Invited Speakers. végétal, France; 4 ADISSEO France SAS, France; 5 AJINOMOTO EUROLYSINE S.A.S., France; 6 ARVALIS - Institut du végétal, France

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1 S6.2 Nutritional Value of Distillers Grains in Poultry P. COZANNET 1, 3, M. LESSIRE 2, J.P. METAYER 3, C. GADY 4, Y. PRIMOT 5, F. SKIBA 6 ; J. NOBLET 1 1 INRA, UMR1079 SENAH, France; 2 INRA, UR83 France; 3 ARVALIS - Institut du végétal, France; 4 ADISSEO France SAS, France; 5 AJINOMOTO EUROLYSINE S.A.S., France; 6 ARVALIS - Institut du végétal, France Dried distillers grains with solubles (DDGS) are a by-product from the ethanol industry from cereals (mainly corn in North America and wheat in Europe). As more DDGS become available with the expected increased ethanol production, it is anticipated that they will be included not only in diets for ruminants but also in pigs and poultry diets. The purpose of this review paper is to consider their introduction in poultry diets. Nutrients content in DDGS and their digestibility vary between ethanol plants. Most of the variability concerns the amino acids (AA) contents and their ileal digestibility (SID) and is due to occurrence of Maillard reactions reflected by their lightness score (L). Consequently, samples with low nutritional value have lowest L values (<50 for wheat DDGS and <40 for corn DDGS corresponding to dark products). Lysine is the most concerned AA with contents ranging between 1.7 and 3.0% of crude protein (CP; N*6.25) for light wheat or corn DDGS. In parallel, lysine SID is also variable (49 to 71% and 78 to 82% for light wheat and corn DDGS, respectively) with the lowest values observed in DDGS with low lysine level in CP. For the darkest products, lysine content and SID close to zero are observed. Energy digestibility varies in parallel with changes in lysine content and SID due to changes in L values but also according to other nutrients such as fat, dietary fibre and residual starch contents. The TMEn for rooster of corn DDGS ranges from 10.8 to 13.8 MJ per kg (89% DM; 12.2 MJ on average) while AMEn measured on wheat DDGS varies between 8.8 and 10.1 MJ per kg (89% DM; 9.5 MJ on average). Energy values change moderately according to species or physiological stage. In total, DDGS from cereals can be used in diets for poultry but only the light products are recommended and their introduction at high inclusion rates is possible only in low density diets. Keywords: distillers grains, poultry, amino acids, energy, digestibility Introduction In recent years, the ethanol production as partial substitute of petrol has rapidly increased and further increases are expected in the future (Windhorst, 2007). Ethanol is currently produced at a commercial scale via enzymatic breakdown of starch and yeast controlled fermentation of glucose into ethanol. Second generation ethanol production based on cellulose is still in a development phase. This production is mainly based on corn in the United States whereas in Canada and Europe, wheat or barley are used in ethanol plants. Distillers dried grains with solubles (DDGS) is the primary resulting by-product of this production. Mainly used so far in ruminant feeds, this by-product has become available for non ruminants according to the increased availabilities. However, knowledge on its characteristics, its nutritional value and its tolerance and practical utilization in poultry feeds is insufficient. Thus, the objective of this review is to summarize literature results from recent research on corn and wheat DDGS in poultry. Most data presented for wheat DDGS originate from a project conducted in France with simultaneous measurements on growing and adult pigs and poultries (Cozannet et al., 2009a, b, c). Composition and chemical characteristics of DDGS Either corn or wheat DDGS are characterized by the nutrient composition of the grain used to produce the ethanol assuming that the product contains the non fermentable fraction of the grain which is more or less equivalent to its non starch fraction. Therefore, the nutrients, except starch, in corn and wheat DDGS would be expected to be