Corn Silage Research Articles

Milking system and diet forage type effect on milk quality of Italian Holstein-Friesian

Moving from conventional (CMS) to automatic (AMS) milking systems could affect milk quality. Moreover, the type and preservation methods of the forages used in the TMR, such as alfalfa hay (HTMR) or corn silage (STMR) have been demonstrated to modify milk composition. Thus, this study investigated the effect of implementing AMS and different diet forage types on the quality of Italian Holstein-Friesian bulk milk. Milk samples (n = 168) were collected monthly from 21 commercial farms in northern Italy during a period of 8 mo. Farms were categorized into 4 groups according to their milking system (CMS vs. AMS) and diet forage type (HTMR vs. STMR). Milk quality data were analyzed through the mixed procedure for repeated measurement of SAS with the milking system, diet forage type, and sampling day as fixed effects. Milking through the AMS led to lower milk fat, freezing point, and β-LG A; longer coagulation time; and higher K content, pH, and β-LG B than CMS. Cows fed STMR produced milk with greater fat, protein, casein, Mg content, titratable acidity, and β-LG A, but with reduced curd firming time, freezing point, and β-LG B than those fed HTMR. In conclusion, milk quality is not only altered by the diet's forage type and characteristics but also by the milking system.

Effect of nicotinic acid supplementation on digestion, metabolism, microbiome, and production in late-lactation Holstein cows

The purpose of this experiment was to determine if nicotinic acid (NA) effects on dairy cows and rumen microbial characteristics are forage type dependent (corn silage, CS; grass silage, GS). Four late lactation (days in milk = 225 +/- 12 d) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The main effects were a CS (66.10% CS) based diet or a GS (79.59%) based diet with or without 12 g/d NA. Each experimental period lasted for 28 d. Milk production and milk components, blood metabolites, apparent total-tract nutrient digestibilities, minutes rumen pH were below 5.8 as an indicator of ruminal acidosis, and body temperature changes were analyzed as indicators of heat stress. Nicotinic acid supplementation did not improve apparent total-tract nutrient digestibility. Feeding a GS-based diet improved NDF and hemicellulose digestibility. Feeding a CS-based diet increased the apparent total-tract digestibility of fat, and minutes rumen pH below 5.8 for a greater proportion of the time. The CS-based diet also improved milk yield, milk fat and protein yields, and energy-corrected milk yield; however, somatic cell count and BHB were also increased. Supplementing NA tended to decrease nonesterified fatty acids, especially when combined with GS where DMI was low. There was a trend for the total protozoa population to increase when GS and NA were fed but decreased when CS and NA were fed. Nicotinic acid tended to decrease rumen protozoal populations of Dasytricha, but increased populations of Ophryoscolex and Diplodiniinae with GS diets and decreased with CS diets. Entodiniinae were increased with CS but NA had no effect. Body temperature was increased when a CS-based diet was fed when compared with a GS-based diet. More research is needed to determine how NA can affect rumen microbial protein synthesis and what kind of diets will provide the optimum effect.

Farm-specific estimates of forage variability result in larger optimal control limits for forage quality monitoring

Variation in forage composition decreases the accuracy of diets delivered to dairy cows. However, variability of forages can be managed using a renewal reward model (RRM) and genetic algorithm (GA) to optimize sampling and monitoring practices for farm conditions. Specifically, use of quality-control-charts to monitor forage composition can identify changes in composition for which adjustment in the formulated diet will result in a better match of the nutrients delivered to cows. The objectives of this study were 1) assess the use of a clustering algorithm to estimate the mean time the process is stable or in-control (d) (TStable) and the magnitude of the change in forage composition between stable periods (ΔForage) for corn silage and alfalfa-grass silage which are input parameters for the RRM; 2) compare optimized farm-specific sampling practices (number of samples (n), sampling interval (TSample) and control limits (ΔLimit) using previously proposed defaults and our estimates for the TStable and ΔForage input parameters; and 3) conduct a simulation study to compare the number of recommended diet changes costs of quality control under the proposed sampling and monitoring protocols. We estimated the TStable and ΔForage parameters for corn silage NDF and starch and alfalfa-grass silage NDF and CP using a k-means clustering approach applied to forage samples collected from 8 farms, 3x/week during a 16-week period. We compared 4 sampling and monitoring protocols that resulted from the 2 methods for estimating TStable and ΔForage (default values and our proposed method) and either optimizing only the control limit (Optim1) or optimizing the control limits, the number of samples, and the number of days between sampling (Optim2). We simulated the outcomes of implementing the optimized monitoring protocols using a quality control chart for corn silage and alfalfa-grass silage of each farm. Estimates of T^Stable and Δ^Forage from the k-means clustering analysis were, respectively, shorter and larger than previously proposed default values. In the simulated quality control monitoring, larger Δ^Forage estimates increased the optimized ΔLimit resulting in fewer detected shifts in composition of forages and a lower frequency of false alarms and a lower quality control cost ($/d). Recommended diet reformulation intervals from the simulated quality control analysis were specific for the type of forage and farm management practices. The median of the diet reformulation intervals for all farms using our optimal protocols was 14 d (Q1 = 8, Q3 = 26) for corn silage and 16 d (Q1 = 8, Q3 = 26) for alfalfa-grass silage.

