Dried distiller´s grains plus solubles supplementation improves low-quality tropical grass utilization on beef steers

ABSTRACT: This study was designed to evaluate the effect of corn dried distiller´s grains (DDGS) supplementation on feed intake, total tract digestibility, and ruminal fermentation of beef steers fed low-quality Guinea grass (Megathyrsus maximus, cv. Gatton panic). Twelve Braford crossbred steers were housed in individual pens (n = 4 steers/treatment), provided with three levels of DDGS supplement: 0%, 0.6%, or 1.2% BW. Steers were blocked by live weight and randomly assigned to treatments within the block. Corn DDGS supplementation increased total OM intake (21.55, 40.23, and 56.69 g/kg BW0.75) and tract OM digestibility (46.33, 49.03, and 72.39 % DM). Total tract digestible OM, CP, NDF and EE intake also increase in response to DDGS supplementation. Forage OM intake decreased when supplementation level reached 1.2 % BW. Also, ruminal pH decreased with DDGS supplementation level (6.88, 6.47, and 6.27). No differences were observed in total volatile fatty acids (VFA) concentration; however, the molar proportion of acetate decreased (77.98, 73.90, and 67.29 % Total VFA) as well as acetate: propionate ratio (4.38, 3.48, and 2.74). On the contrary, propionate proportions increased (18.32, 21.86, and 24.81 % Total VFA). Levels of ammonia and lactate were within suggested values for optimal fermentation and bacterial growth. Low-quality grass supplementation with corn DDGS increased total OM intake and digestibility. Also, DDGS inclusion favorably altered volatile fatty acids profile by reducing the acetate to propionate ratio regarding forage-only diets.

PSXI-16 Evaluation of supplementation strategies for beef cattle bale-grazing grass hay in Winter

Methods of supplementing beef cows while bale grazing grass hay were investigated in a study conducted for four winters, from 2016 to 2019, at the Central Grasslands Research Extension Center near Streeter, ND. Starting in the fall of each year, cows were assigned to eight groups of similar total body weight (BW) and allowed to bale graze one of four bale grazing treatments as follows: a) grass hay, b) grass hay supplemented with alfalfa hay, c) grass hay supplemented with corn DDGS, and d) grass hay treated with a liquid supplement. Two-day body weights and body condition scores (BCS) were taken at the start and end of the study. Final BW were greater (P ≤ 0.05) when cows were supplemented with DDGS and least when cows were not supplemented. Average daily gains were influenced by method of supplementation and year (P ≤ 0.025). When winters were cold, supplementation with alfalfa hay or a liquid supplement were not adequate to maintain cows resulting with weight loss. Final BCS were greatest (P ≤ 0.05) when cows were supplemented with DDGS and lowest on grass hay. Similarly, change in BCS was greatest in DDGS-supplemented cows and lowest on grass hay only. Calf birth weights, weaning weights and daily gains were not influenced (P > 0.05) by method of supplementation. Results suggest that method of supplementation during bale grazing should be based on prevailing environmental conditions during winter. In severely cold winters, good-quality alfalfa hay or a liquid supplement are not adequate to meet requirements of pregnant beef cows in mid-gestation. Under such conditions, supplements such as corn DDGS will be needed to meet animal requirements. Supplementation with good-quality alfalfa hay or grass hay treated with a liquid supplement may be an option during mild winters.

Increasing dietary proportion of wheat grain in finishing diets containing distillers' grains: impact on nitrogen utilization, ruminal pH, and digestive function

