Canola meal replacing distillers grains with solubles for lactating dairy cows

A study was conducted to determine the response to feeding diets containing canola meal (CM) as a protein supplement in place of all or portions of dried distillers grains with solubles (DDGS). Twelve lactating Holstein cows (4 primiparous and 8 multiparous) were fed in a 4 × 4 Latin square design over 4-wk periods. Data were collected wk 3 and 4 of each period. Diets were formulated in which CM was 100, 66, 33, and 0% of the supplemental protein replacing the protein from DDGS. All diets (averaged 15.1% crude protein and 4.5% ether extract) contained 55% forage and 45% concentrate, with the forage being 50% corn silage and 50% alfalfa hay. Dry matter intake (25.4 kg/d) was similar for all diets. Milk production (35.2, 35.8, 34.5, and 34.3 kg/d, respectively, for 100, 66, 33, and 0% CM) was similar for all diets, but tended to be greater with higher proportions of CM. Milk protein concentration (3.04%), fat concentration (3.92%), and fat yield (1.37 kg/d) were similar for all diets, whereas protein yield (1.08, 1.10, 1.05, and 1.03 kg/d, respectively, for 100, 66, 33, and 0% CM) tended to be greater with increasing amounts of CM in the diet. Feed efficiency (1.46 kg of energy-corrected milk/kg of dry matter intake) was similar for all diets. Lysine was the first limiting amino acid for milk protein synthesis when CM or DDGS were fed, whereas methionine was first limiting when the combination diets were fed. Concentrations of ammonia and volatile fatty acids in ruminal contents were similar for all diets. Canola meal is a suitable replacement for DDGS in dairy cow diets.     

Evaluation of palm kernel meal and corn distillers grains in corn silage-based diets for lactating dairy cows

The effects of increasing levels of solvent-extracted palm kernel meal (SPKM) and corn distillers dried grains (CDG) in corn silage-based diets on feed intake and milk production were examined in 2 experiments. In Experiment 1, 20 Holstein cows averaging 100 d in milk (DIM) (SD = 61.5) at the start of the experiment were utilized in an 11-wk randomized complete block design with 4 treatments in 5 blocks to study effects of increasing levels of SPKM in the diet. During a 3-wk preliminary period, cows were fed a standard diet. At the end of the preliminary period, cows were blocked by 4% fat-corrected milk yield, parity number (primiparous and multiparous), and DIM, and were assigned randomly to 1 of 4 experimental diets. The total mixed ration (TMR) consisted of (dry matter basis) 40% corn silage, 5% coarsely chopped wheat straw, and 55% concentrate. The increasing dietary levels of SPKM were achieved by replacing protein sources and citrus pulp with SPKM and urea (0, 5, 10, and 15% SPKM and 0.06, 0.22, 0.38, and 0.55% urea for SPKM0, SPKM5, SPKM10, and SPKM15, respectively). In Experiment 2, 18 Holstein cows averaging 93 DIM (SD = 49.1) at the start of the experiment were utilized in an 11-wk randomized complete block design with 3 treatments in 6 blocks to study effects of increasing levels of CDG in the diet. The preliminary period lasted for 2 wk. Assignment of cows to treatments was the same as in Experiment 1. The TMR consisted of (dry matter basis) 40% corn silage, 5% coarsely chopped wheat straw, and 55% concentrate. The increasing dietary levels of CDG were achieved by replacing soybean meal and citrus pulp with CDG and urea (0, 7, and 14% CDG and 0, 0.22, and 0.49% urea for CDG0, CDG7, and CDG14, respectively). There were no significant treatment effects on dry matter intake, milk yield, or milk composition in Experiment 1. Inclusion of SPKM tended to increase protein and lactose contents of milk. The SPKM0 diet promoted body weight loss. There were no treatment effects in Experiment 2, except for milk protein content, which was decreased by CDG. Plasma Lys concentration tended to be affected by SPKM and CDG inclusions. Plasma concentrations of 3-methylhistidine and Leu seemed to be related to body protein degradation/synthesis. The feeding of SPKM up to 15% in the diet decreased feed costs without detrimental effects on productive responses and tended to increase milk protein content. The inclusion of CDG in diets based on corn silage and corn byproducts might decrease milk protein content due to an unbalanced supply of AA, particularly Lys.     