approximately three fold higher than those in corn or wheat (Table 1). But, the chemical composition of DDGS is much more variable than in the original cereals with large differences between ethanol plants (Spiehs et al., 2002). Overall, factors including method of fermentation process, duration and temperature of drying and amount of solubles blended with distillers grains can affect their chemical and physical characteristics. Colour of DDGS can also vary from light yellow to dark brown. Measured with Minolta colorimeter, luminance values ranged from 43 to 63 in wheat DDGS and 28 to 55 in corn DDGS (Table 1). In addition, only light coloured DDGS have a sweet and fermented smell. These aspects should be taken into account. Therefore, in this review, corn or wheat DDGS with L values higher than 33 and 50, respectively, will be considered as standard while those with L values lower than these limits correspond to overheated DDGS. 132

2 As expected, starch in the grain is converted to ethanol during the fermentation process and only a small amount of starch is present in DDGS (Table 1). In contrast, non fermentable nutrients are concentrated. In comparison with wheat or corn, crude protein, crude fat and crude fibre averaged 36.6, 4.4 and 7.6% of DM in 10 samples of European wheat DDGS and 30.0, 10.7 and 8.6% of DM in USA corn DDGS (Table 1). However, ethanol isn t the only product of fermentation since the process is associated with 93% of ethanol, 3% yeast (Mustapha et al., 2002) and 4% glycerol produced from lipids. Most of the produced compounds remain in the DDGS whereas part of the most volatile compounds such ammonium or glycerol may escape into ethanol during the distillation and drying steps. Although the sum of crude fat, crude protein, NDF, sugars, starch, ash and moisture approximate 100% for the grain, it s only about 85% for either corn or wheat DDGS (Sauvant et al., 2004; Table 1). But some sources may indicate a sum higher than 100%, probably due to analytical mistakes and overestimation of the dietary fibre fraction which contains protein (Stein et al., 2006). These problems were previously reported by Dorleans et al. (1995) for oilseed meals. Sodium sulfite may be used in order to prevent this and achieve lower NDF values (Shurson, 2008). These phenomenons are important in the darkest samples and suggest a positive relationship between drying temperature and protein solubility as reported by Cromwell et al. (1993). Consequently, nitrogen in NDF and ADF contents in wheat and corn DDGS may vary considerably between light and dark products (Table 6). Energy and nutrients digestibility 1 In connection with fat enrichment, corn DDGS contain higher gross energy (GE) contents than the originated grains. The average concentration of GE in 10 samples of corn DDGS proposed by Pedersen et al. (2007) was ± 0.40 MJ GE per kg; the corresponding value for corn is MJ GE per kg (Sauvant et al., 2004; Table 1). However, the digestibility and the metabolizability of energy of corn DDGS in poultry are lower than in cereals due to their higher fiber content (82.9 vs 65.8% for AMEn/GE in corn and corn DDGS, respectively). Consequently, apparent metabolizable energy for zero nitrogen retention (AMEn) for corn and corn DDGS are comparable for roosters (13.0 vs 13.3 MJ per kg respectively; Table 2). In addition, AMEn and AMEn/GE for broilers were lower than in roosters (13.3 vs 11.2 MJ per kg and 55.8 vs 65.8% for broilers and roosters, respectively; Skiba et al., 2009) whereas corresponding values for corn were similar (13.0 vs 12.7 MJ per kg and 82.9 vs 81.1% for broilers and roosters, respectively; Sauvant et al., 2004). This would suggest an important effect of physiological stage on energy digestibility in corn DDGS (Skiba et al., 2009). Fastinger et al, (2006) reported that true metabolizable energy corrected for zero nitrogen retention (TMEn) content in five sources of corn DDGS ranged from 10.4 to 12.6 MJ per kg (12.0 MJ on average) in cecectomized roosters. In addition, based on the analyses of 17 corn DDGS samples and using conventional roosters, Batal and Dale (2006) reported TMEn