Sunflower Meal Inclusion Rate and the Effect of Exogenous Enzymes on Growth Performance of Broiler Chickens

Simple Summary Over the years, there has been an increase in the price of traditionally used protein sources such as soybean meal (SBM) in broiler feed. This has necessitated the need for alternative protein sources that can partially substitute the SBM protein and reduce the cost of feeding. Sunflower meal (SFM), a by-product from the oil processing industry, is available in significantly high quantities throughout the year at lower cost. SFM can be produced in drought-stricken places with good harvest and is less prone to fungal infestation. Although SFM has protein levels ranging between 32 and 37 percent, its inclusion levels in broiler diets have been limited to 5% due to high concentration of non-starch polysaccharides, low metabolizable energy and lysine levels. This presents challenges in feed manufacturing, since composition depends on the amount of oil extracted and retained hulls, with effects on the digestive efficiency of broiler chicks, especially in the first 21 d of growth. The use of multi-enzymes that target specific substrates in SFM can potentially allow an increase in its inclusion levels, thereby reducing the deleterious anti-nutritional effects from non-starch polysaccharides (NSPs). Additionally, multienzyme supplementation can result in flock uniformity and environmental pollution reduction due to less nutrient loss in manure. 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.