The Effect of Enzymes, Steeping and Dietary Protein Level on Apparent Fecal Digestibility and Fecal Output in Pigs fed Corn- Soybean Meal Diets.

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1 The Effect of Enzymes, Steeping and Dietary Protein Level on Apparent Fecal Digestibility and Fecal Output in Pigs fed Corn- Soybean Meal Diets. Jennifer E. Wubben 1, Michelle R. Smiricky 2, David M. Albin 1 and Vince M. Gabert 3 1 M. S. student; 2 Ph. D. student; 3 Assistant Professor; Department of Animal Sciences, University of Illinois at Urbana-Champaign Introduction The digestibility of nutrients by the pig is an important measure of efficiency when evaluating swine diets or ingredients used in swine diets. Any method of feeding or feed additive that significantly increases the digestibility of nutrients could be used to increase the efficiency of, and decrease waste and nutrient losses from, swine production. Feed enzymes have been used to attempt to increase nutrient digestibility in swine (Bedford and Schulze, 1998). Much of the research with fiber-degrading enzymes has been conducted with beta-glucanase (Baas and Thacker, 1996; Li et al., 1996; Baidoo et al., 1998), which is commonly used in diets that mainly consist of barley or wheat. Research conducted with multiple enzymes in the same diet is less common, and the influence of enzymes used in combination on digestibility of nutrients has not been evaluated. Fibrous components of the diet, especially cellulose, have been shown to decrease amino acid digestibility in the pig (Li et al., 1994; Lien, 1995). Thus, a mixture of mainly fiber-degrading enzymes may improve the digestibility of nutrients in the corn-soybean meal diet. Feed (soaking meals in water prior to feeding) has been evaluated, and has been shown to increase weight gain and feed efficiency, as well as the efficacy of supplemental phytase and its effects on phosphorus retention, in a corn-soybean meal diet for growing pigs (Liu et al., 1997). Skoglund et al. (1997) also reported improvements in phosphorus utilization when a barley-rapeseed cake-pea diet was steeped. However, Nasi and Helander (1994), while conducting research with phytase, reported that soaking did not affect the digestibility or retention of any nutrient in a barley-soybean meal diet. The purpose of the present study was to evaluate the effect of six enzymes (cellulase, hemicullulase, amylase, xylanase, alpha-galactosidase and protease), feed for 12 h prior to feeding, and the combination of both of these treatments, on the apparent fecal digestibility of crude protein in, and fecal output of, growing pigs fed corn-soybean meal diets. Materials and Methods

