The nutrient digestibility of high-protein corn distillers dried grains and the effect of feeding various levels on the performance of laying hens

Transcription

1 2009 Poultry Science Association, Inc. The nutrient digestibility of high-protein corn distillers dried grains and the effect of feeding various levels on the performance of laying hens B. Jung and A. Batal 1 Department of Poultry Science, University of Georgia, Athens Primary Audience: Nutritionists, Quality Control Personnel, Feed Mill Managers, Researchers SUMMARY Currently, corn fractionation technologies are being developed by some ethanol plants in an attempt to improve ethanol yield. Front-end fractionation technology involves separating the endosperm, germ, and bran fractions before fermentation. The endosperm fraction is fermented to produce ethanol and a feed coproduct, which is often called high-protein corn distillers dried grains (HP-cDDG). In general, HP-cDDG from the front-end fractionation process is higher in protein and amino acids but lower in fat and phosphorus than traditional corn distillers dried grains with solubles. In experiment 1, a total of 8 samples were analyzed for TME n, and a total of 7 samples were analyzed for total and digestible amino acids by the precision-fed conventional rooster assay and cecectomized rooster assay, respectively. The average (and range) TME n, protein, fat, and fiber values for 8 HP-cDDG samples were 2,851 kcal/kg (2,667 to 3,282 kcal/kg), 44.0 (42.2 to 45.9), 3.03 (1.89 to 5.40), and 7.42% (6.98 to 9.20%; as-fed basis), respectively. The average (and range) total lysine concentration and digestibility coefficient of HP-cDDG were 1.23 (1.13 to 1.38) and 76.1% (67.5 to 85.6%). Experiment 2 was conducted to evaluate the feeding value of HP-cDDG from a plant using front-end fractionation on the performance of laying hens. Five experimental diets were formulated to contain 0, 3, 6, 9, or 12% HP-cDDG. The mash diets were fed to 15 replications of 6 Hy-Line W-36 laying hens per replication from 21 to 41 wk of age. The addition of 3% HP-cDDG significantly improved egg mass as compared with eggs from hens fed the control diet. Overall, at 41 wk no difference in FE, egg yolk color, or specific gravity was attributable to the addition of up to 12% HP-cDDG to the diets as compared with hens fed the control diet. It is important that confirmatory analysis be conducted before using a new fermentation by-product from a new plant or supplier. Highprotein corn distillers dried grains is an acceptable feed ingredient when up to 12% is used in a standard laying hen diet during peak production. Key words: high-protein corn distillers dried grains, amino acid, digestibility, laying hen, hen-day egg production 2009 J. Appl. Poult. Res. 18 : doi: /japr Corresponding author: batal@uga.edu

2 742 DESCRIPTION OF PROBLEM Because of the US government push for increased ethanol production, companies are developing corn fractionation technologies to increase ethanol yield. The most common fractionation technologies are front-end and backend fractionation. Front-end fractionation involves separating the endosperm (rich in starch), germ, and bran fractions of the corn before fermentation. The endosperm fraction is fermented to produce ethanol and a feed coproduct, which is often called high-protein corn distillers dried grains (HP-cDDG). This process eliminates the nonfermentable fractions (the germ and the bran). The other common fractionation technology is back-end fractionation, which involves a 2-step process to extract corn oil after the entire corn kernel is fermented to produce ethanol. The HP-cDDG from a front-end fractionation plant is higher in protein and amino acids but lower in fat and phosphorus than traditional corn distillers dried grains with solubles (DDGS), mainly because the germ (18.1% crude fat) is eliminated before fermentation and no syrup (14.0% crude fat) is added back to the grain [1]. Limited data are available on the nutritional value of HP-cDDG from an ethanol plant using front-end fractionation, and when considering the potential use of a new feed ingredient such as HPcDDG, primary emphasis is placed on obtaining accurate information regarding nutritional composition, ME, and amino acid composition and digestibility. It has been reported that 10 to 20% DDGS can be fed in laying hen diets without negatively affecting egg production, even with no supplementation of lysine [2]. Lilburn and Jensen [3] observed that the incorporation of 20% DDGS to laying hens diets significantly increased Haugh units. Lumpkins et al. [4] found that incorporating 15% DDGS from modern ethanol plants into laying hens diets did not significantly affect egg production or interior and exterior quality. However, limited data are