Because of its high crude protein (CP) content, dietary inclusion of corn dried distillers' grains with solubles (DDGS) in finishing cattle diets can increase the ruminal loss of ammonia-nitrogen (NH3-N), which ends up excreted as urine urea-N (UUN). Increasing dietary fermentable energy supply can enhance ruminal use of N; however, it could also lead to acidotic conditions that compromise digestive function and animal performance. We evaluated the effects of partially replacing dietary corn grain with 20 or 40% (dry matter [DM] basis) wheat grain in finishing diets containing 15% corn DDGS on N utilization, ruminal pH and digestive function. Nutrient intake and digestion, ruminal fermentation characteristics, microbial protein synthesis, route of N excretion, and blood metabolites were measured. Six ruminally-fistulated crossbred beef heifers (initial BW ± SD; 797 ± 58.8 kg) were used in a replicated 3 × 3 Latin square design with 28-d periods. Dietary treatments were either corn (73% of diet DM; CON), 53:20 corn:wheat blend (20W) or 33:40 corn:wheat blend (40W) as the major fermentable energy source. Dry matter intake tended to be lower for heifers fed the 40W than CON and 20W diets. Feeding diets containing wheat grain led to an increase (P = 0.04) in NDF intake. However, there was no diet effect (P ≥ 0.60) on apparent total tract DM and NDF digestibility. Feeding wheat grain led to a decrease (P ≤ 0.03) in mean and minimum pH, an increase (P = 0.04) in pH < 5.8 duration, and a tendency for an increase in the area and acidosis index for pH < 5.8 and 5.5. Nitrogen intake, which was lower (P = 0.04) for 40W than 20W heifers did not differ between CON and 20W heifers. There was no diet effect (P = 0.80) on ruminal NH3-N concentration and estimated microbial N flow. However, feeding diets containing wheat grain led to a decrease (P = 0.045) in UUN excretion (% total urine N). Fecal and total N excretion (% of N intake) increased (P < 0.01) following the addition of wheat grain to the diet. Apparent N retention was lower (P = 0.03) for 40W than CON and 20W heifers. In summary, although it led to a desirable decrease in UUN excretion, feeding wheat grain in corn DDGS-containing diets increased acidotic conditions in the rumen, which possibly led to the tendency for a decrease in DMI. The negative apparent N retention at the 40% wheat grain inclusion also suggests a decrease in nutrient supply, which could compromise feedlot performance.

PSVI-20 Updated Amino Acid, Choline, Betaine, Folic Acid, and Vitamin B12 Concentrations in Corn DDGS and Wheat

Choline and water-soluble vitamins are essential nutrients for monogastric species. Choline is involved in cell structure and function making it a crucial nutrient in cognitive, cardiovascular and liver health. Additionally, choline along with methionine, betaine, folic acid and vitamin B12 are considered methyl donors and play important roles in DNA methylation. Choline deficiency symptoms can include fatty liver, neuromuscular issues, poor immune function and poor growth rates which can affect animal production profitability. While the Swine NRC (2012) has set forth dietary requirements, there is a lack of current information related to how the levels of methyl-containing compounds differ in varying ingredients. Improvements in analytical testing procedures, changes to the genetic makeup of crops, and current processing methods collectively influence nutrient concentrations in feedstuffs. The purpose of this project was to sample and analyze numerous samples of corn dried distiller grains with solubles (corn DDGS) and wheat collected in 2019 to permit quantification of choline and other methyl-containing compounds. Thirty-two corn DDGS samples and 23 wheat samples were collected from 12 states within the United States. Samples were then analyzed at Eurofins Scientific (Des Moines, IA) for dry matter, amino acid, choline, betaine, folic acid, and vitamin B12 concentrations. In general, corn DDGS exhibited lower analyzed methyl-containing nutrient concentrations when compared with wheat (Table 1). Methionine and folic acid contents of both ingredients were similar to those reported by the Swine NRC (2012). However, analyzed choline levels were 20% lower for corn DDGS and 18% higher for wheat than those reported by the Swine NRC. The lack of updated information related to choline and betaine in these two feedstuffs would suggest there may be inaccuracies in formulating diets to meet the requirements for optimal growth and health of pigs.