Evaluation of dried and wet distillers grains included at two concentrations in the diets of lactating dairy cows

The purpose of this study was to determine the lactation performance of dairy cows fed dried or wet distillers grains (DG) with solubles (DDGS or WDGS) at 2 dietary concentrations. A trial using 15 cows was designed as a replicated 5 × 5 Latin square with periods of 4 wk each and data collected during wk 3 and 4 of each period. Diets, on a dry matter basis, were: control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS. All diets contained 25% corn silage, 25% alfalfa hay, and 50% of the respective concentrate mixes. Dry matter intake (DMI) tended to be greater for cows fed control than DG (23.4, 22.8, 22.5, 23.0, and 21.9 kg/d for control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS). Milk yield (39.8, 40.9, 42.5, 42.5, and 43.5 kg/d) was greater for cows fed DG than control. Milk fat percentage (3.23, 3.16, 3.28, 3.55, and 3.40%) was similar for cows fed control and DG, but greater for cows fed WDGS than DDGS. Milk fat yield was greater for cows fed DG than control and tended to be greater for cows fed WDGS than DDGS. Milk fat from cows fed DG, especially 20% DG, was more unsaturated and contained more cis-9, trans-11 conjugated linoleic acid than when fed the control diet. Milk protein percentage (3.05, 3.01, 3.02, 3.11, and 3.06%) was similar for cows fed control and DG but greater for cows fed WDGS than DDGS. Milk protein yield was greater for cows fed DG than control, tended to be greater for cows fed WDGS than DDGS, and tended to be greater for cows fed 20% DG than 10% DG. Milk urea nitrogen was similar for cows fed control and DG but greater for cows fed WDGS than DDGS and tended to be higher for cows fed 20% DG than 10% DG. Ruminal ammonia concentrations were greater for cows fed WDGS than DDGS. Overall, feeding DG improved feed efficiency (1.70, 1.79, 1.87, 1.84, and 1.92 kg of energy-corrected milk/kg of DMI) by increasing yields of milk, protein, and fat while tending to decrease DMI.     

Heat- and lignosulfonate-treated canola meal as a source of ruminal undegradable protein for lactating dairy cows

This experiment used 18 lactating Holstein cows in a 3 x 3 Latin square replicated 6 times to determine the effectiveness of processing with moist heat or moist heat combined with lignosulfonate (LSO3) for increasing the ruminal undegradable fraction of canola meal for use as a protein supplement for lactating dairy cows. Diets were formulated to be isonitrogenous and contained one of 3 forms of canola meal; untreated canola meal (UCM), heat-treated canola meal (HTCM) or heat-and LSO3-treated canola meal (LSO3CM). Total collection of urine and feces was taken from each cow during the last 5 d of each 42-d experimental period. Milk production was greater for cows fed the LSO3CM diet (36.6 kg/d) than for cows fed the UCM diet (34.8 kg/d) but did not differ from cows fed the HTCM diet (35.3 kg/d). Digestibility of crude protein was lower for cows supplemented with LSO3CM and they had reduced concentrations of ruminal ammonia N, blood urea N, and milk urea N compared with cows supplemented with UCM or HTCM. Dry matter intake and apparent digestibilities of neutral and acid detergent fiber were increased in cows fed the LSO3CM diet. Urinary N excretion (as % of N intake) was reduced in cows fed the LSO3CM diet. These results indicate that moist heat combined with LSO3 treatment of canola meal was effective in increasing the proportion of crude protein digested in the lower digestive tract of lactating cows and was therefore used more effectively as a source of protein than UCM or HTCM.     

Evaluation of rumen-protected lysine supplementation to lactating dairy cows consuming increasing amounts of distillers dried grains with solubles

Twenty multiparous Holstein cows were used in four 5 × 5 Latin squares to determine the effects of feeding increasing amounts of distillers dried grains with solubles (DDGS) in diets with or without the supplementation (60 g/d) of a rumen-protected Lys (RPL) product (AminoShure-L, 38% l-Lys; Balchem Encapsulates, New Hampton, NY) on milk yield and composition and plasma concentration of AA. Dietary treatments were (1) control (CON; no DDGS), (2) 10% DDGS (10DG), (3) 20% DDGS (20DG), (4) 10% DDGS plus RPL (10DGRPL), and (5) 20% DDGS plus RPL (20DGRPL). Diets were formulated using the Cornell-Penn-Miner Dairy model (CPM v3.0; http://cahpwww.vet.upenn.edu/node/77) to provide a predicted decreasing supply of Lys (117, 99, and 91% of requirements) for the CON, 10DG, and 20DG diets, respectively. Addition of RPL to the 10DG and 20DG diets (unsupplemented diets) resulted in 2 additional treatments, 10DGRPL and 20DGRPL diets, respectively. The 10DGRPL and 20DGRPL diets met 110 and 100% of the Lys requirements, respectively. Periods lasted 21 d, with the last 3 d for data collection. Compared with cows fed the CON diet, cows fed diets with DDGS had a similar dry matter intake (DMI; 25.4 ± 0.88 kg/d), milk yield (30.7 ± 1.67 kg/d), and composition, except for protein percentage, which was higher (3.15 vs. 3.21 ± 0.05%) and resulted in higher (0.94 vs. 1.00 ± 0.05 kg/d) protein yield by cows fed diets containing 20% DDGS. Unexpectedly, despite diets being formulated based on predicted DMI of 23.3 kg/d and milk yield of 38.5 kg/d, cows had a greater DMI and lower milk yield across all treatments, which resulted in diets that were predicted by CPM Dairy to supply sufficient amounts of Lys (140, 118, and 104% of requirement for the CON, 10DG, and 20DG diet, respectively) and consequently, supplementation with RPL did not have an effect on milk production or composition. Plasma concentration of Lys decreased (11.8%) as DDGS inclusion increased. For other essential AA, plasma concentrations of cows fed diets with DDGS were lower for Arg, His, and Val and greater for Leu and Met compared with cows fed the CON diet. Supplementation with RPL failed to decrease the plasma concentration of other essential AA, which provides support that Lys was not limiting.     

