Dry Matter Disappearance Research Articles

Effects of biochar source, level of inclusion, and particle size on in vitro dry matter disappearance, total gas, and methane production and ruminal fermentation parameters in a barley silage-based diet

This study evaluated the effects of biochar differing in source, inclusion level, and particle size on dry matter disappearance (DMD), total gas and methane (CH4) production, and ruminal fermentation in a barley silage-based diet. The seven biochar products used were coconut (CP001 and CP014) or pine (CP002, CP015, CP016, CP023, CP024)-based. Experiment 1 (Exp. 1) evaluated these biochars at 4.5%, 13.5%, and 22.5% level of diet inclusion, whereas Experiment 2 (Exp. 2) evaluated CP002, CP016, and CP023 at 2.25% and 4.50% of the diet at <0.5, 0.5–2.0, >2.0 mm particle size. Data were analyzed using PROC MIXED in SAS as a randomized complete block design, with biochar source, inclusion level, and particle size (Exp. 2 only) as fixed effects with run and replicate as random effects. Increasing level of biochar inclusion linearly (P < 0.01) decreased DMD in Exp. 1 and did not influence DMD (P > 0.05) in Exp. 2. Total gas, CH4 (mL·g−1 DMD), and ruminal fermentation parameters were not affected by product, inclusion level, or particle size (P > 0.05). In conclusion, biochar of varying source and particle size did not mitigate CH4 production, but reduced DMD at higher inclusion levels in the barley silage-based diet.

The In Vitro Digestion and Fermentation Characteristics of Feedstuffs Inoculated With Cecal or Colic Fluid of Dezhou Donkey

The present study was conducted to evaluate the in vitro dry matter disappearance (IVDMD) and fermentation characteristics of 6 fibrous feedstuffs incubated with donkey cecal or colic microorganisms. The fibrous feeds were corn straw, wheat straw, peanut vine, peanut shell, wheat shell and wheat bran (WB), which are commonly applied in large-scale donkey farms in China. After 48 hours fermentation, the highest IVDMD occurred in WB, and the lowest occurred in peanut shell (P < .05) regardless what inoculum applied. The IVDMD was positively correlated with OM (R = 0.42, P < .01), CP (R = 0.76, P < .01) and EE (R = 0.56, P < .01), while it was negatively correlated with NDF (R = 0.75, P < .01) and ADF (R = 0.79, P < .01). In terms of volatile fatty acids (VFAs), the greatest net VFA production also occurred in WB (P < .05). The acetate and branched-chain volatile fatty acid proportions were greater in the colon culture fluids than in caecum (P < .05), but the propionate proportions were lower in colon than in caecum (P < .05). This resulted in an increase in the ratio of acetate to propionate in colon culture fluids. In summary, based on the highest IVDMD, net VFA production and CP content occurring with the lowest contents of both NDF and ADF, WB had the highest nutritive value compared to other fibrous substrates. The extent of feed degradation and fermentation depended mainly on the nature of the incubated feedstuffs. Nevertheless, further study is required to investigate these fibrous feeds on hindgut fermentation and in vivo nutrient digestibility.

Fibrolytic rumen bacteria of camel and sheep and their applications in the bioconversion of barley straw to soluble sugars for biofuel production.

Lignocellulosic biomass such as barley straw is a renewable and sustainable alternative to traditional feeds and could be used as bioenergy sources; however, low hydrolysis rate reduces the fermentation efficiency. Understanding the degradation and colonization of barley straw by rumen bacteria is the key step to improve the utilization of barley straw in animal feeding or biofuel production. This study evaluated the hydrolysis of barley straw as a result of the inoculation by rumen fluid of camel and sheep. Ground barley straw was incubated anaerobically with rumen inocula from three fistulated camels (FC) and three fistulated sheep (FR) for a period of 72 h. The source of rumen inoculum did not affect the disappearance of dry matter (DMD), neutral detergent fiber (NDFD). Group FR showed higher production of glucose, xylose, and gas; while higher ethanol production was associated with cellulosic hydrolysates obtained from FC group. The diversity and structure of bacterial communities attached to barley straw was investigated by Illumina Mi-Seq sequencing of V4-V5 region of 16S rRNA genes. The bacterial community was dominated by phylum Firmicutes and Bacteroidetes. The dominant genera were RC9_gut_group, Ruminococcus, Saccharofermentans, Butyrivibrio, Succiniclasticum, Selenomonas, and Streptococcus, indicating the important role of these genera in lignocellulose fermentation in the rumen. Group FR showed higher RC9_gut_group and group FC revealed higher Ruminococcus, Saccharofermentans, and Butyrivibrio. Higher enzymes activities (cellulase and xylanase) were associated with group FC. Thus, bacterial communities in camel and sheep have a great potential to improve the utilization lignocellulosic material in animal feeding and the production of biofuel and enzymes.

