Steam-flaked Corn Diets Research Articles

Effects of corn grain processing and phosphorus content in calf starters on intake, growth performance, nutrient digestibility, blood metabolites, and urinary purine derivatives

Corn grain with a high phosphorus (P) content (mainly in the form of phytate-P) may need to be processed to improve the digestibility of nutrients for young calves. Processing corn grains can improve the accessibility of phytate-P to the rumen enzymes and increase the bioavailability of P, which benefits the growth and development of calves. The objective of this study was to investigate the effects of feeding starter diets with steam-flaked corn (SFC) compared with ground corn (GC) with 2 P contents of 0.4% and 0.7% DM basis on intake, growth performance, nutrient digestibility, blood metabolites and urinary purine derivatives in dairy calves. A total of 48 female Holstein dairy calves (3 d old; average initial weight 39.7 ± 3.9 kg) were randomly assigned to a 2 × 2 factorial arrangement of treatments (12 calves/treatment) in a randomized complete block design. The treatment groups were: 1) a starter diet of GC with 0.4% P (GC-0.4P); 2) a starter diet of GC with 0.7% P (GC-0.7P); 3) a starter diet of SFC with 0.4% P (SFC-0.4P); 4) a starter diet of SFC with 0.7% P (SFC-0.7P). Calves received 6 L/d of transition milk on d 2-3 and 5 L/d of whole milk on d 4-30, which was increased to 7 L/d on d 31-45, then decreased to 5 L/d on d 46-60 and reduced to a single feeding of 2 L on d 61-62. All calves had free access to starter feed and water. All calves were weaned on d 63 and remained in the study until d 83. Rumen fluid samples were collected on d 38 (pre-weaning) and d 76 (post-weaning). Blood samples were collected on d 40 and 80 and urine samples were collected on 4 consecutive days from d 79 to 82 to analyze urinary excretion of PD. The phytate-P content ranged from 0.23 to 0.17 for GC and SFC, respectively. In particular, the interaction between corn processing method and P content showed that the SFC-0.7P diets had a greater intake of starter feed during the pre- and post-weaning periods compared with the other experimental groups. In addition, calves fed the SFC-0.7P diet had greater average daily gain, body weight, withers height at weaning, better organic matter digestibility, higher blood β-hydroxybutyrate levels and higher microbial protein synthesis compared with all other groups. Feeding the SFC diet also resulted in improved feed efficiency, improved P digestibility and a tendency toward a lower rumen pH, albeit with a tendency toward an increase in blood glucose concentration during the pre-weaning period. In addition, the inclusion of 0.7% P to the starter diet resulted in increased fiber digestibility and a slight improvement in growth performance, which was particularly evident in hip height. Overall, the inclusion of SFC in the calf starter diet, especially in combination with a 0.7% DM basis P supplement, improved growth performance and nutrient utilization in dairy calves compared with GC.

Effect of corn silage inclusion with different corn processing on finishing steer performance and carcass characteristics

Abstract Objectives were to determine the effect of corn silage inclusion within dry-rolled corn (DRC) or steam-flaked corn (SFC) finishing diets on cattle growth performance and carcass characteristics. The experiment used British and continental crossbred steers (n = 480; initial body weight [BW] = 389 ± 17 kg) in a 4 × 2 factorial arrangement of treatments with six replications per treatment. Treatments consist of four inclusions of corn silage (0%, 15%, 30%, or 45%; dry matter [DM] basis) within either a DRC or SFC diet. A corn silage by corn processing interaction was observed for dry-matter intake (DMI; P = 0.05). As corn silage inclusion increased in the diet, DMI increased linearly (P < 0.01) for both corn processing methods. DM intake was not different between SFC and DRC-fed cattle at 0% (P = 0.33), 30% (P = 0.90), or 45% (P = 0.31) corn silage inclusion. The interaction was due to the DMI of cattle fed 15% silage, as cattle-fed DRC consumed 0.5 kg/d less (P < 0.01) than cattle on the SFC diet. Quadratic effects were observed for final BW, hot carcass weight (HCW), average daily gain (ADG), feed efficiency (G:F), marbling, and fat depth (P < 0.01), regardless of corn processing. Cattle fed 15% or 30% corn silage gained faster (P < 0.01) than those fed 0% or 45% corn silage. Feed efficiency decreased quadratically (P < 0.01) as silage inclusion increased in the diet with G:F similar for cattle fed 0% and 15% silage and decreased curvilinearly for cattle fed 30% and 45% silage. The incidence of liver abscesses was greater (P = 0.03) in cattle fed 0% corn silage than for steers fed 15%, 30%, or 45% corn silage. Corn processing method, independent of silage, had no effect (P = 0.42) on liver abscess incidence. Feeding SFC increased (P < 0.01) steer final BW and HCW when compared to cattle-fed DRC, regardless of silage inclusion. Corn silage inclusion had similar effects on performance in both DRC diets and SFC diets except for DMI. As corn silage inclusion increased in the diet, feed efficiency decreased linearly (P < 0.01). Cattle-fed SFC gained 7.9% more (P < 0.01) and were 6.7% more efficient (P < 0.01) than cattle-fed DRC. In diets containing either DRC or SFC, corn silage can be included at up to 30% of the diet without negative impacts on ADG or HCW.