Responses of nutrient utilization, rumen fermentation and microorganisms to different roughage of dairy buffaloes

Dairy buffaloes are typically fed a high-forage, low-quality diet with high fiber. These conditions result in an inherent energy and protein inefficiency. In order to make full and rational use of feed resources and improve the production level and breeding efficiency of dairy buffaloes, the effects of various roughages on nutrient digestibility, ruminal fermentation parameters, and microorganisms in dairy buffaloes were studied in this experiment. Three ternary hybrid buffaloes, with an average body weight of 365 ± 22.1 kg, were selected and fitted with permanent rumen fistulas. They were fed six different diets, each consisting of 1 kg concentrate supplement and one of six types of roughage, including alfalfa hay (A diet), oat hay (O diet), whole corn silage (W diet), king grass (K diet), sugarcane shoot silage (S diet), and rice straw hay (R diet) according to an incomplete Latin square design of 3 × 6, respectively. The pre-feeding period of each period was 12 d. From day 13 to 15 was the official experimental period. During the prefeeding period, free feed intake for each roughage was determined, and during the experiment, the roughage was fed at 90% of the voluntary feed intake. Digestion and metabolism tests were carried out using the total manure collection method to determine the feed intake and fecal output of each buffalo, and to collect feed and fecal samples for chemical analysis. On day 15, rumen fluid samples were collected two hours after morning feeding to determine rumen fermentation parameters and bacterial 16 S rRNA high-throughput sequencing was performed. The results showed that DM and OM digestibility were greatest for the W diet and lowest for the S diet. The rumen pH of the O diet was significantly greater than that of the W diet. The concentration of rumen fluid NH3-N (mg/dL) increased with increased CP content. The concentration of total volatile fatty acids (mmol/L) in the rumen decreased with increased NDF content but increased with increased NFC content. The relative abundances of Bacteroidetes, Firmicutes, and Spirochaetes were 57.03-74.84%, 14.29-21.86%, and 0.44-1.43% in the different quality roughage groups. Bacteroidetes were mainly Prevotellaceae1 and Rikenellaceae RC_gut_group with relative abundances of 30.17-45.75% and 3.23-7.82%. The relative abundance of Patescibacteria and Spirochaetes decreased with increasing roughage quality. These results provide a theoretical and practical basis for evaluating the nutritional value of dairy buffalo feed, utilizing feed resources, matching rations, feeding scientifically, and protecting animal health.

Effect of acidosis in the late-finishing phase on rumen fermentation in feedlot steers.

The objective was to determine the effects of induced acidosis in the late-finishing phase on rumen fermentation in feedlot steers. Eleven ruminally cannulated steers (body weight [BW] = 795 kg ± 54) were blocked into two groups based on initial BW. For 195 d prior to the start of the study, cattle were consuming a basal finishing diet (60% dry-rolled corn, 15% modified distillers grains, 15% corn silage, and 10% ground corn-based supplement). Steers were randomly assigned to one of the two treatments: control (CON), or induced acidosis (ACD). Both treatments were fasted for 24h then fed the basal finishing diet. Steers on the ACD treatment received 0.05% of BW of wheat starch via rumen cannula at 0800 and 2000 hours on day 1 and ad libitum refeeding following the fast. On days 1 and 2, CON steers were provided 25% of allotted feed every 6h. Rumen fluid was collected every 4h during the challenge period (hours 0 to 48), and 0, 6, and 12h after feeding during the recovery period (hours 54 to 96). Rumen fluid was analyzed for pH, ammonia, volatile fatty acids (VFA), and lactate. Fecal grab samples were collected every 8h to determine fecal pH. A treatment × day interaction (P = 0.03) was observed for dry matter intake during the challenge period with steers on the ACD treatments consuming more on day 1 than CON steers. Intake was not different on day 2 (P = 0.88). A treatment × hour effect (P < 0.01) was observed for ruminal pH during the challenge period with the ACD steers having a lesser pH than CON from hours 12 to 32. Duration of time below a pH of 5.6 during the challenge period was greater (P < 0.01) for ACD steers than CON. During the challenge period, a treatment × time interaction (P = 0.04) was observed for total VFA concentration with ACD steers having greater total VFA concentration from hours 12 to 36. Acetate to propionate ratio (A:P) was affected by treatment × hour (P = 0.04) with CON steers having greater A:P from hours 28 to 48. Rumen ammonia and lactate concentrations did not differ (P ≥ 0.25) between treatments or the interaction with time. Challenge and recovery period fecal pH were not affected (P ≥ 0.13) by treatment, time, or their interaction. Recovery period ruminal pH was not different (P = 0.99) between treatments. For the recovery period, total VFA and ammonia concentration were not affected by treatment, time, or their interaction (P ≥ 0.07). Ruminal pH and VFA were affected in the initial 48h of induced acidosis in the late-finishing phase.

Effect of Regulation of Whole-Plant Corn Silage Inoculated with Lactobacillus buchneri or Bacillus licheniformis Regarding the Dynamics of Bacterial and Fungal Communities on Aerobic Stability.