Ruminal dry matter disappearance, total gas and methane production, and fermentation parameters as affected by fat and protein concentration in by-product supplemented grass hay-based diets

Context Dietary manipulation is an important means to mitigate methane emissions; however, relatively few options exist for forage-based diets. Aims This batch culture study evaluated the effects of crude protein (CP) and fat concentration on ruminal DM disappearance (DMD), total gas (GP) and methane production, and ruminal fermentation in grass hay-based diets supplemented with a range of by-product feeds. Methods Eight treatments provided low or high CP (8 or 12% diet DM, respectively), with range of fat concentrations (1.8–6.0% diet DM), and included: control (grass hay only); corn distillers grains with solubles at 8% (CDDGS8) and 12% CP (CDDGS12); flax at 8% (FS8) and 12% CP (FSCDDGS12); canola meal at 8% (Can8); and sunflower screenings from Winkler (SFW8) or Deloraine (SFD8) at 8%. Data were analysed as a randomised complete block design, with fixed effect of treatment and random effects of block and treatment × block. Comparisons were performed between: (1) control and mean of by-product treatments, (2) low and high CP treatments, (3) CDDGS treatments, (4) FS treatments, and (5) SF treatments. Low- and high-fat treatments at both CP concentrations, and the means of CDDGS and FS treatments differing in fat concentrations were also compared. Key results The DMD did not differ between control and by-product treatments; however, DMD was lower (P &lt; 0.001) in treatments with 8% compared with 12% CP, and was higher (P ≤ 0.009) with low fat compared with high fat, regardless of CP. Total GP was not affected by CP; however, at low CP, treatments with higher fat had lower GP (P ≤ 0.015). Methane production did not differ between any of the low and high CP treatments, but was higher (P ≤ 0.003) in the low-fat compared with high-fat treatments, regardless of CP, as well as in FS versus CDDGS and SFD versus SFW. Conclusions Higher CP increased DMD in vitro, but did not affect GP, methane or fermentation. Implications Higher dietary fat can mitigate enteric methane production, but can negatively impact DMD in grass hay-based diets, which is an important consideration in terms of animal performance.

Effects of calcium salt of linseed oil fatty acid with different oil adsorbents on in vitro gas production and ruminal fermentation characteristics.

We investigated the effects of supplementary calcium salt of fatty acid (CSFA) from linseed oil with different oil adsorbents on in vitro gas production and rumen fermentation characteristics in barley substrate condition. A non-supplementation treatment (CONT) and treatments of six products, CSFA without oil adsorbent (2.1 fatty acid/Ca molar ratio) and CSFAs with silica gel, zeolite, bentonite, diatomite, and vermiculite (2.8 fatty acid/Ca molar ratio), were prepared. The supplementary 2% and 4% CSFA with silica gel (+S) in the substrate reduced CH4 production 56% and 79%, respectively, compared with that in CONT (p < 0.01). The products, except for +S, did not decrease CH4 production. The dry matter (DM) disappearance in CSFAs with oil adsorbents was lower than that in the CSFA without oil adsorbent (74.8%-77.3% vs. 79.3%, p < 0.01), and crude protein (CP) disappearance in +S supplementation was lower than that of the other products (53.5% vs. 57.2%-59.1%, p < 0.01). The +S supplementation decreased acetate proportion and increased propionate proportion (p < 0.01). Our study indicated that although the disappearance of DM and CP might decrease, using silica gel as an oil adsorbent of linseed oil calcium salt with high fatty acid/Ca molar ratio has the potential to mitigate CH4 emissions from ruminants.