Effects of grain processing (cracked vs. steam-flaked) and forage sources (alfalfa hay and wheat straw) as a free-choice provision on growth performance, rumen fermentation, blood metabolites, and behavior of dairy calves

The aim of this study was to investigate the interaction between physical form of starter (PFS) and forage source (FS) with free access to forage on feed intake, growth performance, rumen fermentation, blood metabolites and behavioral traits of dairy calves. A total of 48 7-day-old Holstein calves were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement, with FS [alfalfa hay (AH) and wheat straw (WS)] as free-choice supply and PFS diets (cracked vs. steam-flaked) as main effects. Feeding treatments included (1) starter diet with steam flaked corn (SFC) and free access to AH (SFC-AH), (2) starter diet with SFC and free access to WS (SFC-WS), (3) starter diet with cracked corn (CRC) and free access to AH (CRC-AH) and (4) starter diet with CRC and free access to WS (CRC-WS). The calves were weaned on day 58 and remained in the experiment until day 70. All calves had free access to water and starter feed. The results showed that there was no interaction between PFS and FS in terms of starter intake, forage intake, dry matter intake (DMI), average daily gain (ADG), body weight (BW) or feed efficiency (FE). Calves fed CRC consumed more dry matter, TMR and forage than calves fed SFC diets. Regardless of the PFS diet, weaning weight, total weight and total ADG were higher in calves fed WS, while forage intake was higher in calves fed AH. Calves fed CRC-AH had the lowest rumen pH at day 68 compared to the other groups (except SFC-WS at day 70). An interaction between PFS diets and FS affected rumen proportion of propionate on day 35, since calves, which were fed CRC-AH had the highest molar percentage of propionate than calves fed other diets (except for SF-WS). At day 65, calves fed SFC starter feed had higher plasma glucose concentrations than calves fed CRC. It was found that PFS feed and FS had an interaction effect on BUN at day 65, with calves fed CRC-AH having the highest BUN. Compared to the other groups, calves fed CRC-WS had the highest BHB at day 33 and throughout the period (days 35 and 65). An interaction between PFS diets and FS affected lying time and forage eating time, with CRC-AH calves exhibiting the longest lying time and lowest forage eating time. The time spent on NNOB tended to be longer in SFC-fed calves than in CRC-fed calves, regardless of the forage source. Compared to calves fed SFC, calves fed CRC with high levels of fine particles consumed more dry matter, TMR, and forage while spending less time on NNOB. Furthermore, feeding calves chopped WS instead of AH increased weaning weight, total weight, and total ADG, although forage intake was higher in calves fed AH. In summary, a combination of cracked corn starter with free access to wheat straw appears to provide the best growth outcomes for dairy calves.

223 Impacts of Active Dry Yeast (Saccharomyces cerevisiae) on Gut Permeability in Finishing Beef Cattle

Abstract The objectives of this study were to examine the impacts of active live yeast (Saccharomyces cerevisiae) as a dietary feed additive on dry matter intake, feed sorting, gut permeability, ruminal pH and volatile fatty acids (VFA) concentration, as well as fecal pH and VFA concentration in cattle fed a high-grain finishing diet and subjected to a ruminal acidotic challenge. Fifteen Hereford X Charolais heifers were blocked by BW into three blocks. Heifers were randomly assigned within block to one of two dietary treatments; CON (no additive), or YST (3 g· animal-1· day-1 of active live S. cerevisiae) added to a steam-flaked corn diet (83% steam-flaked corn, 8% wheat straw, 5% soybean meal protein mix, 4% vitamin and minerals on a DM basis). The experimental timeline was as follows: 30 d adaptation (ADPT), 5 d baseline (BASE), 5 d ruminal acidosis challenge (CHAL), and three subsequent 5 d recovery phases (REC1, REC2, and REC3). On day 2 of each phase and days 2 and 4 of CHAL, 179 mM Cr-EDTA and 360 mM Co-EDTA were infused into the omasum and rumen, respectively, as gut permeability markers. Within each phase, in-dwelling pH probes were used to capture reticulo-ruminal pH every 5min for 96 consecutive hours, rumen fluid and fecal grab samples were collected once for every 3 h in a 24 h period, and blood was collected at 2, 4, 12, and 24 h after each Co and Cr infusion. Dry matter intake and feed sorting were measured daily for each animal. Statistical analysis was conducted using PROC GLIMMIX in SAS as a randomized complete block design with block, treatment, and phase as fixed effects and animal as a random effect. Ruminal acidosis was successfully induced using this method, as suggested by the statistically significant reduction in minimum pH and increase in pH range in the CHAL phase compared with other phases of the experiment (P ≤ 0.02). Recovery from the ruminal acidosis challenge was detected within the REC1 phase when comparing minimum pH (CHAL 5.25 vs. REC1 5.54; P = 0.001). Additionally, the sorting behavior of some particle sizes was significantly impacted by phase (P ≤ 0.01). Overall, the addition of yeast to the diet did not impact feed intake, sorting behavior, spot ruminal and fecal pH, volatile fatty acid concentrations in ruminal fluid or feces, or the uptake of Cr-EDTA and Co-EDTA. These results suggest that adding live S. cerevisiae yeast at this dose in a high-grain finishing diet does not impact feed intake, gut permeability, or the production of VFA when ruminal acidosis is induced.

