NDF Disappearance Research Articles

Effects of Different Essential Oil Blends and Fumaric Acid on In Vitro Fermentation, Greenhouse Gases, Nutrient Degradability, and Total and Molar Proportions of Volatile Fatty Acid Production in a Total Mixed Ration for Dairy Cattle

The present study evaluated the inclusion of fumaric acid and essential oil blends (EOBs) containing anise, cedarwood, clove, cumin, eucalyptus, garlic, ginger, lavender, lemongrass, nutmeg, oregano, and peppermint at different proportions on in vitro dry matter (DM) disappearance (DMD), fiber fraction disappearance, the efficiency of microbial production, and the total volatile fatty acids (VFAs). Ten treatments without (control treatment) or with different EOB/fumaric combinations were used in the study with eight replicates. The EOB inclusion level was 200 μL/g of feed (total mixed ration, (TMR)) while fumaric acid was administered at 3% of the TMR (DM basis). The highest DMD, in vitro true degradable DM, partitioning factor (PF24), and in vitro apparent degradable DM were recorded for the fumaric only treatment and the control. Neutral detergent fiber disappearance was reduced with the inclusion of EOB/fumaric combinations. The production of microbial mass and undegraded DM were higher (p < 0.001) for all EOBs and EOB and fumaric treatments. The inclusion of EOB and fumaric combinations reduced (p < 0.001) the total gas production, methane, and ammonia, with a higher PF24 value noted for EOB3 treatment. The inclusion of individual EOB1 containing garlic, lemongrass, cumin, lavender, and nutmeg in a ratio of 4:2:2:1:1 or combined with fumaric acid yielded the highest propionate concentration across all treatments. We concluded that EOBs decreased methane production and nutrient degradability with better results with the individual EOB1 or EOB1/fumaric combination, which showed a potential enhancement in energy production.

Effects of yeast culture and oxalic acid supplementation on in vitro nutrient disappearance, rumen fermentation, and bacterial community composition.

Hemicellulose is an important polysaccharide in ruminant nutrition, but it has not been studied as thoroughly as cellulose. Further research is needed to explore supplements that can improve its digestibility and ruminal buffering effects. Our previous research demonstrated the efficacy of oxalic acid (OA) as an essential nutrient in yeast culture (YC) for improving rumen fermentation performance. Consequently, we conducted in vitro rumen digestion experiments to examine the effects of YC and OA on rumen fermentation and bacterial composition. Two diets containing different levels of hemicellulose were formulated: diet 1 with 10.3% and diet 2 with 17% hemicellulose. Three levels of YC (0.00, 0.625, and 1.25 g/kg) and three doses of OA (0.0, 0.4, and 0.8 g/kg, DM) were added into each diet with a 3 × 3 factorial design. A comprehensive assessment was conducted on a total of 18 experimental treatments at fermentation periods of 0, 6, 12, 24, and 48 h. In the first experiment (diet 1), the supplementation of YC, OA, and their interaction significantly increased in vitro DM disappearance (IVDMD) and NDF disappearance (IVNDFD; p < 0.001). In the second experiment (diet 2), the supplementation of OA and the interaction between YC and OA (p < 0.001) increased IVDMD and IVCPD, but had no significant effects on IVNDFD. The interactions of YC and OA significantly increased ammonia nitrogen (p < 0.001). The production of acetic acid, propionic acid, and total volatile fatty acids (TVFA), and pH levels were significantly higher in treatments supplemented with YC and OA (p < 0.001). YC and OA in both diets significantly altered the rumen bacterial community leading to increased Shannon and Simpson diversity indices (p < 0.001). In both diets, OA supplementation significantly increased the relative abundance of the phylum Bacteroidetes and Prevotella genus. The result also showed a positive correlation between the Prevotella and Selenomonas genera with IVDMD, IVNDFD, propionic acid, and TVFA production, suggesting that these dominant bacteria enhanced nutrient disappearance in the rumen. In conclusion, adding YC and OA resulted in modifications to the bacterial community's composition and diversity, and improved nutrient disappearance. These changes indicate improved rumen fermentation efficiency, which is promising for future in vivo studies.

PSX-11 Effect of Preservation Method on Nutritive Value of Kudzu Forage

Abstract “The vine that ate the South,” also known as kudzu (Pueraria montana [Lour.] Merr.) is a drought-tolerant perennial leguminous vine that was introduced from Asia to the United States as an ornamental crop. It was quickly recognized and favored as a solution to soil erosion during the Dust Bowl. However, due to its ability to quickly overtake existing vegetation, it was ultimately labeled as an invasive species by the USDA. Given current sustainability efforts, interest has renewed in ways to incorporate this invasive species for productive agricultural purposes. The goal of this study was to investigate how preservation (i.e., haying) would affect the nutritive value and digestibility of kudzu forage. Kudzu was harvested from a private property in Auburn, Alabama. Two independent plots on the property were utilized; half of thefresh biomass was immediately removed, and the remaining half was removed at 20% moisturefor the sun-cured sample. Samples were collected from each plot and assayed for NDF, ADF, ADL, and CP. Samples were also assayed for in vitro true and NDF disappearance (IVTD and IVNDFD, respectively) as well as in situ ruminal disappearance. Data were analyzed using SAS v. 9.4. There was no effect of preservation on NDF, ADF, ADL, and CP concentrations (P ≥0.39). However, kudzu samples subjected to sun-curing had greater IVTD (64.3%, P &amp;lt; 0.01) and IVTDOM (63.0%; P &amp;lt; 0.01) and tended to have greater IVNDFD (35.6%; P = 0.06) thanfresh kudzu (59.4, 57.8, and 31.3%, respectively). There was no effect (P ≥ 0.12) of preservation on the potentially degradable fraction, lag time, or rate of digestion of kudzu samples. However, fresh samples had a greater (P &amp;lt; 0.01) undegradable residue than did sun-cured samples (49.3 vs.38.8%). The improvements in digestibility are interpreted to mean that preservation methods, such as sun-curing, may be valuable for increasing the value of kudzu as a roughage source for ruminant livestock production systems.