available on the feeding value of HP-cDDG from a front-end fractionation ethanol plant in laying hen diets. Therefore, the objectives were 2 fold: 1) to determine the nutritional composition, TME n, and amino acid digestibility of HP-cDDG, and 2) to evaluate the feeding value of HP-cDDG from a plant using a front-end fractionation process on laying hen performance, egg quality, and egg yolk color from 21 to 41 wk of age. MATERIALS AND METHODS Experimental Procedures JAPR: Research Report Experiment 1. All procedures concerning animal care and use were approved by the University of Georgia Committee on Laboratory Animal Care. High-protein corn distillers dried grain samples were obtained from 5 different fuel ethanol plants in the Midwest from 2005 to Eight samples were analyzed for TME n and 7 samples were analyzed for true amino acid digestibility by the precision-fed rooster assay, as described by Sibbald and Price [5] and Sibbald [6]. Eight conventional and 7 cecectomized Single Comb White Leghorn roosters were fasted for 24 h and then crop-intubated with 35 g of HP-cDDG. Excreta were collected for a 48-h period, freeze-dried, and weighed. Conventional roosters were used for TME n analysis and the cecectomized roosters were used for true amino acid digestibility analysis. Eight HP-cDDG samples were evaluated for proximate composition and 7 HP-cDDG samples were evaluated for total amino acid quantification (Table 1) [7 10]. Experiment 2. Five experimental diets were formulated to contain 0, 3, 6, 9, and 12% HPcDDG and were formulated to be isonitrogenous (16.8% CP) and isocaloric (2,837 kcal of TME/ kg; Table 2). The diets were formulated to meet or exceed the estimated nutrient recommendations for laying hens based on both the NRC [11] and the 2006 to 2008 Hy-Line variety W-36 commercial management guide [12]. The diets were mixed in 4 batches and each batch was fed for 5 wk from 21 to 41 wk of age. The diets were mixed in batches because this experiment was conducted over 20 wk beginning in the summer, and keeping feed fresh for this length of period is extremely difficult. Thus, to avoid these issues that have detrimental effects on the diets, the diets were mixed in batches. Batch 1 was formulated based on total amino acid recommendations (0.92% lysine, 0.45% methionine, and 0.75% TSAA, which were well above the total amino acid recommendations in the Hy-Line management guide [12]) because the results from the true

3 Jung and Batal: HIGH-PROTEIN DISTILLERS DRIED GRAINS 743 amino acid digestibility and TME trials were not completed. The diets were reformulated once the TME and true amino acid digestibility of this particular HP-cDDG sample were determined. Thus, batches 2, 3, and 4 were formulated based on digestible amino acid recommendations for lysine (0.73% digestible lysine) and ideal amino acid ratios (110 arginine:lysine, 94 TSAA:lysine, 19 tryptophan:lysine, 75 leucine:lysine, 68 threonine:lysine, and 87 valine:lysine). The HPcDDG used in this experiment was completely derived from corn and came from an ethanol plant using a front-end fractionation process in which the corn was fractionated and the germ and bran were removed before fermentation (Table 3). Hy-Line W-36 White Leghorn hens [12] were housed in a completely enclosed fanventilated building with elevated wire cages, Table 1. Composition of high-protein corn distillers dried grains (HP-cDDG, as-fed basis), experiment 1 HP-cDDG 1 Item Average 2 Range Analyzed content TME n, 3 kcal/kg 2,851 2,667 3,282 DM, % CP, % Crude fat, % CF, % Ash, % Total phosphorus, % Analyzed amino acid, 4 % Arginine (9.4) 5 Lysine (8.0) Methionine (8.6) Methionine + cysteine (7.5) Tryptophan (7.6) Histidine (5.1) Leucine (5.0) Isoleucine (5.0) Phenylalanine (7.2) Phenylalanine + tyrosine (7.4) Threonine (5.3) Valine (5.3) Amino acid digestibility coefficient, 4 % Arginine (3.5) 5 Lysine (7.5) Methionine (1.9) Methionine + cysteine (3.5) Tryptophan (6.9) Histidine (2.5) Leucine (1.1) Isoleucine (4.4) Phenylalanine (1.7) Phenylalanine + tyrosine (1.9) Threonine (5.2) Valine (2.6) 1 The HP-cDDG samples were sent to a commercial laboratory for proximate composition analysis (Minnesota Valley Testing Laboratories, New Ulm, MN) and were sent to a commercial laboratory for total amino acid quantification (Experiment Station Chemical Laboratories, University of Missouri, Columbia). 2 The value is the average of 8 samples of HP-cDDG. 3 TME n analysis was determined at the University of Georgia (Athens) by using the precision-fed conventional rooster assay. 4 The values are averages of 7 samples (HP-cDDG). The amino acid digestibility coefficients were determined at the University of Georgia by using the precision-fed cecectomized rooster assay. 5 Values in parentheses are the CV (%).