Evaluation of condensed algal residue solubles as an ingredient in cattle finishing diets and the effects on digestibility and fatty acid flow

Our objective was to evaluate the effects of inclusion of condensed algae residue solubles (CARS) in corn-based cattle finishing diets on performance, carcass characteristics, and duodenal concentrations of fatty acids. In Exp. 1, 480 British (pre- dominately Angus) crossbred steers (initial BW = 432 kg; SD = 40 kg) were finished using a 2 × 3 factorial treat- ment arrangement. Treatments were CARS (0, 2.5, 5% of diet DM) displacing dry-rolled corn:high-moisture corn (DRC:HMC) or steam-flaked corn (SFC). In Exp. 2, feed- ing 0, 2.5, or 5% CARS in SFC diets was evaluated for digestibility and fatty acid flow using 6 ruminally can- nulated steers in a 3 × 3 replicated Latin Square design. The main effects of CARS included quadratic responses (P ≤ 0.01) for carcass-ad-justed final BW, ADG, G:F, hot carcass weight, 12th-rib fat, and YG. The main effects of diet indicated SFC di- ets had greater (P ≤ 0.02) G:F, hot carcass weight, and 12th-rib fat compared with DRC:HMC diets. In Exp. 2, inclusion of CARS in the diet did not affect total-tract DM, OM, or NDF digestibility (P ≥ 0.52). Total fatty acid flow at the duodenum was unaffected (P = 0.18) by treat- ment. However, there was a linear increase (P < 0.01) in C16:0, C18:0, C18:1 trans, C18:1 vaccenic acid, and C22:6 omega-3 docosahexaenoic fatty acid flow as CARS inclu- sion increased. Including 2.5% CARS in finishing diets improved G:F and increased n-3 fatty acids at the duodenum.

Glucogenic and lipogenic diets affect in vitro ruminal microbiota and metabolites differently.

This study was conducted to evaluate the effects of two glucogenic diets (C: ground corn and corn silage; S: steam-flaked corn and corn silage) and a lipogenic diet (L: sugar beet pulp and alfalfa silage) on the ruminal bacterial and archaeal structures, the metabolomic products, and gas production after 48 h in vitro fermentation with rumen fluid of dairy cows. Compared to the C and S diets, the L dietary treatment leaded to a lower dry matter digestibility (DMD), lower propionate production and ammonia-nitrogen concentration. The two glucogenic diets performed worse in controlling methane and lactic acid production compared to the L diet. The S diet produced the greatest cumulative gas volume at any time points during incubation compared to the C and L diet. The metabolomics analysis revealed that the lipid digestion especially the fatty acid metabolism was improved, but the amino acid digestion was weakened in the L treatment than in other treatments. Differences in rumen fermentation characteristics were associated with (or resulting from) changes in the relative abundance of bacterial and archaeal genera. The rumen fluid fermented with L diet had a significantly higher number of cellulolytic bacteria, including the genera of Ruminococcus, Butyrivibrio, Eubacterium, Lachnospira, unclassified Lachnospiraceae, and unclassified Ruminococcaceae. The relative abundances of amylolytic bacteria genera including Selenomonas_1, Ruminobacter, and Succinivibrionaceae_UCG-002 were higher in samples for diets C and S. The results indicated that the two glucogenic diets leaded to a higher relative abundance of bacteria which functions in succinate pathway resulting in a higher propionate production. The steam-flaked corn diet had a higher gas production and lower level of metabolites in fatty acids and amino acids. Most highly abundant bacteria were observed to be not sensitive to dietary alterations of starch and fiber, except for several amylolytic bacteria and cellulolytic bacteria. These finding offered new insights on the digesting preference of ruminal bacteria, which can assist to improve the rumen functioning.