PSI-A-4 The Effects of a Novel Brewer’s Yeast Product on Ruminal Fiber Fermentation in Vitro

Abstract The objective was to evaluate a novel brewer’s yeast product on ruminal fiber fermentation in vitro. The experiment was a completely randomized design and included 4 treatments. Treatments included a negative control (NCON), a commercial brewer’s yeast product (Emprove MX; EMX), and a prototype concentrated brewer’s yeast (T1R8) fed at low and high inclusions (T1R8-L and T1R8-H, respectively). Inclusions for low and high treatments were 0.0008 and 0.0015 g, respectively, to correspond with 7 and 14 g inclusion in a lactating cow diet. Treatments were evaluated in duplicate flasks in 2 replicated runs for a total of four observations per treatment. Flasks contained 2.5 grams dry matter (DM) of substrate to represent a lactating cow diet (30% haylage, 25% corn silage, 20% corn, 15% canola meal, and 10% soybean hulls), and 150mL of rumen fluid mixture (2 McDougall’s buffer:1 rumen fluid ratio). Four F57 sealed Ankom bags were filled with 0.25 grams DM of substrate each to facilitate measuring in vitro DM and neutral detergent fiber disappearance (IVDMD and IVNDFD, respectively). Flasks were incubated at 39°C for 30 hours with sample aliquots collected at hour 0, 8, 16, and 30 to determine pH and volatile fatty acids (VFA). Data were analyzed using the MIXED procedure of SAS 9.4 with IVDMD and IVNDFD considered a main effect of treatment while pH and VFA were analyzed with effects of treatment, time, and their interaction. No differences in IVDMD were observed (P = 0.31) among treatments. Treatment affected (P = 0.01) IVNDFD with EMX (50.6%), T1R8-L (48.6%), and T1R8-H (50.3%) being greater than NCON (45.7%). A treatment by hour interaction (P &amp;lt; 0.01) was observed for total VFA concentration; EMX (71.8 mM), T1R8-L (72.6 mM), and T1R8-H (66.0 mM) were greater than NCON (47.8 mM) at h 8, but all treatments were not different at h 16. A treatment by hour interaction (P &amp;lt; 0.01) was also observed for acetate and propionate; EMX, T1R8-H, and T1R8-L were greater than NCON at h 8, but all treatments were not different at h 16. At h 30, greater propionate was observed for T1R8-H compared with all treatments. No effects of treatment or treatment by hour (P ≥ 0.89) were observed for acetate:propionate ratio. Although a treatment by hour interaction was not observed for pH (P = 0.12), a treatment effect (P = 0.03) indicated T1R8-L was the greatest with EMX being intermediate, and NCON and T1R8-H being the least. Novel brewer’s yeast product T1R8 increased the rate of substrate fermentation in the initial 8 h and increased the extent of fiber degradation after a 30 h in vitro fermentation.

The Effects of Olive Cake Supplementation on Feedlot Performance and Longissimus Muscle Fatty Acid Composition of American Wagyu Steers and In Vitro Rumen Fermentation Characteristics

Wagyu cattle are well known for their greater intramuscular fat content which improves eating quality for consumers. These experiments were designed to investigate the impact of olive cake supplementation on Wagyu steer growth performance, longissimus muscle fatty acid composition, and in vitro rumen fermentation characteristics. We hypothesized that feeding with olive cake would improve animal performance and increase oleic acid (C18:1cis9) composition in the longissimus muscle. Experiment 1: Eighty-three American Wagyu steers (725 ± 10.7 kg) were used in this experiment. Steers were blocked by initial body weight (BW) and randomly assigned within blocks to one of two treatments. Treatments consisted of (1) control (basal ration with no olive cake) or (2) control diet + 5% supplemental olive. Steers were housed in feedlot pens (n = 4 steers/pen; 11 replicates/treatment) and fed a finishing diet typical for Wagyu cattle. Steers were individually weighed every 28 d throughout the 177 d experiment. Longissimus muscle samples were obtained for fatty acid analysis at the time of slaughter. Experiment 2: Rumen fluid from three beef steers (480 ± 10 kg) fitted with rumen canulae was used to investigate the impact of olive cake on in vitro rumen fermentation characteristics. Treatments consisted of (1) control (no olive cake) or (2) 5% olive cake. Results: Experiment 1: Steers receiving olive cake had a lower (p &lt; 0.05) final BW and DM intake when compared to steers receiving the control diet. Longissimus muscle C18:2 and C22:6 n-3 were greater (p &lt; 0.05) and C18:1cis9 tended (p &lt; 0.06) to be greater in steers receiving olive cake when compared to controls. Experiment 2: Dry matter, acid detergent fiber, and neutral detergent fiber disappearance and molar proportions of short chain fatty acids were similar across treatments. The weight percentage of C14:1 was greater in in vitro rumen fluid fermented with olive cake when compared to controls. All other long chain fatty acids were similar across treatments. Under the conditions of this experiment, feeding olive cake at 5% of the diet DM reduced live animal performance and had minimal impacts on longissimus muscle fatty acid composition and in vitro rumen fermentation characteristics.