Nutritive value of mixed napier grass (Pennisetum purpureum)- Leucaena (Leucaena leucocephala) silage for ruminants

The objectives of the study were to determine the chemical composition, ruminal degradability, and apparent digestibility of mixed Napier (Pennisetum purpureum) (PP) -Leucaena (Leucaena leucocephala) (LL) silages. Freshly cut Napier and Leucaena were harvested and mixed at 70:30; 50:50; 30:70 ensiled for six weeks. The chemical composition of the fresh forages and the silages were determined using the AOAC (1990) procedures. Dry matter (DM) and crude protein (CP) ruminal degradability were determined by nylon bag technique using three rumen cannulated Bonsmara steers for periods of 0, 6, 12, 24, 48, 72, 96 and 120 hours. DM and CP ruminal degradability kinetics were described by fitting the data on the model P= a+b (1-e−ct) using the neway computer program where a is the rapidly degradable fraction, b is the slowly degradable fraction and c is the outflow rate. Hay supplemented with 25% mixed PP: LL silages was fed to three castrated male Pedi sheep to evaluate apparent digestibility coefficient and N retention. The fresh cut PP had more CP, Fat, and ash, with less OM. Leucaena was richer in most nutrients than Napier. The study indicated the 50:50 silage was the optimal mix to maximize the overall nutritive value. The DM and CP disappearance constants a, b and c were similar for all silages. PP: LL mixing ratio did not affect the DM and CP degradability kinetics of the silages. There was no effect on total dietary intake, apparent digestibility and N retention.

Lemongrass essential oil reduces Mombasa grass silage gas losses, fibre content and pH after aerobic exposure

Context Ensiling is commonly used to conserve tropical grasses, but low water-soluble carbohydrates content and high moisture content in the grass impair silage fermentation characteristics. Essential oils may be used as silage additives to decrease fermentative losses and improve the nutritional value of silage, and aerobic stability, and in vitro DM disappearance. Aims The present study aimed to evaluate the effect of including lemongrass essential oil (LEO) on the fermentative characteristics, fermentative losses, chemical composition, in vitro disappearance and aerobic stability of Mombasa grass (Megathyrsus maximum) silage. Methods Mombasa grass was ensiled for 60 days in 32 experimental silos (15-L plastic buckets, 28 cm diameter and 25 cm high), in a randomly blocked design. LEO was included at 0.00, 0.67, 1.33 and 2.00 mL per kg of silage fresh matter. Silos were weighed every 15 days, pH and temperature were measured immediately after the silos were opened, and subsamples of silage were taken to measure the fermentative profile, composition of silage effluent, chemical composition and in vitro degradation of silage. Key results Increasing the amount of LEO in Mombasa grass silage caused a linear reduction in ammonia–nitrogen, ethanol (P &lt; 0.05), acid detergent fibre of silage, gas losses and silage pH after aerobic exposure. There was no impact (P &gt; 0.05) on organic acid concentration, effluent production or DM recovery (P &gt; 0.05). Conclusions (Tilley and Terry 1963) Adding LEO to Mombasa grass silage at up to 2.00 mL per kg fresh material (almost 7.5 mL/kg DM) reduces gas losses, ammonia–nitrogen and acid-detergent fibre concentration, and silage pH after aerobic exposure. However, it is not sufficient to improve DM recovery and in vitro disappearance of silage. Implications Lemongrass essential oil shows a positive effect on Mombasa grass silage fermentation, fibre content and silage parameters after aerobic exposure, providing a useful additive in this silage.

Characterization of various wheat types and processing methods using in vitro ruminal batch cultures