136 Mycotoxin Contamination in United States Corn and Corn DDGS from 2019 and 2020 Harvest

Mycotoxins are harmful secondary fungal metabolites central to food and feed safety management. These toxins are detrimental to animal health and even at low levels can compromise performance. Focus on clinical signs like decreased feed intake and vomiting overlook significant impacts of mycotoxicosis, including increased disease incidence and severity, immune dysfunction, inflammation, and modulation of the gastrointestinal environment. The objective of this study was to determine the effect of harvest year on five major mycotoxin groups: aflatoxins (Afla), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), and zearalenone (ZEN) in corn and corn DDGS samples. For each mycotoxin group within ingredient, 2019 harvest (329 corn and 20 corn DDGS) were compared with 2020 harvest (27 corn and 21 corn DDGS). Data were analyzed using GLIMMIX procedure of SAS with harvest year as fixed effect and sample as the experimental unit. Average B-Trich and FUM contamination levels in corn are significantly (P < 0.05) affected by harvest year. However, B-Trich levels remained consistent, whereas FUM decreased (P < 0.05) from 2019 to 2020. Contamination levels in corn for Afla, A-Trich, and ZEN have remained consistent (P > 0.05) from 2019 to 2020. In corn DDGS, B-Trich contamination level was decreased (P < 0.05) from 2019 to 2020, whereas FUM and ZEN contamination levels remained similar (P > 0.05). The 2020 crop risk profile is likely to change as the sample pool expands. A combination of hot weather, storm events, and drought during the 2020 growing season resulted in crop stress and damage, ultimately leading to grain quality and mycotoxin contamination concerns. Due to the continued risk of mycotoxin co-occurrence, expanding mitigation strategies beyond adsorption by mycotoxin deactivation with biotransformation and additional support of immune and liver function is essential.

143 Impact of Replacing Soybean Meal with Corn DDGS and Crystalline Amino Acids on Performance and Carcass Characteristics of Growing Pigs

This study evaluated the effect of replacing soybean meal (SBM) with DDGS and crystalline amino acids on growth and carcass lean. Pigs (n = 512; 38.51±0.13 kg BW) were blocked by BW and sex and placed in 64 pens (4 gilts and barrows per pen). Treatments were arranged as a 2×4 factorial with DDGS included at 0 or 25% and L-lysine-HCl (LYS) added at 0, 0.2, 0.4, and 0.6%. Dietary SBM inclusion declined as LYS increased from 32.06 to 13.14% (Phase 1) and 28.25 to 9.40% (Phase 2) for control diets. It declined from 27.85 to 8.89% (Phase 1) and 24.05 to 5.10% (Phase 2) for DDGS diets. Diets contained 1.00 (Phase 1, 21 days) and 0.90% (Phase 2, 18 days) SID lysine and were balanced for ideal protein and net energy. During Phase 1, DDGS decreased ADG (P = 0.06; 786 vs. 821 g/d). Increasing LYS increased (quadratic, P ≤ 0.05) ADG and ADFI with the greatest response at 0.4% LYS. G:F decreased (linear, P = 0.035) with increasing LYS. During Phase 2, increasing LYS in control, but not DDGS diets, decreased (linear, P < 0.005) ADG and ADFI. G:F declined (P = 0.054) with DDGS inclusion (370 vs. 383 g/kg). Overall, ADG decreased (linear, P = 0.005) as LYS increased in control (959, 929, 908, 860 g/d), but not DDGS diets (863, 908, 931, 832 g/d). ADFI decreased (linear, P = 0.014) with increasing LYS in control (2270, 2198, 2186, 2130 g/d), but increased (quadratic, P = 0.039) in DDGS diets (2112, 2207, 2324, 2103 g/d). DDGS reduced (P≤0.03) ADG (883 vs. 914 g/d), G:F (405 vs. 417 g/kg) and LEA (34.5 vs. 35.3 cm2), while increasing LYS decreased (linear, P < 0.005) G:F (417, 419, 409, 401 g/kg) and LEA (35.34, 35.17, 35.46, 33.64 cm2). Displacement of SBM with DDGS reduced growth and LYS addition negatively affected growth and G:F for diets with SBM, but not DDGS.