196 Interaction of Corn Processing Method and Sweet Bran Inclusion in Finishing Diets

Abstract Two studies were conducted to evaluate the effect of corn processing method and wet corn gluten feed [Sweet Bran (SB); Cargill] concentration on feedlot performance and nutrient digestion. Treatments were arranged as a 2 × 3 factorial, consisting of two corn processing methods [steam-flaked corn (SFC) or a high-moisture corn (HMC) dry-rolled corn (DRC) blend] and 3 inclusions of SB (0, 20, or 40% of diet dry matter). In Exp. 1, yearling steers (n = 480; initial body weight = 363 ± 15.1 kg) were utilized in a randomized block design. A linear interaction was observed for average daily gain (ADG), feed efficiency (G:F), and hot carcass weight (HCW; P &amp;lt; 0.01). At 0% SB, cattle fed SFC had greater ADG and HCW than cattle fed HMC/DRC. As SB increased, ADG and HCW increased at a greater rate for HMC/DRC cattle than SFC cattle resulting in similar ADG and HCW at 40% SB. At 0% SB, cattle fed SFC were 12.4% more efficient than cattle fed HMC/DRC, but as SB increased the improvement declined to 5.3%. In Exp. 2, 6 fistulated steers were utilized in a 6 × 6 Latin square design. Cattle fed SFC had greater starch digestibility (P &amp;lt; 0.01); HMC/DRC cattle tended to have greater neutral detergent fiber digestibility (P = 0.08). As SB increased, cattle fed SFC and HMC/DRC had greater dry matter intakes (DMI) in both studies (P &amp;gt; 0.01), and as a result, greater digestible energy (DE) intakes (P &amp;gt; 0.01). Increased DE intake improved ADG and G:F when feeding SB in Exp. 1 as explained by greater DMI and increased DE observed in Exp. 2. Feeding up to 40% SB in SFC diets doesn't affect feedlot performance and feeding SB in HMC/DRC based finishing diets linearly improves performance at inclusions up to 40%.

Effects of ground, steam-flaked, and super-conditioned corn grain on production performance and total-tract digestibility in dairy cows

This study aimed to evaluate the effects of feeding ground, steam-flaked, or super-conditioned corn on production performance, rumen fermentation, nutrient digestibility, and milk fatty acid (FA) profile of lactating dairy cows. Twenty-four lactating Holstein cows (130 ± 12 d in milk) in a completely randomized block design experiment were assigned to 1 of 3 treatments that contained 31% of one of the following corn types: (1) ground corn; (2) steam-flaked corn; and (3) super-conditioned corn. Actual milk yield was greater in the super-conditioned corn diet than in the steam-flaked and ground corn diets. Dry matter intake, 3.5% fat-corrected milk and energy-corrected milk remained unaffected by treatments; however, milk fat concentration decreased in the super-conditioned corn diet compared with the ground and steam-flaked corn diets. The molar proportion of ruminal acetate decreased in the super-conditioned corn diet compared with the ground and steam-flaked corn diets, whereas the molar proportion of propionate spiked in the super-conditioned corn diet. Ruminal pH dropped in cows fed super-conditioned corn compared with the other 2 diets. A similar pattern was observed for ruminal NH3-N and acetate-to-propionate ratio. Total-tract starch digestibility increased the most in the super-conditioned corn diet followed by the steam-flaked and ground corn diets (96.8, 95.1, and 92.5%, respectively). The neutral detergent fiber digestibility declined in cows fed the super-conditioned corn diet as opposed to other diets (~3.9%). The concentrations of 16:0 and mixed-FA in milk fat dropped in the super-conditioned corn-based diet compared with the ground corn diet. Milk trans-10 18:1 FA increased, whereas trans-11 18:1 FA decreased in cows fed the super-conditioned diet. We concluded that super-conditioned corn has the potential to increase milk yield and starch digestibility in lactating dairy cows; however, reduced milk fat output caused by altering ruminal pH and ruminal FA biohydrogenation pathways may not be desirable in certain markets. Future research is warranted to investigate how super-conditioned corn affects feed efficiency.

199 Inclusion of Sweet Bran™ and wet distillers grains alone or in combination improves performance, carcass merit, and rumen buffering characteristics of feedlot cattle fed steam-flaked corn diets

Abstract This study evaluated the effects of Sweet Bran™ (SB) and/or wet distillers grains with solubles (WDGS) in the diet alone or in combination on performance, carcass characteristics, ruminal pH, and rumination of finishing beef cattle. Steers (n = 455) were randomly allocated to 48 pens and assigned to 1 of 4 steam-flaked corn-based dietary treatments containing: no byproducts (CON), 20% WDGS (WDGS), 20% SB (SB), or 20% SB and 10% WDGS (COMBO). Within each pen, 2 steers were randomly selected to receive a ruminal pH bolus and ear tag to quantify pH and rumination. Diet samples were collected weekly to determine particle size and physically effective fiber. Final BW, DMI, and ADG were greater (P &amp;lt; 0.01) for WDGS, SB, and COMBO than CON. Hot carcass weight was greatest (P = 0.04) for WDGS and SB, intermediate for COMBO, and least for CON. Yield grade tended (P = 0.09) to be greater for WDGS, SB, and COMBO than CON. A numerical increase in abscessed livers was observed for CON. The percentage of particles &amp;gt; 4 mm was greatest (P &amp;lt; 0.01) for CON, intermediate for SB, and least for WDGS and COMBO. However, NDF (P &amp;lt; 0.01) and peNDF (P &amp;lt; 0.01) were greatest for COMBO, intermediate for WDGS and SB, and least for CON. A treatment × time interaction was observed as CON cattle spent less time ruminating at 0800 and 1000 h (P &amp;lt; 0.01) in a 24h period. Ruminal pH was least (P &amp;lt; 0.01) for CON from 0800 to 1800 h. Addition of WDGS and/or SB improved performance and reduced feed cost of gain when incorporated into steam-flaked corn-based finishing diets. Relationships between peNDF, rumination behavior, and ruminal pH suggest that SB and/or WDGS enhance buffering capacity when steam-flaked corn is replaced in the diet.