Impact of adding tannins or medium-chain fatty acids in a dairy cow diet on variables of in vitro fermentation using a rumen simulation technique (RUSITEC) system

This work aimed to evaluate the effect of including 2 functional feed ingredients in a diet with a high proportion of pasture silage on in vitro ruminal fermentation, nutrient disappearances, and ruminal microbiomes. In a rumen simulation technique (RUSITEC) system (6 fermentation units), 4 treatments were evaluated: 1) CONTROL: a diet based on corn and grass silage, regular soybean meal (SBM), and corn; 178 g/kg of crude protein (CP) (used as negative control), 2) TSBM: Replacement of SBM by Mervobest® (used as positive control), 3) PHY (phytogenic mixture (tannins from quebracho and chestnut) at 10 g/kg dry matter (DM) replacing SBM) and 4) MCFA (mixture of medium-chain fatty acids, Aromabiotic Cattle® at 10 g/kg DM replacing SBM). Four runs were performed with 3 diets incubated simultaneously in duplicate using a balanced incomplete block design, lasting 17 days each. The inoculum was obtained from 3 rumen fistulated cows, and artificial saliva was infused at 650 mL/day. Samples were taken from each fermentation unit to determine the gas production, pH, NH3-N, and volatile fatty acids concentrations. The apparent digestibility of diet compounds was determined. Microbial protein synthesis and microbial community diversity were estimated using 15N as an external isotopic marker and by sequencing part of the 16 S rDNA gene, respectively. The TSBM and PHY treatments decreased NH3-N concentrations (P < 0.001) and the DM disappearance (P = 0.004). The crude protein disappearance was the lowest for TSBM followed by PHY (P < 0.001). The true protein disappearance was lower for TSBM and PHY than for CONTROL and MCFA (P < 0.001). The isovaleric acid proportion was lower for TSBM, MCFA, and PHY than for CONTROL. Treatments TSBM and MCFA registered lower neutral detergent fibre disappearance (P < 0.001) than the other diets but without changes in the quantified fibrolytic genera in the ruminal microbiota. The PHY treatment increased the relative abundance of Succinivibrio spp. and reduced that of Methanobrevibacter relative to that of CONTROL and TSBM, which could be linked to lower methanogenesis. The MCFA treatment increased Succinivibrio compared with TSBM and Succiniclasticum spp. compared with CONTROL. These results indicate that PHY inclusion at 10 g/kg DM decreased rumen protein degradation, similar to TSBM; while MCFA decreased rumen protein degradation to a lesser extent. Furthermore, both additives generated changes in the ruminal microbiota that would be associated with lower methane production.

Comparison of in situ ruminal straw fiber degradation and bacterial community between buffalo and Holstein fed with high-roughage diet.

Buffalo exhibits great efficiency in utilizing low-quality roughage, which can be due to the combined effect of host physiological feature and roughage diet fed. The present study was designed to compare the ruminal fiber degradation and the bacterial community attached to straws in buffalo and Holstein when fed with the same high-roughage diet using in situ ruminal incubation technique. Rice and wheat straws were selected as the incubation substrates and sampled at 0, 4, 12, 24, 48, 72, 120, and 216 h of incubation time to measure the kinetics of dry matter (DM) and neutral detergent fiber (NDF) disappearance. Additional two bags were incubated and sampled at 4 and 48 h of incubation time to evaluate the bacterial community attached to straws. The results showed that buffalo exhibited a greater (p ≤ 0.05) fraction of rapidly soluble and washout nutrients and effective ruminal disappearance for both DM and NDF of straw than Holstein, together with a greater (p ≤ 0.05) disappearance rate of potentially degradable nutrient fraction for NDF. Principal coordinate analysis indicated that both host and incubation time altered the bacterial communities attached to straws. Buffalo exhibited greater (p ≤ 0.05) 16S rRNA gene copies of bacteria and greater (p ≤ 0.05) relative abundance of Ruminococcus attached to straw than Holstein. Prolonging incubation time increased (p ≤ 0.05) the 16S rRNA gene copies of bacteria, and the relative abundance of phyla Proteobacteria and Fibrobacters by comparing 4 vs. 48 h of incubation time. In summary, buffalo exhibits greater ruminal fiber degradation than Holstein through increasing bacterial population and enriching Ruminococcus, while prolonging incubation time facilitates fiber degradation through enriching phyla Proteobacteria and Fibrobacteres.

Evaluation of a Bacillus-based direct-fed microbial probiotic on in vitro rumen gas production and nutrient digestibility of different feedstuffs and total mixed rations.