Enhancing the aerobic stability of whole-plant corn silage is essential for producing high-quality silage. Our research assessed the effect of inoculation with Lactobacillus buchneri or Bacillus licheniformis and its modulation of the bacterial and fungal microbial community structure in an aerobic stage of whole-plant corn silage. Following treatment with a distilled sterile water control, Lactobacillus buchneri, and Bacillus licheniformis (2 × 105 cfu/g), whole-plant corn was ensiled for 60 days. Samples were taken on days 0, 3, and 7 of aerobic exposure, and the results showed that inoculation with Lactobacillus buchneri or Bacillus licheniformis improved the aerobic stability of silage when compared to the effect of the control (p < 0.05). Inoculation with Bacillus licheniformis attenuated the increase in pH value and the decrease in lactic acid in the aerobic stage (p < 0.05), reducing the filamentous fungal counts. On the other hand, inoculation with Lactobacillus buchneri or Bacillus licheniformis increased the diversity of the fungal communities (p < 0.05), complicating the correlation between bacteria or fungi, reducing the relative abundance of Acetobacter and Paenibacillus in bacterial communities, and inhibiting the tendency of Monascus to replace Issatchenkia in fungal communities, thus delaying the aerobic spoilage process. Due to the prevention of the development of aerobic spoilage microorganisms, the silage injected with Lactobacillus buchneri or Bacillus licheniformis exhibited improved aerobic stability.

Isolation of Bacillus velezensis from Silage and Its Effect on Aerobic Stability and In Vitro Methane Production of Whole-Plant Corn Silage

Once a silo has been opened, the silage inside will face challenges such as aerobic deterioration, rot, and contamination. Biocontrol bacteria, as a kind of biological antiseptic, are highly effective and natural and are gaining increasing attention. This study aimed to screen a strain with anti-microbial activity against silage spoilage microorganisms and examine its effects on the fermentation quality, aerobic stability, in vitro digestion, and methane production of silage. Lactic acid bacteria, pathogenic and rot-causing microorganisms, were used as indicators to screen the strains for putrefactive silage. The bacteriostatic spectrum, growth performance, and tolerance to the silage environment of the strain were tested. A strain named D-2 was screened from rotten whole-plant corn silage and identified as Bacillus velezensis through physiological and biochemical tests as well as 16S rDNA sequencing. This study found that D-2 exhibits antibacterial effects on several microorganisms, including Escherichia coli, Staphylococcus aureus, Salmonella enteritidis, Aspergillus niger, Saccharomyces cerevisiae, Fusarium oxysporum, and Fusarium graminearum. However, it has no adverse effect on Lactobacillus reuteri, Enterococcus faecium, or Lactobacillus casei. D-2 can attain a stable stage within 10 h and withstand temperatures of up to 70 °C. Moreover, this study found that D-2 had a high survival rate of over 97% after 48 h in a lactic acid environment with pH 4. Freshly chopped whole-plant corn was inoculated without or with D-2 and ensiled for 60 days. The results show that D-2 inoculations increase the content of water-soluble carbohydrates, acetic acid, and propionic acid in the silage and decrease the number of yeasts and molds, the NH4+-N/TN ratio, and the pH. We also found that fermenting whole-plant corn with D-2 significantly increased the in vitro digestibility and the propionic acid content, while also significantly inhibiting methane production. After being exposed to air for 10 days, D-2 can still effectively reduce the total number of yeasts and molds, prevent the decrease in lactic acid bacteria, and inhibit the increase in the pH and NH4+-N/TN ratio of silage products. Overall, D-2 is resistant to pathogenic and rot-causing microorganisms, allowing for easy adaptation to silage production conditions. D-2 can effectively improve aerobic stability and reduce losses in the nutritional value of silage, indicating possible applications for the prevention of silage rot and methane production.

A robust, low-temperature, closed-loop anaerobic system for high-solid mixed farm wastes: advancing agricultural waste management solutions in Canada.

This study investigates the effectiveness of low-temperature (20 ± 1 °C) anaerobic digestion (AD) for two organic multiple farm substrate combinations: Set 1 comprising chicken manure (CM), dairy manure (DM), and waste corn silage (CS) and Set 2 comprising CM, DM, pig manure (PM), and CS. Inoculum adaptation steps were carried out using CM and CM+DM for Set 1 and Set 2, respectively. Over three consecutive operating cycles spanning 245 days with increasing organic loads, 4.3 and 2.8 g VS L-1 d-1 for Sets 1 and 2 during Cycles 1 to 5.1 and 4.6 g VS L-1 d-1for Sets 1 and 2 during Cycle 3, a closed-loop two-stage liquid-solid AD system was employed, with performance assessed via stability ratios of short-chain volatile fatty acids and alkalinity. Results demonstrate that mono-digestion of CM with adapted inoculum yielded the highest biogas production of 424 ± 4 L over 77 days, indicating superior performance by Set 1 during Phase I, whereas a similar performance was observed during Phase 2, where Sets 1 and 2 exhibited highest specific methane yields of 0.233 ± 0.028 and 0.262 ± 0.004 L g-1 VSfed, respectively, over 68 days. Analysis of heavy metal concentrations in digestates revealed a significant decrease compared to initial raw substrate concentrations, highlighting their role as nutrients for microbial growth. This study, the first of its kind, highlights the potential of low-temperature AD systems to manage diverse organic residues/byproducts and offers insights into effective performance monitoring without compromising system integrity.