This study investigated the effect of kernel hardness, processing method, and their interaction on particle size, dry matter (DM) disappearance (DMD), and fermentation characteristics of wheat grain in batch cultures. The study was a completely randomized design with 3 wheat classifications (soft, medium, hard) × 3 processing methods (grinding, dry- and temper-rolling). Fifty-five wheat samples were characterized for chemical traits and classified for kernel hardness. Samples were either ground through 1-mm screen, dry-rolled or temper-rolled to a constant processing index (PI) of 0.80. In vitro gas production (GP) kinetics, fermentation characteristics and DMD at 6, 24 and 48 h of incubation were measured. Crude protein (CP) (g/kg) was lower and starch (g/kg) was higher for soft than medium and hard wheat. The PSD of rolled wheat was affected (P < 0.01) by a wheat hardness × processing interaction. With dry-rolling, soft wheat had more particles retained on the 2.36-mm sieve and less on the 1.18-mm sieve, while, with temper-rolling, soft wheat had more particles retained on the 3.35-mm sieve and less on the 2.36-mm sieve than those for dry- or temper-rolled medium and hard wheat. Kernel hardness × processing was observed (P < 0.01) for DMD and CPD after 24 h and 48 h of incubation; the DMD and CPD were higher (P < 0.01) with dry- than temper-rolled hard or medium wheat, but no differences in DMD and CPD were observed between dry- and temper-rolled soft wheat. A kernel hardness × processing interaction was also noted for total VFA production and molar proportions of propionate after 24 h of incubation (P < 0.05). Dry-rolled soft wheat had a higher (P = 0.04) total VFA concentration and molar proportion of propionate after 24 h of incubation as compared to dry-rolled hard wheat. Compared to grinding, VFA concentrations and proportion of propionate were all reduced by both dry- and temper rolling with the magnitude of these differences generally being greater for soft as compared to medium and hard wheat. In conclusion, regardless of kernel hardness, PSD of dry- and temper-rolled wheat had a significant impact on DMD. Tempering was more effective at reducing the generation of fine particles than dry-rolling, particularly with hard wheat, a factor that may reduce the risk of digestive disturbances in ruminants fed wheat.

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.

The Effect of Feeding Liquid or Dry Creep Feed on Growth Performance, Feed Disappearance, Enzyme Activity and Number of Eaters in Suckling Piglets.

Simple SummaryThe transition from sow’s milk to a vegetable-based diet around weaning is one of the most critical periods in a pig’s life, due to the strong association between undigested nutrients and post weaning diarrhoea. For practical and economic reasons, piglets are weaned before their gastro-intestinal tract has fully developed. Early provision of creep feed could be one way of promoting gut maturation and may thus be used as a preventive tool for post weaning diarrhoea instead of medicinal zinc oxide. Increasing the activity of enzymes involved in the digestive processes might enhance gut maturation, thereby preparing the piglet for weaning. Therefore, the objective of this study was to investigate the effect of dry and liquid creep feed on growth performance, enzyme activity and the number of pigs actually consuming creep feed. In conclusion, in this on-farm setup, the pigs fed the dry diet displayed a greater enzyme activity in the proximal part of the small intestine and a higher weight gain, suggesting more mucosal maturation and adaptation to a vegetable-based diet.The aim of this study was to investigate the effect of two dietary treatments (liquid creep feed (LCF) and dry creep feed (DCF)) offered during the suckling period on feed disappearance, number of eaters, and intestinal enzymatic development at weaning in an on-farm study with 347 piglets. Piglets were allocated to either the DCF or LCF treatment from day 10 to day 24 postpartum for 9 h a day. Red ferric oxide (1%) was added to the diet to categorize piglets into eating categories (good eaters, moderate eaters, or non-eaters) via faecal swabs. At weaning, 40 piglets were sampled for intestinal enzymatic development. The LCF treatment increased the dry matter disappearance from day 10–18 (p < 0.001). The percentage of good eaters, moderate eaters and non-eaters did not differ between treatments (p > 0.05). The DCF pigs displayed greater average daily gain (ADG) pre-weaning (p = 0.024), and a greater body weight (BW) at day 61 (p < 0.001). The activity of lactase, maltase and sucrase in the proximal part of the small intestine were greatest (p < 0.001) in the DCF pigs.

Polymeric Microparticles of Calcium Pectinate Containing Urea for Slow Release in Ruminant Diet.