We evaluated the effects of a Bacillus-based direct-fed microbial (DFM) on total in vitro gas production, dry matter (DM), neutral detergent fiber (NDF), and starch disappearance of different feedstuffs and total mixed rations (TMR) in three different experiments. In experiment 1, six single fiber-based feedstuffs were evaluated: alfalfa hay, buffalo grass, beet pulp, eragrostis hay, oat hay, and smutsvinger grass. Experimental treatments were control (with no probiotic inoculation; CON) or incubation of a probiotic mixture containing Bacillus licheniformis and B. subtilis (3.2 × 109 CFU/g; DFM). The calculation of DFM dose under in vitro conditions was based on the assumption of a rumen capacity of 70 liter and the dose of 3 g of the DFM mixture/head/d (9.6 × 109 CFU). Total in vitro gas production, DM, and NDF disappearance were evaluated at 24- and 48 h posttreatment incubation. Mean treatment effects were observed at 24- and 48 h gas production (P < 0.0001), as DFM incubation increased in vitro gas production by 5.0% and 6.5%, respectively. For nutrient digestibility, mean DM digestibility was increased at 48 h (P = 0.05), whereas mean NDF digestibility increased at both timepoints by incubating DFM in vitro (P ≤ 0.02). In experiment 2, nine commercial dairy TMR were collected and evaluated for the same variables and treatments described in experiment 1, with the additional analysis of starch digestibility at 7 h post in vitro incubation. The only difference was the concentration of the DFM included, being representative for a dosage of 8.8 × 109 CFU/head/d. In vitro gas production was increased only at 48 h due to DFM incubation (P = 0.05), whereas DM and NDF digestibility were improved at 24 and 48 h (P ≤ 0.02). No treatment effects were observed on in vitro starch digestibility (P = 0.31). In experiment 3, a combined analysis of DM and NDF digestibility was performed by using quality values (NDF and crude protein or CP) of 16 substrates. Regardless of CP and NDF levels of the substrates, DFM improved in vitro 24 and 48 h DM and NDF digestibility (P ≤ 0.03). In summary, incubating a Bacillus-based DFM (B. licheniformis and B. subtilis; BOVACILLUS) improved mean in vitro gas production, DM, and NDF digestibility of single feedstuffs and commercial dairy TMR, highlighting the potential of this combination of Bacillus spp. to improve nutrient utilization, mainly fiber.

Effects of supplementing a yeast culture in a pelleted total mixed ration on fiber degradation, fermentation parameters, and the bacterial community in the rumen of sheep

Feeding animals with pelleted total mixed ration (TMR) is a widespread practice as it reduces feed losses during storage, feeding and the animal’s sorting. Supplementation of yeast culture can promote rumen fiber degradation, which may occur through stabilizing rumen pH. There are few studies, however, evaluating the optimal supplementation level of yeast culture in pelleted TMR in which rumen pH has been continuously measured. This study aimed to determine the optimal level of a commercial yeast culture product (of which the number of viable CFU was not measured) mixed and pelleted with the TMR, on fiber degradation in situ, rumen pH dynamics, rumen fermentation variables, and the bacterial community composition of rumen fluid. Under a partial Latin square design, a total of twelve wethers equipped with permanent rumen fistulas were randomly assigned to four treatments of yeast culture at 0, 0.5, 1.0, or 2.0% dietary dry matter. After a 28 d period comprising 21 d for adaptation and 7 d for measurements, each group of three wethers was randomly reassigned to another treatment. Thus, each yeast supplementation level was fed to a total of six animals. In situ dry matter (DMD) and neutral detergent fiber (NDFD) disappearance of corn stover, mean rumen pH, total volatile fatty acids concentration, acetate, propionate, and n-butyrate molar percentages, and the acetate to propionate ratio were influenced (P ≤ 0.05) by dietary treatments. Quadratic (P ≤ 0.03) responses to increasing yeast culture supplementation level were observed for mean rumen pH, daily duration of pH below a 5.8 threshold considered inhibitory for fibrolysis, and the molar percentages of propionate, n-butyrate, and the acetate to propionate ratio. The highest in situ DMD and NDFD occurred when yeast was supplemented at 1%. Increasing yeast culture supplementation level tended to quadratically increase the abundance of fibrolytic bacterial genera NK4A214 and FD2005, which peaked at 1% yeast culture in the diet DM. The molar percentage of n-butyrate was positively correlated with the relative abundance of Rikenellaceae_RC9 and NK4A214. In our study, supplementation of pelleted TMR with 1% yeast culture provided as residual yeast medium components, was optimal for fiber degradation of forage fed to ruminants. Members of genera NK4A214 and FD2005 may contribute extra n-butyrate.

PS-5 In Vitro NDF Digestibility and In Vitro Dry Matter Digestibility and Disappearance Are Similar Between Beef Heifers Differing in Feed Efficiency

