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The objective of this study was to evaluate the effects of different sources of cobalt in a lactating dairy cow diet on in vitro ruminal fermentation. All diets provided the same amount of supplemental Co (1 mg per kg of diet DM) included in a premix with a targeted inclusion level of 2.5% of diet DM. Treatments were cobalt carbonate (CON), and three alternative Co sources; alternative source 1 (AS1), alternative source 2 (AS2), and alternative source 3 (AS3). Eight dual-flow continuous culture fermenters were used in a replicated 4 × 4 Latin square. Experimental periods were 10 d (7 d adaptation and 3 d sample collection). Composite samples of daily effluents were collected and analyzed for NH3-N, lactate, and VFA concentration as well as for nutrient digestibility. Samples of ruminal content were collected from each fermenter at 0, 1, 2, 4, 6, and 8 h after feeding to determine lactate, NH3-N, and pH kinetics. All data were analyzed using PROC MIXED of SAS and the repeated variable of time was included for pH, lactate, and NH3-N. There were neither treatment effects nor interactions between treatment and time for pH, NH3-N, and lactate concentrations, indicating a similar Co kinetics across treatments. With regards to lactate pool, we did not observe treatment effects for L-lactate; however, we observed treatment effects for D-lactate and total-lactate as seen in Table 1. Analyses of total and individual VFA, N utilization, and nutrient degradation are still undergoing, hence, it is possible that Co sources have effects on ruminal fermentation.

Climate change may have an adverse effect on feed production. Hydroponic fodders produced in controlled environments are alternative feeds that may be used for dairy cattle. The objective of this study was to evaluate in-situ dry matter ruminal degradability of hydroponic fodders and corn silage. Two rumen-canulated lactating Holstein cows were used in a complete randomized block design with four treatments and 9 times (0, 2, 4, 8, 12, 24, 48, 72, and 240 h). Treatments were corn silage (CS), hydroponic sprouts of barley, wheat, and triticale. Quadruplicate samples were placed in Dacron bags (10 x 20 cm, 50 μm porosity) and incubated in the rumen. After incubation, samples were washed and dried in an air-forced oven set at 60°C for 48 h and DM recovery was weighted. Ingredients nutrient composition were CS (32.3% NDF, 8.4% CP, and 41.6% starch, 1.3% WSC; % of DM), barley (34.3% NDF, 17.1% CP, and 4.2% starch, 32.9% WSC; % of DM), wheat (23.7% NDF, 23.3% CP, and 8.5% starch, 32.7% WSC; % of DM), triticale (20.0% NDF, 16.2% CP, and 21.7% starch, 33.2% WSC; % of DM). Model included fixed effects of treatment and random effects of cow and replicate(cow). Data were analyzed using PROC MIXED of SAS. Degradation fractions were calculated based on DM disappearance. There were treatment effects (P< 0.01) on fraction A (degradable), fraction B (potentially degradable), fraction C (undegradable), effective ruminal degradability (ERD), and rate of degradation (kd: %/h). Fraction A was greater for triticale (74.1%) compared with wheat (70.2%), CS (63.1%), and barley (55.0%). Fraction B was greater for barley (28.5%) compared with CS (23.2%), wheat (19.1%), and triticale (13.9%). Fraction C was less for wheat (10.6%) than triticale (12.0%), CS (13.7%), and barley (16.4%). The ERD was greater for wheat (90.8%) compared with triticale (89.0%), CS (88.0%), and barley (85.6%). The kdfor barley (2.4%) was less than triticale (4.9%). The kdfor CS (1.8%) was less than triticale (4.9%). Overall, triticale had the greatest fraction A, barley had the greatest fraction B, and wheat had the least fraction C and the greatest ERD and kd.

