High-moisture Corn Research Articles

CONCAVE DESIGN FOR HIGH-MOISTURE CORN EAR THRESHING

In a threshing device, identifying the optimum balance between grain damage and grain loss during threshing is highly relevant while harvesting high-moisture corn ears. The qualitative performance indicators of a threshing device depend on the corn ear properties and process parameters as well as the device's design. Comparative experimental trials of two concaves (control and experimental) of a tangential threshing device were conducted under laboratory conditions by threshing high-moisture corn ears. The control concave's surface line corresponded to a circular arc, whereas that of the experimental concave corresponded to a portion of Archimedes' spiral. The clearance between the crossbars and cylinder rasp bars in the first section of the control concave length increased, whereas in the second section, it decreased. For the experimental concave, the clearance along the entire concave length consistently decreased. The experimental concave yielded approximately half the grain loss of the control during separation in the concave. A rational clearance between the experimental concave crossbars was validated because the portion of damaged grain did not exceed 3% at that point. With clearance l equal to 62.5 mm in the control concave, the grain threshing loss was 2.2%, whereas for the experimental concave, the loss was virtually independent of q and did not exceed the acceptable 0.3% limit. In general, the trials demonstrated that for high-moisture corn ear threshing, the surface line of the concave should correspond to a portion of Archimedes' spiral and the clearances between adjacent crossbars should be 62.5 mm. DOI: http://dx.doi.org/10.5755/j01.mech.24.1.18345

Effect of Corn Processing and Wet Distiller’s Grains with Solubles on Odorous Volatile Organic Compound Emissions from Urine and Feces of Beef Cattle

Abstract. Wet distiller’s grains with solubles (WDGS) are a common feed ingredient in beef feedlot diets but the high nitrogen content of these diets creates air quality issues, primarily due to the aromatic compounds emitted during protein fermentation. Use of high moisture corn (HMC) instead of dry-rolled corn (DRC) in cattle feedlot diets has been shown to reduce some odors associated with excess starch in cattle feedlot diets. We hypothesized that using HMC in place of DRC in diets containing WDGS would reduce some of the odors associated with WDGS-DRC diets. A 4 × 4 replicated Latin square with a 2 × 2 factorial arrangement of treatments was used. Diets contained either DRC or a 2:1 ratio of HMC and DRC, with WDGS at either 25% or 45% of the diet dry matter resulting in four treatments: DRC-25, HMC-25, DRC-45 and HMC-45. Odorous compounds were measured from feces and urine of cattle fed the four diets. Feces from cattle fed diets containing 45% WDGS had a higher flux of p-cresol (9.42 µg m-3 min-1), 4-ethyphenol (0.04 µg m-3 min-1), and total aromatic compounds (13.56 µg m-3 min-1) compared to feces from cattle fed 25% WDGS (3.38, 0.03, and 6.86 µg m-3 min-1, respectively). Corn processing did not influence fecal odor flux. Urinary flux of odorous compounds was largely unaffected by corn processing method and only p-cresol (9.58 µg m-3 min-1), and total aromatic compounds (11.34 µg m-3 min-1) were higher for cattle fed 45% WDGS compared to cattle fed 25% WDGS (7.65 and 9.12 µg m-3 min-1, respectively for p-cresol and total aromatics). Overall there were no significant differences in odor potential, as determined by odor activity value (OAV), for cattle fed diets containing HMC and DRC with either concentration of WDGS. From these results, we interpret that producers may feed diets containing HMC or DRC in combination with WDGS at inclusion rates up to 45% with only minimal impacts of air quality. Keywords: Beef cattle manure, Distiller’s dried grain solubles, Dry-rolled corn, High-moisture corn, Odor, Volatile organic compounds.

Associations of rumen parameters with feed efficiency and sampling routine in beef cattle

