The objective of this experiment was to measure the digestibilities of energy, CP, and AA in 10 samples of corn distillers dried grain with solubles (DDGS) and in corn fed to growing pigs. Twelve growing barrows (initial BW: 34.0 +/- 1.41 kg) were allotted to an 8 x 12 Youden square design with 8 periods and 12 animals. Ten of 12 diets were based on the 10 DDGS samples (66.7%), 1 diet was based on corn (97%), and the last diet was a N-free diet based on cornstarch and sucrose. Chromic oxide (0.3%) was included in all diets as an inert marker. Pigs were provided their respective diets at a level of 3 times their estimated energy requirement for maintenance. The apparent (AID) and standardized (SID) ileal digestibilities for CP and AA were measured in the 10 samples of DDGS and in corn using the direct procedure, but the apparent total tract digestibilities for DM and GE were estimated using the difference procedure. The concentration of DE in each sample of DDGS and in corn was also calculated. The results of the experiment indicated variation among the different sources of DDGS in AID and SID for Lys, which ranged from 35.0 to 55.9% and 43.9 to 63.0%, respectively. For Met, the SID varied between 73.9 and 84.7%. However, the variability among samples in the SID for CP, and for the indispensable AA other than Lys and Met, was relatively low and ranged between 6 and 8 percentage units (i.e., from 64.0 to 70.6%, 74.1 to 80.1%, and 67.4 to 75.3% for Thr, Trp, and Ile, respectively). The SID for Trp in corn (72.8%) was lower (P < 0.05) than in DDGS, but for the remaining indispensable AA, except Arg, the SID for corn were greater (P < 0.01) than for DDGS. The DE concentration in the 10 samples of DDGS varied (P < 0.001) from 3,382 to 3,811 kcal of DE per kg of DM. For corn, the DE was 3,845 kcal per kg of DM. It is concluded that the AID and SID for Lys vary among samples of DDGS, but for most other AA the AID and SID are relatively similar and vary only 6 to 8 percentage units among different samples. Future work should focus on identifying the reasons for the variation in the digestibility of Lys to avoid processing procedures that are detrimental to Lys digestibility.

Five ruminally and duodenally cannulated steers (500 +/- 5 kg of initial BW) were used in a 5 x 5 Latin square to evaluate effects of increasing level of corn distillers dried grains with solubles (DDGS) in growing diets (70% concentrate) on OM intake, site of digestion, ruminal fermentation, and microbial efficiency. Diets consisted of 30% grass hay, 6% concentrated separator by-product, 4% supplement, and 60% dry-rolled corn, sunflower meal, urea, or DDGS (DM basis). Treatments consisted of increasing DDGS at 0, 15, 30, 45, or 60% of diet DM replacing a combination of dry-rolled corn, sunflower meal, and urea. Diets were balanced for growing steers gaining 1.22 kg/d and included 0.25% (DM basis) chromic oxide as a digesta flow marker. Diets were offered to the steers for ad libitum intake each day (10% above the intake of the previous day). Each period consisted of 14 d for adaptation and 7 d for collections. Intake of OM responded quadratically (P = 0.004) with greatest intakes at 15% DDGS and least at 60% DDGS. No differences (P >or= 0.14) were observed in CP intake or duodenal flow of OM, CP, and NDF. Apparent and true ruminal OM digestibilities decreased (linear; P or= 0.19). A cubic (P = 0.02) effect was observed for total ruminal fill (as is basis) with the greatest fill at 0% DDGS and the least fill at 45% inclusion. Replacing dry-rolled corn with up to 60% DDGS in 70% concentrate diets resulted in no adverse effects on total tract OM digestion, although OM intake was reduced at 60% DDGS inclusion.

This study compared high protein dried distillers grains (HPDDG) with soybean meal (SBM), canola meal (CM), and dried distillers grains with solubles (DDGS) as protein supplements in dairy diets. A lactation trial used 12 multiparous cows averaging 78 d in milk at the start of the experiment in a 4 x 4 Latin square design with 28-d periods. Weeks 1 and 2 of each period were used for adjustment and wk 3 and 4 for data collection. Each treatment diet consisted of 55% forage and one of the 4 protein supplements in a concentrate mix. Total mixed diets averaged 15.3% crude protein, with 38% of the protein from one of the 4 protein supplements. Dry matter intake (24.4 kg/d) and crude protein intake (3.57 kg/d) were similar for all 4 diets. Milk production (31.8 kg/d), protein yield (1.05 kg/d), fat yield (1.29 kg/d), and protein percentage (3.31) were similar for all 4 treatment diets. Milk fat percentage was lower when fed DDGS (3.78) than when fed SBM or HPDDG (4.21), but similar with CM (4.07). Feed efficiency (1.44kg of energy-corrected milk/kg of dry matter intake) and nitrogen efficiency (0.29) were not affected by diet. Total milk nitrogen and true milk protein were highest when fed the HPDDG diet. Molar proportions of acetate, propionate, and the acetate to propionate ratio in ruminal contents and ruminal ammonia concentrations were similar for all diets. Arterial and venous concentrations of total essential AA tended to be lower when fed CM, reflecting lower concentrations of His, Ile, Leu, and Val when fed the CM diet. Extraction efficiency of AA from blood by the mammary gland indicated that Met was the first limiting AA when fed the SBM diet, whereas Lys was first limiting for the other diets. Phenylalanine was third limiting with all diets. Feeding HPDDG was equally as effective as feeding SBM, CM, and regular distillers grains as a protein supplement for lactating cows.