The objective of this study was to investigate the immunopotential of mixed ruminal lipopolysaccharides (LPS) on cultured primary bovine ruminal epithelial cells (RECs). Primary bovine RECs were isolated from 6 yearling steers and grown in culture for 3 experiments. In Exp. 1 the objective was to determine the immunopotential of ruminal LPS, in Exp. 2 the objective was to assess tolerance to chronic LPS exposure, and the objective of Exp. 3 was to evaluate antagonistic interactions between ruminal and E.coliLPS. In exp. 1 & 2, RECs were exposed to nonpyrogenic water (CON), 20 μg/mL of E. coliLPS (E. COLI), 10 μg/mL of mixed ruminal-LPS (RUM10), 20 μg/mL of mixed ruminal-LPS (RUM20) and 40 μg/mL of mixed ruminal-LPS (RUM40) either continuously or intermittently. For the continuous exposure, RECs underwent a 6 h exposure, while for the intermittent exposure, the procedure was 1) a 12 h continuous exposure to treatments followed by LPS removal for 24 h and then another 12 h of exposure (RPT), and 2) a 12 h continuous exposure to treatments followed by LPS removal and a recovery period of 36 h (RCV). In exp 3, RECs were exposed to nonpyrogenic water (0:0), 1 μg/mL E. coliLPS (0:1), 1 μg/mL mixed ruminal-LPS:1 μg/mL E. coliLPS (1:1), 10 μg/mL mixed ruminal-LPS :1 μg/mL E. coliLPS (10:1) and 50 μg/mL mixed ruminal-LPS :1 μg/mL E. coliLPS (50:1). Each experiment was done as a complete randomized block design with 6 REC donors. The REC donor was used as a blocking factor. Each treatment had 2 technical replicates, and treatment responses for all data were analyzed with the MIXED procedure of SAS. For all exp., total RNA was extracted from RECs and real-time quantitative PCR was performed to determine the relative expression of genes for toll-like receptors (TLR2 & TLR4), proinflammatory cytokines (TNFα, IL1β, and IL6), chemokines (CXCL2 & CXCL8), growth factor-like cytokines (CSF2 & TGFβ), and a lipid mediator (PTGS2). In exp. 1, the targeted genes were upregulated in response to E. COLI (P<0.01), while all ruminal LPS treatments resulted in a lower transcript abundance (P<0.01). Regarding RPT and RCV condition, in Exp. 2, the expression of targeted genes was downregulated or not affected in response to ruminal LPS treatments. Lastly, in Exp. 3 all targeted genes resulted in decreased transcript abundance on all ruminal LPS ratios (P<0.01). Overall, our results indicate that ruminal LPS have a limited capacity to activate the TLR4/NF-κB pathway and to induce the expression of inflammatory genes.

The objective of this study was to evaluate the effects of Lactobacillus inoculants on fermentation, losses, and aerobic stability of a total mixed ration (TMR) silage. A TMR, formulated to meet the requirements of dairy cows producing 25 kg of milk/d, was applied with the following treatments prior to ensiling: 1) Control (CON), 2) Lactobacillus buchneri (105 cfu/g of fresh forage; LB), and 3) Lactobacillus plantarum (105 cfu/g of fresh forage; LP). TMR silages were ensiled for 15 and 60 d in silos equipped with an apparatus for determination of gravimetric DM, gas, and effluent losses. The experiment was performed in a complete randomized design with a 3 × 2 factorial arrangement of the treatments, with 5 replicates per treatment. Chemical changes, microbial counts, fermentation profile, and aerobic stability were measured after opening the silos. Data were submitted to ANOVA, and means were compared by Tukey and T-test and statistical significance was declared at P ≤ 0.05. After 15 d of ensiling, the inclusion of inoculant decreased NDF (P < 0.05) and butyric acid concentrations (P < 0.05) in TMR. LP had the lowest aerobic stability (P < 0.05) and the greatest loss of DM (P < 0.03). Ensiling for 60 d increased ammonia nitrogen (NH3-N), lactic acid bacteria (LAB), aerobic stability, and concentrations of lactic and acetic acid (P < 0.01) and lowered (P < 0.02) total fermentation losses compared to 15 d across all treatments. After 60 d of ensiling, LP lowered pH to the greatest extent. Treatment had no effect on concentrations of DM, CP, ADF, ash, and EE, as well as in vitro DM digestibility. In conclusion, inoculants containing LP or LB did not improve fermentation profile, did not prolong the aerobic stability, nor reduced losses. Furthermore, the 15-d ensiling period was insufficient for adequate bacterial activity.

