ABSTRACT
The study examined the effect of de-hulled sunflower meal (SFM) inclusion rate and exogenous enzymes (EE) on broilers production performance. A four-feeding phase of pre-starter (1-9 d), grower (10-20 d), finisher (21-28 d) and post-finisher (29-35 d) was used with SFM included as low (BSL) and high (BSH) in all phases. BLS inclusion was 3% throughout phases and BSH inclusion was 7.5%, 10%, 13% and 13.5% for the 4-phases. Each SFM had a negative control (NC) (BSL- and BSH-) and positive (PC) (BSL+ and BSH+) control with additional 80 kcal Apparent Metabolizable Energy. Enzymes: xylanase (X), xylanase + beta-glucanase (XB), xylanase + beta-glucanase + protease (XBP) and xylanase + amylase + protease (XAP) were added to the NC and PC to give 6 treatments. Pen body weight gain (BWG) and feed intake (FI) were determined at 9, 20, 28 and 35 d and feed conversion ratio (FCR) was calculated accordingly. Diets were fed ad libitum to 1920 male Ross 308 broilers. Diet type, enzyme and diet by enzyme interactions were not significantly different amongst treatment diets. During the pre-starter and the grower phase, all studied parameters did not significantly differ from each other. All studied parameters were significantly influenced by enzyme addition and diet-type and enzyme interaction at 35 d except for diet type on FCR. Broilers fed BSH supplemented with XAP recorded the highest BWG (2.69 kg), whereas broiler chickens on BSL and supplemented with XBP recorded the lowest BWG (2.60 kg). SFM can be increased to 13% and 13.5% finisher and post-finisher diets without negatively affecting performance, and X and XAP enzymes can improve BWG of broilers grown to 35 d.
ABSTRACT
This study evaluated different combinations of a probiotic (Bacillus licheniformis), an organic acid mixture (benzoic and fumaric acids), a protease enzyme, and chelated minerals (Cu, Zn, and Mn) as alternatives to zinc-bacitracin antibiotic. Eight hundred Cobb 500 chicks (42.02 ± 2.207 g liveweight) were distributed into 40 pens to which five diets: 1. Commercial broiler diet with no antibiotics (CON); 2. CON + zinc-bacitracin antibiotic (ZnB); 3. CON + chelated minerals + protease enzyme (MinEnz); 4. CON + chelated minerals + protease + organic acids (MinEnzOrg); and 5. CON + chelated minerals + protease + probiotic (MinEnzPro) were allocated. Probiotic, minerals, protease enzyme, and organic acids were included in diets at 0.2 g/kg, 0.3 g/kg, 0.5 g/kg, and 5 g/kg, respectively. Diets promoted a similar feed intake, weight gain, and feed conversion ratio. Birds on MinEnz had the highest basophil content (2.04 × 109/L), while those on ZnB had the highest alanine aminotransferase (8.50 IU/L). Chickens on MinEnz had the heaviest spleens and the largest proventriculi. Meat from CON birds had the highest water holding capacity (22.32%) and cooking losses (27.15%). We concluded that the investigated combinations of feed additives could replace ZnB in broiler diets as they promoted similar growth performance and carcass characteristics.