Evaluation of Using Dietary Phytogenics, as Growth Promoters, on Broiler Performance, Under Normal and Subnormal Temperature Conditions

The present study was carried out to investigate the potential of dietary supplemental mixture of three phytogenics; carvacrol, cinnamaldehyde and capsicum oleoresin (Xtract TM ) as growth promoter, under normal and subnormal temperature conditions. It was hypothesized that this mixture may alleviate the negative effects of cold stress on broilers performance and their immune response. Six hundred, one-day-old male broiler chicks, were subjected to one of two dietary treatments for 35 days: a basal diet as a control and the basal diet plus 100 ppm of Xtract TM . At 21days of age, half the birds in each dietary treatment were raised under one of two different ambient temperature treatments, the recommended normal temperature (22-24C) versus a subnormal temperature (11-17C), until 35 days of age. The results indicated that rearing broilers under subnormal temperature conditions, from 21 to 35 days of age, had significant negative effects on the production performance, carcass meat yield and immune response, as compared to those reared under normal temperature conditions. Under normal and subnormal temperature conditions, feed supplementation of 100 ppm Xtract TM significantly increased final body weight, improved final feed conversion ratio, decreased total mortality rate, enhanced HI titers against Newcastle disease vaccine and consequently increased the profit potential of the birds, as compared to those not supplemented. Feed supplementation with Xtract TM caused a significant increase in dressing percentage, breast meat, carcass meat as well as a significant decrease in abdominal fat. In addition, the Xtract TM treated birds had significantly higher intestinal diameter and villus height than non treated ones. These results provide clear evidence to support the idea that the mixture of three phytogenics; carvacrol, cinnamaldehyde and capsicum oleoresin (Xtract TM ) could be used as cost effective feed additive growth promoter in broilers up to 35 days of age, under normal as well as subnormal temperature conditions. Furthermore, Xtract TM supplementation alleviated the negative effects of cold stress on production performance and immune response in broilers.