Histone deacetylase (HDAC) inhibition attenuates inflammation in rodents and short-chain fatty acids (SCFAs) are effective HDAC inhibitors. Therefore, the objective of this study was to evaluate the role of the SCFAs sodium propionate (SP) and sodium butyrate (SB) as HDAC-dependent regulators of inflammatory gene expression in bovine mammary epithelial cells (MAC-Ts). We postulated that SP and SB would decrease inflammation in MAC-Ts by inhibiting HDAC activity and increasing histone H3 acetylation and consequently decreasing inflammatory gene expression. For this study, MAC-Ts stimulated with lipopolysaccharide (LPS) were used as a model for bovine mammary epithelial cell inflammation. MAC-Ts were cultured in a basal medium. Cell lysates were incubated with SP or SB (0 to 5 mM) for 2 h prior to HDAC substrates incubation for an additional 2 h and HDACs activity was determined. Next, cells were pretreated with SP or SB (0 to 3.0 mM) for 2 h prior to LPS (1 µg/mL) stimulation for an additional 2 h and assessed for histone H3 acetylation. Then, cells were pretreated with SP or SB (1 mM) for 24 h prior to LPS (1 µg/mL) stimulation for an additional 2 h and RNA was isolated for inflammatory gene expression evaluation by PCR array and gene validation was performed using quantitative real-time PCR. One-way ANOVA followed by Tukey post hoc analysis was conducted and statistical significance set at P< 0.05. SP and SB concentration-dependently and selectively inhibited class I HDAC activity, which differed between SCFAs, where SB inhibited (P< 0.05) HDACs 2, 3, and 8, while SP inhibited (P< 0.05) HDACs 2 and 8. Histone H3 acetylation was concentration-dependently increased by SCFAs and likewise the differential regulation of HDAC activity, SCFAs effected differently histone H3 acetylation, where SB increased (P< 0.05) H3K9/14, H3K18 and H3K27 acetylation, while SP increased (P< 0.05) H3K9/14 and H3K18 acetylation. However, SCFAs did not decrease (P> 0.05) overall inflammatory gene expression. Under our experimental conditions, findings suggest that in MAC-Ts, SCFAs regulate epigenetic markers on nucleosomal DNA in addition to regulation of inflammatory gene events independent of HDAC activity. Nevertheless, examination of SCFAs and/or HDACs inhibitors in bovine mammary gland is worth being further investigated to delineate the potential impact of HDAC inhibition and histones hyperacetylation on mammary gland tissue inflammation.

The objectives of this study were to evaluate the effect of reducing dietary CP contents on 1) total and partial nutrient digestion and nitrogen balance and 2) on microbial crude protein (MCP) synthesis and true MCP digestibility in the small intestine obtained with 15N and purine bases (PB) in beef cattle. Eight bulls (4 Nellore and 4 Crossbred Angus × Nellore) cannulated in the rumen and ileum were distributed in duplicated 4 × 4 Latin squares. The diets consisted of increasing CP contents: 100, 120, or 140 g CP/kg DM offered ad libitum, and restricted intake (RI) diet with 120 g CP/kg DM. The experiment lasted four 17-d periods, with 10 d for adaptation to diets and another 7 for data collection. Omasal digesta flow was obtained using Co-EDTA and indigestible NDF (iNDF) as markers, and to estimate ileal digesta flow only iNDF was used. From days 11 to 17 of each experimental period, ruminal infusions of Co-EDTA (5.0 g/d) and 15N (7.03 g of ammonium sulfate enriched with 10% of 15N atoms) were performed. There was no effect of CP contents (linear effect, P= 0.55 and quadratic effect, P= 0.11) on ruminal OM digestibility. Intake of CP linearly increased (P< 0.01) with greater dietary CP. The NH3-N (P< 0.01) and urinary N excretion (P< 0.01) increased in response to dietary CP, whereas retained N increased linearly (P= 0.03). Liquid-associated bacteria (LAB) in the omasum had greater N content (P< 0.05) in relation to the particle-associated bacteria (PAB). There was no difference between LAB and PAB (P= 0.12) for 15N:14N ratio. The 15N:14N ratio was greater (P< 0.01) in RI animals in relation to those fed at voluntary intake. Microbial CP had a quadratic tendency (P= 0.09) in response to CP increase. Microbial efficiency (expressed in relation to apparent ruminally degradable OM and true ruminally degradable OM) had a quadratic tendency (P= 0.07 and P= 0.08, respectively) to CP increasing and was numerically greatest at 120 g CP/kg DM. The adjusted equations for estimating true intestinal digestibility of MCP (Y1) and total CP (Y2) were, respectively, as follows: Y1=−-16.724(SEM = 40.06)+ 0.86X(SEM = 0.05)and Y2= −43.81(SEM = 49.19)+ 0.75X(SEM = 0.05). It was concluded that diets with 120 g/kg of CP optimize the microbial synthesis and efficiency and ruminal ash and protein NDF digestibility, resulting in a better use of N compounds in the rumen. The PB technique can be used as an alternative to the 15N to estimate microbial synthesis.