Characterizing ruminal parameters in the context of sampling routine and feed efficiency is fundamental to understand the efficiency of feed utilization in the bovine. Therefore, we evaluated microbial and volatile fatty acid (VFA) profiles, rumen papillae epithelial and stratum corneum thickness and rumen pH (RpH) and temperature (RT) in feedlot cattle. In all, 48 cattle (32 steers plus 16 bulls), fed a high moisture corn and haylage-based ration, underwent a productive performance test to determine residual feed intake (RFI) using feed intake, growth, BW and composition traits. Rumen fluid was collected, then RpH and RT logger were inserted 5.5±1 days before slaughter. At slaughter, the logger was recovered and rumen fluid and rumen tissue were sampled. The relative daily time spent in specific RpH and RT ranges were determined. Polynomial regression analysis was used to characterize RpH and RT circadian patterns. Animals were divided into efficient and inefficient groups based on RFI to compare productive performance and ruminal parameters. Efficient animals consumed 1.8 kg/day less dry matter than inefficient cattle (P⩽0.05) while achieving the same productive performance (P⩾0.10). Ruminal bacteria population was higher (P⩽0.05) (7.6×1011v. 4.3×1011 copy number of 16S rRNA gene/ml rumen fluid) and methanogen population was lower (P⩽0.05) (2.3×109v. 4.9×109 copy number of 16S rRNA gene/ml rumen fluid) in efficient compared with inefficient cattle at slaughter with no differences (P⩾0.10) between samples collected on-farm. No differences (P⩾0.10) in rumen fluid VFA were also observed between feed efficiency groups either on-farm or at slaughter. However, increased (P⩽0.05) acetate, and decreased (P⩽0.05) propionate, butyrate, valerate and caproate concentrations were observed at slaughter compared with on-farm. Efficient had increased (P⩽0.05) rumen epithelium thickness (136 v. 126 µm) compared with inefficient cattle. Efficient animals also spent 318% and 93.2% more time (P⩽0.05) in acidotic (4.14% v. 1.30%) (pH⩽5.6) and optimal (5.6<pH<6.0) (8.53% v. 4.42%) RpH range compared with inefficient cattle. The circadian patterns revealed lower (P⩽0.05) RpH and no differences (P⩾0.10) in RT pre-, during, and post-prandial periods in efficient compared with inefficient cattle. In essence, superior feed efficiency in cattle seems linked to rumen features consistent with improved efficiency of feed utilization. Microbial abundance, rumen epithelial histomorphology, and RpH, may serve as indicators for feed efficiency in cattle. The divergences of assessments made on-farm and at slaughter should be considered in the development of proxies for feed efficiency.

Lactation response to soybean meal and rumen-protected methionine supplementation of corn silage-based diets

Corn silage, an important forage fed to dairy cows in the United States, is energy rich but protein poor. The objectives of this experiment were to investigate the effects on production of milk and milk components of feeding corn silage-based diets with 4 levels of dietary crude protein (CP) plus rumen-protected methionine (RPM). Thirty-six cows were blocked by days in milk into 9 squares and randomly assigned to 9 balanced 4 × 4 Latin squares with four 4-wk periods. All diets were formulated to contain, as a percent of dry matter (DM), 50% corn silage, 10% alfalfa silage, 4% soyhulls, 2.4% mineral-vitamin supplement, and 30% neutral detergent fiber. Supplemental RPM (Mepron, Evonik Corp., Kennesaw, GA) was added to all diets to maintain a Lys:Met ratio of 3.1 in digested AA. Ground high-moisture corn was reduced and soybean meal (SBM) plus RPM increased to give diets containing, on average, 11% CP (28% corn, 31% starch, 6% SBM, 4 g of RPM/d), 13% CP (23% corn, 29% starch, 10% SBM, 8 g of RPM/d), 15% CP (19% corn, 26% starch, 15% SBM, 10 g of RPM/d), and 17% CP (14% corn, 24% starch, 19% SBM, 12 g of RPM/d). Data from the last 14 d of each period were analyzed using the mixed procedures in SAS (SAS Institute Inc., Cary, NC). With the exception of milk fat and milk lactose content, we found no significant effects of diet on all production traits. We did note linear responses to dietary CP concentration for intake, production of milk and milk components, and MUN. Cows fed the 11% CP diet had reduced DM intake, lost weight, and yielded less milk and milk components. Mean separation indicated that only true protein yield was lower on 13% CP than on 17% dietary CP, but not different between 15 and 17% CP. This indicated no improvement in production of milk and milk components above 15% CP. Quadratic trends for yield of milk, energy-corrected milk, and true protein suggested that a dietary CP concentration greater than 15% may be necessary to maximize production or, alternately, that a plateau was reached and no further CP was required. Although diet influenced apparent digestibility of DM, organic matter, and neutral detergent fiber, digestibility did not increase linearly with dietary CP. However, we observed linear and quadratic effects of dietary CP on acid detergent fiber digestibility. As expected, we found a linear effect of dietary CP on apparent N digestibility and on fecal and urinary N excretion, but no effect of diet on estimated true N digestibility. Ruminal concentrations of ammonia, total AA, peptides, and branched-chain volatile fatty acids also increased linearly with dietary CP. Quadratic responses indicated that 14.0 to 14.8% CP was necessary to optimize digestion and energy utilization. Overall results indicated that, when RPM was added to increase Lys:Met to 3.1, 15% CP was adequate for lactating dairy cows fed corn silage diets supplemented with SBM and secreting about 40 kg of milk/d; N excretion was lower than at 17% CP but with no reduction in yield of milk and milk components.