Effect of source and frequency of rumen-protected protein supplementation on mammary gland amino acid metabolism and nitrogen balance of dairy cattle

The AA profile of MP affects mammary gland metabolism and milk N efficiency of dairy cattle. Further, the frequency of dietary protein supplementation may influence N partitioning leading to reduced N excretion. This study investigated the effect of source and frequency of rumen-protected (RP) protein supplementation on apparent total-tract digestibility, milk production, mammary gland AA metabolism, and N balance of dairy cattle. Twenty-eight Holstein-Friesian cows (2.3 ± 0.9 lactations; 93 ± 27 DIM; mean ± SD) were used in a randomized complete block design and fed a basal TMR consisting of 41% corn silage, 32% grass silage, and 27% concentrate (DM basis) and formulated to meet 100% and 95% of net energy and MP requirements, respectively. Cows were adapted to the basal TMR in a freestall barn for 7 d, moved to individual tiestalls for 13 d of adaptation to dietary treatments, and then moved into climate respiration chambers for a 4-d measurement period. Treatments consisted of the basal TMR (CON; 159 g CP/kg DM) or the basal TMR including 1 of 3 iso-MP supplements: (1) 315-g mixture of RP soybean meal and RP rapeseed meal fed daily (ST-RPSR), (2) 384-g mixture of RP His, RP Lys, and RP Met fed daily (ST-RPAA), and (3) 768-g mixture of RP His, RP Lys, and RP Met fed every other day (OS-RPAA). The basal TMR with the addition of treatment supplements was designed to deliver 100% of required MP over a 48-h period. The mixture of His, Lys, and Met was formulated to deliver digestible AA in amounts relative to their concentration in casein. Compared with ST-RPSR, ST-RPAA increased milk protein and fat concentration, increased the arterial concentration of total His, Lys, and Met (HLM), decreased mammary clearance of HLM, and increased clearance of Phe, Leu, and Tyr (tendency for Leu and Tyr). Rumen-protected protein source did not affect N balance, but the marginal use efficiency (efficiency of transfer of RP protein supplement into milk protein) of ST-RPAA (67%) was higher than that of ST-RPSR (17%). Milk protein concentration decreased with OS-RPAA compared with ST-RPAA. Arterial concentration of HLM increased on the nonsupplemented day compared with the supplemented day with OS-RPAA, and there was no difference in arterial HLM concentration across days with ST-RPAA. Mammary uptake of HLM tended to increase on the nonsupplemented day compared with the supplemented day with OS-RPAA. Supplementation frequency of RP AA did not affect N balance or overall milk N efficiency, but the marginal use efficiency of OS-RPAA (49%) was lower compared with ST-RPAA. Overall, mammary glands responded to an increased supply of His, Lys, and Met by reducing efflux of other EAA when RP His, RP Lys, and RP Met were supplemented compared with RP plant proteins. Mammary glands increased sequestration of EAA (primarily HLM) on the nonsupplemented day with OS-RPAA, but supplementing RP AA according to a 24-h oscillating pattern did not increase N efficiency over static supplementation.

Rapid detection of microplastics in feed using near-infrared spectroscopy

The presence of microplastics in the forage and feedstuffs of domestic animals represents an imminent threat to the entire food chain that may reach humans since the particles could be transferred into the intestinal barriers and contaminate blood and animal products. Until now, there is no simple, rapid, sustainable, and reliable method to detect microplastics in animal feed. The objective of this study was to investigate the ability of near-infrared spectroscopy (NIRS) to detect microplastics in ruminant feeds. Two types of instruments were tested using four feeds (corn silage, mixed hay, rye grass silage, soybean meal) and a total mixed ration. Two types of crumbled contaminants, low-density polyethylene and polystyrene, were accurately mixed at ratios of 0, 1, 3, and 5 mg g-1. The pool of the five matrices examined by the benchmark instrument (714-3333 nm) yielded an accuracy of approximately 0.8 mg g-1 and a detection limit of about 1 mg g-1, however, the errors could be halved in separate calibrations. A short wavelength range (714-1070 nm) or a smart NIRS instrument proved an acceptable discrimination of the concentrations. Following these preliminary results, any validation on other samples with different and powerful NIRS tools is encouraged.