The objective was to evaluate the ruminal fermentation patterns of forage kochia (FK) compared with alfalfa hay (AH) and orchardgrass hay (OH) (Exp. 1), and ephedra (EPH) and immature cheatgrass (CG) compared with OH (Exp. 2), using a dual-flow continuous culture system. Two in vitro experiments were conducted, and in each experiment, treatments were randomly assigned to six dual-flow fermenters (1,223 ± 21 mL) in a replicated 3 × 3 Latin square design, with three consecutive periods of 10 d each, consisting of 7 d for diet adaptation and 3 d for sample collection. Each fermenter was fed a total of 72 g/d (DM basis) and treatments were as follows: Exp. 1: 1) 100% OH, 2) 100% AH, and 3) 100% dried FK. Exp. 2: 1) 100% OH, 2) 100% dried CG, and 3) 100% dried EPH. On day 8, 9, and 10, samples of solid and liquid effluent from each fermenter were taken for digestibility analysis, and subsamples were collected for NH3-N, VFA, and bacterial N determinations. Data were analyzed using the MIXED procedure of SAS. In Exp. 1, treatments did not affect DM, OM, and NDF digestibilities, total VFA and molar proportions of acetate, propionate, butyrate, and branched-chain VFA. True CP digestibility, ruminal NH3-N concentration, and total N, NH3-N, NAN, and dietary N flows (g/d) were greater (P< 0.05) for FK compared with the other forages. However, treatments did not affect bacterial efficiency. In Exp. 2, DM, OM, and CP digestibilities were greater (P= 0.01) for EPH, and NDF digestibility was greater (P< 0.05) for EPH and CG compared with OH. Ephedra had the highest (P< 0.05) pH and acetate:propionate ratio and the lowest (P< 0.05) total VFA concentration. Total VFA, ruminal NH3-N concentration, and NH3-N flow (g/d) were highest (P< 0.05) for CG. Total N flow and bacterial efficiency were highest (P< 0.05) for OH and CG, while the flows (g/d) of NAN, bacterial N, and dietary N were greater (P< 0.05) for OH compared with the other forages. Results indicate that when compared with AH and OH (Exp. 1), FK has similar ruminal fermentation patterns and may be an adequate alternative for beef cattle producers. Furthermore, when compared with OH (Exp. 2), immature CG may also be an adequate forage alternative. This is especially important for areas in which conventional forages may not grow well such as the U.S. arid-land. However, EPH should not be used as the sole forage due to its poor ruminal fermentation as evidenced by the lowest total VFA concentration and propionate molar proportion.