Effects of feeding corn plant residues during the growing phase on steer growth performance and feedlot economics

ABSTRACT Feeding harvested corn crop residues (CCR) to cattle has become increasingly common; however, the poor quality of mature CCR presents nutritional challenges. Therefore, the objectives of these studies were to evaluate the effects of feeding CCR harvested at 2 maturities and the effects of 2 silage additives, Silage SAVOR Plus (propionic acid-based additive) or Silo-King (lactobacillus-based additive), on in situ fiber disappearance, cattle growth performance and carcass characteristics, and economic traits of growing cattle. A total of 128 Angus × Simmental steers (initial BW = 327 ± 40 kg) were allotted to 20 pens and fed 4 treatments in diets that contained 25% forage: (1) corn stover, wetted to 40% DM and ensiled; (2) corn stalklage, harvested at 40% DM and ensiled (STK); (3) STK plus Silo-King; or (4) STK plus Silage SAVOR Plus. Corn stover was harvested 186 d after planting after harvesting dry corn. Corn stalklage was harvested 158 d after planting after harvesting high moisture corn. Growing diets contained CCR at 25% inclusion (DM basis) and were fed from d 0 to 85. From d 86 to 186, steers were fed a common finishing diet. Corn crop residue samples were incubated in 2 ruminally fistulated steers to determine in situ DM disappearance and NDF disappearance. There were no effects of treatment on in situ DM disappearance (P = 0.40) or in situ NDF disappearance (P = 0.34). There were no treatment effects (P ≥ 0.19) on steer growth performance from d 0 to 85 and from d 86 to 186; thus, there were no effects (P ≥ 0.14) of treatment on overall steer performance, carcass characteristics, and economic traits for the entire 186 d. Feeding mature CCR resulted in similar ruminal fiber degradation, steer growth, carcass performance, and economic traits when compared with immature CCR in diets fed to growing steers, and there was no benefit of additive inclusion.

Characterization of linoleic acid (C18:2) concentration in commercial corn silage and grain hybrids

Corn silage and high-moisture corn grain are commonly recognized as risk factors for biohydrogenation-induced milk fat depression and may be due to the high concentration of linoleic acid (C18:2) in corn. Corn silage and corn grain have a low concentration of fatty acids (FA), but due to their high inclusion rate in diets they contribute substantially to unsaturated FA intake. The first objective of this study was to characterize the contribution of individual plant parts to total FA in whole-plant chopped corn. The second objective was to characterize the variation in FA profile in commercial silage and grain hybrids and evaluate the relationship between FA profile and other nutrients. To determine the location of FA in the corn plant, 4 stalks from 4 different commercial hybrids were separated into stalk, husk and shank, leaves, cob, and kernels. On a dry matter basis, 80.5% of total FA were in the kernels, 11.8% in the leaves, 5.1% in the stalk, 1.7% in the cob, and 1.0% in the husk and shank. More than 96% of the oleic acid (C18:1) and 92.5% of the C18:2 was in the kernels, whereas 71.0% of the linolenic acid (C18:3) was in the leaves. Next, the FA composition of fresh whole-plant chopped corn from 124 silage hybrids and grain from 72 grain hybrids was determined over 2 yr from test plots in Pennsylvania. Last, to extend the characterization, FA composition of whole-plant corn silage from 45 hybrids grown in test plots in South Dakota were characterized. In the fresh whole-plant chopped corn from PA test plots, C18:2 as a percentage of total FA averaged from 48.7% in 2013 (percentiles: 10th = 45.2, 90th = 52.2) and 48.0% in 2014 (percentiles: 10th = 44.1, 90th = 49.4). Concentration of C18:2 in corn grain averaged 57.5% in the 2013 (percentiles: 10th = 53.4, 90th = 60.8) and 56.1% in 2014 (percentiles: 10th = 53.5, 90th = 59.4). In the corn silage from South Dakota, the concentration of C18:2 as percentage of total FA averaged 45.4% (percentiles: 10th = 39.4, 90th = 50.2) and C18:2 concentration as a percent of dry matter averaged 1.1% (percentiles: 10th = 0.76, 90th = 1.41). An increase in the concentration of C18:2 was associated with a decrease in C18:3 in fresh whole-plant chopped corn and with a decrease in C18:1 in corn grain. Total FA and C18:2 (as a percentage of dry matter) were positively correlated with starch and negatively correlated with neutral detergent fiber in both fresh whole-plant chopped corn and corn silage samples, whereas no correlation with these traits was observed for C18:2 as a percentage of total FA. In conclusion, FA concentration and profile of corn silage reflects to a great extent the FA composition of kernels and the proportion of grain in the silage. The variation in C18:2 across hybrids provides the opportunity to develop selection programs to decrease C18:2 in corn silage and grain. Selection based on C18:2 concentration as a percent of total FA is preferred as this trait did not correlate with other nutritional properties.

ANTAGONISTIC ACTIVITY OF BACILLUS SUBTILIS STRAINS, PERSPECTIVE COMPONENTS FOR CREATION OF ROLLED HIGH-MOISTURE CORN PRESERVATIVES

Antagonistic activity of Bacillus subtilis strains, perspective components for creation of rolled highmoisture corn preservatives was investigated. Investigated B. subtilis strains showed antagonistic activityagainst pathogenic and conditionally-pathogenic microorganisms. Test-cultures of Escherichia coli andStaphylococcus аureus showed the highest sensibility to the antagonistic B. subtilis strains. B. subtilisstrains B6у and В1 showed the best ability to inhibit the growth of pathogenic and conditionallypathogenic microorganisms.Flora genus composition on rolled high-moisture corn grain was studied. Flora of rolled highmoisture corn grain is presented by the genus Penicillium in 52% of cases, a remainder consists of thegenus species Fusarium (13%), Rhisopus (13%), Gliocladium (11%), and Mucor (11%). Abovementioned micromycetes showed high sensibility towards investigated B. subtilis strains. Antagonistic B.subtilis strains showed the highest rate of antifungal activity against test-cultures of micromycetes of thegenus species Mucor, Rhisopus, and Penicillium.