for corn DDGS in poultry ranging from 10.8 to 13.8 MJ per kg (12.2 MJ per kg on average). These values are lower than the values measured for corn (14.4 and 13.0 MJ per kg for TME and AMEn; Dale, 1994; Sauvant et al., 2004). Fastinger et al., (2006) attempted to develop a predictive equation for TMEn based on fat, fiber, protein, and ash content. Fat content was the best predictor of TMEn content, but the prediction was poor (R²=0.29). Adding fiber, protein, and ash to the regression model improved moderately the prediction equation (R²=0.45). Gross energy content is higher in wheat DDGS than in wheat (18.67 vs MJ per kg). As for corn DDGS, metabolizability in rooster is lower for wheat DDGS than for wheat (51.3 vs 78.8%). Consequently, the mean concentration of AMEn in 7 sources of wheat DDGS was 9.6 ± 0.4 MJ per kg in roosters (Cozannet et al., 2009b; Table 2) whereas corresponding value is 12.2 MJ per kg for wheat. In this latter study, the AMEn values were also measured in broilers, laying hens and turkeys in order to evaluate the effect of species, age and physiological stage. Values are reported in Table 2. The AMEn value in roosters is always higher than in layers, broilers and turkeys; this difference was significant only for turkeys and layers but not for broilers. This finding suggests that wheat DDGS should be assigned at least three AMEn values. Nevertheless, strong correlations between AMEn values measured in broilers, layers and turkeys and AMEn values in roosters (unpublished data) suggest that AMEn values of wheat DDGS in roosters can be used for estimating energy values in other ages/physiological stages and avian species (Cozannet et al., unpublished). 1 Energy values are standardized at 89% dry matter 133

3 Amino acids content and digestibility Average protein and essential amino acids (AA) contents of wheat (n=7) and corn (n=4) DDGS are summarized in Table 3. According to process, AA profiles (% N*6.25) should be in close agreement with those of initial cereals. Nevertheless, yeasts used for starch fermentation represent an additional protein source equivalent to about 5% of the total DDGS protein content (Indeglew, 1993). In addition, the level of soluble fractions added into distillers grains influence the protein content and the AA profile. But, as illustrated in Table 3, the AA profile is quite comparable in DDGS and the corresponding cereal, except for lysine and arginine with lower contents in DDGS. In addition, even though CP contents are rather constant between samples, the lysine and arginine levels in CP are highly variable: 1.7 to 3.0% and 3.7 to 4.6%, respectively for wheat DDGS and 1.8 to 2.8% and 3.4 to 3.9%, respectively for corn DDGS. Consequently, unlike corn or wheat or their milling by-products, poor correlations exist between lysine or arginine (in % of DM) and CP content. In other terms, CP content cannot be used as an indicator of lysine or arginine levels in wheat or corn DDGS. These assumptions are more obvious when dark DDGS are included in the relationships (Table 6). The standardized ileal digestibilities (SID) of essential AA of DDGS measured with caecectomized roosters are presented in Table 4. The CP digestibility ranges between 76 and 85% for wheat DDGS and 80 and 86% for corn DDGS (Ergul et al., 2003). Most amino acids in corn and wheat DDGS have a SID that is approximately 7 and 4 percentage units less than in the corresponding cereals; that is mainly a consequence of the greater concentration of dietary fibre in DDGS than in cereals. The difference is more accentuated for lysine, especially for wheat DDGS (minus 23 and 6 points for wheat and corn DDGS, respectively), presumably reflecting a loss in digestibility due to the drying of DDGS. In addition, the SID of arginine and lysine appears highly variable since it ranged for lysine from 0 to 71% in 10 samples of wheat DDGS (Cozannet et al., 2009); the lowest values were observed in dark products with the probable occurrence of Maillard reactions (Table 6). Consequently, lysine and arginine contents and SID values represent a major concern in wheat and corn DDGS as feeds