4 744 JAPR: Research Report Table 2. Composition of dietary treatments (as-fed basis), experiment 2 Treatment, 21 to 26 wk of age Treatment, 27 to 41 wk of age Item Control 3% HP-cDDG 1 6% HP-cDDG 9% HP-cDDG 12% HP-cDDG Control 3% HP-cDDG 6% HP-cDDG 9% HP-cDDG 12% HP-cDDG Ingredient, % Corn Soybean meal (47%) Limestone Poultry fat Defluorinated phosphate Vitamin mix Salt d l-methionine Mineral mix HP-cDDG Wheat middlings l-lysine hydrochloride Calculated content, % TME, kcal/kg 2,837 2,837 2,837 2,837 2,837 2,837 2,837 2,837 2,837 2,837 CP, % Methionine, 4 % Digestible methionine (0.41) (0.41) (0.41) (0.40) (0.40) (0.47) (0.43) (0.41) (0.41) (0.40) TSAA, % Digestible TSAA (0.65) (0.66) (0.67) (0.68) (0.69) (0.74) (0.70) (0.69) (0.69) (0.69) Lysine, % Digestible lysine (0.77) (0.77) (0.77) (0.76) (0.76) (0.78) (0.74) (0.73) (0.73) (0.73) Threonine, % Digestible threonine (0.51) (0.50) (0.49) (0.48) (0.47) (0.56) (0.56) (0.56) (0.55) (0.55) Valine, % Digestible valine (0.66) (0.66) (0.67) (0.68) (0.68) (0.73) (0.74) (0.74) (0.75) (0.75) Available phosphorus, % Calcium, % Analyzed content, 5,6 % Moisture CP Methionine TSAA Continued

5 Jung and Batal: HIGH-PROTEIN DISTILLERS DRIED GRAINS 745 Table 2 (Continued). Composition of dietary treatments (as-fed basis), experiment 2 Treatment, 21 to 26 wk of age Treatment, 27 to 41 wk of age Item Control 3% HP-cDDG 1 6% HP-cDDG 9% HP-cDDG 12% HP-cDDG Control 3% HP-cDDG 6% HP-cDDG 9% HP-cDDG 12% HP-cDDG Lysine Threonine Valine Crude fat CF Ash Total phosphorus HP-cDDG = high-protein corn distillers dried grains. 2 Vitamin mix provided the following (per kg of diet): thiamine mononitrate, 2.4 mg; nicotinic acid, 44 mg; d-calcium pantothenate, 12 mg; vitamin B12 (cobalamin), 12.0 µg; pyridoxine hydrochloride, 4.7 mg; d-biotin, 0.11 mg; folic acid, 5.5 mg; menadione sodium bisulfate complex, 3.34 mg; choline chloride, 220 mg; cholecalciferol, 27.5 µg; trans-retinyl acetate, 1,892 µg; all-rac α-tocopheryl acetate, 11 mg; ethoxyquin, 125 mg. 3 Trace mineral mix provided the following (per kg of diet): manganese (MnSO4 H 2 O), 60 mg; iron (FeSO 4 7H 2 O), 30 mg; zinc (ZnO), 50 mg; copper (CuSO 4 5H 2 O), 5 mg; iodine (ethylene diamine dihydroiodide), 0.15 mg; selenium (NaSeO 3 ), 0.3 mg. 4 Batch 1 (diet fed from 21 to 26 wk of age) was formulated based on total amino acids (0.92% lysine, 0.45% methionine, and 0.75% TSAA). Batches 2, 3, and 4 (diets fed from 27 to 41 wk of age) were formulated based on digestible amino acid ratios (0.73% digestible lysine minimum, 110 arginine:lysine, 94 TSAA:lysine, 19 tryptophan:lysine, 75 leucine:lysine, 68 threonine:lysine, and 87 valine:lysine, % digestible amino acid-to-lysine ratio minimum). 5 The diet samples were sent to a commercial laboratory for proximate composition analysis (Minnesota Valley Testing Laboratories, New Ulm, MN). 6 The values are averages of batches 2, 3, and 4, which were fed from 27 to 41 wk age. Each batch was fed for 5 wk.