Determination of in vitro dry matter, protein, and fiber digestibility and fermentability of novel corn co-products for swine and ruminants

New processes are being used in some dry-grind ethanol plants in the United States and Brazil to improve ethanol yield and efficiency of production while also providing nutritionally enhanced corn co-products compared with conventional corn distillers dried grains with solubles (DDGS). The objectives of this study were to determine the chemical composition and in vitro digestibility of 5 conventional corn DDGS sources and 10 emerging novel corn co-products for swine and ruminants, and compare co-products produced using similar processes in the United States and Brazil. Chemical composition, on a dry matter (DM) basis, among the 15 co-products ranged from 18.5 to 54.7% for crude protein (CP), 12.3 to 51.4% for neutral detergent fiber (NDF), 1.6 to 8.6% for acid detergent fiber, 4.7 to 12.3% for ether extract, and 1.6 to 8.6% for ash. For swine, in vitro hydrolysis of DM and CP were greater (P < 0.01) for the 3 U.S. corn DDGS sources compared with the 2 Brazilian corn DDGS sources, but in vitro fermentability of DM was comparable (P > 0.05) among all sources except one U.S. DDGS source that had less fermentable DM. High protein and yeast dried distillers grains (Ultramax, UM; StillPro, SP) co-products also had comparable (P > 0.05) DM fermentability for swine, but UM co-products had greater (P < 0.01) DM and CP hydrolysis compared with SP. High protein distillers dried grains (HP-DDG) from Brazil had greater (P < 0.01) DM and CP hydrolysis, but less (P < 0.01) DM fermentability for swine than HP-DDG produced in the U.S, using the same process. For ruminants, total DM digestibility was greater (P < 0.01) in conventional DDGS sources from the U.S. compared with the 2 DDGS sources from Brazil. Total protein digestibility for ruminants was comparable and above 81% for all co-products except for a DDGS source from Brazil, a HP-DDG source from the U.S., and a UM sample. Interestingly, the corn fiber + solubles co-product had not only relatively high digestibility of NDF (67.9%), DM (91.6%), and total CP (81.9%) for ruminants, but it also had relatively high total tract digestibility of DM (86.2%) and CP (69.9%) for swine. These results suggest that nutrient digestibility of conventional DDGS sources produced in the U.S. appear to be greater than corn Brazilian DDGS sources, but new process technologies being implemented in ethanol and co-product production in both countries can enhance the nutritional value of corn co-products for both swine and ruminants.

122 Nutrient digestibility of heat pretreated or multienzyme treated corn whole stillage for pigs

A study was conducted to determine standardized ileal digestibility (SID) of amino acids (AA) and net energy value (NE) for pigs of heat-pretreated or enzyme-predigested corn whole stillage (WS; slurry material that is dried into DDGS). Ten ileal-cannulated barrows (initial BW = 65.6 ± 3.5 kg) were fed 5 diets in a replicated 5 × 5 Latin square design. The diets were cornstarch-based, containing corn DDGS, untreated WS (C-WS), heat-pretreated WS (Heat-WS) or enzyme-predigested WS (Predigested-WS), and N-free diet. Digestibility of AA in feedstuffs was determined by the direct method. Energy digestibility in feedstuffs was determined by difference from the N-free diet. The WS was heat pretreated at 140 °C and 70 psi for 15 min. Predigestion of the WS was achieved by incubating with multienzyme that supplied xylanase, celullase, α-galactosidase at 2.4, 2.0 and 2.3 mg per gram of WS, respectively, for 12 h at 55 °C. On DM basis, DDGS, C-WS, Heat-WS, Predigested-WS contained 32.8, 30.8, 28.18, and 39.7% CP, 39.8, 51.0, 52.2 and 53.8% NDF, and 4.5, 4.6, 5.7 and 4.5% EE, respectively. The SID of Lys for C-WS (75.5%) was greater (P < 0.05) than that for C-DDGS (67.4%) and Heat-WS (53.9%), but lower (P < 0.05) than for Predigested-WS (84.1%). The NE value for C-WS (2,793 kcal/kg) did not differ from that of C-DDGS (2,668 kcal/kg DM). The NE value for C-WS was greater (P < 0.05) than that for Heat-WS (1,834 kcal/kg DM) and lower than that for Predigested-WS (2,814 kcal/kg DM). In conclusion, enzymatic predigestion of WS increased its SID of Lys and NE value, and hence it can be an attractive technology to increase the nutritive value of corn DDGS for pigs. Heat pretreatment reduced SID of AA and NE values of the WS.