In ruminant feeding, mechanisms for controlling the rate of ammonia release in the rumen are important for increasing the efficiency of transforming dietary nitrogen into microbial protein. Three microencapsulated formulations, with increased urea concentrations of 10 (MPec1), 20 (MPec2) and 30% (MPec3) from the w/w, based on the mass of citrus pectin solution, employ the external ionic gelation/extrusion technique. The properties of microencapsulated urea were examined as a completely randomized design with 5 treatments each with 10 replicates for evaluation, and the ratios of dietary to free urea were compared using 5 fistulated male Santa Ines sheep in a Latin 5 × 5 square design. The degradation kinetics showed that the rate of controlled release from the microencapsulated systems was significantly reduced compared with that of free urea (p < 0.05). The population density of ruminal protozoa increased when sheep received the microencapsulated urea (p < 0.05). The disappearance of dry matter and crude protein reached a degradation plateau during the first minutes for the MPec1 and MPec2 systems and was slower for MPec3. The MPec1 and MPec2 systems presented higher (p < 0.05) blood serum concentrations of albumin, urea nitrogen (BUN), creatinine and total cholesterol and did not affect (p > 0.05) the other blood metabolites. The MPec2 systems are recommended because they consist of microspheres with more (p < 0.05) controlled core release, delaying the peak of urea released in the rumen and BUN without affecting (p < 0.05) ruminal pH and temperature. Microencapsulation with calcium pectinate provided better utilization of urea, reducing the risk of ruminant intoxication.

Effects of lignocellulolytic enzymes on the fermentation profile, chemical composition, and in situ ruminal disappearance of whole-plant corn silage.

The objective of this study was to examine the enzyme activities of an enzymatic complex produced by Pleurotus ostreatus in 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. ostreatus cultivation 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.

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.

PSXIV-14 Supplementation of high-grain diet with red osier dogwood affects in vitro digestibility and fermentation characteristics

Abstract Red osier dogwood (ROD) is a native shrub plant rich in phenolic compounds with antimicrobial properties. The objective of this study was to evaluate the effects of substituting barley silage with either raw ROD or ROD extract (RODE) in high-grain (HG) diet under a low media pH (5.8) on gas production (GP), dry matter (DM) disappearance (DMD) and fermentation characteristics in batch cultures. The study was a completely randomized design with 4 treatments: 1) control diet (10% barley silage and 90% barley concentrate, DM basis), control diet supplemented with 2) monensin (30 mg/kg diet DM; positive control), 3) substitution of 3% ROD or 4) 3% RODE for an equal portion of silage. Inoculum was obtained from 2 ruminally fistulated beef heifers offered the HG diet. Substrate ground (1 mm) was incubated for 24 h and the experiment repeated twice. The GP did not differ among treatments (147 ml/g DM), but the DMD differed (P &amp;lt; 0.02) at highest for control (69.4%), lowest for ROD (58.4%) and intermediate for other treatments (64.1%). Total volatile fatty acid (VFA) concentration (mM) tended (P&amp;lt; 0.08) to be lower with ROD (80.5) and monensin (80.1) than control (83.9). Acetate proportion was greater (P = 0.02) with ROD (46.2%) and RODE (46.9%) than control (42.4%) and monensin (42.3%). However, the propionate proportion was greater (P = 0.05) with monensin (32.1%) than other treatments (averaged 30.1%). Consequently, acetate to propionate ratio (A:P) of ROD (1.52) and RODE (1.56) was higher than monensin (1.32; P &amp;lt; 0.01) and control (1.44; P &amp;lt; 0.08). Differences in variables measured between ROD and RODE were minimal. These results indicated that the decreased DMD along with increased A:P with addition of ROD or RODE suggests that both ROD and RODE may be beneficial to HG fed cattle for reducing risk of rumen acidosis without negatively impacting fibre digestion.

PSX-B-8 Effect of supplementing red osier dogwood extract on in vitro gas production, feed digestibility and fermentation characteristics of high-forage diet