Microelements Effect on the General Sheep Performance

Our research shows that the content of microelements (cobalt, copper, iodine) in local feed (alfalfa grass, corn silage, barley and wheat straw, etc.) is very low, and in some cases completely absent. This negatively affects animal productivity. Taking this into account, in 2022-2023 we studied the effect of microelements cobalt, iodine and copper on the overall productivity of sheep. During the experiments, each head of sheep was given daily 10 mg of cobalt chloride, 10 mg of potassium iodide and 10 mg of copper sulfate. The results of a 120-day experiment and our observations show that sheep receiving these microelements had 5,7% more wool and 10,3% greater lamb birth rate compared to sheep that did not receive microelements. Microelements had a positive effect on sheep wool yield, wool length, live weight of the animal, and the development of the lamb in the womb. In the sheep of the experimental group that received micronutrient nutrition, the wool yield was 78 g, and the length of the wool was 0,8 cm longer than in the control group. The live weight of sheep and lambs receiving micronutrients was 3,92 kg at birth and 26,55 kg at weaning, and the live weight of sheep lambs not receiving micronutrients was 3,70 kg and 24,65 kg. Thus, in the conditions of Nakhchivan AR, it is considered advisable to widely use microelements to increase the overall productivity of sheep.

Soybean molasses increases subcutaneous fat deposition while reducing lipid oxidation in the meat of castrated lambs.

This study aimed to evaluate the effect of including soybean molasses (SM) on performance, blood parameters, carcass traits, meat quality, fatty acid and muscle (longissimus thoracis) transcriptomic profiles of castrated lambs. Twenty Dorper × Santa Inês lambs (20.06 ± 0.76kg BW) were assigned to a randomized block design, stratified by BW, with the following treatments: CON - 0g/kg of SM and SM20 - 200g/kg of SM on DM basis, allocated in individual pens. The diet consisted of 840g/kg concentrate and 160g/kg corn silage for 76 days, with the first 12 days as an adaptation period and the remaining 64 days on the finishing diet. The SM20 diet increased blood urea concentration (P = 0.03) while reduced glucose concentration (P = 0.04). Lambs fed SM showed higher subcutaneous fat deposition (P = 0.04) and higher subcutaneous adipocyte diameter (P < 0.01), in addition to reduced meat lipid oxidation (P < 0.01). Soybean molasses reduced the quantity of branched-chain fatty acids in longissimus thoracis (P = 0.05) and increased the quantity of saturated fatty acids (P = 0.01). In the transcriptomic analysis, 294 genes were identified as differentially expressed, which belong to pathways such as oxidative phosphorylation, citric acid cycle, and monosaccharide metabolic process. In conclusion, diet with SM increased carcass fat deposition, reduced lipid oxidation, and changed the energy metabolism, supporting its use in ruminant nutrition.

165 Comparing corn earlage to a blend of corn silage and grain when fed at two different inclusions for finishing cattle

Abstract An experiment was conducted to evaluate the effects of feeding earlage as the sole source of roughage and grain in a finishing diet when compared with corn silage plus grain at equal forage NDF inclusions in the diet. Crossbred yearling steers [n = 216; initial body weight (BW) = 471 ± 14.1kg] were fed one of 4 experimental diets in a 2 × 2 factorial treatment arrangement with roughage type and forage inclusion being the 2 factors. Treatment diets were formulated for earlage to provide all the grain the diet (74%) which provided 14.8% forage and was compared with 29.6% corn silage and 44.4% corn as a 50:50 blend of dry rolled corn (DRC) and high moisture corn (HMC). The other two diets were formulated for corn silage to provide a standard roughage inclusion for finishing diets (i.e., corn silage at 15% to supply 7.5% forage in the diet). To match 7.5% roughage with earlage providing all the roughage, another diet included earlage at 37%, with an additional 37% corn included as the 50:50 blend of HMC and DRC. All diets included 20% wet distiller’s grains (WDGS) and 6% supplement. The two inclusions of forage were either 7.5 or 14.8% forage as either earlage or corn silage. Earlage was assumed to provide 20% forage and corn silage to provide 50% forage, on a DM basis. Cattle were stratified into 3 BW blocks, then assigned randomly assigned to pens within block, and treatment assigned randomly to pens. A total of 24 pens containing 9 steers in each were used with pen as the experimental unit. Feeding performance, carcass characteristics and liver abscess prevalence were evaluated using the MIXED procedure of SAS with BW block and treatment being fixed effects. No interactions between roughage type or forage inclusion were observed for performance or carcass traits (P &amp;gt; 0.13) except for marbling or liver abscesses (P &amp;lt; 0.09). When cattle were fed a diet with corn silage as the roughage source, greater dry matter intakes (DMI) and average daily gain (ADG) were observed (P ≤ 0.01), but feed efficiency was not significantly different (P = 0.35). However, when evaluating effects of NDF inclusion, cattle fed 7.5% forage in the diet were 6.8% more efficient than cattle fed 14.8% forage and tended to have greater gain (P = 0.10), but no significant differences were observed for intake (P = 0.11). These data suggest that cattle fed earlage will eat and gain less than cattle fed a blend of corn silage and grain when estimated forage is equivalent, and when earlage is fed as the sole source of grain, cattle will be less efficient than when conventional roughage inclusions are fed.