Abstract Feed efficiency is a critical component of improving beef production. Previous research has indicated that differences among lowly and highly feed efficient animals may be the result of differences in digestibility through the gastrointestinal tract. The objective of this study was to evaluate differences in neutral detergent fiber (NDF) and in vitro dry matter digestibility (IVDMD) in the rumen and cecum over time. To determine feed efficient animals to utilize, 134 yearling heifers were individually fed ad libitum for 84 days using a Calan Broadbent Feeding system (Northwood, NH, USA). Heifers were fed a total mixed ration containing 86% ground brome hay, 10% wet distillers grains with solubles, and 4% mineral supplement. Heifers were stratified by body weight and at the end of the feeding period, and sixteen heifers with the least and greatest average daily gain (ADG) were chosen for sampling. Low ADG heifers (n = 8) gained 0.5 ± 0.6 kg/d and high ADG heifers (n = 8) gained 0.85 ± 1.0 kg/d. Rumen content and cecal content were collected from heifers and incubated to determine in vitro NDF and IVDMD over 0, 6, 12, 24, 36, and 48 hours. Samples were incubated in triplicate in individual conicals utilizing the Tilly and Terry method. After incubation, samples were freeze-dried. After freeze-drying, 0.3g of sample was added to F57 fiber bags for determination of NDF disappearance using the ANKOM 200 fiber analysis system. Samples were grouped by site and time of incubation to avoid errors between samples. Data were analyzed using the MIXED procedure of SAS, with fixed effects of treatment (efficiency), collection site (rumen or cecum), incubation time, and interactions. Significance was determined at P ≤ 0.05 and tendencies at 0.05 ≤ P ≤ 0.10. There was a significant effect of site (P &amp;lt; 0.0001), and incubation time (P &amp;lt; 0.0001), as well as a site × incubation interaction (P = 0.01) for NDF disappearance. Treatment did not impact NDF disappearance (P = 0.53), and site × treatment was not significant (P = 0.26), however a tendency for a treatment × incubation time was observed (P = 0.08). In vitro dry matter digestibility was significantly affected by time of incubation (P &amp;lt; 0.0001), site × incubation (P = 0.01), and site × treatment (P = 0.03). Treatment did not affect IVDMD (P = 0.87), nor did site of sampling site (P = 0.64), and a treatment × incubation effect was not observed (P = 0.14). In conclusion, the efficiency of cattle was determined to not play a role in NDF disappearance or in vitro dry matter digestibility. These data indicate that additional factors, including forage type, microbial communities, and host genetics, play a larger role in influencing differences in forage digestibility.

Effect of Dietary Rumen-Degradable Starch to Rumen-Degradable Protein Ratio on In Vitro Rumen Fermentation Characteristics and Microbial Protein Synthesis.

Simple SummarySynchronizing the energy and nitrogen supply in the rumen was reported to improve feed efficiency; however, synchronization indicators were rarely reported. The present study was conducted using a batch culture technique to evaluate the optimal rumen-degradable starch (RDS) and rumen-degradable protein (RDP) ratio (SPR) for synchronizing the energy and nitrogen supply for dairy cows. The in vitro disappearance of dry matter and neutral and acid detergent fiber, gas production and microbial crude protein synthesis quadratically increased with increasing the SPR and peaked at 2.3. Although an in vivo study could be further needed, our results provided an optimal SPR range for dairy cows to synchronize the energy and nitrogen supply.The objective of this study was to investigate the effects of dietary rumen-degradable starch (RDS, g/kg of DM) to rumen-degradable protein (RDP, g/kg of DM) ratios (SPR) on in vitro rumen fermentation characteristics and microbial protein synthesis (MCPS). Treatments were eight diets with SPR of 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 and 2.6 and were formulated to be isoenergetic, isonitrogenous, and isostarch. Substrates were anaerobically incubated in sealed culture vials (100 mL) for 6, 24 or 48 h. Three incubation runs were conducted within two consecutive weeks. With the increase of the dietary SPR, the gas production (GP), in vitro dry matter disappearance (IVDMD) and concentration of MCPS and total volatile fatty acids (TVFA) linearly increased after 6 h of incubation (p ≤ 0.01), whereas they quadratically increased and peaked at the SPR of 2.3 after 24 and 48 h of incubation (p < 0.05). In response to dietary SPR increasing, the in vitro neutral detergent fiber disappearance (IVNDFD) quadratically increased (p < 0.01), and the ammonia nitrogen (NH3-N) concentration linearly decreased (p < 0.01) after 6, 24 and 48 h of incubation. Based on the presented results, an SPR of 2.3 is recommended for formulating a diet due to its greatest IVDMD, IVNDFD, GP, TVFA and MCPS. However, as the results obtained are strictly dependent on the in vitro conditions, further in vivo studies are needed to verify our findings.

Effect of ergot alkaloids and a mycotoxin deactivating product on in vitro ruminal fermentation using the Rumen simulation technique (RUSITEC).

The rumen simulation technique (RUSITEC) was used to investigate the effect of ergot alkaloids (EA) and a mycotoxin deactivating product (Biomin AA; MDP) on nutrient digestion, ruminal fermentation parameters, total gas, methane, and microbial nitrogen production. Ruminal fermentation vessels received a feedlot finishing diet of 90:10 concentrate:barley silage (DM basis). Using a randomized complete block design, treatments were assigned (n = 4 vessels/treatment) within two RUSITEC apparatuses in a 2 × 2 factorial arrangement. Treatments included: (1) control (CON) diet (no EA and no MDP); (2) CON diet + 1 g/d MDP; (3) CON diet + 20 mg/kg EA; and (4) CON diet + 20 mg/kg EA + 1 g/d MDP. The study was conducted over 14 d with 7 d of adaptation and 7 d of sample collection. Data were analyzed in SAS using PROC MIXED including fixed effects of EA, MDP, and the EA×MDP interaction. Random effects included RUSITEC apparatus and cow rumen inoculum (n = 4). Ergot alkaloids decreased dry matter (DMD) (P = 0.01; 87.9 vs. 87.2%) and organic matter disappearance (OMD) (P = 0.02; 88.8 vs. 88.4%). Inclusion of MDP increased OMD (P = 0.01; 88.3 vs. 88.9%). Neutral detergent fiber disappearance (NDFD) was improved with MDP; however, an EA×MDP interaction was observed with MDP increasing (P < 0.001) NDFD more with EA diet compared to CON. Acetate proportion decreased (P = 0.01) and isovalerate increased (P = 0.03) with EA. Consequently, acetate:propionate was reduced (P = 0.03) with EA. Inclusion of MDP increased total volatile fatty acid (VFA) production (P < 0.001), and proportions of acetate (P = 0.03) and propionate (P = 0.03), and decreased valerate (P < 0.001), isovalerate (P = 0.04), and caproate (P = 0.002). Treatments did not affect (P ≥ 0.17) ammonia, total gas, or methane production (mg/d or mg/g of organic matter fermented). The inclusion of MDP reduced (P < 0.001) microbial nitrogen (MN) production in the effluent and increased (P = 0.01) feed particle-bound MN. Consequently, total MN decreased (P = 0.001) with MDP. In all treatments, the dominant microbial phyla were Firmicutes, Bacteroidota, and Proteobacteria, and the major microbial genus was Prevotella. Inclusion of MDP further increased the abundance of Bacteroidota (P = 0.04) as it increased both Prevotella (P = 0.04) and Prevotellaceae_UCG-003 (P = 0.001). In conclusion, EA reduced OMD and acetate production due to impaired rumen function, these responses were successfully reversed by the addition of MDP.