Magnesium oxide (MgO) is one of the most used Mg supplements in livestock. However, to avoid relying upon only one Mg source, it is important to have alternative Mg sources. Therefore, the objective of this study was to evaluate the effects of the interaction of two Mg sources with buffer use on the ruminal microbiota composition, ruminal fermentation, and nutrient digestibility in lactating dairy cows. Twenty lactating Holstein cows were blocked by parity and days in milk into five blocks with four cows each, in a 2 × 2 factorial design. Within blocks, cows were assigned to one of four treatments: 1) MgO; 2) MgO + Na sesquicarbonate (MgO+); 3) calcium–magnesium hydroxide (CaMgOH); 4) CaMgOH + Na sesquicarbonate (CaMgOH+). For 60 d, cows were individually fed a corn silage-based diet, and treatments were top-dressed. Ruminal fluid was collected via an orogastric tube, for analyses of the microbiota composition, volatile fatty acids (VFA), lactate, and ammonia nitrogen (NH3–N). The microbiota composition was analyzed using V4/16S rRNA gene sequencing, and taxonomy was assigned using the Silva database. Statistical analysis was carried out following the procedures of block design analysis, where block and cow were considered random variables. Effects of Mg source, buffer, and the interaction between Mg Source × Buffer were analyzed through orthogonal contrasts. There was no interaction effect of the two factors evaluated. There was a greater concentration of NH3–N, lactate, and butyrate in the ruminal fluid of cows fed with CaMg(OH)2, regardless of the buffer use. The increase in these fermentation intermediates/ end-products can be explained by an increase in abundance of micro-organisms of the genus Prevotella, Lactobacillus, and Butyrivibrio, which are micro-organisms mainly responsible for proteolysis, lactate-production, and butyrate-production in the rumen, respectively. Also, dietary buffer use did not affect the ruminal fermentation metabolites and pH; however, an improvement of the apparent total tract digestibility of dry matter (DM), organic matter (OM), neutral fiber detergent (NDF), and acid fiber detergent (ADF) were found for animals fed with dietary buffer. In summary, there was no interaction effect of buffer use and Mg source, whereas buffer improved total tract apparent digestibility of DM and OM through an increase in NDF and ADF digestibility and CaMg(OH)2increased ruminal concentration of butyrate and abundance of butyrate-producing bacteria.Magnesium oxide is the most used source of magnesium (Mg) in livestock diets; however, dairy operations can benefit from other Mg sources, such as calcium–magnesium hydroxide (CaMg(OH)2). This study demonstrated that CaMg(OH)2can improve ruminal fermentation by modulating ruminal microbiota composition, regardless of ruminal buffer use.Magnesium oxide (MgO) is extensively used as a dietary magnesium (Mg) source in dairy cow diets. However, dairy operations can benefit from other Mg sources. Thus, we evaluated the replacement of dietary MgO with calcium–magnesium hydroxide (CaMg(OH)2) in diets with and without ruminal buffer and their effects on the ruminal microbiota composition, ruminal fermentation, and nutrient digestibility in lactating dairy cows. The study used 20 lactating Holstein cows that were blocked in groups of four and randomly assigned to one of the four treatments. The ruminal content, feed, feces, and urine were collected for analysis of the microbiota composition, ruminal fermentation, nitrogen metabolism, and apparent nutrient digestibility. There was no interaction effect of dietary buffer use and Mg source, while buffer improved total tract apparent digestibility of the dry matter and fiber components; CaMg(OH)2increased the ruminal concentration of butyrate and the abundance of butyrate-producing bacteria. In summary, we conclude that using CaMg(OH)2can improve ruminal fermentation regardless of buffer use, which indicates that we can take advantage of the mineral formulation in the diet to modulate the ruminal microbiota composition.

