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Apparent digestibility of wheat bran nutrients with or without exogen enzymes addition in weaned piglets
Non ruminant animals have a limited capacity for food digestion with low digestibility as those with high fiber or phytic acid contents. Some researches indicated that enzyme additions may decrease the effects of antinutritional factors present in vegetable feedstuffs, improving its digestion and nutrient utilization. Using weaned piglets, this study evaluated the apparent digestibility of dry matter (DM), crude protein (CP), mineral matter, energy (DE) and, metabolizable energy (ME) and nitrogen retention of the wheat bran (WB) supplied or not with exogen enzymes. Twenty-five crossbred barrows with initial weight 9.35 kg ± 1.61 kg, were allotted in a completely randomized design under five treatments and five replicates. The experimental unit was represented by one pig within its respective metabolic cage. The experimental period was 10 d, in which 5 d for cage adaptation and 5 d for feces and urine collection. The treatments were: Control diet (CD); CD + 30 % wheat bran (WB); CD + 30% WB + 200 mg/kg of carbohydrase (WB+Carb); CD + 30% WB + 50 mg/kg of phytase (WB+Phy); CD + 30% WB+ Carb + Phy (WB+Carb+Phy). The control diet was based on corn (61.33%), skim milk powder (10%) and dried whey (15%). The enzymes were: commercial phytase (10,000 FTU/g); carbohydrase providing 10% of Galactomananase, 10% of Xilanase, 10% of ß-glucanase, 60% of malted barley and 10% of α-galactosidase. Data were analyzed by ANOVA and LS Means using the GLM procedure (SAS Inst. Inc., Cary, NC). Significance was defined as P<0.05. Carbohydrase and phytase combination improved the digestibility coefficients (P<0.05) in most of the variables, excepting nitrogen retention which did not show statistical difference among treatments. Wheat bran without enzyme addition had lower values for DE and ME (2,862 and 2,804 kcal/kg), respectively. The higher values observed for DE and ME were: WB+Carb+Phy (3,164 and 3,082 kcal/kg) without statistical difference with WB+Carb (3,098 and 3,056 kcal/kg) (P=0.4785 and P=0.9766) and WB+Phy (3,051 and 2,996 kcal/kg) (P=0.0970 and P=0.5421) (values expressed on dry matter). Lower digestibility of CP was observed for WB and WB+Phy (72.52 and 73.98%) respectively, which statistical results were similar to WB+Carb diet (75.69%) (p=0.9324). The enzymes showed an effective improvement on digestibility of wheat bran for young pigs after weaning.
Keywords: carbohydrase, metabolism, phytase