2 Animals and treatments. Eight barrows (Line 337 sire x C22 dams; PIC, Franklin, KY) with an average initial body weight of 43 kg were randomly assigned to two 4 x 4 Latin squares. The barrows were housed in individual metabolism crates in a temperature-controlled barn, and were used for four experimental periods. Four experimental diets, formulated to contain either 14% or 18% crude protein and.3% chromic oxide, were used. Two of the diets contained supplemental enzymes (diets B and D), and two of the diets did not contain enzymes (diets A and C; Table 1). The diets with enzymes contained 3,400 units of cellulase/kg diet; 165,000 units of hemicellulase/kg diet; 2,128 units of amylase/kg diet; 21,280 units of protease/kg diet; 1,596 units of xylanase/kg diet; and 1,800 units of alpha-galactosidase/kg diet. The barrows were fed one of four experimental treatments in each square control diet (A or C); control diet plus for 12 h prior to feeding; enzyme diet (B or D); and the enzyme diet plus for 12 h prior to feeding. Water was added to the steeped meals on a 1.45:1 weight basis, and was available to all pigs from a low-pressure drinking nipple ad libitum. Each period consisted of a 4 d adaptation phase and 5 d collection phase with total fecal collection. The pigs were fed 1.8, 1.92, 2.0, and 2.06 kg/d respectively during periods 1-4. Feeding occurred at 0900 and 2100 h. Feces were pooled within barrow and period, and were then frozen at 10 o C. Chemical and statistical analysis. Samples of diets and 57 o C oven-dried feces were ground with liquid nitrogen in a coffee mill. For dry matter determinations, empty 50 ml glass beakers that had been in a 105 o C oven overnight were weighed immediately after removal from the oven. Samples of diets and feces were then weighed into the beakers, and the beakers plus sample were placed into the oven overnight. The next day each beaker and sample were weighed, and dry matter was calculated. The same samples were then ashed in a muffle furnace for 16 h at 450 o C. Organic matter was determined by the difference between ash percentage and 100. Then, the samples were used for chromic oxide determination according to Fenton and Fenton (1979). Crude protein was determined for diets and feces according to the AOAC (1995). The apparent fecal digestibility values and fecal output of the experiment treatments were subjected to statistical analysis as Latin square designs with four replicates per treatment using PROC GLM of SAS (1990). Means of dietary treatments and experimental periods within square were compared using the Student-Newman-Keuls multiple range test (Ott, 1993). Oneway ANOVA was used to evaluate the effect of protein level (square) on the measured parameters (SAS, 1990). Results and Discussion The apparent fecal digestibilities of dry matter, crude protein and organic matter, and fecal output are presented in Table 2. Digestibility was not affected (P >.05) by any of the treatments. The use of feed enzymes in conjunction with numerically reduced crude protein digestibility. Fecal output on a wet basis was not affected (P >.05) by any of the treatments. However, pigs in the 18% crude protein square fed supplemental enzymes tended to produce less feces (P =.07) on a wet basis than all other treatments. Fecal output on a dry matter basis from pigs in the 14% crude protein square was not affected (P >.05) by treatment. However, in the 18% crude protein square, pigs fed the enzyme-supplemented diet produced fewer feces (P <.05) on a dry matter basis. Thus, the use of multiple enzymes resulted in fewer fecal solids produced compared to all other treatments in the 18% crude protein square. Apparent protein

3 digestibility and fecal output, both on a dry and wet basis, were higher (P <.05; P =.08) for pigs fed the 18% crude protein diet compared to those fed the 14% crude protein diet, which were expected (Data not shown). To our knowledge, this is the first study to investigate the influence of a combination of enzymes on nutrient digestibility and fecal output using a corn-soybean meal diet. Implications Multiple enzymes and did not affect fecal digestibility in growing pigs fed corn-soybean meal diets with 14% or 18% crude protein. Fecal output was not affected by treatments in the 14% crude protein square, but fecal output on a dry matter basis was lowered by the use of feed enzymes in the 18% crude protein square. Also, pigs fed 18% crude protein diets had higher crude protein digestibility coefficients and fecal output. Thus, feeding growing pigs 18% crude protein diets supplemented with the six enzymes used in this study at a total dietary inclusion level of 1% reduced fecal output. Further research with pigs at different ages and physiological states, as well as different diets, should be conducted to further evaluate the efficacy of feeding multiple enzymes and. Acknowledgments The authors wish to acknowledge the financial support of the Illinois Council on Food and Agricultural Research (C-FAR) for this experiment. Literature Cited AOAC Official Methods of Analysis (16 th Ed.). Association of Official Analytical Chemists, Arlington, VA. Baas, T.C., and P.A. Thacker Impact of gastric ph on dietary enzyme activity and survivability in swine fed b-glucanase supplemented diets. Can. J. Anim. Sci. 76: Baidoo, S.K., Y.G Liu, and D. Yungblut Effect of microbial enzyme supplementation on energy, amino acid digestibility and performance of pigs fed hulless barley based diets. Can. J. Anim. Sci. 78: Bedford, M.R., and H. Schulze Exogenous enzymes for pigs and poultry. Nutr. Res. Rev. 11: Bidlingmeyer, B.A., S.A. Cohen, and T.L. Tarvin Rapid analysis of amino acids using pre-column derivatization. J. Chromatogr. 336: Fenton, T.W., and M. Fenton An improved procedure for the determination of chromic oxide in feed and feces. Can. J. Anim. Sci. 76: Li, S., W.C. Sauer, and R.T. Hardin Effect of dietary fibre level on amino acid