PSVIII-1 Determination of in vitro DM, N and NDF digestibility and fermentability in novel corn co-products for swine

New process technologies are being implemented in the ethanol industry resulting in new high protein corn co-products (HPCP) containing more gross energy and amino acids than conventional distillers dried grains with solubles (DDGS). Thus, estimates of nutrient digestibility for HPCP are needed to assess potential feeding value for swine. Furthermore, yellow dent corn is the predominant grain source in U.S. ethanol and co-product production whereas flint corn is used in Brazil. This study determined and compared in vitro dry matter (DM), nitrogen (N), and neutral detergent fiber (NDF) digestibility and fermentability of U.S. and Brazil corn DDGS and new HPCP. In vitro methods evaluated DM, N, and NDF digestibility and fermentability of 2 corn DDGS samples from U.S. (POET and ICM), 2 DDGS samples from Brazil (BR1 and BR2), 1 corn fiber and solubles sample (CF+S), 3 high protein distillers grains (HP-DDG) samples (BR-HP, US-HP, US-HPG1.5), and 2 HP-DDG samples containing high yeast (Ultramax; UM) and StillPro (SP). Digestibility of DM from hydrolysis varied and was greatest for UM (87.13%; P < 0.001) compared with all other co-products. Fermentability of DM was greater (P < 0.001), and similar for UM (85.6%), SP (76.8%), and US-HP-DDG (72.8%) compared with other co-products. Digestibility of N was greater for UM (91.2%; P < 0.001) compared with all other co-products. NDF digestibility was greater (P < 0.001) for UM (62.5%) and SP (60.5%) compared with all other co-products. POET and ICM DDGS had greater (P < 0.001) DM hydrolysis (78.7% and 68.2%, respectively), than BR1 (37.2%) and BR2 (35.0%) and N digestibility (POET = 65.0%; ICM = 58.9%) compared with BR1 (54.4%) and BR2 (43.4%). These results suggest greater nutritional value for Ultramax and StillPro than conventional DDGS and HP-DDG sources (U.S. and Brazilian) due to greater DM, N, and NDF digestibility.

Can the digestibility of corn distillers dried grains with solubles fed to pigs at two stages of growth be enhanced through management of particle size using a hammermill or a roller mill?

The objective of this study was to determine the impact of reducing the mean particle size (PS) of corn distillers dried grains with solubles (DDGS) with a hammermill (HM) or with a roller mill (RM) on the apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), N, acid hydrolyzed ether extract (AEE), and fiber components in growing and finishing pigs. Twenty-four growing barrows were housed in individual pens and were randomly assigned to a 3 × 2 factorial design (n = 8): three grinding methods [either corn DDGS ground with an HM to a PS of 450 μm; corn DDGS ground with an RM to a PS of 450 μm; and corn DDGS with a PS of 670 μm (not further ground)] and two body weight (BW) periods (growing pigs with an average initial BW of 54.7 ± 0.9 kg, and finishing pigs with an average initial BW of 107.8 ± 1.5 kg BW). Fecal samples were collected for each BW period in the last 3 d of an 11-d feeding period. Titanium dioxide was used as an indigestible marker. Digestibility data were analyzed using the MIXED procedure of SAS. Results showed that finishing pigs tended to have better ATTD of DM than growing pigs (P = 0.09) and had increased ATTD of GE and N than growing pigs (P = 0.03 and P < 0.01, respectively). On the other hand, growing pigs had better ATTD of AEE than finishing pigs (P = 0.01). Pig BW period did not affect the ATTD of neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicellulose. Reducing the mean PS of corn DDGS with either HM or RM (from 670 to 450 µm) improved the ATTD of DM and GE (P < 0.01 and P < 0.01), tended to improve the ATTD of N (P = 0.08), and improved the ATTD of AEE (P < 0.01). No effect of reducing PS was observed for the ATTD of NDF, ADF, or hemicellulose. There were no differences between HM and RM in any of the ATTD variables tested. In conclusion, reducing PS of corn DDGS from 670 to 450 μm either with an HM or with an RM improved the digestibility of DM, GE, and AEE and modestly improved the digestibility of N in growing and finishing pigs. However, reducing the PS of corn DDGS did not affect the digestibility of fiber components.