Performance and feeding behavior of dairy cows fed high-concentrate diets containing steam-flaked or ground corn varying in particle size

Steam-flaked corn (SFC) and ground corn (GC) of different particle sizes were evaluated for their effects on dry matter intake (DMI), milk yield and components, chewing activity, ration sorting, ruminal fermentation, and digestibility in lactating dairy cows. Eight multiparous Holstein cows in mid-lactation (46.6 ± 3.5 kg/d milk production and 101 ± 10 d in milk) were used in a double 4 × 4 Latin square design with 21-d periods. Cows were fed diets (dry matter basis) containing 36.2% forage (alfalfa hay and corn silage), 37.4% corn grain, and 26.4% other ingredients. The corn grain was ground (coarse: 1.08 mm; medium: 0.84 mm; and fine: 0.73 mm) or steam-flaked (SFC; density = 0.40 kg/L). The dry matter proportion retained on an 8-mm sieve was greater for the SFC diet than for the GC diets. There were no treatment effects on DMI, milk yield, fat-corrected milk, energy-corrected milk, fat or lactose yield, protein or lactose content, or milk urea nitrogen concentration. However, digestibility of dry matter and organic matter were greater for fine GC and SFC than the other diets. In addition, cows fed SFC had lower total-tract starch digestibility than cows fed GC diets. Cows fed SFC tended to have lower propionate proportion (22.8 vs. 27.1 mM) and total volatile fatty acid concentration (88.6 vs. 99.8 mM) in ruminal fluid than those fed GC diets. Acetate and butyrate concentration, acetate to propionate ratio, and ruminal concentration of ammonia-nitrogen were not affected by treatments. Ruminal pH (6.46 vs. 6.01) as well as milk fat content (2.75 vs. 2.59%) and efficiencies (fat-corrected milk/DMI and energy-corrected milk/DMI) were greater for SFC than GC, regardless of its particle size. Milk fat content tended to increase linearly with increasing particle size of GC. Eating activity (min/d) tended to be less for SFC compared with GC, but rumination activity (min/d) and total chewing activity (min/d) were not affected by processing or particle size. The results of study indicate that, compared with GC, steam flaking of corn with 400 g/L density increased milk fat content and efficiency of high-producing dairy cows without any negative effect on milk yield. For GC, milk fat content tended to linearly increase and starch digestibility decreased linearly with increasing particle size.

Specific enrichment of microbes and increased ruminal propionate production: the potential mechanism underlying the high energy efficiency of Holstein heifers fed steam-flaked corn

Corn grain has a high starch content and is used as main energy source in ruminant diets. Compared with finely ground corn (FGC), steam-flaked corn (SFC) could improve the milk yield of lactating dairy cows and the growth performance of feedlot cattle, but the detailed mechanisms underlying those finding are unknown. The rumen microbiome breaks down feedstuffs into energy substrates for the host animals, and contributes to feed efficiency. Therefore, the current study was conducted to investigate the ruminal bacterial community changes of heifers fed differently processed corn (SFC or FGC) using 16S rRNA sequencing technologies, and to uncover the detailed mechanisms underlying the high performance of ruminants fed the SFC diet. The results revealed that different processing methods changed the rumen characteristics and impacted the composition of the rumen bacteria. The SFC diet resulted in an increased average daily gain in heifers, an increased rumen propionate concentration and a decreased rumen ammonia nitrogen concentration. The relative abundance of the phylum Firmicutes and Proteobacteria were tended to increase or significantly increased in the heifers fed SFC diet compared with FGC diet. In addition, the relative abundance of amylolytic bacteria of the genera Succinivibrio, Roseburia and Blautia were elevated, and the cellulolytic bacteria (Ruminococcaceae_UCG-014 and Ruminococcaceae_UCG-013) were decreased by the steam flaking method. Spearman correlation analysis between the ruminal bacteria and the microbial metabolites showed that the rumen propionate concentration was positively correlated with genera Succinivibrio and Blautia abundance, but negatively correlated with genera Ruminococcaceae_UCG-014 abundance. Evident patterns of efficient improvement in rumen propionate and changes in rumen microbes to further improve feed conversion were identified. This observation uncovers the potential mechanisms underlying the increased efficiency of the SFC processing method for enhancing ruminant performance.