PSVI-1 Backgrounding and finishing systems for cattle fed corn silages and corn grains differing in amylase expression

Abstract Amylase is a key enzyme involved in the hydrolysis of starch, which typically constitutes the predominant source of energy in feedlot cattle diets. Performance of cattle during the backgrounding phase can influence performance during the subsequent finishing phase. Our objective was to assess growth performance of backgrounding steers fed diets that contained combinations of corn silage (S) and steam-flaked corn (G) from hybrids with high amylase expression (Enogen corn; E; Syngenta Seeds, LLC) or common corn hybrid (C), as well as subsequent finishing performance, carcass characteristics, and liver abscess incidence when fed G produced from the same hybrids. Crossbred steers (n = 911; 306 ± 8 kg initial body weight) were assigned randomly to one of four backgrounding treatments with 12 replicates in a randomized complete block experiment using a factorial treatment arrangement. Factor 1 consisted of two corn silage hybrids (ES or CS), and factor 2 consisted of two SFC hybrids (EG or CG). In the subsequent finishing phase, animals were assigned to one of two treatments consisting of two grain hybrids (EG or CG) with 24 replicates per treatment. Backgrounding diets (dry basis) contained 20.1% flaked corn and 41.6% corn silage, and finishing diets contained 81.5% flaked corn with triticale silage as a common roughage source. There was no three-way interaction for measures of interest, and no differences among treatment combinations with respect to average daily gain (ADG) or incidence of abscessed livers (P &amp;gt; 0.10). Steers fed CG during the backgrounding phase ate more than steers fed EG (P = 0.04), thus leading to improved overall efficiency of steers fed EG in the backgrounding phase compared with their counterparts fed CG (P &amp;lt; 0.01; Table 1). Overall efficiency tended to be greater for cattle fed CG during the finishing phase (P = 0.06) compared with cattle fed EG during the finishing phase. There was a tendency for interaction between G fed in the backgrounding and G fed in the finishing phase for hot carcass weight (P = 0.07), such that steers fed the same hybrid in both phases had greater carcass weight compared with those fed different hybrids in the backgrounding and finishing phases. Type of grain fed in the backgrounding and finishing phases, but not silage, impacted overall system efficiency.

87 Evaluating the effects of an amino acid-formulated diet on ruminal fermentation in vitro

Abstract The objective was to determine the effect of an amino acid-formulated diet on ruminal fermentation in vitro. While most amino acid-formulated diets focus on improving the amino acid composition of rumen undegradable protein, additional benefits to microbial fermentation within the rumen are unknown. The experiment was a completely randomized design with a factorial treatment arrangement (2 donor diets and 2 substrates). Four ruminally cannulated steers were fed one of two donor diets: control (CON; 55% dry rolled corn, 20% corn silage, 15% dry distiller’s grain, and 10% supplement) and amino acid-formulated (AAF; 51% dry rolled corn, 15% corn silage, 14% dry distillers grain, 10% heat-treated soybean meal, and 10% supplement). After a 30-d diet adaptation period, rumen fluid was collected and pooled by donor diet for the in vitro fermentation. Additionally, two different substrates were used to represent each donor diet. Flasks contained 2.5 g dry matter (DM) of substrate and 150 mL of rumen fluid mixture (2 McDougall’s buffer:1 rumen fluid). Treatments were evaluated in triplicate flasks in two replicated runs for a total of six observations per treatment. Four sealed Ankom F57 bags were filled with 0.25 g DM of substrate each to facilitate measuring in vitro DM disappearance (IVDMD). Flasks were incubated at 39°C with sample aliquots collected at h 0, 4, 8, 12, and 24 to determine pH, ammonia, and volatile fatty acids (VFA). Data were analyzed using the MIXED procedure of SAS 9.4 with a repeated measures analysis. Ammonia, pH, and VFA were analyzed with effects of donor diet, substrate, time, and all interactions. A treatment by hour interaction was detected (P &amp;lt; 0.01) for pH; fluid from steers fed CON was greater than AAF at h 4, 8, 12, and 24. A treatment by hour interaction was also detected (P = 0.02) for ammonia; fluid from steers fed CON was greater than AAF at h 24, but was not different at other time points. Total VFA was affected by hour (P &amp;lt; 0.01) as it increased over time, but substrate did not have an effect (P = 0.21). A treatment by hour interaction (P = 0.06) tended to be observed for molar proportions of acetate as AAF and CON were similar at h 0 but AAF was increasing greater than CON over time. A treatment by hour interaction was observed (P = 0.01) for molar proportions of propionate; at h 4 at 8, CON was greater than AAF. No effect (P ≥ 0.32) of donor diet, substrate or their interaction were observed on IVDMD. Overall, an amino acid-formulated diet for cannulated steers did impact ruminal fermentation in vitro, mostly altering molar proportions of volatile fatty acids and ammonia release from protein degradation.