Prediction of the digestibility and energy contents of non-conventional by-products for pigs from their chemical composition and in vitro digestibility

The objective of the present study was to determine some prediction equations of gross energy content (GE), organic matter digestibility (OMd), gross energy digestibility (GEd) and the content of digestible (DE) and metabolizable energy (ME) of agro-industrial by-products for pigs, using the chemical composition and an in vitro digestibility method. Mean values of chemical composition (dry matter, DM; organic matter, OM; gross energy, GE; crude protein, CP; ether extract, EE; crude fiber, CF; neutral detergent fiber, NDF, and acid detergent fiber, ADF) were available from previous work and an in vitro OM digestibility method (IN VITRO) was performed. A total of eight by-products (liquid bakery by-product, brewer’s by-product, hominy feed, high-moisture corn, mayonnaise, almond meal, cocoa meal and kiwi fruit) were used in this study, and their in vivo OMd and GEd were known from previous experiments. The best equation for GE prediction was: GE=9.58 EE+6.50 CP+4.28 carbohydrates (OM-CP-EE) (R2=1.00; CV=5.52). When only the chemical composition was used as independent variables, NDF and ADF were the best predictors (R2=0.65–0.78; CV=12.30–10.85) for OMd and GEd, and EE plus ADF for DE and ME (R2=0.94–0.88; CV=13.10–16.64). However, the best-fitted equations were: OMd=30.90–0.302 ADF+0.639 IN VITRO (R2=0.95; CV=4.99); GEd=34.81–0.493 ADF+0.589 IN VITRO (R2=0.96; CV=4.93); DE=846.34+5.081 EE+3.045 IN VITRO (R2=0.97; CV=8.57), and ME=687.45+5.057 EE+3.150 IN VITRO (R2=0.97; CV=9.78). Additionally, when the two high EE by-products (mayonnaise and almond meal; EE >50%) were excluded, the most accurate equations for DE and ME were: DE=1415.96+2.764 IN VITRO (R2=0.97; CV=3.10), and ME=1262.92+2.868 IN VITRO (R2=0.97; CV=2.68). These results indicated that GE, OMd, GEd, DE and ME may be accurately predicted from chemical composition, and especially from the in vitro OM digestibility.

Effects of agronomic factors on yield and quality of whole corn plants and the impact of feeding high concentrations of corn silage in diets containing distillers grains to finishing cattle.

Corn plants were sampled over 2 consecutive years to assess the effects of corn hybrid maturity class, plant population, and harvest time on whole corn plant quality and yield in Nebraska. A finishing experiment evaluated the substitution of corn with corn silage in diets with corn modified distillers grains with solubles (MDGS). The first 2 harvest dates were at the mid- and late-silage harvest times whereas the final harvest was at the grain harvest stage of plant maturity. Whole plant yields increased as harvest time progressed (yr 1 quadratic P < 0.01; yr 2 linear P < 0.01). However, differences in TDN concentration in both years were quite minimal across harvest time, because grain percentage increased but residue NDF in-situ disappearance decreased as harvest time was delayed. In the finishing experiment, as corn silage inclusion increased from 15 to 55% (DM basis) by replacing dry rolled and high moisture corn grain with corn silage in diets containing 40% MDGS, DMI, ADG, and G:F linearly decreased (P ≤ 0.01), with the steers on the 15% corn silage treatment being 1.5%, 5.0%, and 7.7% more efficient than steers on treatments containing 30, 45, and 55% corn silage, respectively. Calculated dietary NEm and NEg decreased linearly as corn silage inclusion increased indicating that net energy values were greater for corn grain than for corn silage. In addition, dressing percentage decreased linearly (P < 0.01) as silage inclusion increased suggesting more fill as silage inclusion increases in diets. Cattle fed greater than 15% corn silage in finishing diets based on corn grain will gain slower and be slightly less efficient and likely require increased days to market at similar carcass fatness and size. When 30% silage was fed with 65% MDGS, DMI, and ADG were decreased (P < 0.01) compared to feeding 30% silage with 40% MDGS suggesting some benefit to including a proportion of corn in the diet. Conversely, when 45% silage was fed with 40% MDGS, ADG, and G:F were greater (P < 0.04) than when 45% silage was fed with just grain implying a greater energy value for MDGS than for corn grain. Substituting corn silage for corn grain in finishing diets decreased ADG and G:F which would increase days to finish to an equal carcass weight; however, in this experiment, increasing corn silage levels with MDGS present reduced carcass fat thickness without significantly decreasing marbling score.