6 746 Table 3. Composition of high-protein corn distillers dried grains (HP-cDDG, as-fed basis), experiment 2 Item HP-cDDG, 1 % Analyzed content TME n, 2 kcal/kg 2,883 (3.6) DM, % 92.4 CP, % 45.6 Crude fat, % 5.4 CF, % 9.2 Ash, % 1.9 Total phosphorus, % 0.32 Available phosphorus, 3 % 0.19 Analyzed amino acid, % Arginine 1.91 (93.5) 4 Lysine 1.38 (85.6) Methionine 1.10 (93.0) Methionine + cysteine 1.95 (91.3) Tryptophan 0.29 (95.5) Histidine 1.05 (88.1) Leucine 6.70 (92.9) Isoleucine 1.99 (91.3) Phenylalanine 2.72 (92.7) Phenylalanine + tyrosine 4.79 (92.9) Threonine 1.74 (87.5) Valine 2.36 (90.8) 1 The HP-cDDG sample for this experiment was sent to a commercial laboratory for proximate composition analysis (Minnesota Valley Testing Laboratories, New Ulm, MN) and was sent to a commercial laboratory for total amino acid quantification (Experiment Station Chemical Laboratories, University of Missouri, Columbia). 2 TME n analysis was determined at the University of Georgia (Athens) by using the precision-fed conventional rooster assay. Value in parentheses is the CV. 3 Calculated: total phosphorus relative bioavailability value of 58, which was determined by Kim et al. [16], divided by Values in parentheses are the amino acid digestibility coefficients, which were determined at the University of Georgia by using the precision-fed cecectomized rooster assay. in which they were exposed to a 16L:8D daily lighting schedule. The laying hens were provided feed and water ad libitum throughout the study and were randomly assigned to 1 of the 5 dietary treatments, with 15 replicates containing 6 laying hens per replicate, 90 laying hens per treatment. One laying hen was placed in a cage. The experiment was conducted for 20 wk from August 2007 to January Analyses The HP-cDDG sample was sent for proximate composition [7, 8] and amino acid concentration [9, 10] analyses. The diets (batches 1, 2, 3, and 4) were also sent for proximate composition analysis of nutrient contents [7, 8]. Henday egg production was measured daily and egg weights were measured on a weekly basis after all eggs were collected for that day (4 eggs from each replication were used for the weekly egg weights). Egg mass was calculated by multiplying hen-day egg production by egg weight divided by 100. Body weight and feed intake were measured every 5 wk and FE was calculated by dividing feed intake by egg mass. Exterior (shell) quality was tested by specific gravity and the test (range of salt solutions, from to 1.095) was conducted every 4 wk with the eggs collected for that day (4 eggs from each replication were used for the weekly specific gravity measurements) [13]. Every 4 wk, three eggs per replicate (45 eggs/treatment, after all the eggs had been collected from the day before the analysis) were evaluated for interior quality by determining Haugh units and yolk color. Haugh units were measured using a QCD (Quantum Chromodynamics) Super System [14]. This instrument was connected to a computer equipped with software to record egg weight (in grams) and albumen height (in millimeters) automatically and to calculate the Haugh units [15]. Albumen height was measured with part of the QCD Super System at a point halfway between the yolk and the edge of the widest expanse of albumen. Yolk color was tested using a Minolta colorimeter [16]. Samples of egg yolk were placed into a clear plastic dish, mm, with heavy white paper placed underneath and transparent vinyl placed on the surface of the egg yolk. The colorimeter took 3 measurements and averaged them into 3 axis values of L* (lightness), for white and black; a* (redness), representing red and green; and b* (yellowness), representing yellow and blue. Low values for L* indicated a dark color, whereas higher scores indicated a light color (0 = black, 100 = white). Higher values for a* and b* indicated greater degrees of redness and yellowness, respectively. When mortality occurred, the hen-day egg production and feed intake were adjusted accordingly. Statistical Analysis JAPR: Research Report Data from all variables were initially analyzed using the GLM procedure of SAS software for

