Effects of enzyme supplementation on replacing corn with barley in diet of broiler chicks
GHORBANALI SADEGHI and MAHMOOD HABIBIAN
Two experiments were carried out to evaluate the effects of an enzyme complex (Agrozyme®, a cocktail of cellulolytic, amylolytic, and proteolytic enzymes) on barley energy content and its nutritive value for broiler chicks. In the first experiment, the effect of enzyme on barley energy content was determined using adult Leghorn cockerels. In the second experiment, the effects of the enzyme on performance, carcass characteristics, and nutrient digestibility of broilers fed diets containing 0, 50 and 100% replacement of diet corn with barley was investigated using 360 1-d-old chicks. Enzyme had no effect on barley energy content (first experiment). During 1 to 21 d period, chicks fed diet in which 100% of corn was replaced by barley had lower weight gain than those fed diet in which 50% of corn was replaced by barley. The high barley diet resulted in a significant increase in feed conversion ratio. During 21 to 35 d period, chicks fed the corn diets had lower weight gain than those fed barley containing diets. Enzyme had no effect on weight gain, but feed conversion ratio was improved by enzyme when chicks fed high barley diet. In the overall period, enzyme addition had no effect on performance. Carcass and abdominal fat weight was reduced, whereas the small intestine weight was increased when chicks fed diet in which 100% of corn was replaced by barley. Dietary treatments had no effect on dry matter, crude protein, and crude fat digestibilities.
Key words: broilers, digestibility, Hordeum vulgare, metabolizable energy