that using 1% dietary hydroglyceroalcoholic willow bark extract [7] and 0.05% willow bark extract powder [4] improved the biochemical blood parameters and liver oxidative status of heat-stressed broilers and decreased the number of pathogens in the caecum.…”