Two experiments were conducted to determine the effects of feeding 3 corn-milling coproducts on intake, milk production, ruminal fermentation, and digestibility of lactating Holstein cows. In experiment 1, three corn-milling coproducts were fed at 15% of the diet dry matter (DM) to 28 Holstein cows averaging (±SD) 625 ± 81 kg of body weight and 116 ± 33 d in milk to determine effects on DM intake and milk production. In experiment 2, the same rations were fed to 4 ruminally fistulated, multiparous Holstein cows averaging 677 ± 41 kg of body weight and 144 ± 5 d in milk to determine the effects on ruminal fermentation and digestibility. In both experiments, cows and treatments were assigned randomly in 4 × 4 Latin squares over four 21-d periods. Treatments were formulated by replacing portions of forage and concentrate feeds with 15% coproduct and included 1) 0% coproduct (control), 2) dried distillers grains plus solubles (DDGS), 3) dehydrated corn germ meal (germ), and 4) high-protein dried distillers grains (HPDDG). Feed intake was recorded daily, and milk samples were collected on d 19 to 21 of each period for analysis of major components. Rumen fluid was collected at 10 time points over 24 h post feeding on d 21 of experiment 2. In experiment 1, DM intake was greater for the germ (24.3 kg/d) and DDGS treatments (23.8 kg/d), but DDGS was not different from the control (22.9 kg/d) and HPDDG treatments (22.4 kg/d). Milk production paralleled DM intake and tended to be greater for the germ (32.1 kg/d) and DDGS treatments (30.9 kg/d), but the DDGS treatment was not different from the control (30.6 kg/d) and HPDDG treatments (30.3 kg/d). However, yields of milk fat, milk protein, and 3.5% FCM were similar and averaged (±SEM) 1.1 ± 0.1, 0.9 ± 0.03, and 31.7 ± 1.3 kg/d. Milk urea nitrogen was greater for the HPDDG (15.9 mg/dL) and germ treatments (15.5 mg/dL) than for the control (15.0 mg/dL) and DDGS treatments (14.9 mg/dL). In experiment 2, DM intake and milk production were not different across treatments and averaged 26.1 ± 2.3 and 28.3 ± 3.9 kg/d. Ruminal pH (6.26 ± 0.08) and total concentration of volatile fatty acids (125.3 ± 4.2 mM) were similar. Acetate concentration was higher for the control treatment than the DDGS, germ, and HPDDG treatments (81.7 vs. 75.8, 75.0, and 78.4 mM). Concentrations of propionate and butyrate were not different and averaged 27.8 ± 1.2 and 14.3 ± 0.9 mM across treatments. The acetate:propionate ratios for the control, germ, and HPDDG treatments were greater than for the DDGS treatment (3.02, 2.88, and 2.91 vs. 2.62). Dry matter, organic matter, and neutral detergent fiber digestibilities were similar across treatments and averaged 63.5 ± 2.7, 67.3 ± 2.2, and 43.5 ± 4.2%. Milk production followed DM intake in experiment 1, and yield of major milk components was not affected. Results of these experiments indicate that dairy rations can be successfully formulated to include 15% of diet DM as corn-milling coproducts while maintaining or increasing DM intakes and yields of mil...

