The Interactive Effects of Easyzyme and Phytase in Diets Containing High-Fiber Co-Products on Growth Performance of Nursery Pigs

Two experiments were conducted to determine the effects of a dietary non-starch polysaccharide enzyme (Easyzyme, Archer Daniels Midland Co., Decatur, IL) or phytase (Phyzyme, Danisco Animal Nutrition, St. Louis, MO) addition in corn-soybean meal or high-fiber diets on nursery pig growth performance. In Exp. 1, 192 nursery pigs (PIC 327 × 1050, initially 21.8 lb) were allotted to 1 of 4 dietary treatments arranged in a 2 × 2 factorial. Main effects were diet type (corn-soybean meal or corn-soybean meal plus 30% wheat middlings) with or without added dietary enzyme (Easyzyme Mixer 1, 1 lb/ton). Each experiment involved 6 pigs per pen and 8 replications per treatment. All diets contained 340.5 phytase units (FTU)/lb. From d 0 to 21, pigs fed corn-soybean meal diets had greater (P < 0.001) ADG than those fed diets containing 30% wheat midds. Added Easyzyme had no effect on ADG. ADFI and F/G exhibited a diet type × Easyzyme interaction (P < 0.03). In corn-soybean meal diets, Easyzyme had no effect on ADFI or F/G, whereas in diets containing 30% wheat midds, Easyzyme increased ADFI and worsened F/G.


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The Interactive Effects of Easyzyme and Phytase in Diets Containing High-Fiber Co-Products on Growth Performance of Nursery Pigs1 A. B. Graham, J. M. DeRouchey, M. D. Tokach, R. D. Goodband, S. S. Dritz2 , S. Nitikanchana 2 , J. A. De Jong, and J. L. Nelssen

Summary
Two experiments were conducted to determine the effects of a dietary non-starch polysaccharide enzyme (Easyzyme, Archer Daniels Midland Co., Decatur, IL) or phytase (Phyzyme, Danisco Animal Nutrition, St. Louis, MO) addition in corn-soybean meal or high-fiber diets on nursery pig growth performance.In Exp. 1, 192 nursery pigs (PIC 327 × 1050, initially 21.8 lb) were allotted to 1 of 4 dietary treatments arranged in a 2 × 2 factorial.Main effects were diet type (corn-soybean meal or corn-soybean meal plus 30% wheat middlings) with or without added dietary enzyme (Easyzyme Mixer 1, 1 lb/ton).Each experiment involved 6 pigs per pen and 8 replications per treatment.All diets contained 340.5 phytase units (FTU)/lb.From d 0 to 21, pigs fed corn-soybean meal diets had greater (P < 0.001) ADG than those fed diets containing 30% wheat midds.Added Easyzyme had no effect on ADG.ADFI and F/G exhibited a diet type × Easyzyme interaction (P < 0.03).In corn-soybean meal diets, Easyzyme had no effect on ADFI or F/G, whereas in diets containing 30% wheat midds, Easyzyme increased ADFI and worsened F/G.In Exp. 2, 350 nursery pigs (PIC 1050, initially 25.5 lb) were allotted to 1 of 7 dietary treatments arranged in a 2 × 3 factorial plus control.Pigs were fed either a corn-soybean meal-based diet with no Easyzyme or phytase (Phyzyme) or 1 of 6 diets containing 10% wheat midds, 10% hominy, and 10% corn germ meal with or without Easyzyme and 0, 500, or 1,200 FTU/kg phytase.In this experiment, available P was formulated to the pig's requirement before adding phytase to determine if it affected the digestibility of other nutrients that might enhance growth performance.In the experiment with 5 pigs per pen and 10 replications per treatment, from d 0 to 21, pigs fed the control corn-soybean meal-based diet had greater ADG, ADFI, and better F/G than pigs fed co-product-based diets.Added Easyzyme had no effect on ADG and ADFI, but worsened F/G.Increasing phytase had no effect on ADG, ADFI, or F/G.These results suggest that adding high-fiber co-products to diets decreased ADG and worsened F/G compared with corn-soybean meal diets.Added Easyzyme or high concentrations of phytase in diets adequate in P had no positive effects on growth performance.Key words: by-products, enzyme, fiber, phytase, nursery pig