602 The impact of time on feed and partial replacement of high-moisture corn with a high-lipid high-fiber pellet on steer performance, visceral organ weight, fat deposition, and carcass composition

The objective of this experiment was to determine the impact of time on feed and the partial replacement of starch with a high-fat, high-fiber by-product based pellet. Angus crossbred steers (n = 97; initial BW 469.3 ± 45.8 kg) were randomly assigned to one of two isocaloric dietary treatments: control (CON; n = 48) steers were fed a finishing diet consisting of 10% haylage, 77% high-moisture corn, 11% soybean meal, and 2% of a salt, vitamin, and mineral pre-mix including monensin; or high-fat, high-fiber pellet (HLHF; n = 49). The HFHF contained 29.8% wheat shorts, 26.2% corn DDGS, 18.8% soy hulls, 19.2% corn gain, and 6% tallow and replaced 30% (DM basis) of the high moisture corn in CON. Steers were randomly assigned to pens equipped with Insentec feeders to record individual feed intake. Steers were randomly split into two blocks in order to facilitate sample collection at the abattoir. On d 1 of the feeding period and every 6 wk thereafter, 10 steers from each treatment were selected at random and slaughtered. Organ and visceral fat weights were recorded, and rib sections were cut into muscle, fat, and bone in order to estimate carcass composition. Data were analyzed as a randomized complete block using PROC MIXED in SAS and included the fixed effects of diet, time on feed, and random effects of pen and block. Contrasts between diet and linear effects of time on fed were used for mean separation and significance was declared at P ≤ 0.05. Steer initial BW did not differ (P ≥ 0.43); however, final BW increased linearly (P < 0.001), but did not differ with dietary treatment (P = 0.55). Overall ADG did no differ with dietary treatment (P = 0.63), but decreased linearly with increasing time on feed (P = 0.015). Empty rumen mass was 12.4 and 11.4 ± 0.24 for CON and HLHF (P = 0.004). Abomasum weight tended to be heavier for HLHF than CON steers (P = 0.06). Carcass traits did not differ with dietary treatment (P > 0.51). Rib dissection indicated that rib section weights of lean, bone, intermuscular, body and subcutaneous fat did not differ with dietary treatment (P ≥ 0.24). Overall these data indicate that partially replacing starch with a high-lipid, high-fiber pellet had limited impacts on growth performance and carcass traits and energy partitioning in steers.

Persistence of Escherichia coli O157:H7 and Total Escherichia coli in Feces and Feedlot Surface Manure from Cattle Fed Diets with and without Corn or Sorghum Wet Distillers Grains with Solubles

Feeding corn wet distillers grains with solubles (WDGS) to cattle can increase the load of Escherichia coli O157:H7 in feces and on hides, but the mechanisms are not fully understood. The objective of these experiments was to examine a role for the persistence of E. coli O157:H7 in the feces and feedlot pen surfaces of cattle fed WDGS. In the first study, feces from steers fed 0, 20, 40, or 60% corn WDGS were inoculated with E. coli O157:H7. The E. coli O157:H7 numbers in feces from cattle fed 0% corn WDGS rapidly decreased (P < 0.05), from 6.28 to 2.48 log CFU/g of feces by day 14. In contrast, the E. coli O157:H7 numbers in feces from cattle fed 20, 40, and 60% corn WDGS were 4.21, 5.59, and 6.13 log CFU/g of feces, respectively, on day 14. A second study evaluated the survival of E. coli O157:H7 in feces from cattle fed 0 and 40% corn WDGS. Feces were collected before and 28 days after the dietary corn was switched from high-moisture corn to dry-rolled corn. Within dietary corn source, the pathogen persisted at higher concentrations (P < 0.05) in 40% corn WDGS feces at day 7 than in 0% WDGS. For 40% corn WDGS feces, E. coli O157:H7 persisted at higher concentrations (P < 0.05) at day 7 in feces from cattle fed high-moisture corn (5.36 log CFU/g) than from those fed dry-rolled corn (4.27 log CFU/g). The percentage of WDGS had no effect on the E. coli O157:H7 counts in feces from cattle fed steam-flaked corn-based diets containing 0, 15, and 30% sorghum WDGS. Greater persistence of E. coli O157:H7 on the pen surfaces of animals fed corn WDGS was not demonstrated, although these pens had a higher prevalence of the pathogen in the feedlot surface manure after the cattle were removed. Both or either the greater persistence and higher numbers of E. coli O157:H7 in the environment of cattle fed WDGS may play a part in the increased prevalence of E. coli O157:H7 in cattle by increasing the transmission risk.