223 Effects of high protein DDGS in SFC or DRC-based diets on nutrient digestibility and ruminal fermentation characteristics

Abstract The effect of high protein dried distillers grains plus solubles in steam flaked corn (SFC) or dry rolled corn (DRC)-based diets on rumen fermentation and nutrient digestion was evaluated. Six ruminally and duodenally cannulated heifers were utilized in a 6×6 Latin Square experiment using a 2×3 factorial treatment design. One factor was SFC or DRC-based diets, and the other factor was a control with no DGS (CON), regularly produced DDGS (DDGS), or High Protein DDGS (HiPro) included at 30% in the diet (DM basis). Data were analyzed using the MIXED procedure of SAS, with individual steer within period as the experimental unit. There was an interaction of apparent total tract starch digestibility (P 0.01), as including either DDGS or HiPro reduced starch digestibility in DRC-based diets and tended (P = 0.06) to reduce starch digestibility in SFC-based diets. Digestibility of starch was greater (P &lt; 0.01) for SFC versus DRC-based diets across distillers treatments. Dry matter and OM apparent total tract digestibility was lowest (P &lt; 0.01) for HiPro and DDGS was intermediate. There was no difference in molar acetate proportions (P &gt; 0.43) between treatments. Dry rolled corn tended (P = 0.08) to have greater propionate proportion than SFC (44 vs 38%; respectively). Ammonia concentration was greater (P &lt; 0.01) for DRC-based diets, and greatest for CON (P &lt; 0.01) over DDGS and HiPro treatments. Average ruminal pH was unaffected by treatment (P &gt; 0.16). Digestible energy (Mcal/kg) tended (P = 0.08) to be greater for CON over HiPro and DDGS. The use of HiPro did not affect apparent total tract nutrient digestibility as compared to DDGS in SFC or DRC-based diets. The use of either distillers product did result in a reduction in energy intake and digestibility, without affecting ruminal metabolic parameters.

PSII-14 Effects of high protein DDGS in SFC or DRC-based diets on finishing performance of steers

Abstract The effect of high protein dried distillers grains plus solubles in steam flaked corn (SFC) or dry rolled corn (DRC)-based diets on finishing performance was evaluated. Crossbred steers (n = 360, 288 ± 0.54 kg) were blocked into 3 BW blocks and assigned randomly to one of 36 pens. The treatment design was a 2 × 3 factorial. One factor was SFC or DRC-based diets, and the other factor was a control with no DGS (CON), regularly produced DDGS (DDGS), or High Protein DDGS (HiPro) included at 30% in the diet (DM basis). Data were analyzed using MIXED procedure of SAS, with pen serving as the experimental unit. There was an interaction (P = 0.02) between distillers treatment and corn processing for G:F, as including DDGS in DRC diets increased G:F from 0.157 to 0.163, with no difference when using HiPro (P = 0.18; 0.161). In SFC-based diets, there was a tendency (P = 0.11) for DDGS and HiPro to reduce G:F from 0.175 in CON diets to 0.171 in both DDGS and HiPro. When including HiPro, G:F tended (P = 0.10) to decrease SFC-based diets, with no difference (P = 0.18) in DRC-based diets. Gain increased using either distillers source (P 0.01) compared to feeding CON, and tended (P = 0.10) to be greater for DDGS than HiPro. Dry matter intake was lower (P &lt; 0.01) for cattle fed SFC-based diets than DRC-based diets, resulting in greater (P &lt; 0.01) G:F. Carcass adjusted final body weights mimicked the response observed in ADG, as DDGS tended (P = 0.10) to have a greater final bodyweight than HiPro and both were heavier (P &lt; 0.01) than CON. Including either DDGS or HiPro in DRC-based diets improved G:F, but including DDGS or HiPro in SFC-based diets had no impact on G:F.

Effect of dietary crude protein degradability and corn processing on lactation performance and milk protein composition and stability

The present study aimed to evaluate the effect of crude protein degradability and corn processing on lactation performance, milk protein composition, milk ethanol stability (MES), heat coagulation time (HCT) at 140°C, and the efficiency of N utilization for dairy cows. Twenty Holstein cows with an average of 162 ± 70 d in milk, 666 ± 7 kg of body weight, and 36 ± 7.8 kg/d of milk yield (MY) were distributed in a Latin square design with 5 contemporaneous balanced squares, 4 periods of 21 d, and 4 treatments (factorial arrangement 2 × 2). Treatment factor 1 was corn processing [ground (GC) or steam-flaked corn (SFC)] and factor 2 was crude protein (CP) degradability (high = 10.7% rumen-degradable protein and 5.1% rumen-undegradable protein; low = 9.5% rumen-degradable protein and 6.3% rumen-undegradable protein; dry matter basis). A significant interaction was observed between CP degradability and corn processing on dry matter intake (DMI). When cows were fed GC with low CP degradability, DMI increased by 1.24 kg/d compared with cows fed GC with high CP degradability; however, CP degradability did not change DMI when cows were fed SFC. Similar interactions were observed for MY, HCT, and lactose content. When cows were fed GC diets, high CP degradability reduced MY by 2.3 kg/d, as well as HCT and lactose content, compared with low CP degradability. However, no effect of CP degradability was observed on those variables when cows were fed SFC diets. The SFC diets increased dry matter and starch total-tract digestibility and reduced β-casein (CN) content (% total milk protein) compared with GC diets. Cows fed low-CP degradability diets had higher glycosylated κ-CN content (% total κ-CN) and MES, as well as milk protein content, 3.5% fat-corrected milk, and efficiency of N for milk production, than cows fed high-CP degradability diets. Therefore, GC and high-CP degradability diets reduced milk production and protein stability. Overall, low CP degradability increased the efficiency of dietary N utilization and MES, probably due to changes in casein micelle composition, as CP degradability or corn processing did not change the milk concentration of ionic calcium. The GC diets increased β-CN content, which could contribute to reducing HTC when cows were fed GC and high-CP degradability diets.