4 digestibility in young pigs. Can. J. Anim. Sci. 74: Li, S., W.C. Sauer, and S.X. Huang Effect of b-glucanase supplementation to hulless barley- or wheat-soybean meal diets on the digestibilities of energy, protein, b-glucans, and amino acids in young pigs. J. Anim. Sci. 74: Lien, K.A Endogenous protein in ileal digesta: estimation of the mucin content and an evaluation of the 15 N-isotope dilution technique. Ph.D. thesis. University of Alberta, Edmonton. Liu, J., D.W. Bollinger, and D.R. Ledoux Soaking increases the efficacy of supplemental phytase in a low-phosphorus corn-soybean meal diet for growing pigs. J. Anim. Sci. 75: Nasi, M., and E. Helander Effects of microbial phytase supplementation and soaking of barley soybean meal on availability of plant phosphorus for growing pigs. Acta. Agric. Scand. Sect. A. 44: Ott, R.L An Introduction to Statistical Methods and Data Analysis. Wadsworth Publishing Company, Belmont, CA. SAS SAS/STAT User s Guide (Release 6.08). SAS Inst. Inc., Cary, NC. Skoglund, E., T. Larsen, and A.S. Sandberg Comparison between and pelleting a mixed diet at different calcium levels on phytate degradation in pigs. Can. J. Anim. Sci. 77: Table 1. Formulation (%) of the experimental diets (as-fed basis) Diet Crude protein 14% 14% 18% 18% Ingredient A B C D Corn Soybean meal Soybean oil Dicalcium phosphate Calcium carbonate Vitamin premix a Trace mineral premix b L-Lysine HCl DL-Methionine L-Tryptophan L-Threonine Folic acid Corn starch c Cellulase d

5 Hemicell D e Alpha-Gal 600 L f Avizyme g Chromic oxide a Provided the following (per kg of diet): choline, 121 mg; niacin, 16.5 mg; pantothenic acid, 12.1 mg; riboflavin, 4.4 mg; vitamin B 12,.02 mg; vitamin E, 44.1 IU; vitamin A, 3310 IU; vitamin D, 331 IU; vitamin K, 2.21 mg. Supplied by Archer Daniels Midland Company, Effingham, IL. b Provided the following (per kg of diet): sodium, 2.8 g; chloride, 2.8 g; copper, 7.79 mg; iodine,.34 mg; iron, 87.4 mg; manganese, 19.4 mg; selenium, 0.29 mg; zinc, 97.2 mg. Supplied by Archer Daniels Midland Company, Effingham, IL. c Clinton Brand, Archer Daniels Midland Company, Effingham, IL d Sigma Chemical Company, provided 3,400 cellulase units per kg diet. e ChemGen, provided 165,000 hemicellulase units per kg diet. f Novo Nordisk, provided 1,800 alpha-galactosidase units per kg diet. g FinnFeeds, provided 2,128 amylase units; 21,280 protease units; and 1,596 xylanase units; per kg diet. Table 2. Apparent fecal digestibilities of dry matter, organic matter, crude protein and fecal output of the experimental treatments Treatment Item A A plus B B plus SEM a Dry matter, % 86.4 b 86.3 b 86.5 b 86.1 b 0.57 Organic matter, % 88.4 b 88.4 b 87.6 b 87.0 b 0.76 Crude protein, % 81.4 b 79.5 b 82.2 b 81.4 b 1.28 Fecal output (dry), g/d b b b b Fecal output (wet), g/d b b b b Treatment Item C C plus D D plus SEM a Dry matter, % 87.0 b 86.1 b 86.0 b 86.3 b 0.47 Organic matter, % 89.1 b 88.4 b 88.6 b 88.7 b 0.63 Crude protein, % 84.5 b 82.7 b 84.2 b 83.4 b 0.98 Fecal output (dry), g/d b b c b 5.12 Fecal output (wet), g/d b b b b a Standard error of the mean (n=4). b,c Means in the same row with different superscript letters differ (P <.05).