No abstract

This study was conducted to evaluate the effect of zinc-methionine (ZnM) on growth performance, nutrient utilization, antioxidant status and immune response in broiler chickens reared at high ambient temperature. A total of 480 one-day-old chicks were randomly distributed into 24 floor pens (20 chicks/ pen) and were given either a control diet, 0 ZnM (G0) or 25, 50 and 100 mg/kg ZnM (G1, G2 and G3, respectively). The growth performance was significantly affected by the treatments, ZnM supplementation increased body weight gain and improved feed conversion (p < .05) in broilers. Protein utilization was improved by feeding ZnM (p < .05). Plasma total cholesterol was decreased, while plasma HDL-cholesterol was tending to be increased. Interestingly, an increase in ZnM supplementation enhanced Zn concentrations (p < .05) in breast muscle along with a reduction in malondialdehyde concentration and saturated fatty acids (p < .05) and an augmentation in unsaturated fatty acids (p < .01). Dietary ZnM supplementation resulted in a significant increase in serum glutathione peroxidase concentration which accompanied with an improving in humoral immune response. It could be concluded that dietary organic Zn supplementation improved growth performance, nutrient digestibility, Zn content in raw meat, antioxidative properties and humoral immunity and reduced meat lipid peroxidation in broilers under high ambient temperature.

This experiment was conducted to study that effect of a phytogenics (herbal mixture) supplementation as alternative to antibiotics on the growth performance and immune response in broilers. Three thousand broiler male chicks at 1 day of age were housed in floor pens and divided into five experimental groups with five replicates of 120 birds each. The first group was fed the basal diet without any additive in feed or water; the second group was fed the basal diet, and the drinking water was supplemented with mixture of antibiotics (Doxycycline 1 g/5 L + Colistine sulfate 1 g/5 L) for the first 10 days of life. The other three treatments of chickens were fed the control diet supplemented with herbal mixture at a level of 0.5, 1.0, and 1.5 kg/ton, respectively. Dietary herb mixture supplementation improved growth performance significantly in comparison with control group. In addition, herb mixture supplementation reduced plasma total cholesterol and triglycerides concentrations, whereas, high density lipoprotein HDL-cholesterol and glutathione peroxidase (GPX) were increased significantly. Furthermore, herb mixture supplementation increased plasma levels of total protein and antibodies titers for Newcastle disease virus before and after the infection. It could be concluded that dietary herb mixture supplementation had positive effects on growth performance, antioxidative properties, and humoral immunity in broiler chickens.

The present study was conducted to show that dietary supplementation with a fungus, Aspergillus awamori, modifies muscle fatty acid profiles in broiler chickens. A total of thirty chicks, selected from a group of 100 chicks aged 15 d, were divided into a control group and two treatment groups (ten birds per treatment). The control group was fed a basal diet, and the treatment groups were fed basal diets supplemented with A. awamori at levels of 0·05 and 0·2 %. From the start of the study at 15 d, the birds were raised for an additional 12 d, and growth and the muscle fatty acid profile were evaluated. Although feed intake was decreased by the fungus, body-weight gain and breast muscle weight were increased, and thus, feed efficiency was improved. Abdominal fat and plasma cholesterol and TAG were decreased, while plasma HDL-cholesterol and breast muscle fat content were increased. Interestingly, muscle a-tocopherol content was increased and muscle thiobarbituric acid-reactive substances were decreased by A. awamori. Furthermore, there was an observed decrease in SFA and an increase in unsaturated fatty acids in the muscle fat due to the fungus feeding. The mRNA of fatty acid synthase, acetyl-CoA carboxylase and D-6 desaturase in the muscle were all increased, while the mRNA of 3-hydroxyl-3-methylglutaryl-CoA reductase and carnitine palmitoyl transferase 1A were decreased by the fungus. In conclusion, the present study clearly shows that the muscle lipid profile could be modified by the addition of A. awamori to the diet.