Abstract Red osier dogwood (ROD) is native shrub plant in Canada and rich in bioactive compounds. The objective of this study was to evaluate the effects of ROD extract supplementation in a high-forage (HF) diet on gas production (GP), dry matter (DM) disappearance (DMD) and fermentation characteristics in batch cultures with varying media pH. The study was a completely randomized design with 4 levels of ROD extract (0, 1, 3 and 5% of substrate) × 2 media pH (5.8 and 6.5) factorial arrangement. The study was conducted in three replicate experiments. Substrate contained 60% barley silage and 40% barley concentrate (DM basis). Inoculum was obtained from 2 ruminally fistulated beef heifers offered the HF diet. Substrate (0.5 g DM) ground (1 mm) was incubated for 48 h in a culture bottle. Data were analyzed using Mixed procedure of SAS with fixed effects of treatments and random effect of experiment. There was no interaction between media pH and level of ROD on GP, DMD and fermentation characteristics. Increased media pH (5.8 vs. 6.5) increased (P &amp;lt; 0.01) GP (averaged 164 vs. 275 ml/g substrate), DMD (50.6 vs. 60.6%), and total VFA production (63 vs. 71 mM). Increasing ROD extract levels did not affect GP but linearly (P = 0.05) decreased DMD from 62.1 to 58.9% at pH 6.5. Although total VFA production was not affected, increasing ROD extract linearly (P &amp;lt; 0.01) increased the proportion of acetate (47.9 to 49.7%) and propionate (20.5 to 22.3%) at pH 5.8; whereas at pH 6.5, acetate to propionate ratio quadratically (P = 0.04) changed to be lower with 3% ROD extract (2.08) than other treatments (2.21). These results indicated that supplementation of HF diet with ROD extract may improve fibre digestion at low media pH, and improve fermentation efficiency at high media pH.

PSXI-11 Assessing in situ rumen degradability of late season kudzu (Pueraria montana var. lobata)

Abstract Kudzu (Pueraria montana var. lobata) is an invasive weed species native to eastern Asia affecting much of the southeastern United States. Its broad leaves and viny growth allow it to outcompete native plant species for sunlight and nutrients. Kudzu, however, is a leguminous plant, making it a potential feedstock for ruminant species. Browsing ruminants in areas affected by kudzu could benefit animal productivity while serving to ameliorate rapid plant growth. This study specifically sought to assess the overall rumen degradability, rate of digestion, digestible fraction, and indigestible fraction using an in situ methodology. In situ rumen degradability was analyzed using four ruminally fistulated steers as individual experimental units over two repeated trials. Samples were incubated at 1, 12, 24, 36, 48, 60, and 72 h. Kudzu used in these trials was collected during September, making analysis in this study a reflection of degradability toward the end of the growing season. Data were analyzed as a randomized complete block design with repeated measures showing no significant differences between steers or trials (P &amp;gt; 0.05). Overall degradability across all steers and times was 69.79%. Significant changes in dry matter disappearance across all steers were observed at 1, 12, and 24 h (P &amp;lt; 0.05) with values of 33.86, 64.78, and 74.26%, respectively, and highest observed degradability at 72 h (79.55%). Incubation times between 24 and 72 h were not used in determining rate of digestion as dry matter disappearances throughout these times were not significantly different (P &amp;gt; 0.05). Rate of digestion (kd) was determined, using linear regression, to be 1.68% ∙ h-1 along with a digestible fraction (Do) of 28.29% and indigestible fraction (U) of 22.03%. The results of this study reflect that kudzu maintains a relatively high level of rumen degradability toward seasonal senescence, making it a functional feedstock even into the cooler months.

267 Effect of Hay Type on the Winter Growth of Bos Grunniens Raised in Eastern Kentucky

Abstract Bos grunniens (yak) have been utilized as a source of fiber, milk, dung, meat and transportation in the high-altitude regions of Asia for centuries. Limited research has been conducted on the species in North America. The objective of this on-farm research was to evaluate the effect of hay type on growth rate of growing yaks. Forages evaluated included alfalfa (A), orchardgrass-red clover (O) and a cool-season pasture grass species mixture (P). The experimental design was a partially balanced 3x3 Latin square with an extra pen. Yaks were stratified to pens by age and sex resulting in a pen of mixed sex (3 males/2 females) recently weaned calves, a pen of five yearling females, and two pens of five yearling males. Each period lasted for 45 days and animal weights were collected at the beginning and end to assess weight change and daily gain. Hay offered was weighed and feeding losses were visually estimated to determine hay DM disappearance. Forage samples were collected and analyzed for nutrient content. Data were analyzed using the PROC GLM procedure of SAS. No carryover effects were noted and means were separated using Tukey’s multiple comparison test where α=0.10. Forage type had a significant impact on period weight change of growing yaks during the winter with O having greater weight gain (9.5 kg) than P (-4.7 kg) with A being intermediate (8.5 kg). Forage DM disappearance when expressed as percent of body weight was greater for A (2.70) compared to P (2.25) while O (2.28) was not different from either. Forage type and quality can impact weight gain and forage disappearance during the winter months for growing yaks with higher quality forage providing greater weight gain.