7 Jung and Batal: HIGH-PROTEIN DISTILLERS DRIED GRAINS 747 a completely randomized design. Statistical significance of differences among treatments was assessed using Duncan s new multiple range test. A probability level of P < 0.05 was used to determine the statistical significance of differences among the dietary treatments [17]. RESULTS AND DISCUSSION Experiment 1 Proximate composition, TME n, and amino acid digestibility coefficients for the HP-cDDG samples are presented in Table 1. The average TME n of the HP-cDDG samples measured (2,851 kcal/kg, range between 2,667 and 3,282 kcal/kg) was not much different from the value (2,957 kcal/kg) reported by Kim et al. [18]. Crude protein values ranged between 42.2 and 45.9% and averaged 44.0%, which was again similar to the values (44.1 and 41.1%) reported by Kim et al. [18] and Widmer et al. [19], respectively. The crude fat averaged 3.03% and ranged from 1.89 to 5.40%, which was similar to the value (2.9%) stated by Kim et al. [18]. Total phosphorus averaged 0.34%, which was again similar to the values (0.33 and 0.37%) reported by Kim et al. [18] and Widmer et al. [19], respectively. Conventional corn DDGS has a much higher level Table 4. Effect of feeding high-protein corn distillers dried grains (HP-cDDG) to laying hens on hen-day egg production, egg weight, egg mass, feed intake, and feed conversion, experiment 2 Treatment Variable Control 3% HP-cDDG 6% HP-cDDG 9% HP-cDDG 12% HP-cDDG SEM Hen-day egg production, 1 % 21 to 26 wk 90.5 b 94.2 a 92.5 ab 94.0 a 93.3 ab to 31 wk 92.8 b 96.4 a 94.3 ab 94.2 ab 95.7 a to 36 wk to 41 wk 88.7 b 91.4 ab 91.8 a 89.5 ab 89.5 ab to 41 wk 90.9 b 93.8 a 92.8 ab 92.6 ab 93.3 a Egg weight, 2 g 21 to 26 wk 50.2 ab 50.8 a 50.2 ab 50.5 a 49.3 b to 31 wk to 36 wk 57.5 ab 58.4 a 57.8 ab 57.7 ab 56.9 b to 41 wk to 41 wk 55.5 ab 56.2 a 55.6 ab 55.8 ab 55.0 b Egg mass, 3 g 21 to 26 wk 45.4 b 47.8 a 46.5 ab 47.4 ab 46.0 ab to 31 wk 51.1 b 53.7 a 51.9 b 52.1 ab 52.3 ab to 36 wk to 41 wk 52.5 b 54.8 a 54.6 a 53.3 ab 53.8 ab to 41 wk 50.4 b 52.7 a 51.6 ab 51.6 ab 51.3 b Feed intake, g/d per hen 21 to 26 wk 83.1 b 87.7 a 85.1 ab 86.5 a 83.2 b to 31 wk to 36 wk to 41 wk 94.1 b a 97.8 ab a 99.3 ab to 41 wk 92.6 b 95.8 ab 95.4 ab 96.8 a 94.9 ab Feed conversion, g of feed intake/g of egg mass 21 to 26 wk to 31 wk 1.81 b 1.71 a 1.85 b 1.79 ab 1.81 b to 36 wk to 41 wk 1.79 a 1.83 ab 1.79 a 1.93 b 1.85 ab to 41 wk 1.84 ab 1.82 b 1.85 ab 1.88 a 1.85 ab a,b Means within a row and variable without a common superscript differ significantly (P < 0.05). 1 Means represent 15 replications per treatment (6 hens per replication). 2 Means represent 15 replications per treatment (3 eggs per replication). 3 Egg mass = hen-day egg production egg weight/100.

8 748 JAPR: Research Report Table 5. Effect of feeding high-protein corn distillers dried grains (HP-cDDG) to laying hens on interior egg quality (Haugh units), exterior quality (specific gravity), and BW, experiment 2 Treatment Variable Control 3% HP-cDDG 6% HP-cDDG 9% HP-cDDG 12% HP-cDDG SEM Haugh units 1 25 wk wk wk wk wk Average Specific gravity 1 25 wk wk wk wk wk Average BW, 2 g/hen 25 wk 1,361 1,370 1,357 1,361 1, wk 1,444 1,452 1,445 1,450 1, wk 1,493 1,511 1,515 1,514 1, wk 1,561 1,591 1,564 1,567 1, wk 1,602 1,612 1,614 1,618 1, Means represent 15 replications per treatment (3 eggs per replication, 45 eggs per treatment). 2 Means represent 15 replications per treatment (6 hens per replication). of total phosphorus (0.76%) and fat (10%) than HP-cDDG, likely because the germ fraction of the corn is removed and no syrup is added back to the grains after distillation. The germ fraction of the corn kernel contains the majority of the oil found in corn, and the removal of this fraction appears to reduce the fat concentration of the resulting grain significantly. Crude fiber ranged between 6.98 and 9.20% and averaged 7.42%; this was somewhat surprising because one would expect the CF to be much lower than the CF of conventional corn DDGS (8.5%) because of the removal of bran. The average (digestibility coefficient) lysine, methionine, and threonine levels in HP-cDDG were 1.23 (76.1), 0.97 (92.0), and 1.59% (81.6%), respectively, which were similar to the total average levels (1.23, 0.83, and 1.52%, respectively) reported by Widmer et al. [19] and the digestibility coefficient values (73.1, 90.2, and 83.1%, respectively) reported by Kim et al. [18]. Experiment 