THE EFFECTS OF PROCESSING AND/OR ENZYME TO IMPROVE THE FEED VALUE OF WHEAT DISTILLERS DRIED GRAINS WITH SOLUBLES FOR TURKEYS

Abstract

Based on ongoing research, the poultry industry is utilizing increasingly more wheat distillers dried grains with solubles (wDDGS) as a feed ingredient. High fiber in wDDGS is a major factor contributing to reduced nutrient intake and digestion of nutrients in the diet. Hence, the research conducted looks at emerging technologies (e.g., enzymes and/or feed processes (extrusion) and/or wet feeding) to overcome the limitations in diets containing higher levels of WDDGS. The dietary treatments were evaluated by monitoring turkey performance and utilization of the nutrients. All dietary treatments in the respective experiments were formulated to meet or exceed the nutrient requirement of the Hybrid Converter turkey standards. With the exception of experiment 2 (0-72d) test diets were fed from 7-21d. In Experiment 1, 0 and 30% wDDGS diets were supplemented with protease (P+; 0.126 g/kg) or β-mannanase (M+; 0.05g/kg); further, diets containing 0, 10, 20 and 30% wDDGS with no enzyme were compared. A positive (P<0.05) main effect of 30% was reported for 21d body weight (BW) and feed conversion ratio (FCR). A significant main effect [21d apparent metabolizable energy (AME); 30%] and interactions [(enzymes x levels (0 and 30%); 21d AME and nitrogen retention (NR)] were found. A quadratic (P<0.01) response was found for FCR, that was superior for 30%. A quadratic (P<0.01) response was also found for both NR and AME; both were highest for 10% wDDGS diets. In Experiment 2, diets containing 0, 15 and 30% wDDGS with no enzyme were compared; further, the 30% wDDGS diet was supplemented with enzymes (protease or β-mannanase). Water intake per pen was monitored beginning at 7 d. There was no effect of dietary treatment on overall feed intake (FI) and body weight (BW). Total feed conversion ratio (FCR) (P<0.05; 0-72d) was significantly improved for birds fed 30% wDDGS regardless of enzyme treatment compared other dietary treatments. There were trends for higher water intake (mL/b/d) with 30%P+ diets as compared to the other diets. The higher water intake may be a factor of the higher fiber in this diet, but it was exacerbated by only the protease enzyme. Experiment 3 evaluated the effect of extrusion (EX) and an enzyme cocktail (E; 0.5g/kg) on wDDGS. Diets containing 0, 15 and 30% wDDGS with/without enzyme were tested; further, the 15 and 30% wDDGS with/without EX and E were compared. There was no effect of EX or E on BW and FI. Feeding higher WDDGS (30%) depressed performance, but an improved NR and AME was recorded. In Experiment 4, a small study was conducted to evaluate if wet feeding (WF; 1.2 mL water: 1.0 g feed) of diets with 30% wDDGS would impact turkey poult performance. The WF significantly improved BW, FI and FCR. It is apparent from these studies that high levels of WDDGS were not detrimental to overall performance. The high levels of wDDGS with no loss of production would result in a higher demand of wDDGS for use in turkey diets. Overall, we saw no improvements in performance with individual supplementation of protease, β-mannanase or an enzyme cocktail. Neither was extrusion of wDDGS beneficial. Voluntary feed consumption is improved when diets are wetted before feeding.