Introduction
Co-product ingredients are increasingly used to reduce ever-rising feed costs.Diet formulation must account for the fact that most co-product ingredients are higher in fiber and lower in energy than corn (corn ME = 1,551 kcal/lb; wheat middlings ME = 1,372 kcal/lb; NRC, 19983 ).Wheat middlings (midds), a co-product of wheat milling, are often used in swine diets, but the high fiber concentration in wheat midds has proven to have negative effects on growth performance in the nursery.In a recent study, increasing wheat midds decreased ADG as a result of decreased ADFI (De Jong et al.,  2011 4 ).
Because of the high fiber in diets containing wheat midds, supplemental enzymes are often added to the diet in hopes of making the fiber more digestible and improving growth performance.A recent hypothesis is that added phytase in diets already adequate in available P could potentially increase digestibility of nutrients other than P.
The objective of these experiments was to compare growth performance of pigs fed corn-soybean meal-based diets to those fed diets containing high levels of co-product ingredients with or without the addition of a dietary non-starch polysaccharide enzyme (Easyzyme, Archer Daniels Midland Co., Decatur, IL) or supplemental phytase (Phyzyme, Danisco Animal Nutrition, St. Louis, MO).

Procedures
The protocol for this experiment was approved by the Kansas State University Institutional Animal Care and Use Committee.Experiment 1 was conducted at the Kansas State University Swine Teaching and Research Center, and Exp. 2 was conducted at the K-State Segregated Early Weaning Facility, Manhattan, KS.
In Exp. 1, a total of 192 nursery pigs (PIC 327 × 1050, initially 21.8 lb and 35 d of age) were used in a 21-d trial to determine the effects of a dietary non-starch polysaccharide enzyme, Easyzyme, in corn-soybean meal or high-fiber diets on nursery pig growth performance.After weaning, pigs were fed common pretest diets for 15 d.Pens of pigs were then allotted to 1 of 4 dietary treatments with 6 pigs per pen and 8 replications per treatment.Each pen (5 ft × 5 ft) had metal slatted floors, one 5-hole self-feeder, and a nipple waterer.Throughout the study, the pigs had ad libitum access to feed and water.
The dietary treatments were arranged in a 2 × 2 factorial with main effects of diet type (corn-soybean meal vs. corn-soybean meal plus 30% wheat midds) with or without Easyzyme (Table 1).All diets contained phytase at 340.5 FTU/lb of complete diet.All pigs and feeders were weighed on d 0, 7, 14, and 21 to determine ADG, ADFI, and F/G.In Exp. 2, the objective was not only to evaluate Easyzyme in high-co-product diets, but also to examine the effects of superdosing phytase in diets with adequate available P. A total of 350 nursery pigs (PIC 1050, initially 25.5 lb and 42 d of age) were used in a 21-d trial to determine the effects of Easyzyme and Phyzyme addition in corn-soybean meal or high-fiber co-product diets on nursery pig growth performance.Pigs were fed