PSVI-4 Effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet

Abstract The objective was to characterize the effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet. Cattle entering the feedlot undergo a transition period where the amount of concentrates in the diet is gradually increased to mitigate the risks of ruminal acidosis. Despite a dietary adaptation, rumen acidosis still affects feedlot cattle later in the finishing phase. Ruminally cannulated steers [n = 11; body weight (BW) = 795 kg ± 54) were blocked into 2 groups based on initial BW. Before the start of the study, cattle had been consuming a finishing diet (60% dry rolled corn, 15% modified distiller’s grains, 15% corn silage, and 10% ground corn based supplement) for more than 150 d. Steers were randomly assigned to 1 of 2 treatments: control (CON) or acidosis (ACD). For the experiment, steers were fasted for 24 h and at the conclusion received the same finishing diet. Steers on ACD steers were also ruminally dosed 0.05% BW of wheat starch on h 0 and h 12 to induce acidosis. Rumen fluid was collected every 4 h for 48 h to analyze ruminal pH, ammonia, volatile fatty acids (VFA), and lactate. Fecal grab samples were collected every 8 h for 48 h to determine fecal pH. Data were analyzed with the MIXED procedure of SAS 9.4 with the effects of treatment, time, and their interaction. A treatment × hour (P &amp;lt; 0.01) effect was observed for ruminal pH with the ACD steers having a lower pH than CON from h 12 to 32. Fecal pH was not affected by treatment, time, or their interaction (P ≥ 0.12). Steers fed ACD had greater total VFA concentration than CON (P &amp;lt; 0.01). A treatment × hour interaction (P &amp;lt; 0.01) was observed for acetate molar proportion with CON having greater percentage acetate at h 24 through 32. Additionally, there was a treatment × hour interaction (P &amp;lt; 0.01) for propionate molar proportion with ACD steers having greater propionate at h 28 and 32, and then at h 40 and 44. Butyrate was not affected (P ≥ 0.58) by treatment × hour or treatment. Acetate to propionate ratio (A:P) was affected by treatment × hour (P &amp;lt; 0.01) with CON steers having greater A:P after h 28. Rumen ammonia and lactate concentrations did not differ (P ≥ 0.25) by treatment or the interaction with h. In steers adapted to a high concentrate diet, acidosis only altered ruminal fermentation in regards to ruminal pH and VFA concentrations.

232 Evaluation of a phytogenic feed additive with essential oils and plant extracts on growth performance in single sourced steer calves fed a forage-based diet during the initial 53 d receiving period

Abstract The receiving period of a feedlot calf is one of the most stressful stages in the life of that animal and can result in respiratory disease caused, in part, by reduced feed intake and transit stress. Feeding a phytomolecule compound in combination with current therapeutic strategies may aid in controlling systemic inflammation and improve the performance of newly received calves. This study determined whether a phytogenic feed additive with essential oils and plant extracts (PFA) influences measures of growth and growth efficiency during the feedlot receiving phase. The two treatments were a control group fed no additive (CON) and a treatment group fed PFA additive at a rate of 0.25 g/45.4 kg of body weight (BW; PFA). Steers were transported 285 km from an auction facility to the Ruminant Nutrition Center in Brookings, SD where they were vaccinated against viral respiratory diseases and clostridial species, and administered pour-on anthelmintic. Steers were divided into 10 replicate pens of 8 steers (305 ± 30 kg) per treatment (n = 160 steers) in a randomized complete block design. The steers were fed a basal diet [dry matter (DM) basis] containing corn silage (74%), DDGS (21%), a liquid supplement (5%), and monensin sodium (Rumensin-90, Elanco Animal Health) at 25 g/907 kg (DM basis) for 53 d. Steers were fed 2X daily with intakes closely managed for the first 14 d during adaptation to the receiving diet then a slick bunk management strategy was applied for the remainder of the study. No mortality was observed in this study, and one steer was treated for respiratory disease from the CON group. There were no significant differences observed in BW, average daily gain (ADG), variation in ADG, dry matter intake, or feed conversion efficiency from d 1 to 29, 29 to 53, or during the cumulative receiving period (P ≥ 0.11) between the CON and PFA groups. NEm and NEg did not differ between the treatments (P ≥ 0.79). The ratio of observed-to-expected dietary net energy was also not affected by dietary treatment (P ≥ 0.71). The steers used in this study were in good health and had minimal morbidity (0.63%) with no mortality during the 53-d receiving study which contributed to the feed additive having no appreciable influence on the growth and health outcomes in this study.

PSV-10 Evaluation of the effect of probiotic feed additives in the diet to improve dairy production and quality measures

Abstract There is limited information regarding the effectiveness of probiotic feed additives in the diet of lactating dairy cows. This study aimed to determine the effect that Fastrack probiotic had on the yield and milk quality measures of lactating dairy cows. To accomplish this goal, lactating Holstein cows (n = 80) were equally divided into two treatment groups: one supplemented with a probiotic (PRO) and one that did not receive the probiotic supplement (CON). The cows remained in their treatment groups for the duration of the 120-d study and were given ad libitum access to a total mixed ration consisting of 35% corn silage, 30% rolled corn, 10.5% soybean meal, 23% DDGS, and 1.5% mineral supplement. Cows on the PRO treatment were given 1 kg of DDGS once a day at milking that had the probiotic mixed in while the CON treatment were given 1 kg of the same DDGS that did not have the probiotic included. Preliminary results of this study show a decrease in individual treatment records for cows on the PRO treatment and an increase of 2 kg of milk yield per day.