2 The nutritional profile of the HP-cDDG used in experiment 2 is listed in Table 3. The henday egg production, egg weight, egg mass, feed intake, and FE results for experiment 2 are summarized in Table 4. The inclusion of 3 and 9% HP-cDDG to the diets significantly improved (P < 0.05) hen-day egg production from 21 to 26 wk of age, and 3 and 12% HP-cDDG inclusion to the diets also significantly improved (P < 0.05) hen-day egg production from 26 to 31 wk of age as compared with the control diet. From 36 to 41 wk of age, 6% HP-cDDG inclusion to the diets significantly increased (P < 0.05) henday egg production as compared with the control diet. Overall, from 21 to 41 wk of age, the inclusion of 3 and 12% HP-cDDG to the diets significantly improved (P < 0.05) hen-day egg production as compared with the control diet, but the hen-day egg production of the hens fed diets with 6 and 9% HP-cDDG did not differ from that of hens fed the control diet. This difference may be due to the higher feed intake of the birds fed diets with HP-cDDG as compared with the birds fed the control diet. No effect on egg weight was attributable to the inclusion of up to 12% HP-cDDG to the diets as compared with the control diet. Although the inclusion of 3% HP-cDDG to the diet signif-

9 Jung and Batal: HIGH-PROTEIN DISTILLERS DRIED GRAINS 749 Table 6. Effect of feeding high-protein corn distillers dried grains (HP-cDDG) to laying hens on egg yolk color, 1 experiment 2 Treatment Color score 2 Control 3% HP-cDDG 6% HP-cDDG 9% HP-cDDG 12% HP-cDDG SEM a* 25 wk wk 0.03 c 0.11 bc 0.14 ab 0.16 ab 0.30 a wk 0.35 b 0.32 b 0.20 ab 0.10 a 0.17 ab wk 0.89 c 0.88 c 0.72 ab 0.66 a 0.81 bc wk 1.52 c 1.50 c 1.45 bc 1.26 ab 1.15 a Average b* 25 wk wk 26.2 ab 25.9 ab 26.4 a 26.3 ab 25.7 b wk wk 25.6 b 26.1 ab 26.2 a 26.2 a 26.1 ab wk Average L* 25 wk wk 60.2 a 59.8 abc 60.0 ab 59.7 bc 59.3 c wk 60.0 ab 59.9 ab 60.2 a 59.6 b 60.0 ab wk wk 60.5 ab 60.4 ab 60.7 a 60.0 b 60.1 b Average a c Means within a row without a common superscript differ significantly (P < 0.05). 1 Means represent 15 replications per treatment (3 eggs per replication, 45 eggs per treatment). 2 Measured using a Minolta colorimeter (Minolta Corporation, Ramsey, NJ). Higher values for a* and b* indicate a greater degrees of redness and yellowness, respectively; L* = lightness of egg yolk, where 0 = black to 100 = white. icantly improved (P < 0.05) egg mass from 21 to 31 wk of age as compared with the control diet, egg mass from the hens fed the other diets (6, 9, and 12% HP-cDDG) did not differ from that of hens fed the control diet. From 31 to 36 wk of age, there was no difference in egg mass among the treatments. From 36 to 41 wk of age, 3 and 6% HP-cDDG inclusion to the diets significantly improved (P < 0.05) egg mass as compared with the control diet. Overall, the inclusion of 3% HP-cDDG to the diet significantly improved (P < 0.05) egg mass, but egg mass from hens fed the other diets (6, 9, and 12% HP-cDDG) did not differ from that of hens fed the control diet. The inclusion of 3 and 9% HP-cDDG to the diets significantly increased (P < 0.05) feed intake from 21 to 26 wk of age and 36 to 41 wk of age as compared with the control diet, but there was no difference in feed intake among the other treatments from 26 to 36 wk of age. Overall, the inclusion of 9% HP-cDDG to the diet significantly increased (P < 0.05) feed intake, but feed intake of hens fed the other diets (3, 6, and 12% HP-cDDG) did not differ from that of hens fed the control diet. The increased feed intake of birds fed the 9% HP-cDDG diet may be due to low amino acid levels for batches 2 and 3, but not batches 1 and 4 (Table 2); thus, the birds may have increased their intake to compensate for the low amino acid levels. These low amino acid levels were not observed for any of the other dietary treatments even though all the diets were mixed from the same basal diet. There was no effect on FE among the treatments from 21 to 26 wk of age and 31 to 36 wk of age, but from 26 to 31 wk of age, the inclusion of 3% HP-cDDG to the diet significantly improved (P < 0.05) FE as compared with the control diet. Overall, however, no effect on FE was attributable to the inclusion of up to 12% HP-cDDG to the diets. In this study, feeding laying hens diets with up to 12% HP-cDDG did not affect egg production, egg weight, or egg mass. Currently, there is no published work on feeding HP-cDDG to laying hens. However, there are studies reporting the effects of feeding DDGS on laying hen