for poultry. The combination of low lysine content in CP and low SID of lysine in dark or overheated DDGS suggests not including such ingredients in feeds for non ruminant animals. Such results also suggest that colour determination might be a quick and reliable method for estimating the lysine digestibility of DDGS and identifying DDGS sources with poor AA digestibility (Table 6). In addition, our survey suggests that overheating would affect to a higher extent the digestibility of wheat DDGS (Table 6). Nevertheless, a poor relationship was found between lysine digestibility and colour score (r = 0.64) for wheat DDGS (Cozannet et al., 2009) whereas Batal and Dale (2006) reported a better relationship (r = 0.87) for corn DDGS. However, for wheat DDGS, a better prediction was obtained with lysine content in CP (Lys) according to a quadratic regression model (Lysine SID = Lys 13.1 Lys², R² = 0.95) or a linear-plateau regression model (R² = 0.87) with a breakpoint of 1.3% lysine in CP and a 61% plateau SID value. This breakpoint value is lower than the values obtained in pigs for corn DDGS (2.8%; Shurson et al., 2008) or wheat DDGS (1.9%; Cozannet et al., 2009a). Poultry performance Most results on performance of poultry fed DDGS concern corn DDGS. When diets formulation do not take into account proper values, neither for digestible lysine content nor for metabolizable energy, experiments on broilers and turkeys in which growth performance were evaluated indicate an increase in feed:gain ratio with increased inclusion levels of DDGS (Lumpkins et al., 2004; Métayer et al., 2009) or no detrimental effect (Waldroup et al., 1981). In addition, these effects were more pronounced in young than in older birds and dependent on DDGS quality (Robertson et al., 2003). Most of the authors speculate that performance reduction with higher DDGS inclusions is due to an over estimation of lysine in the product, resulting in marginal deficiency of this amino acid. Therefore, based upon such results, Lumpkins et al., (2004) suggested that a safe inclusion level of corn DDGS was 6% in the starter period and 12 to 15% in the grower and finisher periods for broilers whereas Thacker et al., (2007) suggested that wheat DDGS could be incorporated safely up to 15%. Nevertheless, more accurate lysine content estimation would allow higher incorporation levels. Thus, Wang et al, (2007) didn t show any detrimental effect of corn DDGS inclusion level up to 25% in broilers in the grower and finisher periods with low density diets formulated on digestible amino acids levels. For turkey hens, Robertson et al, (2003) demonstrated that 10% corn DDGS can be fed in the growing-finishing phases with no detrimental effects on growth performance as long as the actual energy value or lysine levels are considered. Unfortunately, there is no similar information for wheat DDGS fed to poultry. Results close to those obtained with corn DDGS are expected. 134

4 Conclusions Either corn or wheat DDGS are a potential source of energy and proteins in poultry diets. Variability exists within and between ethanol plants and between published reference sources. Nutritionists using DDGS in poultry diets should be aware of the variability in nutrients content and in their digestibility. Based on available literature, it seems that the composition of corn DDGS is more stable than for wheat DDGS. The reason for this is unclear; procedures for ethanol extraction and conditioning of by-products might be more optimal and stabilized for corn DDGS. Colour score appears as a promising method for a rapid reliable estimation of both energy and amino acids digestibility. Better knowledge of product quality might prevent any detrimental effect on animals fed DDGS and allow higher inclusion levels. Our review also suggests that the processing of DDGS should be adapted and optimized in order to get a high quality by-product. References: BATAL, A.B., and DALE, N.M. (2006) True metabolizable energy and amino acid digestibility of dried distiller grain and solubles. Journal of Applied Poultry Research 15: CARRE, B. and BRILLOUET, J.M. (1989) Determination of water-insoluble cell walls in feeds: Interlaboratory study. Journal Association of official Analytical Chemists 72: COZANNET, P., PRIMOT, Y., GADY, C., METAYER, J.P., CALLU, P., LESSIRE, M., LE TUTOUR, L., GERAERT, P.A., SKIBA, F. and NOBLET J. (2009a). Valeur nutritionnelle des drêches de blé européennes chez le porc en croissance. 