Cereal grains are the predominant starch source (SS) for dairy cows; however, starch digestibility varies greatly depending on source, grain processing, and potentially interactions between these factors. The objective was to study the effects of the interactions between SS, and particle sizes (PS) on ruminal fermentation, nutrient flow, starch digestibility, and lactation performance of dairy cows. Four ruminally cannulated multiparous Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Two SS (corn or sorghum) used in this study were either finely or coarsely ground (using a 1- or 4-mm screen sieve). Digesta flow was quantified using the reticular sampling technique, applying the triple-marker method. Data were analyzed using the GLIMMIX procedure of SAS version 9.3 (SAS Institute Inc., Cary, NC, USA). For ruminal pH, data were analysed with time as repeated measure. There were no interactions between SS and PS on production or intake, flow, and digestibility of nutrients. Dry matter intake was greater for the corn diet compared to the sorghum diet (25.15 vs. 21.98 kg/d), which consequently affected nutrient intake, however, PS did not affect intake. Milk yield was not affected by SS; however, it was greater for cows fed fine grains than cows fed coarser grains (25.32 vs. 23.16 kg/d). Milk fat and milk protein were not affected by SS or PS. Interactions (SS × PS) were observed for ruminal pH, reticular pH, and volatile fatty acids (VFA) concentrations but not for ruminal NH3–N concentration. Ruminal and reticular pH were greater for sorghum when coarsely ground and the total VFA concentration was decreased, compared to coarse corn and fine sorghum; however, coarsely grinding corn did not affect ruminal or reticular pH nor VFA concentration. Acetate concentration was lower for corn when finely ground; however, finely grinding sorghum did not affect acetate. Decreasing PS increased ruminal digestibility of starch (87.18% vs. 83.43%), reduced the flow of starch to the reticulum (0.79 vs. 0.96 kg/d) but decreased neutral detergent fiber digestibility in the rumen (30.23% vs. 34.88%). Although SS were differently affected by processing, the effects of PS on production, intake, flow, and digestibility of nutrients were observed regardless of the SS. Furthermore, the effects of decreasing PS on pH and VFA concentrations were more pronounced in sorghum compared to corn.Decreasing grain particle size increased ruminal digestibility, reducing starch flow to the reticulum but also decreased ruminal neutral detergent fiber degradability. Reducing grain particle size improves starch utilization regardless of the starch source (sorghum or corn) for lactation dairy cows.Starch digestibility varies greatly depending on starch source (SS), grain processing, and potentially interactions between these factors. Four ruminally cannulated lactating Holstein cows were fed a total mixed ration that varied in SS and particle sizes (PS) to evaluate the interactions between SS and PS on ruminal fermentation, nutrient flow, starch digestibility, and lactation performance of dairy cows. There were no interactions between SS, and PS on production, intake, flow, and digestibility of nutrients; however, interactions were observed for ruminal pH, reticular pH, volatile fatty acids (VFA) concentrations, and in some VFA molar proportions.

Our aim was to determine whether the method used to estimate truly digestible neutral detergent fiber (tdNDF) affects calculated concentrations of total digestible nutrients (TDN1x) and net energy of lactation (NEL3x) of canola meal (CM). Samples were collected from 12 CM processing plants in Canada over 4 yr (2011 to 2014, n= 47) and analyzed for dry matter (DM), crude protein (CP), ether extract (EE), ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (ADL), and neutral detergent insoluble CP (NDICP). Ruminal in situ incubation of CM samples was performed at 0, 24, 48, 96, and 288 h to determine NDF fractions (A, B, and C), effective ruminal NDF digestibility (ERNDFD), and indigestible NDF (iNDF) of CM. Three tdNDF-estimation methods were evaluated: 1) National Research Council (NRC) = 0.75 × (NDF − NDICP − ADL) × {1− [ADL/ (NDF − NDICP)]0.667}; 2) iNDF = 0.75 × (NDF − NDICP − NDF remaining after 288 h in situ); and 3) ERNDFD estimated from in situ NDF digestion kinetics. Resulting tdNDF values were used for calculation of TDN1xand NEL3xaccording to NRC (2001) equations. Data were analyzed with MIXED procedure of SAS 9.4 to determine the effect of processing plant on chemical composition, NDF degradation kinetics and NEL3xof CM. Effect of tdNDF estimation method on calculated TDN1xand NEL3xof CM was also evaluated. Model for analysis of processing plant included the fixed effect of plant and the random effect of year (plant) as replication, while analysis of tdNDF methods included the fixed effect of tdNDF estimation method and the random effects of processing plant and of year(plant) as replication. There was an effect of processing plant on DM (P =0.03), CP (P <0.01), EE (P <0.01), and NDF (P <0.01) of CM. Processing plant also had an effect on NDF fractions A (P <0.01) and B (P =0.02) but did not affect fraction C and ERNDFD. The tdNDF estimation method had an effect on tdNDF (P <0.01), TDN1x(P <0.01), and NEL3x(P <0.01) of CM, yielding average NEL3xvalues of 1.72, 1.87, and 2.07 Mcal/kg for NRC, iNDF, and ERNDFD, respectively. Our results indicate that calculated energy concentration of CM according to NRC (2001)equations varies depending on the method used for estimation of tdNDF. Further research will be needed to determine the most accurate estimation method.