Saccharomyces cerevisiae fermentation product in dairy cow diets containing dried distillers grains plus solubles

Sixteen multiparous Holstein cows (127 ± 52 d in milk) were used in 4 replicated 4 × 4 Latin squares with 4-wk periods to evaluate interactions of dietary inclusion of a fermentation product of Saccharomyces cerevisiae (SC; XPC, Diamond V Mills, Cedar Rapids, IA) and dried distillers grains plus solubles (DDGS) on production of milk and milk components when fed diets containing approximately 30% dietary neutral detergent fiber with calculated forage neutral detergent fiber of 19.3% of diet dry matter (DM). Treatments were a 2 × 2 factorial arrangement with SC included at 0 or 14 g/d and DDGS at 0 or 20% of diet DM. Diets consisted of 27% corn silage, 18% alfalfa hay, and 55% concentrate mix on a DM basis. Diets not containing DDGS included additional corn, soybean meal, expeller soybean meal, soyhulls, and rumen inert fat to remain isocaloric and isonitrogenous with DDGS diets. Dry matter intake (26.0 kg/d) was similar for all diets. Milk production increased with the addition of SC to diets (43.6 vs. 42.0 kg/d for diets without SC) and decreased for cows fed diets containing DDGS (42.0 kg/d vs. 43.6 kg/d for diets not containing DDGS). Milk fat percentage (3.05 vs. 3.22% for DDGS and non-DDGS diets, respectively) and yield (1.27 vs. 1.41 kg/d) were decreased by the addition of DDGS but were not affected by the addition of SC. Concentrations of long-chain, polyunsaturated, trans-, and conjugated fatty acids in milk of cows fed DDGS were increased, but milk fatty acid profiles were not affected by SC. Milk true protein concentrations were similar for all diets; however, the addition of SC increased yield of true protein (1.32 vs. 1.27 kg/d). Concentrations of milk urea nitrogen increased when SC was included in the diet with DDGS. The DDGS decreased yields of energy-corrected milk (39.4 vs. 42.1 kg/d) and tended to decrease feed efficiency (1.53 vs. 1.61 kg of energy-corrected milk/kg of dry matter intake). Body weights and condition scores were not affected by treatments. Results suggest that diets containing minimal amounts of forage fiber and DDGS at 20% of diet DM will contribute to decreased milk production and milk fat depression. The addition of SC did improve milk and milk protein yields but did not prevent milk fat depression caused by DDGS. Production responses to SC were similar when cows were fed DDGS or non-DDGS diets.     

The energy content of wet corn distillers grains for lactating dairy cows

Forty-five energy balances were completed with 12 multiparous, lactating Holstein cows in a study designed to determine the energy content of wet corn distillers grains. Treatments were applied in a repeated switchback design and consisted of total mixed diets containing 31.4% corn silage, 18.4% alfalfa hay, and either 30.7% rolled corn and 16.7% soybean meal or 17.0% rolled corn and 31.2% wet corn distillers grains (dry matter basis). Replacement of corn and soybean meal with wet corn distillers grains reduced dry matter intake 10.9% but did not affect milk production. Neither digestible nor metabolizable energy were affected by diet composition. Heat and milk energy output did not differ by diet, but body energy retained was 2.8 Mcal/d less in cows fed the wet corn distillers grains diet. Multiple regression estimates of maintenance metabolizable energy requirement and partial efficiencies of metabolizable energy used for lactation and body energy deposition did not differ by diet. Pooled estimates were 136.2, 0.66, and 0.85, kcal of metabolizable energy/ body weight0.75 per day, respectively. Calculated by difference, wet corn distillers grains was estimated to contain 4.09, 3.36, and 2.27 Mcal/kg of dry matter as digestible, metabolizable, and lactational net energy, respectively. These energy estimates were 7 to 11% and 10 to 15%, respectively, greater than those reported for dried corn distillers grains by the 1989 and 2001 dairy NRC publications.     