195 Interaction of Urea with Frequency and Amount of Distillers Grains Supplementation for Growing Steers on a High Forage Diet

Abstract Two studies determined the interactions of urea inclusion to a dried distillers grains plus solubles (DDGS; 29.4% CP, 5.48% ether extract) supplement fed at 2 amounts and 2 frequencies to steers consuming ad libitum Smooth Bromegrass hay (6.8% CP). In Exp. 1, 120 (247 kg; SD = 20) steers were fed individually for 84 d with treatments arranged in a 2 x 2 x 2 factorial. Supplement was fed every day (D) or 3x/week (ALT), amount of supplement fed was 6.36 kg/week (LO) or 12.73 kg/week (HI) and contained either no urea (-U) or 1.3% urea (+U). In Exp. 2, 8 ruminally cannulated steers (310 kg; SD = 25) were used in an 8 x 6 row-column design with 8 steers and 6, 14-d periods. Treatment design was the same as Exp. 1, except that supplement was fed at a rate of 0.4% (LO) or 0.8% of BW (HI) and supplement was fed either daily (D) or every other day (ALT). In Exp. 1, ADG was 0.30 kg/d greater, and hay DMI was reduced by 0.39 kg/d for HI vs. LO (P &amp;lt; 0.01). Hay DMI was reduced by 0.54 kg/d for ALT vs. D (P &amp;lt; 0.01). In Exp. 2, hay DMI was also reduced HI vs. LO (P &amp;lt; 0.01). Rumen pH was decreased on the day of feeding for steers on ALT (P &amp;lt; 0.01) and was reduced for steers fed HI vs. LO. A reduction in in situ NDF disappearance was observed on the day ALT received supplement between HI and LO (P &amp;lt; 0.01). However, there was no difference between NDF digestibility between D and ALT (P &amp;gt; 0.05). Urea had no effect on digestion or ADG, suggesting RDP was not deficient. Dried distillers grains can be supplemented infrequently without reducing animal performance.

Monensin and concentrate supplementation level affect forage ruminal measurements and forage in situ disappearance of bermudagrass fed to beef cattle

The objective of this study was to evaluate the effects of monensin and concentrate supplementation levels on bermudagrass (Cynodon dactylon) in situ disappearance and ruminal measurements. The experiment was conducted in Ona, Florida, and treatments were the factorial arrangement of 2 supplementation levels [0.4 (low) or 4 kg/d (high)] and 2 monensin levels (0 or 20 mg/kg of the DMI) distributed in a Latin square design. The supplement was 17.1% CP and 79.1% TDN. Steers receiving the higher supplementation level had greater (P = 0.01) total DMI (1.4 vs. 1.0 ± 0.1% BW), but there was no difference in forage DMI (P = 0.72, mean = 1.0 ± 0.1% BW). Monensin did not affect total DMI or forage DMI (P ≤ 0.74). There was a monensin × supplementation level interaction on ruminal propionate concentration. The interaction occurred because there was no effect (P = 0.64) of monensin with low supplementation (mean = 12 ± 1.2 mol/100 mol); however, monensin increased (P = 0.01) propionate on the high supplementation level (19 vs. 15 ± 1.5 mol/100 mol). There was no effect (P > 0.05) of monensin on potential DM, CP, and NDF disappearance; however, greater supplementation level increased (P < 0.03) potential DM and NDF disappearance. Monensin did not change forage disappearance measurements but increased ruminal propionate concentrations in steers receiving higher supplementation level. Higher supplementation level was effective to increase total DMI and forage DM and NDF disappearance.

Interaction of urea with frequency and amount of distillers grains supplementation for growing steers on a high forage diet.