236 The effects of replacing dried distiller’s grains with solubles with heat-treated soybean meal on nutrient intake and digestibility in forage-based diets

Abstract Cattle growth is calculated through dry matter intake, average daily gain and gain:feed measures that assume performance and digestibility are correlated. Hence, evaluating nutrient digestibility and flow provides additional explanations for subsequent growth performance. Therefore, five fistulated Jersey steers [Initial body weight (BW) = 288 ± 22 kg) fitted with ruminal, duodenal, and ileal cannulas were utilized in a 4 × 5 row-column design to determine intake and total tract nutrient digestibility when replacing dried distiller’s grains plus solubles (DDGS) with heat-treated soybean meal (TSBM) in forage-based growing diets. The 56-d study contained 4 periods, each period lasting 14 d [9 d of adaptation and 5 d of collection (d 0 to 4)]. Dietary treatments partially replaced DDGS, included at 16% diet dry matter (DM), with TSBM at increasing inclusion levels of 0 (TSBM0), 4 (TSBM4), 8 (TSBM8), and 12% (TSBM12) DM. Basal diets contained 43.5% corn silage, 36.5% oat hay, and 4% meal supplement (DM). Chromic oxide was incorporated into the diet daily at 0.25% DM as a digesta marker. Steers were housed in individual tie stalls during the 5-d collection period. Treatment diets were fed daily at 0800 h with orts being weighed at 0730 h and subsampled on d 0 to d 4 each period. Fecal collection bags were harnessed to each steer from d 0 to d 4 to collect fecal weight and subsampled twice daily (0700 and 1900 h). Digestibility and feed intake were analyzed utilizing the MIXED procedure of SAS with treatment and period as fixed effects and animal as a random effect. There were no differences (P ≥ 0.14) in DM, organic matter (OM), neutral detergent fiber (NDF), starch and nitrogen (N) intakes among treatments. Fecal DM, OM, NDF, starch, and N output resulted in no treatment effects (P ≥ 0.24). Subsequently, total tract apparent digestibility differences (P ≥ 0.32) were not detected for DM, OM, NDF, and starch content. However, N total tract apparent digestibility was significantly different (P &amp;lt; 0.03) with TSBM0 resulting in less N digestibility than TSBM12 (65.54% and 71.59%, respectively). Replacing a portion of DDGS with TSBM does not result in deleterious digestive effects in forage-based growing diets. As a result, the utilization of DDGS or TSBM as the primary protein source will depend on growth performance, feedstuff availability and economics.

94 Effects of orally administered Megasphaera elsdenii during finishing diet realimentation on feedlot steer fecal consistency, clinical depression, and rumination

Abstract The objective of the study was to determine the effects of oral administration of Megasphaera elsdenii NCIMB 41125 (ME) during finishing diet realimentation on fecal consistency, clinical depression, and rumination of feedlot steers. Steers [n = 60; initial body weight (BW) = 591 kg ± 38 kg] were assigned to microbial supplement treatment in a randomized complete block design. Treatments were 1) no ME (CON); and 2) orally administered microbial supplement (1 x 1010 colony forming units ME/capsule; LP) immediately before diet reintroduction. Preceding study initiation, steers consumed a finishing diet with 88% concentrate [dry matter (DM) basis] primarily consisting of whole shelled corn and corn silage for 200 d. Steers were transported from a local feedyard 27 km and upon arrival offered ad libitum long stem hay. Forty-eight h after arrival, steers were reintroduced to a 90% concentrate (DM basis) finishing diet with consisting of dry-rolled corn, dried distiller’s grains plus solubles, liquid supplement, and wheat hay. The diet was introduced initially at 1.5% BW on 0 d, and daily delivery was increased until cattle reached their intake plateau at which point a slick bunk management system was employed. At initial processing, all steers received respiratory and clostridial vaccines and were fitted with wireless rumination tags to track daily rumination throughout the 42-d study. Fecal consistency (FCS) and clinical depression scores (CD) were collected starting 24 h after diet initiation, and subsequent collections occurred at 24 h intervals until 168 h. Fecal consistency was recorded on 20 random pen surface fecal samples and CD was recorded for individual steer. Categorical distributions for FCS and CD were analyzed with the Fisher’s Exact Test. Rumination data was analyzed as a linear mixed model with fixed effects of treatment, days on feed (DOF), and their interaction with a random effect of block and DOF as a repeated measure. For all analyses, P ≤ 0.05 was declared significant and 0.05 &amp;gt; P ≤ 0.10 was considered a tendency. No difference (P ≥ 0.49) was observed for CD at all time points. Additionally, no difference (P ≥ 0.12) was observed for FCS at 24, 48, 72, 120, 144, and 168 h. Fecal consistency tended (P = 0.10) to differ at 96 h, with CON exhibiting a 67% decrease in FCS 1 and 2. No significant (P ≥ 0.78) treatment × DOF interaction was noted for daily minutes ruminating. A significant (P &amp;lt; 0.01) DOF effect was realized for daily minutes ruminating. Minutes ruminating differed (P &amp;lt; 0.01) between treatments, with CON steers ruminating 6% more minutes daily than LP steers. Oral administration of ME had minimal effects on FCS and CD and decreased daily rumination time in feedlot steers during finishing diet realimentation.