Lactation performance and amino acid utilization of cows fed increasing amounts of reduced-fat dried distillers grains with solubles

The use of a solvent-extraction process that removes corn oil from distillers grains produces a reduced-fat co-product (RFDG). To determine the optimal concentration of RFDG in mid-lactation diets, 22 multiparous and 19 primiparous Holstein cows were used in a completely randomized design for 8 wk, including a 2-wk covariate period. The RFDG was included at 0, 10, 20, and 30% of the diet on a dry matter basis, replacing soybean feedstuffs. Increasing RFDG in diets had no effect on dry matter intake (23.1 kg/d) or milk production (35.0 kg/d). Milk fat percentage increased linearly from 3.18 to 3.72% as RFDG increased from 0 to 30% of the diet. Similarly, milk fat yield tended to increase linearly from 1.08 to 1.32 kg/d. Milk protein percentage (2.99, 3.06, 3.13, and 2.99% for diets with RFDG from 0 to 30%) responded quadratically, whereas protein yield was not affected by treatment. Milk urea N decreased linearly from 15.8 to 13.1 mg/dL. The efficiency of N utilization for milk production was not affected by including RFDG (26.1%), whereas the efficiency of milk production (energy-corrected milk divided by dry matter intake) tended to increase linearly with increasing RFDG in the diet. Similarly, concentrations of plasma glucose increased linearly. Arterial Lys decreased linearly from 66.0 to 44.8 μM/L, whereas arterial Met increased linearly from 16.5 to 29.3 μM/L. Arteriovenous difference of Lys decreased linearly from 42.6 to 32.5 μM/L, whereas that of Met was unaffected. The extraction of Lys by the mammary gland increased linearly from 64.3 to 72.2%, whereas that of Met decreased linearly from 71.6 to 42.7%. Feeding up to 30% of RFDG in a mid-lactation diet supported lactation performance similarly to cows fed the soybean protein-based diet (0% RFDG).     

Production effects of extruded soybean meal replacing canola meal in the diet of lactating dairy cows

This study investigated the effects of extruded soybean meal (ESBM) in comparison with canola meal (CM) fed on an equivalent crude protein (CP) basis on lactational performance and ruminal fermentation of dairy cows. Following a 2-wk covariate period, 48 Holstein cows averaging (±SD): 146 ± 46 d in milk (DIM) and 43 ± 7 kg/d milk yield (MY) were assigned 1 of 2 treatment diets in a randomized complete block design experiment, which included a 2-wk period for dietary treatment adaptation before experimental data were collected. Following the adaptation period, samples and experimental data were collected for a total of 7 wk. Cows were blocked based on parity, DIM, and MY. Treatment diets contained 15.8% CM (containing 41.2% CP) or 13.2% ESBM (with 48.7% CP) of total mixed ration dry matter (DM), with similar inclusion of other feed ingredients. The CM diet was supplemented with canola oil, whereas the ESBM diet was supplemented with soybean hulls to achieve similar ether extract and neutral detergent fiber contents between the diets. Urea and rumen-protected Met and Lys were added to both diets to meet or exceed cow recommendations. Whole-ruminal digesta samples were collected from 10 (5 per treatment) ruminally cannulated cows. Eight cannulated cows were removed during the last week of the experiment to participate in another study. Treatment did not affect DM intake and MY or energy-corrected MY of the cows. Energy-corrected MY, apart from experimental wk 5, was similar between treatments. Apart from experimental wk 3 and 7, milk fat concentration and yield were greater for cows fed ESBM compared with CM. In multiparous cows only, milk true protein yield was greater for cows fed CM compared with ESBM. Ruminal concentration of total volatile fatty acids and the molar proportion of acetate were greater for ESBM, and propionate and valerate were greater in cows fed CM. Acetate to propionate ratio was greater for cows fed ESBM versus CM diet. Compared with the CM diet, the ESBM diet increased plasma concentrations of Ile, Leu, and Phe but not the sum of essential AA. Apparent total-tract digestibility of acid detergent fiber was greater in cows fed ESBM relative to CM. In this experiment, CM and ESBM included on an equal CP basis in the diet of dairy cows, resulted in similar DM intake, MY, and feed efficiency.     

Effect of dietary supplementation with heat-treated canola meal on ruminal nutrient metabolism in lactating dairy cows

An experiment was conducted to quantify the effects of incremental levels of heat-moisture-treated canola meal (TCM) fed to dairy cows on the relationship between ruminal nutrient digestion and milk production. Experimental diets were fed to 4 multiparous rumen-cannulated Nordic Red cows, averaging (mean ± standard deviation) 681 ± 54.8 kg of body weight, 111 ± 16 d in milk, and 29.1 ± 9.1 kg of milk/d at the start of the study, in a Latin square design with four 21-d periods. The 4 experimental dietary treatments consisted of a basal diet of grass silage and crimped barley, and 3 diets in which the crimped barley was replaced with TCM, giving 3 incremental levels of protein supplementation. Nutrient flow was quantified by the omasal sampling technique using 3 markers (Cr, Yb, and indigestible neutral detergent fiber). Continuous infusion of ¹⁵N was used to label bacterial crude protein. Additionally, ruminal sampling and evacuations and measurements of total-tract digestibility were conducted. The experimental diets provided 132, 148, 164, and 180 g of crude protein/kg of dry matter. The increased level of TCM linearly increased dry matter intake from 15.1 to 16.6 kg/d and energy-corrected milk yield from 21.0 to 25.6 kg/d. The increased proportion of TCM when substituting barley with TCM was associated with greater total-tract digestibility of neutral detergent fiber and potentially digestible neutral detergent fiber, which could be explained by increased digestion rate of potentially digestible neutral detergent fiber. Omasal flow of nonammonia N naturally increased with greater dietary TCM inclusion, but the increased intestinal supply of rumen-undegradable protein was partly offset by diminished microbial protein synthesis when feeding more TCM. This was also reflected in a decreased proportion of milk protein from ruminal bacterial protein when TCM supplementation increased.     