Determination of the energy contents and nutrient digestibility of corn, waxy corn and steam-flaked corn fed to growing pigs.

ObjectiveThe research was conducted to determine the digestible (DE) and metabolizable energy (ME) contents as well as the apparent total tract digestibility (ATTD) of nutrients in corn, waxy corn and steam-flaked corn fed to growing pigs.MethodsEighteen growing pigs with initial body weight of 15.42±1.41 kg were randomly allotted to three diets including a corn diet, a waxy corn diet and a steam-flaked corn diet in a completely randomized design. Each treatment contained six replicates. The experiment lasted for 12 days, which comprised 7-d adaptation to diets followed by a 5-d total collection of feces and urine. The energy contents and the nutrient digestibility in three ingredients were calculated using direct method.ResultsCompared to normal corn, both the amylose and dietary fiber contents in waxy corn were numerically lower, but the starch gelatinization degree was numerically greater. Moreover, the DE and ME contents as well as the ATTD of neutral detergent fiber and acid detergent fiber (ADF) in waxy corn were significantly greater (p<0.05) than those in normal corn when fed to growing pigs. Furthermore, the steam-flaked corn had greater (p<0.05) DE and ME contents, and ATTD of ether extract and ADF compared to normal corn.ConclusionBoth variety and processing procedure have influence on chemical compositions, energy contents and nutrient digestibility of corn. The waxy corn and steam-flaked corn had greater degree of starch gelatinization and DE and ME contents compared to normal corn when fed to growing pigs.

Dietary protein level and corn processing method: Lactation performance, milk fatty acid composition, rumen and blood parameters of lactation dairy cows

The objective of this experiment was to evaluate the interactive effects of corn processing and dietary protein level on milk production and composition, as well as rumen and plasma metabolites in lactation dairy cows. Eight multiparous mid lactating Holstein cows, averaging 105 ± 9 d in milk and producing 47.2 ± 3 kg milk/d were randomly assigned in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments. Experimental diets contained either finely ground corn (FGC) or steam flaked corn (SFC) each with either low protein (LP, 14.8%) or high protein (HP, 16.2%) content. Data were analyzed using PROC MIXED of SAS with significance declared at P ≤ 0.05. Cows fed HP diets had greater milk production and lower milk fat percentage than those for cows fed LP diets. Cows on LP diets however had greater medium-chain fatty acid (FA) and saturated FA but lower monounsaturated FA, polyunsaturated FA and unsaturated FA compared with cows on HP diets. Reduction of milk fat for cows on HP was associated with lower amount of short and medium chain FA and higher unsaturated FA content in milk fat. Blood glucose (74.7 vs 69.3 mg/dL) and cholesterol (275.2 vs 262.9 mg/dL) were greater for cows fed SFC than cows fed FGC. Corn processing had no detectable effect on milk production; however, cows on FGC had greater milk fat percentage and production and lower milk: feed ratio than cows fed SFC. Cows fed SFC had greater amount of short chain FA and polyunsaturated FA and lower C16:0 (30.5 vs 29.3) and C18:0 (9.1 vs 8.2) in milk fat than cows fed FGC. Treatments had no effect on ruminal VFA concentration and pH. Milk and blood urea, and rumen nitrogen (N) were lower for cows when fed SFC or LP diets. Cows fed SFC or LP had greater N efficiency than cows fed FGC or HP diets. These findings showed that cows supplemented with SFC or fed LP diets had a more efficient use of dietary N. Results indicate that employing a 14.8% CP diet is insufficient for maximum milk production even with corn flaking. Cows fed LP diets had similar milk: feed ratio and greater N efficiency. Compared with FGC diets, SFC diets improved feed and N efficiency while reducing N loss and increasing the glucose concentration.