Two studies were conducted to determine interactions of urea inclusion to a dried distillers grains plus solubles (DDGS; 29.4% crude protein, 5.48% ether extract) supplement fed at two amounts and two frequencies to steers on a high forage diet. In Exp. 1, 120 (247 kg; SD = 20) steers were fed individually for 84 d. Steers received ad libitum grass hay (6.8% crude protein) and one of eight treatments. Treatment design was a 2 × 2 × 2 factorial. Supplement was fed daily or three times per week, amount of supplement fed was 6.36 kg dry matter (DM)/week [0.37% body weight (BW); LO] or 12.73 kg DM/week (0.74% BW; HI) and contained either no urea or 1.3% urea on a DM basis. Steer BW was measured at the start and end of the trial and hay DM intake (DMI) was measured weekly. In Exp. 2, ruminally cannulated steers (310 kg; SD = 25) were used in a row-column design with eight steers and six 14-d periods. Treatments assigned were the same as Exp. 1, except that supplement was fed at 0.4% of BW (LO) or 0.8% of BW (HI) and supplement was fed either daily (DY) or every other day (ALT). Hay DMI, rumen ammonia-N, rumen pH, in situ neutral detergent fiber (NDF) disappearance, and rumination were measured. In Exp. 1, average daily gain (ADG) was affected by amount of supplement with steers on HI gaining 0.30 kg/d more (P < 0.01) than LO. Hay DMI was reduced by increased amount of supplement (0.39 kg/d; P < 0.01) and by decreased frequency of supplementation (0.54 kg/d; P < 0.01). In Exp. 2, hay DMI was also reduced due to increased amount of supplement and decreased frequency of supplementation (P < 0.01). Rumen pH was decreased on the day of supplement feeding for steers on ALT (P < 0.01) and reduced for steers fed HI vs. LO. There was no difference in NDF digestibility between DY and ALT (P > 0.05). For ALT steers, there was reduction (P < 0.01) in in situ NDF disappearance for the HI compared to LO amount of supplementation on the day of supplementation. Infrequent supplementation of DDGS results in no difference in ADG but decreased hay DMI compared to daily supplementation. Urea had no effect on digestion or ADG, suggesting rumen degradable protein was not deficient when supplementing DDGS. There is little change in rumen fermentation parameters between frequency of supplement feeding, indicating that forage digestion is not impacted by supplementation frequency. Dried distillers grains can be supplemented infrequently without a reduction in animal performance.

Effects of harvest date and growth stage on triticale forages in the southwest USA: kinetics of in vitro disappearance of fiber and dry matter.

Recently, there has been interest in including triticale (X Triticosecale Wittmack) within forage programs in the southwest USA. Our objectives were to evaluate in vitro disappearance kinetics of neutral detergent fiber (NDF) and dry matter (DM) for cultivars identified during 2019 as positively or negatively deviant from typical cultivars, based specifically on regressions of 48-h in vitro disappearance of NDF on growth stage (GRST). All NDF analyses included the use of heat-stable α-amylase and sodium sulfite, as well as correction for residual ash (asNDFom). Seven triticale cultivars were established on December 18, 2019 at the University of Arizona Maricopa Agricultural Center, located near Maricopa, AZ. Forage plots were arranged in a randomized complete block design with three complete blocks (replications), and then harvested on seven dates the following late-winter and spring (February 26, March 17, April 1, April 14, April 28, May 12, and May 26). Based on a linear model, GRST was highly variable among cultivars on March 17 (44 ± 10.6), April 1 (57 ± 12.1), April 14 (67 ± 8.9), and April 28 (79 ± 7.2) compared with other harvest dates (SD ≤ 1.7). For concentrations of asNDFom, all cultivars exhibited linear (P ≤ 0.042) and quadratic (P < 0.001) polynomial contrasts in response to harvest date, and all cultivars except Merlin Max (P ≥ 0.063) exhibited at least one additional cubic or quartic effect (P ≤ 0.015). A contributing factor to the unique response by Merlin Max was the numerically greater maximum canopy height (145 ± 9.8cm) compared with the mean of all cultivars (107 ± 17.7cm), which also was associated with greater percentages of stem, as well as reduced percentages of DM partitioned within the grain head. Regressions of asNDFom disappearance after 30- or 48-h incubations on GRST indicated this was an effective independent variable (R2 ≥ 0.927), and responses were most often linear in nature. Generally, relationships for DM disappearance were quadratic, ostensibly due to the complicating effect of grain fill, but GRST was again an effective predictor variable with R2 statistics ≥ 0.852 for 12 of 14 combinations of cultivar and incubation time. Predicted percentages of digestible DM attributed to asNDFom disappearance were ≥50.3% through the fully flowered stage of growth, but digestible contributions from nonfiber components following the onset of grain fill profoundly affected overall DM digestibility among cultivars harvested at later GRST.

Efeitos de antibióticos promotores de crescimento e do concentrado sobre o consumo, digestibilidade, degradabilidade e variáveis ruminais de novilhos de corte

ABSTRACT The objective of this study was to evaluate the addition of antibiotic growth promoters to concentrate on intake, digestibility, in situ degradability and ruminal variables in steers. Four steers in a Latin square design were fed hay (ad libitum), concentrate [10g kg-1 of body weight (BW)] and mineral mix (0.272g kg-1 of BW). The additives (0.75mg kg-1 of BW) were incorporated in the mineral mix as follows: Control (no antibiotics), lasalocid (LASA), salinomycin (SALI) or virginiamycin (VIRG). Antibiotic did not affect intake, pH, volatile fatty acids (VFA) and digestibility of dry matter (DM), organic matter, crude protein, ethereal extract, and non-fibrous carbohydrates. The LASA and SALI tended (P=0.09) to reduce the digestibility of neutral detergent fiber (NDF). The SALI and VIRG tended (P=0.09) to reduce the DM disappearance, and VIRG tended (P=0.06) to reduce the NDF disappearance in the rumen. The SALI and VIRG reduced the effective degradation and only SALI reduced the concentration of N-NH3 in the rumen. Thus, the antibiotics did not affect intake, pH, VFA and digestibility, but decreased the degradation of fiber and only SALI reduced the concentration of ammonia nitrogen (N-NH3) in the rumen.