Effects of feeding triticale dried distillers grains plus solubles as a nitrogen source on productivity of lactating dairy cows

The objective of this study was to compare triticale dried distillers grains plus solubles (TDDGS) as a source of dietary N with other high-protein feeds commonly used in North America: corn dried distillers grains plus solubles (CDDGS), canola meal (CM), and soybean meal (SBM). Rumen degradable protein (% of crude protein, CP) after 16 h of incubation in the rumen was higher for CDDGS and TDDGS (69.3% and 64.5%, respectively) than for CM (62.2%) and SBM (53.0%). For the lactation study, experimental diets were formulated to supply 30% of dietary CP from TDDGS, CDDGS, CM, or SBM. These diets contained 22.3% forage neutral detergent fiber and approximately 19.2% CP and were fed to 12 multiparous Holstein cows (130 ± 40 d in milk) in a 4 × 12 Latin rectangle design with 21-d periods. Neither dry matter intake nor milk yield was affected by treatment, averaging 25.5 and 35.5 kg/d, respectively. Plasma concentrations of Arg, Lys, and Thr were greater for cows fed CM or SBM compared with those fed TDDGS or CDDGS, whereas plasma concentrations of Leu and Phe were lower for cows fed CM or SBM compared with those fed TDDGS or CDDGS. Cows fed CDDGS had lower milk CP yield compared with cows fed CM (1.07 vs. 1.16 kg/d). Contrarily, milk CP and milk lactose yields were not different for cows fed TDDGS compared with CM or SBM. These data suggest that TDDGS can replace CM or SBM in the diets of lactating dairy cows without adverse effects on production. Furthermore, although dried distillers grain has been generally accepted as a feed high in ruminal undegradable protein, CDDGS and TDDGS used in the present study had high in situ ruminal degradable crude protein. Further investigation is warranted to determine the extent of variation in ruminal protein degradation among different types of dried distillers grains.     

Replacement of starch from corn with nonforage fiber from distillers grains and soyhulls in diets of lactating dairy cows

Forty Holstein cows were used in a completely randomized design with a 2-wk covariate period followed by a 6-wk experimental period to evaluate incremental substitution of nonforage fiber provided by dried distillers grains with solubles (DDGS) and soyhulls (SH) for starch provided by corn in the diet. Diets provided decreasing concentrations of starch: 29% starch with 0% DDGS; 26% starch with 7% DDGS; 23% starch with 14% DDGS; and 20% starch with 21% DDGS. Diets contained 27% corn silage, 22% alfalfa hay, and 51% concentrate mix and were formulated to be 17% crude protein, 4.7% fat, and 23% neutral detergent fiber from forage. Total neutral detergent fiber increased as DDGS and SH were included in the diet. Soyhulls were included in a linear fashion along with DDGS to replace soybean meal and expeller soybean meal, thereby maintaining a similar crude protein content across diets. Dry matter intake decreased linearly; consequently, feed efficiency tended to increase linearly as starch was replaced by nonforage fiber. There was no effect of diet on milk production or milk fat and protein percentage or yield. Milk fatty acid profiles were similar across diets. Other response variables, including 4% fat-corrected milk, total solids, and milk urea nitrogen, were unaffected by dietary treatments. Ruminal volatile fatty acid concentration did not differ between diets. Concentrations of blood glucose and β-hydroxybutyrate were similar across diets. Results from this research suggest that nonforage fiber from DDGS can partially substitute for starch from corn in dairy cow diets without affecting milk production and milk composition. Economic analysis of the diets showed that feeding DDGS and SH in substitution of corn was cost-effective. Results from this experiment indicate that DDGS and SH can replace corn as an energy source to decrease feed costs.     