The objective of this study was to examine the enzyme activities of an enzymatic complex produced by Pleurotus ostreatusin different pH and the effects of adding increased application rates of this enzymatic complex on the fermentation profile, chemical composition, and in situ ruminal disappearance of whole-plant corn silage (WPCS) at the onset of fermentation and 30 d after ensiling. The lignocellulolytic enzymatic complex was obtained through in vitro cultivation of P. ostreatus.In the first experiment, the activities of laccase, lignin peroxidase (LiP), manganese peroxidase, endo- and exo-glucanase, xylanase, and mannanase were determined at pH 3, 4, 5, and 6. In the second experiment, five application rates of enzymatic complex were tested in a randomized complete block design (0, 9, 18, 27, and 36 mg of lignocellulosic enzymes/kg of fresh whole-plant corn [WPC], corresponding to 0, 0.587, 1.156, 1.734, and 2.312 g of enzymatic complex/kg of fresh WPC, respectively). There were four replicates per treatment (vacuum-sealed bags) per opening time. Bags were opened 1, 2, 3, and 7 d after ensiling (onset of fermentation period) and 30 d after ensiling to evaluate the fermentation profile, chemical composition, and in situ dry matter and neutral fiber detergent disappearance of WPCS. Laccase had the greatest activity at pH 5 (P< 0.01), whereas manganese peroxidase and LiP had the greatest activity at pH 4 (P< 0.01; P< 0.01). There was no effect of the rate of application of enzymatic complex, at the onset of fermentation, on the fermentation profile (P> 0.21), and chemical composition (P> 0.36). The concentration of water-soluble carbohydrate quadratically decreased (P< 0.01) over the ensiling time at the onset of fermentation, leading to a quadratic increase of lactic acid (P =0.02) and a linear increase of acetic acid (P =0.02) throughout fermentation. Consequently, pH quadratically decreased (P< 0.01). Lignin concentration linearly decreased (P =0.04) with the enzymatic complex application rates at 30 d of storage; however, other nutrients and fermentation profiles did not change (P >0.11) with the enzymatic complex application rates. Addition of lignocellulolytic enzymatic complex from P. ostreatuscultivation to WPC at ensiling decreased WPCS lignin concentration 30 d after ensiling; however, it was not sufficient to improve in situ disappearance of fiber and dry matter.

This study aimed to evaluate the effect of dietary yerba mate (Ilex paraguariensis) extract (YME) on muscle metabolomics and physicochemical properties of lamb meat. Thirty-six uncastrated male lambs (90 d old) were fed experimental diets, which treatments consisted of 0%, 1%, 2%, and 4% inclusion of YME. Animals were fed for 50 d before slaughter. Muscle and meat samples were collected for metabolomics and meat quality analysis, respectively. The experiment was carried out in a randomized block design and analyzed using orthogonal contrasts. There was a quadratic effect of YME inclusion in tenderness (P< 0.05) and a positive linear effect on meat lightness (P< 0.05). No qualitative changes (P> 0.05) on individual metabolites were observed; however, changes in the quantitative metabolic profile were observed, showing that animals fed 1% and 2% of YME have a greater concentration of desirable endogenous muscle antioxidants, with direct impact on metabolic pathways related to beta-alanine metabolism and glutathione metabolism. Therefore, YME dietary supplementation up to 2% of the diet to lambs had little to no effects on the majority of meat quality traits evaluated; moreover, 4% of YME inclusion negatively affected feed intake and meat quality traits.