PSXIV-6 País grape marc (Vitis vinifera, País) inclusion in concentrate diets reduces ammonia nitrogen but not methane production in an in vitro batch culture

Abstract País Grape (Vitis vinifera L.) is an ancestral variety used in Chilean wine industry. It has a higher content of proanthocyanidins than commercial varieties such as Carmenère or Pinot Noir, resulting in País grape marc (PGM) with high contents of condensed tannins. As such, PGM inclusion in ruminant diets would have the potential to reduce enteric methane (CH4) emissions and decrease urinary N excretion. The objective of this study was to evaluate the effects of substitution of mixed hay (MH) with PGM in a high concentrate diet [65% dry matter (DM)] on in vitro dry matter disappearance (IVDMD), ruminal fermentation parameters, gas and CH4 production. Treatments were: T1 (Control) = 20% MH, 15% corn silage, 65% concentrate; T2 = 10% MH, 10% PGM, 15% corn silage, 65% concentrate; T3 = 20% PGM, 15% corn silage, 65% concentrate. The study was a randomized complete design with 3 treatment and 3 replicates, incubated for 24 h at 39º C. Data were compared by Tukey test and polynomial contrasts. There was a linear reduction in NH3-N (P = 0.001) as dietary PGM increased. Inclusion of PGM reduced NH3-N by 50% when added at 10% DM, and 71.7% at 20% DM. However, there also was 4% reduction in IVDMD (P ≤ 0.001) and gas production (P = 0.012) in the 20% GM diet. There were no treatment effects (P ≥ 0.05) on CH4 production or yield. Fermentation efficiency determined by the partition factor increased linearly (P = 0.013) as PGM inclusion increased, suggesting that it increases organic matter to be degraded. Based on this study it could be concluded that PGM is an alternative source of fiber for ruminants on concentrate diets, as it can result in improved rumen fermentation efficiency and a substantial reduction in ruminal ammonia nitrogen concentration (NH3-N).

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.

PSXIII-4 Effects of “País” grape marc on in vitro methane production and ruminal fermentation parameters of a forage diet

Abstract Grape marc (GM) is a viticulture by-product used as cattle supplement in periods of shortage of conventional feed sources. It contains fats, high concentrations of polyphenols and has been reported to reduce enteric methane (CH4) emissions. In-vitro batch culture was used to study the effects of substitution of mixed hay (MH) for a traditional Chilean variety (Vitis vinifera “País”) of GM on in vitro dry matter disappearance (IVDMD), rumen fermentation parameters (short chain fatty acids, pH, partitioning factor), gas and CH4 production in a 60% forage diet (dry matter, DM). The study was a randomized complete design with 3 treatments and 3 replicates, incubated for 24 h at 39º C. Treatments were: T1 (Control): 20% MH, 40% corn silage, 40% concentrate; T2 = 10% MH, 10% GM, 40% corn silage, 40% concentrate; T3 = 20% GM, 40% corn silage, 40% concentrate. Means were compared with the Tukey test (P &amp;lt; 0.05), and polynomial contrasts. Substitution of MH with GM significantly reduced ammonia nitrogen (NH3-N) by 50% (P &amp;lt; 0.05), although it did not affect IVDMD, gas production or other rumen fermentation parameters (P &amp;gt; 0.05). Total CH4 (mg) linearly decreased (P = 0.013) as concentrations of GM increased. Methane production (mg/g DM incubated) and yield (mg/g DM digested) decreased linearly (P = 0.002 and P = 0.003, respectively) as inclusion of GM increased. Inclusion of GM at 20% reduced CH4 production by 19% and CH4 yield by 16.4%. These results indicate that partial substitution of dietary fiber sources with traditional Chilean País GM in high fiber diets is a viable feeding alternative, and can decrease environmental impact (lower CH4 and ammonia emissions) of ruminant livestock, without negatively affecting rumen fermentation parameters.