Fifteen Holstein cows (10 multiparous and 5 primiparous) in early to mid lactation (79.3 +/- 9.2 d in milk) were used in a multiple 5 x 5 Latin square design with 4-wk periods to evaluate and compare the use of condensed corn distillers solubles (CCDS) and dried distillers grains with solubles (DDGS) in the total mixed ration. The forage portion of the diets was kept constant at 27.5% corn silage and 27.5% alfalfa hay (dry matter basis). Diets were 1) 0% distillers grains products (control); 2) 18.5% DDGS; 3) 10% CCDS; 4) 20% CCDS; and 5) a combination diet of 18.5% DDGS with 10% CCDS. Diets 2 and 3 contained 2% fat from DDGS or CCDS, whereas diet 4 contained 4% fat from CCDS and diet 5 contained 4% fat from the blend of DDGS and CCDS. The diets were balanced to provide 17% crude protein with variation in acid detergent fiber, neutral detergent fiber, and fat concentration. Dry matter intake (21.5 kg/d) was similar for all diets. Milk yield (33.8, 36.2, 35.5, 36.0, and 36.0 kg/d) tended to be greater for diets 2 to 5 than for diet 1, whereas yields of fat (1.04 kg/d), protein (1.02 kg/d), fat percentage (2.94), and protein percentage (2.98) were similar for all diets. Energy-corrected milk (32.2 kg/d) and feed efficiency (1.58 kg of energy-corrected milk/kg of dry matter intake) were similar for all diets. Milk urea nitrogen (15.0, 10.9, 11.1, 11.0, and 11.4 mg/dL) as well as blood urea nitrogen (15.6, 12.5, 14.6, 13.8, and 14.2 mg/dL) were decreased in diets 2 to 5 compared with diet 1. Milk concentrations of long-chain fatty acids as well as polyunsaturated fatty acids were greater and medium-chain fatty acid concentrations were lower for diets 2 to 5 compared with diet 1. Concentrations of cis-9, trans-11 conjugated linoleic acid (CLA; 0.33, 0.68, 0.51, 0.85, and 1.07 g/100 g of fatty acids) as well as trans-10, cis-12 CLA (<0.01, 0.01, <0.01, 0.02, and 0.02 g/100 g of fatty acids) were greater for diets 2 to 5 compared with diet 1. Molar proportions of ruminal acetate decreased and propionate increased for diets 2 to 5 compared with diet 1. The results showed that CCDS is as effective as DDGS in replacing soybean meal and corn grain in the total mixed ration.

Limited data are available regarding the influence of thiamine supplementation on the incidence of polioencephalomalacia (PEM) in lambs fed diets containing increased concentrations of S in the diet (>0.7%). Therefore, our objective was to evaluate the influence of thiamine supplementation on feedlot performance, carcass quality, ruminal hydrogen sulfide gas concentrations, and incidence of PEM in lambs fed a finishing diet containing 60% distillers dried grains with solubles (DDGS; DM basis). Two studies were conducted using completely randomized designs to evaluate the influence of concentration of thiamine supplementation. Study 1 used 240 lambs fed in 16 pens, whereas study 2 used 55 individually fed lambs. Lamb finishing diets contained 60% DDGS, which resulted in a dietary S concentration of 0.73% (DM basis). Treatments diets were based on the amount of supplemental thiamine provided: 1) no supplemental thiamine (CON), 2) 50 mg/animal per day (LO), 3) 100 mg/animal per day (MED), or 4) 150 mg/animal per day (HI). Additionally, in study 2, a fifth treatment was included, which contained 0.87% S (DM basis; increased S provided by addition of dilute sulfuric acid) and provided 150 mg of thiamine/animal per day (HI+S). In study 1, ADG decreased quadratically (P = 0.04), with lambs fed the CON, LO, and MED diets gaining BW at a greater rate than lambs fed the HI diet. In study 1, DMI responded quadratically (P < 0.01), whereas G:F tended to differ linearly (P = 0.08) to concentration of thiamine supplementation, with MED lambs having greater DMI and decreased G:F. No differences (P > or = 0.17) in lamb performance were observed in study 2. In both studies, most carcass characteristics were unaffected, with the exception of a tendency for decreased carcass conformation (study 1; P = 0.09) and greater flank streaking (study 2; P = 0.03). No differences in ruminal hydrogen sulfide concentration (P > 0.05) among treatments were apparent until d 10, at which point lambs fed the LO diet had less hydrogen sulfide concentrations than all other treatments. Lambs fed HI had the greatest concentrations of hydrogen sulfide on d 31 (1.07 g of hydrogen sulfide /m(3); P < 0.009). Ruminal pH did not differ (P = 0.13) and averaged 5.6 +/- 0.06. No clinical cases of PEM were observed during the course of either study. The use of thiamine as a dietary additive to aid in the prevention of PEM in finishing lambs does not appear to be necessary under the conditions of this study.