Isolipidic additions of fat from corn germ, corn distillers grains, or corn oil in dairy cow diets

Eight multiparous and 8 primiparous Holstein cows were used in a replicated 4 × 4 Latin square design with 4-wk periods to determine the effects on dairy cow performance of feeding corn germ (CG) compared with dried distillers grains with solubles (DDGS) or corn oil (CO). Four isolipidic dietary treatments were formulated: a control diet, a 14% corn germ diet (CGD), a 30% dry distillers grains with solubles diet (DGD), and a 2.5% corn oil diet (COD). All diets were formulated to contain 6.0% fat, with the fat in the control diet provided by a ruminally inert fat source. Dry matter intake was decreased by feeding the COD compared with the CGD; however, no difference in dry matter intake was observed among the control diet, the DGD, and the COD. Dietary treatments had no effect on milk yield, energy-corrected milk, or 4% fat-corrected milk. Feeding CG had no effect on milk fat percentage when compared with the control diet; however, milk fat percentage tended to decrease with DDGS and decreased with CO when compared with the CGD. Milk protein percentage decreased when cows were fed the COD compared with the control diet. Feeding CO tended to decrease milk fat yield compared with CG; however, dietary treatments had no effect on milk protein and lactose yield. Feed efficiency was not affected by dietary treatments and averaged 1.55 kg of energy-corrected milk/kg of dry matter intake. Feeding DDGS and CO increased the concentration of vaccenic and conjugated linoleic acid in milk fat. Concentrations of monounsaturated and polyunsaturated fatty acids in milk were increased in response to feeding the 3 corn coproducts. Fat from CG appears to be relatively protected in the rumen when compared with that from DDGS and CO and therefore will not affect the production of milk fat to the degree of the more available fat in DDGS and CO.     

Effects of partially replacing barley silage or barley grain with dried distillers grains with solubles on rumen fermentation and milk production of lactating dairy cows

Dried distillers grains with solubles (DDGS) has been commonly used as a dietary protein source for lactating dairy cows. However, there is a paucity of data evaluating the use of DDGS as a partial replacement of forage or grain. The objective of this study was to determine the effects of partially replacing barley silage or barley grain with corn/wheat-based DDGS on dry matter intake (DMI), chewing activity, rumen fermentation, and milk production. Six ruminally cannulated lactating Holstein cows were used in a replicated 3 × 3 Latin square design with 21-d periods. Cows were fed the control diet (CON: 45% barley silage, 5% alfalfa hay, and 50% concentrate mix), a low forage (LF) diet or a low grain (LG) diet, in which barley silage or barley grain was replaced by DDGS at 20% of dietary dry matter, respectively. All diets were formulated to contain 18% crude protein and fed as total mixed rations. Compared with CON, cows fed the LF diet had greater DMI (26.0 vs. 22.4 kg/d), yields of milk (36.4 vs. 33.0 kg/d), milk protein (1.18 vs. 1.05 kg/d), and milk lactose (1.63 vs. 1.46 kg/d), but milk fat yield was not affected. The LF diet decreased chewing time compared with the CON diet (29.7 vs. 39.1 min/kg of DMI), but did not affect rumen pH and duration of rumen pH below 5.8. Compared with CON, feeding the LG diet tended to increase minimum and maximum rumen pH, but did not affect DMI, milk yield, and milk composition in this study. These results indicate that a partial replacement of barley silage with DDGS can improve the productivity of lactating dairy cows without negatively affecting rumen fermentation and milk fat production. Barley grain can also be partially replaced by DDGS in diets for lactating dairy cows without causing negative effects on productivity.     

Feeding reduced-fat dried distillers grains with solubles to lactating Holstein dairy cows does not alter milk composition or cause late blowing in cheese

Feeding dried distillers grains with solubles (DDGS) to lactating dairy cows has been implicated as a cause of late blowing defects in the production of Swiss-style cheeses. Our objectives were (1) to test the effect of feeding reduced-fat DDGS (RF-DDGS; ～6% fat) to lactating dairy cows on the composition of milk and on the suitability of the milk for production of baby Swiss cheese and (2) to evaluate the effect of diet on cow lactation performance. Lactating Holstein dairy cows were fed both dietary treatments in a 2 × 2 crossover design. Cows were housed in a 48-cow freestall pen equipped with individual feeding gates to record feed intake. The control diet was a corn, corn silage, and alfalfa hay diet supplemented with mechanically expelled soybean meal. The experimental diet was the same base ration, but 20% (dry matter basis) RF-DDGS were included in place of the expelled soybean meal. The RF-DDGS diet was additionally supplemented with rumen-protected lysine; diets were formulated to be isoenergetic and isonitrogenous. Cows were allowed ad libitum access to feed and water, fed twice daily, and milked 3 times daily. For cheese production, milk was collected and pooled 6 times for each dietary treatment. There was no treatment effect on milk yield (35.66 and 35.39 kg/d), milk fat production (1.27 and 1.25 kg/d), milk fat percentage (3.65 and 3.61%), milk protein production (1.05 and 1.08 kg/d), lactose percentage (4.62 and 4.64%), milk total solids (12.19 and 12.28%), and somatic cell count (232.57 and 287.22 × 10³ cells/mL) for control and RF-DDGS, respectively. However, dry matter intake was increased by treatment, which implied a reduction in feed efficiency. Milk protein percentage also increased (3.01 and 3.11%), whereas milk urea nitrogen decreased (14.18 and 12.99 mg/dL), indicating that protein utilization may be more efficient when cows are fed RF-DDGS. No differences in cheese were observed by a trained panel except cheese appearance; control cheese eyes were significantly, but not practically, larger than the RF-DDGS cheese. These results indicate that RF-DDGS can be effectively used in the rations of lactating Holstein cows with no deleterious effects on milk production and composition and metrics of the physiology of the cow (i.e., blood glucose and nonesterified fatty acids); however, feeding RF-DDGS increased dry matter intake, which decreased feed efficiency. Finally, feeding RF-DDGS did not negatively influence quality and suitability of milk for production of baby Swiss cheese.     