Quality of Chopped Maize Can Be Improved by Processing

The aim of this study was to assess the effect of different maize processing technologies, comparing treatments with conventional rollers (control), MCC MAX rollers and a Shredlage crop processor on the quality of chopped maize. All the three types of chopped maize were harvested on the same day from the same field where the same maize hybrid was grown. The chemical composition of chopped maize, degree of grain processing and particle size fractions, and the effect of the treatments on rumen disappearance of dry matter, organic matter, NDF and starch were assessed. The highest degree of grain processing was achieved with the Shredlage processor (79.2%), and at the same time this processing method had a tendency to produce the highest proportion of physically effective fibre (37.2%). Compared to the conventional rollers (control), the chopped maize produced using the Shredlage processor had higher disappearance of dry matter, organic matter and NDF after 48 h of rumen incubation and of starch after 24 h of incubation. The MCC MAX rollers provided higher disappearance of all nutrients compared to the control treatment after both 24 and 48 h of incubation.

Offering soybean molasses adsorbed to agricultural by-products improved lactation performance through modulating plasma metabolic enzyme pool of lactating cows.

BackgroundAgricultural by‐products, such as corncob powder (CRP), wheat bran (WB), rice husk (RH), defatted bran (DB), and soybean hulls (SH), were widely used as ruminant feed. However, the combination effect of soybean molasses mixed with agricultural by‐products on cow lactating performance remains poorly understood.Methods In vitro fermentation simulation technique was used to select the high ruminal fermentation performance of agricultural by‐products mixed with soybean molasses. The selected mixtures were conducted to further explore the feeding effect on milk performance and blood metabolic enzyme on lactating dairy cows.ResultsIn in vitro simulation, it was confirmed that SH‐SM showed better fermentation performance (including higher maximum gas production, acetate, propionate, and total VFA, but less initial fractional rate of degradation) than other four molasses‐adsorbents, while WB‐SM had the greatest DM and NDF disappearance and NH3‐N and butyrate concentrations among substrates. After the simulation selection, we performed the feed experiment with SH‐SM and WB‐SM compared to the control. For lactating performance, higher (p < .01) milk fat and total milk solid content were observed in WB‐SM, and a tendency improvement of milk protein content (p < .01) was observed in both of the cows fed with WB‐SM and SH‐SM. Among lactating periods, the blood glutamic‐pyruvic transaminase, α‐amylase, and lactate dehydrogenase which associated with amino acid metabolism and carbohydrate metabolism were improved in lactating dairy cows fed with WB‐SM and SH‐SM.ConclusionDietary agricultural by‐products (like wheat bran and soybean hulls) mixed with soybean molasses enhance the lactating performance of dairy cows by improving the host metabolism process of amino acids and carbohydrates. The mixed strategy for agricultural by‐products shows another strong evidence for the resource reuse on dairy industry and reducing the by‐product pollution.

150 Effect of Ergot Alkaloids and a Mycotoxin Deactivating Product on in vitro Rumen Fermentation Using the Rumen Simulation Technique (RUSITEC)

Abstract A rumen simulation technique (RUSITEC) investigated effects of ergot alkaloids (E) and a mycotoxin deactivating product (Biomin® AA; B) on nutrient digestion, rumen fermentation, total gas and methane emissions. Fermenters received a finishing diet of 90:10 concentrate:barley silage. Using a randomized complete block design, treatments were assigned (4 vessels/treatment) within two RUSITECs in a 2 × 2 factorial. Treatments included: 1) control diet, 2) control + 1 g B, 3) control + 20 ppm E, and 4) control + 20 ppm E + 1 g B. The study had a 14-d experimental period, with 7-d adaptation and 7-d sample collection. Data were analyzed in SAS using PROC mixed including fixed effects of E, B, and E×B interaction. Random effects included RUSITEC apparatus and cow rumen inoculum (n = 4). Ergot decreased dry matter disappearance (DMD) (P &amp;lt; 0.05; 87.9 vs. 87.2%) and organic matter disappearance (OMD) (P &amp;lt; 0.05; 88.8 vs. 88.4%). Adding B increased OMD (P &amp;lt; 0.05; 88.3 vs. 88.9%) and neutral detergent fiber disappearance (NDFD) (P &amp;lt; 0.01); however, an E×B interaction was observed for NDFD (P &amp;lt; 0.01) with B promoting greater increases with E. Ergot decreased acetate proportions (P &amp;lt; 0.01) and increased isovalerate (P &amp;lt; 0.05). Consequently, acetate:propionate was reduced (P &amp;lt; 0.05) with E. Inclusion of B increased total volatile fatty acids (P &amp;lt; 0.01), and proportions of acetate (P &amp;lt; 0.05) and propionate (P &amp;lt; 0.05), and decreased valerate (P &amp;lt; 0.01), isovalerate (P &amp;lt; 0.01), and caproate (P &amp;lt; 0.01). Treatments did not affect (P ≥ 0.17) ammonia-N, total gas, or methane production (mg/d or mg/g of OM fermented). In conclusion, E reduced OMD and acetate production, but these responses were reversed by the addition of B.