41 ème Journées de la Recherche Porcine: COZANNET, P., GADY, C., Primot, Y., METAYER, J.P., LESSIRE, M., LE TUTOUR, L., GERAERT, P.A., SKIBA, F. and NOBET, J. (2009b). Composition chimique et digestibilité iléale des acides amines des drêches de blé européennes : quelles variabilité? 8 ème Journées de la Recherche Avicole: 49. COZANNET, P., METAYER, J.P., GADY, C., PRIMOT, Y., LESSIRE, M., LE TUTOUR, L., GERAERT, P.A., SKIBA, F. and NOBET, J. (2009c). Valeur énergétique des drêches de blé chez le coq entier et le poulet en croissance. 8 ème Journées de la Recherche Avicole: 55. CROMWELL, G. L., HERCKELMAN, K. L. and STAHLY, T.S. (1993) Physical, chemical and nutritional characterisrics of distillers dried grains with solubles for chicks and pigs Journal of Animal Science 71: DALE, N. (1994). True metabolizable energy of corn fractions. Journal Applied Poultry Research 3: DORLEANS, M., MANDRAN, N. and SANVANT D. (1995). Study of the use of a protease with van Soest procedure. Anim. Feed Science and Technology 61: ERGUL, T., MARTINEZ AMEZCUS, C., PARSONS, C.M., WALTERS, B., BRANNON, J. and NOLL, S.L. (2003) Amino acid digestibility in corn distillers dried grains with solubles. Poultry Science. 82 (Suppl. 1): 70. FASTINGER, N.D., LATSHAW, J.D. and MAHAN, D.C. (2006) Amino Acid availability and true metabolizable energy content of corn dried grains with solubles in adult cecectomized roosters. Poultry Science 85: INGLEDEW, W.M. (1993) Yeast for production of fuel ethanol The Yeast 2nd Edition Vol. 5 Yeast. Technology. Academic Press. New York, NY. LUMPKINS, B.S., BATAL A.B. and DALE., N.M. (2004). Evaluation of distillers dried grain with solubles as a feed ingredient for broiler. Poultry Science 83: METAYER, J.P., GAUZERE, J.M., GADY, C., SKIBA, F. and VILARINO, M. (2009) Valeur nutritionnelle d une drêche de blé chez le coq et le poulet effet du niveau d incorporation et de l ajout d un complexe multi-enzymatique sur les performances croisance des poulets standards. 8 ème Journées de la Recherche Avicole: 56. MUSTAPHA, A.F., McKINNON, J.J. and CHRISTENSEN, D.A. (1999) Chemical characterization and in vitro crude protein degradability of thin stillage derived from barley- and wheat-based ethanol production. Animal Feed Science and Technology. 80: PEDERSEN, C., BOERSMA, M.G. and STEIN, H.H. (2007) Digestibility of energy and phosphorus in ten samples of distillers dried grains with solubles fed to growing pigs. Journal of Animal Science 85: ROBERTSON, K.D. (2003) Use of dried distillers grain with solubles in growing-finishing diets of turkey hens. International Journal of poultry science 2: SAUVANT, D., PEREZ, J.M. and TRAN, G. (2004) Tables of composition and nutritive value of feed materials Pigs, poultry, cattle, sheep, goats, rabbits, horses, fish. INRA Editions, Versailles, France SKIBA, F., METAYER, J.P., CLAVE, H. and QUENTIN, M. (2009) Valeur énergétique d une 135

5 drêche de maïs sur les performances zootechniques de poulet de chair. 8 ème Journées de la Recherche Avicole: 57. SPIEHS, M.J., WHITNEY, M.H. and SHURSON, G.C. (2002) Nutrient database for distiller's dried grains with solubles produced from new ethanol plants in Minnesota and South Dakota. Journal of Animal Science 80: SHURSON, J. (2008) Distiller grain by-products in livestock and poultry feeds. July 29 STEIN, H.H., GIBSON, M.L., PEDERSEN, C. and BOERSMA, M.G. (2006) Amino acid and energy digestibility in ten samples of distillers dried grain with solubles fed to growing pigs. Journal of Animal Science 84: THACKER, P.A. and WIDYARATNE, G.P. (2007) Nutritional value of diets containing graded levels of wheat distillers grains with solubles fed to broiler chicks. Journal of the Science of Food Agriculture 87: WALDROUP, P.W., OWEN, J.A., RAMSEY, B.E. and WHELCHEL D.L. (1981) The use of high levels of distillers dried grains plus solubles in broiler diets. Poultry Science 60: WANG, Z., CERRATE, S., COTO, C., YAN, F. and WALDROUP P.W. (2007) Utilization of distiller dried grains with solubles (DDGS) in broiler diet using a standardized nutrient Matrix. International Journal of Poultry Science 6: WINDHORST, H.W. (2007) Bio energy production, a threat to the global egg industry? World Poultry Science Journal 63:

