Growth performance, carcass traits, and blood biochemistry of broiler chicks fed with low-fibre sunflower meal and phytase

This study was designed to evaluate the impact of graded replacements of soybean meal (SBM) with low-fibre sunflower meal (LF-SFM), with and without phytase supplementation, on growth performance, carcass traits, and plasma profile of broilers. A total of 800 mixed sex one-day-old broiler chicks (Cobb 500) were randomly assigned to eight dietary treatment groups (five replicates each) in a 4 × 2 factorial arrangement, including four levels of LF-SFM (0%, 25%, 50%, and 75% to replace SBM) and two levels of microbial phytase (0 or 0.2 g/kg diet). Feed conversion ratio (FCR), and bodyweight gain (BWG) were decreased significantly if LF-SFM replaced more than 25% SBM. There was no significant effect between the interaction of the main factors (LF-SFM × phytase) on growth performance during the starter, grower, finisher and the overall period. The addition of phytase had no beneficial effects on performance traits. Carcass traits were not influenced by feeding LF-SFM or enzyme addition. However, increasing the level of LF-SFM (50% and 75%, respectively) in diets reduced the abdominal fat, whereas the weight of the small intestine was increased. Plasma metabolic profile was not affected by LF-SFM levels in broiler diets, except for high-density lipoproteins cholesterol (HDL-C) and total cholesterol (T-Cho), which were not affected by the dietary enzyme. It is concluded that the diets with LF-SFM levels up to 25% generated growth performance and carcass traits comparable with the diet that contained SBM.