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.