Case Study: Fermentation of frozen whole-plant corn silage and high-moisture corn after thawing

The study objectives were to evaluate (1) the effect of thawing unfermented whole-plant corn (WPC; Exp. 1) on fermentation capacity after several months of frozen storage, and (2) the effect of temperature on fermentation profile of thawed high-moisture corn (HMC; Exp. 2) stored frozen for a longer period and then fermented at 2 ambient temperatures. Unfermented WPC and HMC samples were obtained from the University of Wisconsin–Madison Agricultural Research Station (Arlington, WI) at harvest, immediately frozen, and stored at −20°C for 4 or 17 mo, respectively. Both, WPC and HMC samples were thawed, homogenized, and divided into 24 or 33 subsamples, respectively. Subsamples were vacuum sealed in plastic bags and randomly assigned to treatments with 3 replications each. Experiment 1 treatments received 0, 0.5, 1, 2, 3, 7, 14, and 28 d of fermentation. Experiment 2 treatments were mini-silos fermenting in the dark either at warm (at room temperature 20°C; WR) or cold (in the refrigerator set for 3°C; CD) temperatures and allowed to ferment for 1, 3, 7, 14, or 28 d, plus 3 random subsamples analyzed as fresh samples. Gradual increases in lactate and acetate concentrations were observed in Exp. 1, along with a gradual decrease in pH (P = 0.001). A temperature × ensiling time interaction was observed (P < 0.001) in Exp. 2 for all fermentation profile measurements. This was related to fermentation occurring in WR but not in CD treatments. These findings suggest that WPC and HMC maintain fermentation capacity upon thawing even after being frozen for a prolonged period in storage, but fermentation will not occur until warm temperature is reached.

Addition of glycerol to lactating cow diets stimulates dry matter intake and milk protein yield to a greater extent than addition of corn grain.

The objective of this study was to determine if the addition of glycerol to the diet of dairy cows would stimulate milk protein yield in the same manner as the addition of corn grain. Twelve multiparous lactating dairy cows at 81 ± 5 d in milk were subjected to 3 dietary treatments in a replicated 3 × 3 Latin square design for 28-d periods. The diets were a 70% forage diet considered the basal diet, the basal diet with 19% ground and high-moisture corn replacing forages, and the basal diet with 15% refined glycerol and 4% added protein supplements to be isocaloric and isonitrogenous with the corn diet. Cows were milked twice a day and samples were collected on the last 7 d of each period for compositional analysis. Within each period, blood samples were collected on d 26 and 27, and mammary tissue was collected by biopsy on d 28 for Western blot analysis. Dry matter intake increased from 23.7 kg/d on the basal diet to 25.8 kg/d on the corn diet and 27.2 kg/d on the glycerol diet. Dry matter intake tended to be higher with glycerol than corn. Milk production increased from 39.2 kg/d on the basal diet to 43.8 kg/d on the corn diet and 44.2 kg/d on the glycerol diet. However, milk yield did not differ between corn and glycerol diets. Milk lactose yields were higher on the corn and glycerol diets than the basal diet. Milk fat yield significantly decreased on the glycerol diet compared with the basal diet and tended to decrease in comparison with the corn diet. Mean milk fat globule size was reduced by glycerol feeding. Milk protein yield increased 197 g/d with addition of corn to the basal diet and 263 g/d with addition of glycerol, and the glycerol effect was larger than the corn effect. The dietary treatments had no effects on plasma glucose concentration, but plasma acetate levels decreased 27% on the glycerol diet. Amino acid concentrations were not affected by dietary treatments, except for branched-chain amino acids, which decreased 22% on the glycerol diet compared with the corn diet. The decreases in plasma acetate and branched-chain amino acid concentrations with glycerol and the larger effects of glycerol than corn on milk protein and fat yields suggest that glycerol is more glucogenic for cows than corn grain.

An investigation of feeding high-moisture corn grain with slow-release urea supplementation on lactational performance, energy partitioning, and ruminal fermentation of dairy cows

The objective of this experiment was to determine if lactational performance and energy partitioning by dairy cows would differ in response to dietary corn grain (CG) types [steam-flaked corn (SFC) vs. high-moisture corn (HMC)] and slow-release urea (SRU) supplementation. Eight multiparous Holstein cows (32 ± 8.2 d in milk) were used in a duplicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement to test four dietary treatments: SFC without SRU, SFC with SRU, HMC without SRU, and HMC with SRU. Supplementation of SRU tended to increase intakes of dry matter (DM) or increased crude protein (CP) intake under SFC, but no effect under HMC, leading to CG × SRU interactions on DM and CP intakes. Neither type of CG nor SRU supplementation affected milk production. The HMC fed at 14.3% DM allowed cows to partition more net energy into body weight (BW) compared with those fed SFC diets, whereas supplementing SRU tended to decrease the portion of net energy partitioned into BW gain under both SFC and HMC diets. These collective results demonstrate that feeding HMC with SRU can be a practical option in high-forage lactation diets to maintain or improve nutrient and energy utilization efficiency.

