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 statu

Artemisia Annua as Phytogenic Feed Additive in the Diet of Broilers (14-35 Days) Reared under Heat Stress (32 ºC)

ABSTRACT The 21 days feeding trial was conducted on 90, Cobb 500 broilers (aged 14 days), assigned to 3 groups (C, E1 and E2) housed in an experimental hall at 32° C constant temperature and 23 h light regimen. During the growth period (14-35 days), the conventional diet (C) had corn and soybean meal as basic ingredients. Unlike the conventional diet formulation (C), the diet formulations for the experimental groups also included 0.005% Artemisia annua oil (E1) and 0.005% Artemisia annua oil plus 1% Artemisia annua powder (E2). Six broilers per group were slaughtered at 35 days of age in order to measure the weight of the carcass and internal organs of broilers, and samples of intestinal and caecal content were collected for bacteriological assessment (Enterobacteriaceae, E. coli, staphylococci, Lactobacilli, Salmonella spp.).The following parameters were monitored during the experimental period: bodyweight (g); average daily feed intake (g feed/broiler/day); average daily weight gain (g/broiler/day); feed conversion ratio (g feed/g gain). Under heat stress (32 ºC), E2 broilers (mixture of A. annua oil and powder) had a significantly (p<0.05) higher average of daily feed intake than the broilers receiving the C diet or the diet supplemented just with A. annua oil (E1). Both samples of intestinal and caecal content, showed the lowest count (p<0.05) of Enterobacteriaceae, E. coli and staphylococcus colony forming units in E2 broilers. Diet with A. annua oil and powder provided proper conditions for lactic acid bacteria proliferation in the intestine and caecum of heat stressed broilers

Anomalous flux dynamics in magnesium diboride films

The flux dynamics in magnesium diboride films becomes altered by scattering resulting in an unprecedented quenching of flux motion that is beyond conventional vortex pinning. At currents approaching the pair-breaking value and magnetic fields approaching the upper-critical field, the conductance diverges and the current-resistance and temperature-conductance curves become parallel, showing mainly a shift in the transition due to pair-breaking with minimal signs of flux motion. © 2005 Elsevier B.V. All rights reserved