The feeding value of corn distillers solubles for lactating dairy cows

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 × 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.     

Production of dairy cows fed distillers dried grains with solubles in low- and high-forage diets

The objective of the study was to investigate the effects of dietary forage and distillers dried grains with solubles (DDGS) concentration on the performance of lactating dairy cows. Twelve Holstein cows were blocked by parity and milk production and assigned to replicated 4 × 4 Latin squares with a 2 × 2 factorial arrangement of treatments. Diets were formulated to contain low forage [LF; 17% forage neutral detergent fiber (NDF)] or high forage (HF; 24.5% forage NDF) and DDGS at 0 or 18% of diet dry matter. The forage portion of the diet consisted of 80% corn silage and 20% alfalfa hay (dry matter basis). A portion of the ground corn and all of the expeller soybean meal and extruded soybeans from 0% DDGS diets were replaced with DDGS to formulate 18% DDGS diets. Overall, we found no interactions of forage × DDGS concentrations for any of the production measures. We observed no effect of diet on dry matter intake. Milk yield was greater when cows were fed LF diets compared with HF diets (43.3 vs. 41.5 kg/d). Milk fat concentration (3.03 vs. 3.38%) was lower for cows fed LF diets compared with HF diets, whereas protein concentration (3.11 vs. 2.98%) and yield (1.34 vs. 1.24 kg/d) were greater for cows fed LF diets compared with HF diets. Yields of fat, total solids, energy-corrected milk, and feed efficiency were not affected by diets. Cows partitioned equally for milk, maintenance, and body reserves. Replacing starch from ground corn and protein from soybean feeds with DDGS at either 17 or 24.5% of forage NDF concentration in the diet was cost-effective and did not affect the production performance of lactating dairy cows.     

Continuous 11-week feeding of reduced-fat distillers grains with and without monensin reduces lactation performance of dairy cows

This study investigated the effects of continuous feeding of high inclusion of reduced-fat corn distillers grains with solubles with and without monensin on dry matter intake (DMI), production, milk fatty acid profile, and plasma AA profile in lactating cows. The experiment was conducted for 12 wk (1-wk covariate, 2-wk diet adaptation, and 9-wk experimental period of data collection) with 36 Holstein cows in a randomized complete block design. Cows were blocked by parity, days in milk, and milk yield and assigned to the following diets: (1) control (CON), (2) CON with reduced-fat corn distillers grains with solubles included at 28.8% (dry matter basis) replacing soybean meal, soyhulls, and supplemental fat (DG), and (3) DG with monensin (Rumensin; Elanco Animal Health, Greenfield, IN) supplemented at a rate of 20 mg/kg of DM offered (DGMon). Orthogonal contrasts were used to compare CON versus DG and DGMon and to compare DG versus DGMon. Milk yield was not affected (40.3 vs. 40.8 kg/d) by DG and DGMon compared with CON. However, for DG and DGMon compared with CON, decreased DMI (24.9 vs. 26.4 kg/d), milk fat yield (1.12 vs. 1.55 kg/d), milk protein yield (1.24 vs. 1.32 kg/d), and energy-corrected milk yield (37.7 vs. 43.5 kg/d) were observed. Feeding DGMon compared with DG did not affect DMI (24.4 vs. 25.4 kg/d) and milk yield (39.2 vs. 41.3 kg/d) but decreased milk fat yield (1.08 vs. 1.23 kg/d), milk protein yield (1.20 vs. 1.28 kg/d), and energy-corrected milk yield (36.0 vs. 39.4 kg/d). Interactions between treatment and week for DMI, milk fat yield, and energy-corrected milk indicate that production responses to DG and DGMon versus CON were decreased over the experimental period. Cows fed DG and DGMon had increased milk fat concentration of trans-10,cis-12 18:2, trans-10 18:1, and long-chain (>16C) and polyunsaturated fatty acids and decreased short-chain (<16C) and odd- and branched-chain fatty acids compared with CON. No difference was observed between DG and DGMon in milk fatty acid profile. In the current study, feeding a high-DG diet did not sustain DMI and production, and supplementing monensin to a high-DG diet further decreased DMI and production.     