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either a corn-soybean meal-based diet with no Easyzyme or Phyzyme or 1 of 6 diets containing 10% wheat midds, 10% hominy, and 10% corn germ meal with or without Easyzyme and 0, 500, or 1,200 FTU/kg phytase (Table 2).The assigned ME energy values in diet formulation for wheat midds, hominy, and corn germ meal were 1,372, 1,456, and 1,399 kcal/lb, respectively.Hominy and corn germ meal were provided by Archer Daniels Midland.
After arrival at the nursery, pigs were fed common pretest diets for 21 d.Pens of pigs were then allotted to 1 of 7 dietary treatments with 5 pigs per pen and 10 replications per treatment.Each pen (4 ft × 5 ft) had slatted floors, one 5-hole self-feeder, and a nipple waterer.Throughout the study, the pigs had ad libitum access to feed and water.
Data were analyzed in a completely randomized design with pen as the experimental unit.Analysis of variance was used with the MIXED procedure of SAS (SAS Institute, Inc., Cary, NC).Exp. 1 evaluated main effects of diet type and added Easyzyme and their interaction.In Exp. 2, contrasts were made to compare diet type (corn-soybean meal vs. high-fiber co-product diets), then main effects of added Easyzyme and increasing Phyzyme and their interaction were evaluated within the high-fiber co-product diets.

Results and Discussion
In Exp. 1, pigs fed the corn-soybean meal-based diet had 8% greater (P < 0.001) ADG than pigs fed the diets with 30% wheat midds (Table 3).This ADG response is consistent with the findings of De Jong et al. (2011 4 ), who observed a 6% decrease in ADG with the addition of 20% wheat midds.In the present study, there was a diet type × enzyme interaction (P < 0.03) for ADFI and F/G.In pigs fed the corn-soybean meal diet, addition of Easyzyme had no effect on ADFI or F/G, but in pigs fed diets with 30% wheat midds, added Easyzyme increased ADFI and worsened F/G.Jones et al. (2010 5 ) observed no improvement in pig growth performance when diets contained 30% dried distillers grains with solubles (DDGS) with or without Easyzyme, the same enzyme used in this experiment.Jacela et al. (2010 6 ) also observed no beneficial effects on pig growth or feed efficiency for a variety of dietary enzymes in either corn-or corn-DDGS-based diets.
For Exp. 2, similar to Exp. 1, pigs fed the corn-soybean meal-based diet had 9% greater ADG and 6% better F/G (P < 0.001) than pigs fed the co-product-based diet (Tables 4  and 5), and added Easyzyme had no effect on ADG or ADFI but worsened (P < 0.001) F/G.Added phytase improves the digestibility of phytate P in feed ingredients for swine and poultry.In addition, phytase may improve the digestibility of other nutrients in the diet.The diets in Exp. 2 were adequate in P; therefore, the objective was to determine if

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high levels of phytase might positively affect pig performance.In this study, increasing added phytase had no effect on ADG or F/G (Table 6).In conclusion, with the high-fiber co-product diets used in these experiments, neither Easyzyme nor added phytase improved pig performance.

Table 1 .
Composition of diets, Exp. 1 (as-fed basis) 1 1 Treatment diets fed for 21 d.2Phyzyme 600 (Danisco Animal Nutrition, St. Louis, MO) provided 340.5 phytase units (FTU)/lb, with a release of 0.12% available P.3Easyzyme Mixer 1 (Archer Daniels Midland Company, Decatur, IL) was added to the diet in place of corn at a rate of 1lb/ton.

Table 2 .
Composition of diets, Exp. 2 (as-fed basis) 1 Phyzyme 600 (Danisco Animal Nutrition, St. Louis, MO) was added in place of corn to provide either 500 or 1200 phytase units (FTU)/kg phytase.3EasyzymeMixer 1 (Archer Daniels Midland Co., Decatur, IL) was added in place of corn at a rate of 1lb/ton. 2

Table 5 .
Main effects of Easyzyme inclusion in high-fiber co-product nursery diets (Exp.2) 1 A total of 350 pigs (PIC 1050, initially 25.53 lb BW and 42 d of age) were used in a 21-d growth trial with 5 pigs per pen and 10 replications per treatment. 2Easyzyme Mixer 1 (Archer Daniels Midland Company, Decatur, IL) was added in place of corn at a rate of 1 lb/ton. 1

Table 6 .
Main effects of added phytase in high-fiber nursery diets (Exp.2) 1