Effects of dietary crude protein concentration on late-lactation dairy cow performance and indicators of nitrogen utilization

The objectives of this study were to measure performance responses and to evaluate indictors of N utilization in late-lactation cows fed diets with incremental reductions in crude protein (CP) concentration. Holstein cows (n = 128; 224 ± 54 d in milk) were stratified by parity and days pregnant (86 ± 25 d) and randomly assigned to 1 of 16 pens in a randomized complete block design. For 3 wk, all cows received a covariate diet containing 16.9% CP [dry matter (DM) basis]. For the subsequent 12 wk, pens were randomly assigned to 1 of 4 treatments that contained 16.2, 14.4, 13.1, or 11.8% CP (DM basis). Diets were offered once daily and contained 32.5% corn silage, 32.5% alfalfa silage, 13.5% high-moisture corn, and 21.5% concentrate mix. A reduction in dietary CP was achieved by replacing soybean meal with soy hulls in the concentrate mix (DM basis). Dry matter intake, milk urea N (MUN; mg/dL), and the yield of milk urea N (g/d) decreased linearly with dietary CP. Compared with a 16.2% CP diet, a 14.4% CP diet did not alter milk yield throughout the study, but the 13.1 and 11.8% CP diets reduced milk yield after 4 and 1 wk, respectively. Furthermore, milk protein percentage was reduced for all dietary CP less than 16.2%, but this negative effect was temporary and disappeared after 7 wk for the 14.4% CP diet. In contrast, MUN adjusted to a new steady state within 1 wk for all dietary treatments. Modeling quadratic responses with a plateau led to predictions of no reduction in fat- and protein-corrected milk (32.6 kg/d) and yields of fat (1.31 kg/d), lactose (1.49 kg/d), and true protein (1.12 kg/d) until dietary CP decreased below 15.5, 15.3, 15.9, and 16.2%, respectively. In this study, MUN and the yield of MUN were highly correlated with N intake, milk protein yield, and fat- and protein-corrected milk. Surprisingly, N use efficiency (milk protein N/intake N) was not correlated with any variables related to N utilization and reached an apparent upper limit of approximately 30%. Although this observation may be associated with feeding diets deficient in metabolizable protein, late-lactation cows in this study adjusted to low dietary CP concentration better than anticipated as milk production was 2.6, 3.6, 6.4, and 8.0 kg/d higher than National Research Council (2001)-predicted metabolizable protein-allowable milk for dietary CP of 16.2, 14.4, 13.1, and 11.8%, respectively.

Nutritional additives in high moisture corn silage

Nutritional additives in high moisture corn silage

Impact of feeding de-oiled wet distillers grains plus solubles on beef shelf life.

Research was conducted to determine the effect of feeding de-oiled wet distillers grains plus solubles (WDGS) on beef fatty acid profile, retail shelf life and development of oxidation products during retail display (RD). A total of 336 crossbred yearling steers (initial BW = 351.08 ± 19.05 kg) were fed 1 of 7 dietary treatments: an all corn control (1:1 blend of dry rolled and high moisture corn), 35%, 50%, or 65% inclusion of WDGS, either full-fat or de-oiled. Within each treatment 15 Choice carcasses were randomly selected ( = 105), strip loins were obtained, aged 7 and 21 d, and representative steaks from each strip loin were placed in RD conditions for 7 d. Fatty acid profiles were determined (mg/100 g tissue basis) and differences ( ≤ 0.05) were found in the C16:1, C18:1T, C18:2 and total polyunsaturated fatty acids (PUFA) among dietary treatments. Palmitoleic acid (C16:1) was predominant ( < 0.0001) in the corn control group, intermediate in the 35% de-oiled WDGS group, but no differences ( > 0.05) were observed between all other diets. Elaidic acid (C18:1T) was greater ( = 0.01) in the 65% full-fat WDGS group, least for the corn control group, and intermediate for all other diets. Linoleic acid (C18:2) was greater ( = 0.0001) in all 3 full-fat WDGS groups and 65% de-oiled WDGS group (290.98 mg/100 g, on average), intermediate in the 50% and 35% de-oiled WDGS groups (231.08 and 227.16 mg/100 g, respectively) and least for the corn control group (177.70 mg/100 g). The PUFA content was greater ( < 0.01) in all 3 full-fat WDGS groups and 65% de-oiled WDGS group (337.13 mg/100 g, on average), intermediate in the 50% and 35% de-oiled WGDS groups (274.77 and 273.84 mg/100 g, respectively) and least for the corn control group (223.98 mg/100 g). Dietary treatment did not alter discoloration ( = 0.30) or lipid oxidation ( = 0.36). Shear force decreased with age and RD ( < 0.0001) but dietary treatment had no effect on shear force ( = 0.93). In general, feeding 35% and 50% de-oiled WDGS had intermediate PUFA content relative to a corn control or full-fat WDGS diet. Feeding de-oiled WDGS did not seem to increase beef shelf life and does not negatively alter beef quality parameters in relation to full-fat WDGS.