6 Table 1: Composition of wheat DDGS and corn DDGS; comparison with wheat and corn Wheat a Wheat DDGSb a Corn Corn DDGSc Mean (Min - Max) Mean (Min - Max) Dry Matter ( ) ( ) Composition, % DM Ash ( ) ( ) Protein (N*6.25) ( ) ( ) Crude fat ( ) ( ) Crude fiber ( ) ( ) NDF d ( ) ( ) ADF d ( ) ( ) ADL d ( ) 0.6 WICW e ( ) 10.5 Starch ( ) ( ) Sugars ( ) 1.9 Gross energy, MJ/kg e ( ) ( ) a Sauvant et al. (2004). b Cozannet et al. (2009a): n=7, products with luminance > 50. c Spiehs et al. (2002): n=12, for dry matter, ash, protein, crude fat, crude fiber, NDF, ADF; Pedersen et al. (2007), n=10, for gross energy and starch. d Cell wall fractions in wheat DDGS were determined according to the methods of Van Soest with prior proteolytic (protease from streptococcus griseus) and amylolytic (thermamyl 120L) treatments. e Water insoluble cell walls determined according to Carré et Brillouet (1989); gross energy is standardized for a 89% DM content Table 2: Apparent metabolizable energy corrected for zero nitrogen deposition (AMEn) and AMEn/gross energy ratio in wheat DDGS and corn DDGS fed to roosters, layers, broilers or turkeys; comparison with wheat and corn a Rooster Layer Broiler Turkey ( ) ( ) Mean (Min-Max) Mean (Min- Max) Mean (Min-Max) Mean Wheat b AMEn/GE, % AMEn, MJ per kg Wheat DDGS c (47.3- (46.4- (41.9- AMEn/GE, % ) ) ) 45.5 (8.76- (8.64- (7.78- AMEn, MJ per kg ) ) ) 8.49 Corn b AMEn/GE, % AMEn, MJ per kg Corn DDGS d (51.2- TMEn/GE, % ) TMEn, MJ per kg AMEn/GE, % 65.8 ( ) (Min- Max) AMEn, MJ per kg a DM content is standardized at 89%. b Sauvant et al. (2004) c Cozannet et al. (2009c): n=7, products with luminance above 50. d Skiba et al. (2009): n=1; AMEn for rooster; Adisseo, unpublished data: n=12; AMEn for broiler; Batal and Dale (2006): n=17, TMEn for rooster; Fastinger et al. (2006): n=5; TMEn/GE for rooster. 137

7 Table 3: Concentration of CP and essential amino acids (AA) in wheat, wheat DDGS, corn and corn DDGS (% N*6.25). Wheat DDGS b Corn DDGS c (Min - (Min - Wheat a Mean Max) Corn a Mean Max) Crude protein, % DM ( ) 9.4 Essential AA Arg ( ) ( ) His ( ) ( ) Lys ( ) ( ) Phe ( ) ( ) Leu ( ) ( ) Ile ( ) ( ) Val ( ) ( ) Met ( ) ( ) Thr ( ) ( ) Trp ( ) ( ) Total ( ) ( ) Nonessential AA ( ) ( ) a Sauvant et al. (2004). b Cozannet et al. (2009b): n=7; products with luminance above 50. c Fastinger et al. (2006): n=4 Table 4: Standardized ileal digestibility of CP and amino acids (AA) in wheat DDGS and corn DDGS; comparison with wheat and corn b Wheat DDGS (n=7) c Corn DDGS (n=4) Wheat a Mean (Min - Max) Corn a Mean (Min - Max) Crude protein (76-85) 88 Essential AA Arg (72-81) (89-90) Hist (71-83) (85-89) Lys (49-71) (78-82) Phe (84-90) (89-90) Leu (76-86) (88-93) Ile (70-84) (84-86) Val (72-85) (81-85) Met (74-84) (89-90) Thr (66-76) (78-80) Trp 75 (68-78) 89 (88-90) Total (68-82) (76-78) N o n e ss e n t i a l A A (79-88) (68-76) a Sauvant et al. (2004). b Cozannet et al.(2009b): n=7, products with luminance > 50. c Fastinger et al. (2006) 138

8 Table 5: Digestive utilization of nutrients in wheat DDGS or corn DDGS: impact of colour Wheat DDGS a Corn DDGS b Dark Light Dark Light Lightness Dietary fibre, % DM NDF c ADF c N in ADF, % DM d Lysine content, % N*6, Amino acid digestibility, % Crude protein Non essential AA Essential AA Lysine AMEn value, MJ per kg e Rooster Layer Broiler Turkey a Cozannet et al. (2009b,c): 3 dark products and 7 light products b Fastinger et al. (2006): n=5 for lysine content and crude protein, non essential AA, essential AA digestibility; Cromwell et al. (1993): n=9 for N in ADF, NDF, ADF and lysine content c See Table 1 d Nitrogen retained in ADF residue e DM content is standardized at 89% for AMEn values 139