Novel corn milling co-products developed from technological advancements in ethanol production vary widely in chemical composition and nutrient availability. The objectives of this study were to characterize feed protein fractions and evaluate differences in rumen-undegradable protein (RUP) and its digestible fraction (dRUP), amino acid concentration, and in vitro gas production of 7 corn milling co-products. The crude protein (CP; % of dry matter) of co-products was 12.7 for germ, 26.9 for dried distillers grains plus solubles that had no heat exposure before fermentation (DDGS1), 45.4 for highprotein dried distillers grains (HPDDG), 12.7 for bran, 30.2 for wet distillers grains plus solubles (WDGS), 23.1 for wet corn gluten feed (WCGF), and 26.0 for dried distillers grains plus solubles that had heat exposure before fermentation (DDGS2). Two ruminally and duodenally fistulated Holstein steers weighing 663 ± 24 kg were used to determine RUP and dRUP with the in situ and mobile bag techniques. Samples of each feed were ruminally incubated for 16 h, and mobile bags were exposed to simulated abomasal digestion before insertion into the duodenum and subsequent collection in the feces. Protein fractions A, B 1 , B 2 , B 3 , and C were characterized as follows (% CP): germ = 30.0, 15.0, 38.1, 13.5, 3.4; DDGS1 = 17.0, 7.0, 67.0, 4.8, 4.2; 0.6, 82.4, 8.8, 0.8; bran = 33.5, 4.0, 54.3, 6.0, 2.2; WDGS = 18.6, 2.4, 53.1, 11.0, 14.9; WCGF = 36.6, 15.9, 33.2, 10.1, 4.1; and DDGS2 = 17.9, 2.1, 41.1, 11.1, 27.9. The proportions of RUP and dRUP were different and are reported as follows (% CP): DDGS2 = 56.3, 91.9; HPDDG = 55.2, 97.7; WDGS = 44.7, 93.1; DDGS1 = 33.2, 92.1; bran = 20.7, 65.8; germ = 16.5, 66.8; and WCGF = 11.5, 51.1. The concentrations of Lys and Met in the RUP were different and are listed as follows (% CP): germ = 2.9, 2.0; DDGS1 = 1.9, 2.0; HPDDG = 2.0, 3.2; bran = 3.2, 1.5; WDGS = 1.9, 2.3; WCGF = 3.5, 1.6; and DDGS2 = 1.9, 2.4. In vitro gas production (mL/48 h) was highest for germ (52.1) followed by bran (50.1), WDGS (40.7), DDGS2 (40.1), WCGF (39.0), DDGS1 (38.6), and HPDDG (37.5). Comparison of co-products defined differences in chemical composition, protein fractionation, ruminal availability, and microbial fermentation.

The objectives of this study were to evaluate the dynamics of gas production of several corn (co)products, to develop equations to predict the rate of ruminal fiber digestion, to estimate total digestible nutrients (TDN) and net energy for lactation (NE L ), and to assess the stochasticity of chemical composition and nutritive value variability. Four corn milling (co)products were evaluated in this study: high protein dried distillers grains (HP-DDG), corn bran (BRAN) and dehydrated germ (GERM), and a dried distillers grains plus soluble produced with a low-heat drying process (BPX). Alfalfa hay was used as an internal standard feed in the in vitro fermentation dynamics analysis. Standard chemical analyses, in vitro digestibility, and in vitro gas production techniques were used to obtain the necessary physicochemical characterization of feeds. The in vitro dry matter digestibility at 24 and 48 h of incubation decreased exponentially as acid detergent insoluble nitrogen increased. However, the degree of in vitro dry matter digestibility reduction was more accentuated at 24 than at 48 h of incubation. The difference among these feeds regarding the dynamics of the anaerobic fermentation within different substrates (intact feed, and fiber and defatted residues) was evaluated. Results suggested that the proportion of fiber digested in the rumen was affected by the degree of sample processing and fat removal. Fractional fermentation rate (kf) of neutral detergent residue (without sodium sulfite) and defatted fiber residue for BRAN, GERM, HP-DDG, and BPX was estimated to be 0.0635 and 0.0852 h −1 , 0.0803 and 0.0914 h , respectively. The most influential variables affecting kf NDR of HP-DDG and BPX also affected the predicted TDN, suggesting that fiber quality is essential to ensure higher TDN values for these feeds. Our study indicated that it is possible to routinely quantify the rate of fiber digestion and this approach may be based on common analytical procedures namely estimates of neutral detergent fiber, acid detergent fiber, acid detergent insoluble nitrogen, ether extract, and acid detergent lignin. Our simulations of TDN values demonstrated that differences in fermentability and chemical composition of these corn (co)products might considerably affect the supply of energy to lactating dairy cow. The analytical methods developed in this study may serve as a valuable tool to assess nutrient quality and uniformity when samples differ in chemical composition.