Short communication: Associations between feed push-up frequency, feeding and lying behavior, and milk yield and composition of dairy cows

Feeding management factors have great potential to influence activity patterns and feeding behavior of dairy cows, which may have implications for performance. The objectives of this study were to assess the effects of feed push-up frequency on the behavioral patterns of dairy cows, and to determine associations between behavior and milk yield and composition. Lactating Holstein dairy cows (n = 28, parity = 1.9 ± 1.1; mean ± SD) were housed in tiestalls, milked twice per day, and offered ad libitum access to water and a total mixed ration (containing, on a dry matter basis: 25% corn silage, 25% grass/alfalfa haylage, 30% high-moisture corn, and 20% protein/mineral supplement), provided twice per day. Cows were divided into 2 groups of 14 (balanced by days in milk, milk production, and parity) and individually exposed to each of 2 treatments in a crossover design with 21-d periods; treatment 1 had infrequent feed push-up (3×/d), whereas treatment 2 had frequent feed push-up (5×/d). During the last 7 d of each period, dry matter intake and milk production were recorded and lying behavior was monitored using electronic data loggers. During the last 2 d of each period, milk samples were collected for analysis of protein and fat content and feed samples of fresh feed and orts were collected for particle size analysis. The particle size separator had 3 screens (19, 8, and 1.18 mm) and a bottom pan, resulting in 4 fractions (long, medium, short, fine). Sorting was calculated as the actual intake of each particle size fraction expressed as a percentage of the predicted intake of that fraction. Feed push-up frequency had no effect on lying time [11.4 ± 0.37 h/d; mean ± standard error (SE)], milk production (40.2 ± 1.28 kg/d) and composition (milk protein: 3.30 ± 0.048%; milk fat: 3.81 ± 0.077%), or feed sorting. Cows sorted against long particles (78.0 ± 2.2%) and for short (102.6 ± 0.6%) and fine (108.4 ± 0.9%) particles. Milk fat content decreased by 0.1 percentage points for every 10% increase in sorting against long particles and was not associated with lying behavior or other cow-level factors. Milk protein content decreased by 0.03 percentage points for every hour decrease in lying time and by 0.04 percentage points for every 10% increase in sorting against long particles. These results suggest that sorting against long ration particles may negatively affect milk composition. Additionally, we did not find that altering feed push-up frequency affected feed sorting or cow standing and lying patterns.

Effects of increasing soybean hulls in finishing diets with wet or modified distillers grains plus solubles on performance and carcass characteristics of beef steers

Two experiments evaluated feeding soybean hulls (SBH) in finishing diets that contain distillers grains plus solubles on performance and carcass characteristics. Dietary concentrations of SBH were 0, 12.5, 25, and 37.5% of diet DM. In Exp. 1, 167 crossbred yearling steers (395 ± 22 kg of BW) were fed for 117 d in a randomized block design in which pelleted SBH replaced dry-rolled corn. All diets contained 25% modified distillers grains plus solubles, 15% corn silage, and 5% liquid supplement. As SBH concentration increased, DMI decreased linearly (P = 0.04). Gain and G:F decreased linearly (P < 0.01) in response to increasing concentrations of SBH, which decreased relative energy value from 91 to 79% of corn. Hot carcass weight linearly decreased (P < 0.01) by 24 kg as SBH increased. In Exp. 2, a randomized block design used 160 backgrounded steer calves (363 ± 16 kg of BW) in a 138-d finishing study with 0, 12.5, 25, or 37.5% SBH in the meal form. Basal ingredients consisted of a 1:1 ratio of high-moisture corn and dry-rolled corn, 40% wet distillers grains plus solubles, 8% sorghum silage, and 4% dry meal supplement. There was a tendency (P = 0.12) for a quadratic increase in ADG and G:F as dietary SBH increased, with numerically greatest ADG and G:F with 12.5% SBH. Feeding 12.5 to 25% SBH with 40% wet distillers grains plus solubles (Exp. 2) had little effect on performance but decreased ADG and G:F in diets with 25% modified distillers grains plus solubles (Exp. 1).

Identification of the major yeasts isolated from high moisture corn and corn silages in the United States using genetic and biochemical methods

The objective of this study was to identify species of yeasts in samples of high moisture corn (HMC) and corn silage (CS) collected from farms throughout the United States. Samples were plated and colonies were isolated for identification using DNA analysis. Randomly selected colonies were also identified by fatty acid methyl esters (FAME) and by physiological substrate profiling (ID 32C). For CS, Candida ethanolica, Saccharomyces bulderi, Pichia anomala, Kazachstania unispora, and Saccharomyces cerevisiae were the predominant yeasts. Pichia anomala, Issatchenkia orientalis, S. cerevisiae, and Pichia fermentans were the prevalent species in HMC. The 3 identification methods were in agreement at the species level for 16.6% of the isolates and showed no agreement for 25.7%. Agreement in species identification between ID 32C and DNA analysis, FAME and ID 32C, and FAME and DNA analysis was 41.1, 14.4, and 2.2%, respectively. Pichia anomala and I. orientalis were able to grow on lactic acid, whereas S. cerevisiae metabolized sugars (galactose, sucrose, and glucose) but failed to use lactic acid. The yeast diversity in CS and HMC varied due to type of feed and location. Differences in species assignments were seen among methods, but identification using substrate profiling generally corresponded with that based on DNA analysis. These findings provide information about the species that may be expected in silages, and this knowledge may lead to interventions that control unwanted yeasts.