The Effect of Borage (Borago officinalis) Extract on Growth Performance and Immune System of Broilers at High-Density Conditions

The present study was conducted to investigate the effects of borage extract (BE) on growth performance and the immune system of broilers at high-stocking-density. A total of 330 male Ross 308 broilers were distributed in a completely randomized design with six experimental treatments each with three replications. Treatments were T1: 10 broilers/m2 (positive control group), T2: 20 broilers/m2 (negative control group), T3: 20 broilers/m2 + 150 mg/l of borage extract (BE), T4: 20 broilers/m2 + 300 mg/l of BE, T5: 20 broilers/m2 + 450 mg/l of BE, and T6: 20 broilers/m2 + 600 mg/l of BE. Weight gain, feed intake, and feed conversion ratio (FCR) were measured weekly and immune responce were examined twice. The use of BE could improve weight gain, feed intake, and FCR in broilers reared at a high-stocking-density. BE treatment improved the immune response of broilers. According to the results, the use of BE at 600 mg/l is useful in reducing the effects of density stress. Therefore, BE can be used as a nutritional strategy to improve the bird performance in stressful conditions.

Effect of zinc methionine or zinc sulfate supplementation on milk production and composition of milk in lactating dairy cows

Eighteen lactating dairy cows were used to compare the effects of organic and inorganic Zn supplements on milk production and chemical composition of milk. Animals received three diets in a randomized block design: basal diet with no supplemental Zn (control, 42 mg Zn/kg), basal diet plus 500 mg Zn/kg of dry matter (DM) as zinc sulfate monohydrate (ZnS) and basal diet plus 500 mg Zn/kg of DM as zinc methionine (ZnM). Results showed that milk and fat-corrected milk yield in dairy cows were not significantly affected by Zn source although a numerical increase was observed. The percentages of protein, lactose, fat, solid nonfat, total solid, and density of milk were not significantly different between treatments. However, dairy cows that received ZnM tended to produce more milk and fat-corrected milk with a lower somatic cell count as compared to controls. The zinc concentration in milk in the ZnM and ZnS groups was higher (P < 0.05) than in milk from the control group, but there were no significant differences between ZnS and ZnM groups.