10 750 performance. Early studies with laying hens demonstrated that DDGS or corn fermentation solubles could be used at 10 to 20% inclusion levels in diets without affecting egg production and egg weight [2, 3, 20]. More recently, Roberson et al. [21] and Swiatkiewicz and Koreleski [22] found that corn DDGS had no effect on egg production, egg weight, and egg mass among treatments (0, 5, 10, or 15% DDGS) at most ages, which was similar to what we observed in this study. However, Roberson et al. [21] reported a linear decrease in egg production (52 to 53 wk of age), egg weight (63 wk of age), and egg mass (51 wk of age) as the level of DDGS increased during certain time periods. Swiatkiewicz and Koreleski [22] also found that feeding 20% corn DDGS negatively affected laying rate and daily egg mass. Similarly, incorporation of 15% DDGS obtained from modern ethanol plants into a low-energy diet decreased egg production from 26 to 34 wk of age, but inclusion of 15% DDGS in a commercial (high-density) diet did not negatively affect laying hen performance from 22 to 42 wk of age [4]. Interior egg quality (Haugh units), exterior quality (specific gravity), and BW results were not affected by HP-cDDG inclusion (Table 5). Overall, the average Haugh units tended to increase as the level of HP-cDDG increased in the diets, which was similar to the results reported by Liburn and Jensen [3] and Waldroup and Hazen [23] for fermentation feed by-products. Lilburn and Jensen [3] reported that inclusion of 20% corn fermentation solubles in laying hen diets significantly improved Haugh units. Waldroup and Hazen [23] reported a similar response for Haugh units with the use of corn-dried steep liquor concentrate. However, Lumpkins et al. [4] reported no difference between diets with 0 or 15% DDGS. A specific gravity value of 1.08 or above is used by laying hen industry personnel as an indicator of good eggshell quality. All treatments resulted in a specific gravity value of 1.08 or above. There were no differences among treatments during the experiment, which agrees with the reports of Roberson et al. [21] and Lumpkins et al. [4] that specific gravity was not affected by adding DDGS to the diets. There was no effect on BW from adding HP-cDDG to the diets. JAPR: Research Report The egg yolk color results are summarized in Table 6. A possible effect of DDGS and HP-cD- DG on egg yolk color is of interest to researchers and producers, considering that DDGS is of corn origin and the xanthophyll in corn is a main contributor to yolk pigmentation. Herber- McNeill and Van Elswyk [24] and Roberson et al. [21] found that for detecting differences in yolk color, the yolk redness (a*) measurement was more sensitive than yolk lightness (L*) or yolk yellowness (b*) scores. Yolk redness (a*) from the hens fed the 6, 9, and 12% HP-cDDG diets was significantly (P < 0.05) increased as compared with yolk redness from hens fed the control diet at 29, 33, 37, and 41 wk of age. Lumpkins et al. [4] observed no change in yolk color when 15% DDGS was added to the diet. The inclusion of HP-cDDG (3, 6, 9, and 12%) to the diets did not significantly affect the yellowness (b*) of the yolk as compared with the yolks of hens fed the control diet at 25, 29, 33, and 41 wk of age. However, the inclusion of 6 and 9% HP-cDDG significantly improved (P < 0.05) yolk yellowness (b*) as compared with the yolks of hens fed the control diet at 37 wk of age. Overall, yolk lightness (L*) was not affected by including HP-cDDG (3, 6, 9, and 12%) in the diets as compared with the yolk lightness of hens fed the control diet. However, including 9 and 12% HP-cDDG in the diets significantly decreased (P < 0.05) yolk lightness (L*) as compared with the yolk lightness of hens fed the control diet at 29 wk of age. Using a Minolta Chroma Meter, Roberson et al. [21] found that yolk redness (a*) increased linearly (P < ), whereas yolk lightness (L*) decreased linearly (P < and 0.007) at 63 and 66 wk of age because of feeding up to 15% DDGS, which generally agrees with the results of this study. CONCLUSIONS AND APPLICATIONS 1. It is important that confirmatory analysis be conducted on HP-cDDG before using this new by-product because the HPcDDG from different plants and suppliers may vary. 2. The average TME n, protein, fat, fiber, total phosphorus, lysine, TSAA, and threonine values of HP-cDDG were 2,851