Performance and amino acid utilization of early lactation dairy cows fed regular or reduced-fat dried distillers grains with solubles

The objective of this study was to evaluate lactation response and AA utilization of early lactation cows fed 2 types of dried distillers grains with solubles (DG): regular (DDGS) or reduced-fat (RFDGS). Thirty-six Holstein cows 19.7 ± 2.6 d in milk at the start of the experiment were used in a randomized complete block design for 14 wk including a 2-wk covariate period. Treatments consisted of the following diets: 1) control (CON) diet containing 0% DG; 2) diet containing 22% DDGS; and 3) diet containing 20% RFDGS. Distillers grains replaced soybean meal, expeller soybean meal, and soyhulls from the CON diet. Diets were formulated to be similar in crude protein, ether extract, neutral detergent fiber, and net energy for lactation concentrations. Dry matter intake (24.7 kg/d) and milk yield (39.3 kg/d) were similar for all diets. Milk fat and lactose percentages were unaffected by diets; however, protein percentage was greater for cows fed the DG diets compared with the CON diet. Consequently, milk protein yield was also greater for the DG diets compared with CON. Milk urea nitrogen decreased for cows fed DG diets and averaged 11.8, 10.9, and 10.1 mg/dL, respectively, for CON, DDGS, and RFDGS. Feed efficiency tended to be greater and N efficiency was greater for cows fed DG compared with CON. Body weight (711 kg), body weight change (+0.49 kg/d), and body condition score (3.36) were similar for all diets, but cows fed CON tended to gain more body condition (+0.14) than cows fed DG diets. Amino acid utilization was evaluated at the peak of milk production corresponding to wk 9 of lactation. Arterial Lys concentration was lower with DG diets (70.4, 58.6, and 55.8 μM/L). Cows fed DG had greater arterial Met concentration (21.3 μM) compared with CON (14.9 μM). Arterio-venous difference of Lys was similar across diets, whereas that of Met was greater for the DG diets compared with the CON diet (10.3 vs. 13.0 μM/L). Extraction efficiency of Lys by the mammary gland was greater for DG diets than for CON (76.1 vs. 65.4%). Mammary uptake of Lys (2.56 g/kg of milk) was similar for all diets, and the uptake of Met tended to increase in cows fed DG diets. Plasma glucose, triglyceride, and total cholesterol were unaffected by treatment; however, cows fed DG diets had lower β-hydroxybutyrate and tended to have lower nonesterified fatty acid concentrations than cows fed the CON diet. Despite the apparent deficiency of Lys, milk protein percentage was increased in cows fed DG diets.     

Effect of substitution of soybean meal by canola meal or distillers grains in dairy rations on amino acid and glucose availability

Canola meal (CM) or by-products of ethanol production (dried distillers grain, DDG) may offer an economical alternative to soybean meal (SBM) in North American dairy rations. These protein supplements can effectively replace SBM and, in 2 recent meta-analyses, CM had a positive effect on milk and milk protein yields compared with SBM. The objective of this study was to determine if the positive responses observed with inclusion of CM in dairy rations could be explained by an increased availability of His, Lys, Met, or glucose. Eight Holstein dairy cows were used in a replicated 4 × 4 Latin square with 14-d periods. Cows were fed isonitrogenous (17.2% crude protein) and isoenergetic (1.56 Mcal/kg of net energy of lactation) diets formulated to slightly exceed nutrient requirements. Diets contained 38% grass hay and 62% corn-based concentrate including SBM, CM, corn high-protein DDG (HPDDG), or wheat DDG plus solubles (WDDGS) as the single protein supplement. The effect of protein supplements on availability of His, Lys, Met, and glucose was estimated using variations in the whole-body (WB) flux of these nutrients, determined by isotopic dilution. As planned, dry matter intake and milk and milk protein yields were not affected by treatments and averaged 23.7, 31.4, and 1.14 kg/d, respectively. Lactose yield did not differ among diets although milk lactose content tended to be lower with CM and WDDGS diets than with SBM and HPDDG diets. Lysine availability was affected by treatments: the highest WB irreversible loss rate (ILR) was observed for the CM diet (371 g/d) and the lowest for HPDDG diet (290 g/d); values for SBM and WDDGS were intermediate (330 and 316 g/d, respectively). Availability of His and Met did not vary among diets and WB ILR averaged, respectively, 129 and 124 g/d; the CM diet, however, had numerically the highest His and Met ILR. Plasma concentrations of most of the essential AA were higher with the CM diet and lower with the HPDDG diet, the exception being Leu for which the concentration was highest for the HPDDG diet. Glucose WB rate of appearance was altered by diet, with the highest mean observed for SBM (3,036 g/d) and the lowest for CM (2,795 g/d); the 2 diets with the lowest WB glucose rate of appearance (CM and WDDGS) also had the lowest dietary starch concentration. Overall, this study suggested that positive responses in milk and milk protein yields observed with inclusion of CM in dairy rations could be linked to a greater supply of metabolizable protein, including some essential AA, especially His, Lys, and Met, as glucose availability was certainly not increased in cows fed the CM diet.