Dietary protein level and corn processing method: Intake, digestibility, and feeding behavior of lactating dairy cows✰

The effects of corn processing and dietary protein level and their interaction on intake, digestibility, and feeding behavior in dairy cow was examined using eight multiparous Holstein dairy cows in mid-lactation (105 ± 9 days in milk and 47.2 ± 3 kg/day milk production at the start of the experiment) that were placed in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments. Experimental diets contained either finely ground corn (FGC) or steam-flaked corn (SFC) based on either low protein (LP, 14.8%) or high protein (HP, 16.2%) content. Diets contained 40% forage (corn silage and alfalfa hay) and 40% corn grain. Dry matter intake did not differ between HP and LP diets. In contrast, cows fed LP had greater total tract digestibility compared with that for HP-fed cows. Cows fed LP had greater chewing time and lower chewing rate (g of DM/min) compared to those for cows fed HP. Cows receiving SFC had a lower intake of nutrients and tended to have greater ADF and starch digestibility than cows fed FGC. There was an interaction between corn processing and level of protein with respect to the apparent total tract digestibility with cows fed FGC with HP resulted in the lowest digestibility. Steam-flaked corn had lower density and greater moisture and mean particle size than the FGC. In comparison with FGC, SFC did not pass through the 8-mm sieve and caused significant increase in physical effectiveness factor (pef) and physically effective fiber (peNDF) in SFC diets compared to that for FGC diets. Cows fed SFC sorted against longer particles (P = 0.04) to a greater extent than cows fed FGC. Dietary protein level had no detectable effect on sorting index. Chewing time did not differ for cows fed SFC or FGC; however, cows fed SFC had lower chewing and rumination rate (g of DM/min). Chewing time per kg of DM and CP were greater and per kg of peNDF were lower in cows fed SFC rather than cows fed FGC. Results indicated that corn processing and dietary protein level may interact to affect nutrient digestibility, but did not affect the feeding and chewing behavior of lactating cows under our experimental conditions. Results also showed that dietary peNDF content and chewing activity can be effectively manipulated by steam flaking of corn, and cows fed SFC had greater peNDF and energy intake despite lower DMI.

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.

Effect of level and source of supplemental tannin on growth performance of steers during the late finishing phase

ABSTRACTTwo trials were conducted to evaluate the effect of tannin supplementation of steers during the feedlot finishing phase. In Trial 1, 96 Holstein steers (478 ± 6.5 kg) were used to evaluate the effects of level of supplemental condensed tannin (0%, 0.2%, 0.4%, and 0.6% of dry matter basis) on growth performance. Supplemental tannin increased (6.5%, P = 0.05) weight gain, gain efficiency (5.5%, P = 0.04), and tended to increase dietary net energy (3.2%, P = 0.06). In Trial 2, 96 Holstein steers (392 ± 4 kg) were used to evaluate the effect of tannin sources on growth performance. Treatments consisted of a steam-flaked corn diet supplemented with (1) no supplemental tannin, (2) 0.6% condensed tannin, (3) 0.6% hydrolysable tannin, and (4) a blend of 0.3% condensed and 0.3% hydrolysable tannin. Tannin supplementation tended to increase average daily gain (ADG, 6.8%, P = 0.08) and dry matter intake (DMI, 4%, P = 0.04). It is concluded that tannin supplementation promotes greater DMI, and hence, ADG of steers during the finishing feedlot phase. The basis for this effect on feed intake is not certain, but is apparently independent of potential tannin effects on metabolizable protein supply. Source of supplemental tannin (condensed vs. hydrolysable) have minimal effects on overall growth performance response to supplementation.

Volatile organic compound flux from manure of cattle fed diets differing in grain processing method and co-product inclusion

Odor emissions from livestock production have become increasingly important in the past decade. Odors derived from animal feeding operations are caused by odorous VOC emitted from the mixture of feces and urine, as well as feed and silage which may be experiencing microbial fermentation. Distillers grains are a by-product of corn grain fermentation used to produce fuel ethanol, and this industry has grown rapidly throughout the U.S. in past years. Therefore, the use of wet distillers grains with solubles (WDGS) in feedlot cattle diets has also increased. The objective of this research was to determine specific VOC emissions from feces and urine or a mixture of both, from cattle fed steam flaked or dry-rolled corn (DRC)-based diets containing either 0% or 30% WDGS. Flux of dimethyl trisulfide was greater from feces of cattle fed DRC than steam-flaked corn (SFC) diets. No other differences in flux from feces were detected across dietary treatments for phenol, 4-methylphenol, indole, skatole, dimethyl disulfide, and flux of volatile fatty acids (VFA) such as acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids (P > 0.15). Flux of skatole, acetic acid, and valeric acid from urine was greater for cattle fed SFC than DRC diets (P < 0.05). Moreover, dimethyl disulfide flux was greater for cattle fed DRC vs. SFC diets (P = 0.05). When evaluating WDGS inclusion in the diet, flux of acetic acid and heptanoic acid from urine was greater when cattle were fed diets containing 0% WDGS than 30% WDGS (P < 0.05). When combining urine and feces in the ratio in which they were excreted from the animal, flux of propionic acid was greater when cattle were fed DRC vs. SFC diets (P = 0.05). Based on these results, the majority of the VOC, VFA, and odor flux from cattle feeding operations is from the urine. Therefore, dietary strategies to reduce odor from cattle feeding facilities should primarily focus on reducing excretion of odorous compounds in the urine.