11 Jung and Batal: HIGH-PROTEIN DISTILLERS DRIED GRAINS 751 kcal/kg, 44.0, 3.03, 7.42, 0.34, 1.23, 1.85, and 1.59%, respectively. 3. Feeding up to 12% HP-cDDG to laying hens had no effect on egg weight, feed intake, egg yolk color, and exterior or interior egg quality. 4. High-protein corn distillers dried grains is an acceptable feed ingredient in laying hen diets. REFERENCES AND NOTES 1. Shurson, J., and A. S. Alghamdi Quality and new technologies to produce corn co-products from ethanol production. Pages in Using Distillers Grains in the U.S. and International Livestock and Poultry Industries: The Current State of Knowledge. Cent. Agric. Rural Dev., Iowa State Univ., Ames. 2. Matterson, L. D., J. Tlustohowicz, and E. P. Singsen Corn distillers dried grains with solubles in rations for high-producing hens. Poult. Sci. 45: Liburn, M. S., and L. S. Jensen Evaluation of corn fermentation solubles as a feed ingredient for laying hens. Poult. Sci. 63: Lumpkins, B., A. Batal, and N. Dale Use of distillers dried grains plus solubles in laying hen diets. J. Appl. Poult. Res. 14: Sibbald, I. R., and K. Price Variation in the metabolizable energy values of diets and dietary components fed to adult roosters. Poult. Sci. 54: Sibbald, I. R Passage of feed through the adult rooster. Poult. Sci. 58: Minnesota Valley Testing Laboratories, New Ulm, MN. 8. Association of Official Analytical Chemists (AOAC) Official Methods of Analysis. 18th ed. Rev. 1. Assoc. Off. Anal. Chem., Gaithersburg, MD. Official methods (CP), (crude fat), (CF), (ash), and (total phosphorus). 9. Experiment Station Chemical Laboratories, University of Missouri, Columbia. 10. Determination of amino acids was conducted using an HPLC procedure with a Beckman 6300 analyzer (Beckman Coulter Inc., Fullerton, CA) with an ion-exchange column. Amino acid profile was performed by AOAC official method E(a,b,c) [8]. Analyses of methionine and cysteine were performed separately after performic acid hydrolysis, and analysis of tryptophan was performed by alkaline hydrolysis using AOAC official method [8]. 11. NRC Nutrient Requirements of Poultry. 9th rev. ed. Natl. Acad. Press, Washington, DC. 12. Hy-Line International, West Des Moines, IA. 13. Bennett, C. D Measuring table egg shell quality with one specific gravity salt solution. J. Appl. Poult. Res. 2: TSS QCD System, Technical Services and Supplies, Chessingham Park, Dunnington, York, UK. 15. Haugh, R. R The Haugh unit for measuring egg quality. US Egg Poult. Mag. 43: , Minolta CR300 Colorimeter, Minolta Corporation, Ramsey, NJ. 17. SAS Institute SAS User s Guide: Statistics. Version ed. SAS Inst. Inc., Cary, NC. 18. Kim, E. J., C. Martinez Amezcua, P. L. Utterback, and C. M. Parsons Phosphorus bioavailability, true metabolizable energy, and amino acid digestibilities of high protein corn distillers dried grains and dehydrated corn germ. Poult. Sci. 87: Widmer, M. R., L. M. McGinnis, and H. H. Stein Energy, phosphorus, and amino acid digestibility of high-protein distillers dried grains and corn germ fed to growing pigs. J. Anim. Sci. 85: Harms, R. H., R. S. Moreno, and B. L. Damron Evaluation of distiller s dried grain with solubles in diets of laying hens. Poult. Sci. 48: Roberson, K. D., J. L. Kalbfleisch, W. Pan, and R. A. Charbeneau Effect of corn distiller s dried grains with solubles at various levels on performance of laying hens and yolk color. Int. J. Poult. Sci. 4: Swiatkiewicz, S., and J. Korleski Effect of maize distillers dried grains with solubles and dietary enzyme supplementation on the performance of laying hens. J. Anim. Feed Sci. 15: Waldroup, P. W., and K. R. Hazen Examination of corn dried steep liquor concentrated and various feed additives as potential sources of a Haugh unit improvement factor for laying hens. Poult. Sci. 58: Herber-McNeill, S. M., and M. E. Van Elswyk Dietary marine algae maintains egg consumer acceptability while enhancing yolk color. Poult. Sci. 77: