Dry Matter Disappearance Research Articles

Steam Explosion Pretreatment Changes Ruminal Fermentation in vitro of Corn Stover by Shifting Archaeal and Bacterial Community Structure.

Steam explosion is an environment-friendly pretreatment method to improve the subsequent hydrolysis process of lignocellulosic biomass. Steam explosion pretreatment improved ruminal fermentation and changed fermentation pattern of corn stover during ruminal fermentation in vitro. The study gave a comprehensive insight into how stream explosion pretreatment shifted archaeal and bacterial community structure to change ruminal fermentation in vitro of corn stover. Results showed that steam explosion pretreatment dramatically improved the apparent disappearance of dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF). Steam explosion pretreatment significantly increased the molar proportion of propionate and decreased the ratio of acetate to propionate. At archaeal level, steam explosion pretreatment significantly increased the relative abundance of Methanobrevibacter, which can effectively remove metabolic hydrogen to keep the fermentation continuing. At bacterial level, the shift in fermentation was achieved by increasing the relative abundance of cellulolytic bacteria and propionate-related bacteria, including Spirochaetes, Elusimicrobia, Fibrobacteres, Prevotella, Treponema, Ruminococcus, and Fibrobacter.

Effects of barley type and processing method on rumen fermentation, dry matter disappearance and fermentation characteristics in batch cultures

The objective of this study was to investigate the effects of barley type (two-row versus six-row) and processing method (grinding, dry-rolling and temper-rolling) on processing quality, dry matter (DM) disappearance (DMD), and fermentation characteristics in batch culture. The study was a completely randomized design with 2 barley types × 3 processing methods in a factorial arrangement. Thirty barley cultivars/lines were selected from a set of 85 cultivars/lines that were previously screened for in vitro DMD. The mean DMD values (g/kg) were 328 (low), 520 (medium), and 688 (high) after 48 of incubation. Ten representative samples of each DMD group (low, medium and high) of two- and six-row barley were selected. Barley samples were ground (1-mm screen), and dry- or temper-rolled to a processing index (PI) of 0.80. Particle size distribution (PSD) of rolled barley across 4.00-, 3.35-, 2.36-, 1.18-, 0.85-mm sieves, gas production (GP) kinetics, DMD and fermentation traits at 6, 24 and 48 h of incubation were measured. Two-row had higher kernel weight, test weight, plumpness, starch and ether extract content, and lower fibre content than six-row barley (P < 0.01).The PSD of rolled barley was affected by barley type, processing and their interaction (P < 0.01). More (P < 0.01) coarse particles were retained on the 3.35-mm sieve for two-row versus six-row barley (dry-rolled, 0.44 versus 0.34; and temper-rolled, 0.91 versus 0.85). Compared to six-row, two-row barley had greater (P < 0.01) DMD after 6 and 48 h and greater (P = 0.02) crude protein disappearance (CPD) after 48 h. Ground barley had higher DMD, CPD, microbial N production and molar proportion of propionate and total VFA production than rolled barley (P < 0.01); whereas these variables did not differ between dry- and temper-rolled barley. A barley type × processing interaction for DMD, CPD and GP kinetics was identified (P < 0.01). Coarse particles were negatively, while fine particle were positively correlated with DMD (P < 0.01). These results indicate that although PSD of dry- and temper-rolled barley differed, impacts on GP and DMD were small, particularly for two-row barley. The differences in DMD at 6 or 48 h between two- and six-row barley suggest that barley type can impact both the rate and extent of barley digestion in the rumen. These differences suggest that there is considerable opportunity to select barley varieties based on responses to processing and ultimately their feed value for ruminants.

Predicting in situ dry matter disappearance of chopped and processed corn kernels using image-analysis techniques

ABSTRACT Objective Corn silage processing score (CSPS) is a well-known and often-used indicator of starch availability in whole-plant corn silage. However, obtaining results from a laboratory can take days or more. The objective of this work was to test an image-analysis method as a tool for quantitative assessment of corn kernel particle size and feed quality during harvest. Materials and Methods Kernel processor gap settings of 1, 2, 3, and 4 mm were assessed using the standard sieving method and with an image-analysis method. In situ slowly disappearing DM in ruminally cannulated lactating dairy cows was also assessed at the various kernel processor gap settings and compared with the 2 CSPS estimation methods: image analysis and sieving. Results and Discussion The image-analysis method was able to statistically separate mean estimated CSPS (P = 0.014) across the different crop processor gap settings for fresh samples. Image analysis CSPS estimation of fresh samples was highly correlated with in situ DM disappearance results [r(10) = 0.77] using a 12-h incubation time. These results indicate that image processing is a viable tool for estimating CSPS and feed quality. Implications and Applications A smartphone application, SilageSnap, was developed that uses the image-processing algorithm to estimate CSPS. This novel tool provides in-field estimation of CSPS that translates into actionable information regarding feed quality to inform machine adjustment decisions, which farmers, dairy nutritionists, and custom harvesters have not had in the past.

Nutritional evaluation of selected fodder trees: Mulberry (Molus alba Lam.), Leucaena (Leucaena luecocephala Lam de Wit.) and Moringa (Moringa oleifera Lam.) as dry season protein supplements for grazing animals

Leaves of Mulberry (Morus alba Lam.), Leucaena (Leucaena leucocephala Lam de wit.) and Moringa (Moringa oleifera Lam.) were evaluated as dry season protein supplements for grazing animals based on chemical composition, in vitro and in sacco nutrient digestibility and a Rabbit feeding trial. All tree fodder forages had similar dry matter (DM) content, but crude protein was higher in Moringa (28.6%) followed by Leucaena (24.5%), Mulberry (24.1%) and Lucerne (18.0%). Ash content was highest in Mulberry followed by Moringa and Lucerne with Leucaena having lowest amounts. Polyphenols ranged from 2.72 to 3.64%, with Leucaena having highest and Mulberry lowest amounts. Dietary fibre were highest in Mulberry and Moringa, but there were no significant differences (P < 0.05) between Leucaena and Lucerne. In vitro gas production and DM disappearances were higher in Moringa followed by Mulberry and Lucerne with Leucaena having lowest amounts. Except for Leucaena, DM disappearances were increased when rumen fluid from dairy cattle steers was used. In sacco DM disappearances were 33.7% for Leucaena, 78.2% for Lucerne, 50.2% for Moringa and 50.7% for Mulberry. In vitro and in sacco crude fibre and neutral detergent fibre disappearances were relatively lower, but reflected DM disappearances. The Rabbit feeding trial showed diets based on Moringa, Leucaena and combined fodder forages to have significantly better performance than Mulberry and grass hay alone. The conclusion was that tested tree fodder forages have potential of being used as dry season protein supplements for grazing animals on traditional smallholder farms.

Energy values and protein digestibility of soybean milk by-product in pigs based on in vitro assays

Background: Soybean milk by-product (SMBP) is a potential alternative feed ingredient in swine diets due to its high protein content. However, information on energy and nutritional values of SMBP used as swine feed ingredient is limited. Objective: To estimate energy values and protein digestibility of SMBP in pigs based on in vitro assays. Methods: Four SMBP samples were obtained from 3 soybean milk-producing facilities. In vitro total tract disappearance (IVTTD) and in vitro ileal disappearance (IVID) of dry matter (DM) in the SMBP samples were determined. In vitro ileal disappearance of crude protein was determined by analyzing crude protein content in undigested residues after determining IVID of DM. Digestible and metabolizable energy of SMBP were estimated using gross energy, IVTTD of DM, and prediction equations. Results: Sample 4 had greater IVTTD of DM than that of sample 3 (97.7 vs. 94.4%, p&lt;0.05), whereas IVID of DM in sample 4 was lower compared with sample 1 (53.5 vs. 65.0%, p&lt;0.05). In vitro ileal disappearance of crude protein in sample 2 was greater than that in sample 1 and 3 (92.6 vs. 90.6 and 90.1%; p&lt;0.05). The estimated metabolizable energy of SMBP ranged from 4,311 to 4,619 kcal/kg as-is basis and the value of sample 3 was the least (p&lt;0.05) among SMBP samples. Conclusion: Energy values and protein digestibility should be determined before using SMBP in swine diets.

Losses, chemical composition and aerobic stability of rye silage cv. Temprano subjected to different pre-flowering cuttings with or without fungicide

The present study evaluated the fermentation, chemical characteristics and ruminal disappearance of dry matter of silages of rye cv. Temprano harvested at the stage of floury grain, managed with or without cutting at the vegetative stage and with or without application of Fluxapyroxad + Pyraclostrobin-based fungicide at the pre-flowering phenological stage. This was a 2x2 factorial randomized block experimental design, with 2 cutting regimes (0 and 1 cut) and 2 application management (with and without fungicide), with six replications, where each repetition is represented by a plot of 9.45m², with the treatments SC-SF: without cut at the vegetative stage and without fungicide application; SC-CF: without cut at the vegetative stage with fungicide application; UC-SF: a cut at the vegetative stage with pre-flowering fungicide application; UC-CF: a cut at the vegetative stage and without fungicide application. UC-CF silages were better in the general context, due to the better fiber composition with an average 6.75% reduction in neutral detergent fiber and acid detergent fiber and a 17.10% reduction in lignin content, but, due to its higher DM content, it presented a less efficient fermentation process in terms of organic acid concentration and aerobic stability. However, it did not change the DM losses or ruminal degradability, and there is also the use of DM harvested at the vegetative stage that certainly has a superior quality. The use of fungicide provided only better dry matter index and better fiber composition and improved the fermentation process resulting in lower DM losses without altering the aerobic stability of silages.

Chemical parameters and ruminal disappearance of Secale cereale rye forage in different harvest systems with or without fungicide

The objective of the study was to evaluate the chemical parameters and the ruminal disappearance of dry matter of forage from the rye Secale cereale, cv. Temprano managed in different harvest regimes at the vegetative stage, with or without application of a fungicide based on Fluxapyroxade + Piraclostrobin at the pre-flowering stage. This was a randomized block experimental design and the treatments consisted of evaluating the forage harvested at floury grain stage, as follow, SCSF: no cut at the vegetative stage, no application of fungicide; SCCF: no cut at the vegetative stage with fungicide application; UCSF: one cut at the vegetative stage, no application of fungicide; UCCF: one cut with fungicide application; DCSF: two cuts at the vegetative stage, no fungicide application; DCCF: two cuts with fungicide application. In general, one cut at the vegetative stage and a subsequent cut for ensiling at floury grain stage was the best system used in cv. Temprano, based on the chemical parameters and ruminal disappearance. This system provided a better composition of fiber carbohydrates with lower contents of Acid Detergent Fiber (41.55%) and Lignin (10.79%) after cutting and resulted in a better disappearance rate of dry matter at the rumen level (0.46 %) per hour of exposure, highlighting the cut at the vegetative stage that produced a material with 20.76% Crude Protein and 52.69% Neutral Detergent showing its nutritional quality for use in grazing land or as haylage. The application of fungicide provided significant improvements in the contents of crude protein (8.24% vs 7.23%) and mineral matter (3.02% vs 2.82%) of the plant at the time of ensiling, which generated better dry matter disappearance rates in the rumen.

Addition of polyvinyl alcohol (PVA) to lactated Ringer’s solution (LRS) prevents equine embryos from adhering to plastic search dishes after initial recovery

To assess the impact of protein on fermentation by equine cecal microorganisms, cecal fluid from 4 cecally cannulated horses was used to inoculate fermentation bottles containing buffer, forage, and supplemental protein. In experiment 1, sodium caseinate (SC) provided 0, 0.5%, 1%, 2%, or 4% additional crude protein (CP) to bottles containing alfalfa or native warm-season prairie grass hay. Bottles were equipped with continuous gas pressure monitors and placed into a shaking incubator for 48 hours at 39°C. Cultures with alfalfa had greater (P < .0001) in vitro dry matter disappearance (IVDMD), neutral detergent fiber disappearance (NDFD), acid detergent fiber disappearance (ADFD), cumulative gas production, and total volatile fatty acid (VFA). Sodium caseinate increased gas production (P ≤ .05) and decreased pH (P < .003) in cultures with grass hay. Sodium caseinate at 1%, 2%, or 4% additional CP increased IVDMD, NDFD, and ADFD (P < .01), while 4% additional CP also increased total VFA (P < .01). For experiment 2, SC, fishmeal, soybean meal (SBM), whey, porcine blood plasma, and L-lysine hydrochloride were added to supply 2% additional CP to cultures with grass hay. All protein sources decreased pH and increased IVDMD, NDFD, and ADFD (P ≤ .01), with the largest effects elicited by SC, L-lysine, and whey (P ≤ .05). Total VFA (P ≤ .04) and gas (P ≤ .05) production increased with L-lysine, whey, SC, SBM, and fishmeal. While protein supplementation had minimal effects on cultures containing alfalfa, it altered fermentation of grass hay, more notably with more soluble protein sources.

Effects of Sodium Caseinate and Varying Protein Sources on In Vitro Fermentation of Forages by Mixed Equine Cecal Microorganisms

To assess the impact of protein on fermentation by equine cecal microorganisms, cecal fluid from 4 cecally cannulated horses was used to inoculate fermentation bottles containing buffer, forage, and supplemental protein. In experiment 1, sodium caseinate (SC) provided 0, 0.5%, 1%, 2%, or 4% additional crude protein (CP) to bottles containing alfalfa or native warm-season prairie grass hay. Bottles were equipped with continuous gas pressure monitors and placed into a shaking incubator for 48 hours at 39°C. Cultures with alfalfa had greater (P < .0001) in vitro dry matter disappearance (IVDMD), neutral detergent fiber disappearance (NDFD), acid detergent fiber disappearance (ADFD), cumulative gas production, and total volatile fatty acid (VFA). Sodium caseinate increased gas production (P ≤ .05) and decreased pH (P < .003) in cultures with grass hay. Sodium caseinate at 1%, 2%, or 4% additional CP increased IVDMD, NDFD, and ADFD (P < .01), while 4% additional CP also increased total VFA (P < .01). For experiment 2, SC, fishmeal, soybean meal (SBM), whey, porcine blood plasma, and L-lysine hydrochloride were added to supply 2% additional CP to cultures with grass hay. All protein sources decreased pH and increased IVDMD, NDFD, and ADFD (P ≤ .01), with the largest effects elicited by SC, L-lysine, and whey (P ≤ .05). Total VFA (P ≤ .04) and gas (P ≤ .05) production increased with L-lysine, whey, SC, SBM, and fishmeal. While protein supplementation had minimal effects on cultures containing alfalfa, it altered fermentation of grass hay, more notably with more soluble protein sources.

In vitro ruminal fermentation of fenugreek (Trigonella foenum-graecum L.) produced less methane than that of alfalfa (Medicago sativa)

ObjectiveThe objective of this study was to compare fenugreek (FG) with alfalfa (Alf) in ruminal fermentation and methane (CH4) production in vitro.MethodsWhole-plant FG harvested at 11- and 15-wk and Alf harvested at early and mid-bloom maturities, alone or as 50:50 mixture of FG and Alf at the respective maturity, were assessed in a series of 48-h in vitro batch culture incubations. Total fermentation gas and methane gas production, dry matter (DM) disappearance, volatile fatty acids, microbial protein and 16S RNA gene copy numbers of total bacteria and methanogens were determined.ResultsCompared to early bloom Alf, FG harvested at 11-wk exhibited higher (p<0.05) in vitro DM and neutral detergent fibre disappearance, but this difference was not observed between the mid-bloom Alf and 15-wk FG. Regardless plant maturity, in vitro ruminal fermentation of FG produced less (p<0.001) CH4 either on DM incubated or on DM disappeared basis than that of Alf during 48-h incubation. In vitro ruminal fermentation of FG yielded similar amount of total volatile fatty acids with higher (p<0.05) propionate percentage as compared to fermentation of Alf irrespective of plant maturity. Microbial protein synthesis was greater (p<0.001) with 11-wk FG than early bloom Alf as substrate and 16S RNA gene copies of total bacteria was higher (p<0.01) with 15-wk FG than mid-bloom Alf as substrate. Compared to mid-bloom Alf, 15-wk FG had lower (p<0.05 to 0.001) amount of 16S RNA methanogen gene copies in the whole culture during 48-h incubation.ConclusionIn comparison to Alf, FG emerges as a high quality forage that can not only improve rumen fermentation in vitro, but can also remarkably mitigate CH4 emissions likely due to being rich in saponins.

Evaluation of selected categories of pet treats using in vitro assay and texture analysis.

Treats are important contributors to the economics of the U.S. pet product industry. Not only do pet owners use them to build an emotional bond or interact with their pets, but treats also can deliver functional or health benefits. The objective of this study was to evaluate the digestion and safety of selected commercial treats by measuring their in vitro dry matter disappearance (DMD) using the modified in vitro method of Boisen and Eggum, which was developed to simulate in vivo digestibility of nonruminant animals. Twenty-five commercial treats were classified into six categories based on their appearance, size, and functionality. These categories included biscuit, chew, dental, meat product, rawhide, and cat treat. Each commercial product was analyzed in triplicate and in vitro DMD was calculated after enzymatic digestion and incubation. A wide variation in DMD was observed among and within different treat categories in both gastric and gastric + small intestinal phases of digestion. For the gastric phase, DMD ranged from 8.40% to 92.20%, whereas intestinal phase digestion had a DMD range of 35.10–100% (P < 0.05). In general, treats from meat products, dental, chew, biscuit, and cat treat categories had a high DMD (>85%) after the intestinal phase, whereas DMD of rawhide treats varied from 35.10% to 95.70%. Principal component analysis, in addition, has visually shown that rawhide treats displayed the largest portion of variation from the other treats. A low DMD at gastric phase is a concern because it may pose a risk for gastrointestinal blockage and intolerance, particularly for treats of large size that remained intact during this phase. In vitro DMD results can be used as a potential predictor of in vivo digestibility, facilitate recommendations about pet treat safety for professionals and manufacturers in the pet industry, and assist pet owners in the treat selection process and with treat purchasing decisions.

Effects of inclusion of purple prairie clover (Dalea purpurea Vent.) with native cool-season grasses on in vitro fermentation and in situ digestibility of mixed forages

BackgroundIncorporation of legume species into native North American pastures is considered an effective method to increase native pasture productivity and improve the nutritive value of forage. This study evaluated the effects of inclusion of purple prairie clover (PPC, Dalea purpurea Vent.), a native legume forage, with native cool-season grasses on the in vitro fermentation and in situ digestibility of mixed forages.MethodsWhole plant PPC and mixtures of cool-season grasses were harvested when the PPC reached the vegetative (VEG), full flower (FL) and seedpod (SP) stages, and were combined in ratios (DM basis) of 0:100, 25:75, 50:50, 75:25 and 100:0 at each maturity. In vitro ruminal incubations using these mixtures were conducted for 48 h to determine gas production (GP), in vitro DM disappearance (IVDMD), total volatile fatty acids (VFA) and ammonia-N production. Mixtures of forages harvested when the PPC reached the FL stage and 50:50 mixture of forages harvested at VEG, FL and SP stages were incubated in the rumen of three heifers for 0, 2, 6, 12, 24, 48, 72 and 96 h to determine in situ degradabilities of DM, neutral detergent fibre (aNDF) and crude protein (CP).ResultsContents of aNDF and ADF increased (P < 0.01), while CP decreased (P < 0.001) as PPC matured. Concentrations of extractable condensed tannins in PPC ranked as FL > VEG > SP (P < 0.05). Regardless of PPC proportions in the mixture, GP decreased (P < 0.05) with increasing PPC maturity. Increasing PPC proportions linearly increased (P < 0.001) GP, IVDMD and total VFA at VEG, but linearly decreased (P < 0.001) them at SP. Irrespective of PPC maturity, ammonia-N production linearly increased (P < 0.01) with increasing proportions of PPC and the concentration was higher (P < 0.05) at VEG than at FL and SP stages. Increasing proportion of PPC at either maturity linearly increased (P < 0.001) molar percentage of acetate (A) and branched-chain VFA, but linearly decreased (P < 0.001) molar percentage of propionate (P), resulting in a linearly increase (P < 0.001) in the A:P ratio. Increasing FL PPC in the mixture linearly and quadratically (P < 0.01) increased a (soluble fraction), but linearly and quadratically decreased (P < 0.01) b (potentially degradable fraction) for DM and aNDF, resulting in linear (P < 0.05) and quadratic (P < 0.01) increases in DM and aNDF maximum potential degradabilities (a + b). Effective degradabilities of DM and aNDF were also linearly and quadratically increased (P < 0.05), and CP was quadratically increased (P < 0.05) with increasing FL PPC, with the greatest effective degradability being observed with ratios between 50:50 and 75:25. Ruminal maximum potential degradabilities of DM and aNDF decreased (P < 0.001) as the forage matured. Effective degradability of DM ranked as VEG > FL > SP (P < 0.001), whereas the effective degradability of aNDF was similar between VEG and FL and both were greater (P < 0.01) than SP.ConclusionsInclusion of vegetative PPC in a mixed forage diet resulted in the greatest digestibility and incorporation of PPC before seedpod stage with native grasses had a positive effect on ruminal fermentation. Effects of PPC on ruminal digestion depend on both the stage of maturity and its proportion in mixed legume-grass pastures. Pastures containing 50% of PPC in full flower stage would likely provide the greatest quality diet to grazing ruminants subject to potential animal selectivity.

Comparison of ruminal digestibility of Origanum onites L. leaves in dairy buffalo and cows.

This experiment evaluated the ruminal digestibility of Turkish oregano leaves in dairy buffalo and cows. Ruminally cannulated, multiparous Brown Swiss cows (n = 3) and water buffalo (Bubalus bubalis; n = 3) were used in the experiment. The ad libitum basal diet was balanced to NRC requirements for a dry, nonpregnant multiparous dairy cow (680kg) and consuming 12.8kg of DM/day. Air-dried, ground, weighed oregano leaves were inserted in the rumen of all animals before the morning feeding within heat-sealed nylon bags (4 replicates per treatment and time point). After incubation (4, 8, 24, 48, and 72h), dry matter (DM), crude protein (CP), aNDFom, and ADFom concentrations were determined and compared to initial leaf chemical composition. The means for in situ disappearance (ISD, %) of DM, aNDFom, and ADFom did not differ between the species, but ISD of CP was greater in buffalo than the cows (P = 0.05) after 72h incubation. The lag time of kinetic degradation curves, the potentially degradable fraction (b), hourly degradation rate (c), and undegradable fraction were similar between species. The immediately degraded fraction (a) and effective digestibility (ED) of CP were greater in buffalo than the cows (P = 0.04), but the a fraction and ED of other nutrients showed no differences between the species. In conclusion, CP of oregano leaves are degraded more rapidly in the rumen of dairy buffalo than cows, primarily due to a large difference in the rapidly soluble CP fraction in the buffalo.

Effect of ammonia fibre expansion (AFEX) treatment of rice straw on in situ digestibility, microbial colonization, acetamide levels and growth performance of lambs

The objective of this study was to evaluate the effect of AFEX treatment (ARS) of rice straw (RS) on the in situ degradability, microbial colonization, growth performance and acetamide levels in ewe lambs. Alfalfa, rice straw and AFEX-treated rice straw were incubated in nylon bags in the rumen for 0, 1, 3, 6, 12, 24, 36, 48, 72 and 120 h to determine DM and NDF disappearance kinetics. Sequencing of 16S rRNA was used to characterize colonizing bacterial and archaeal profiles. Lambs (N = 40; 37.1 ± 3.5 kg) were fed pelleted diets that contained: 1) ALF = 250 g/kg of alfalfa; 2) RS = 250 g/kg of rice straw; 3) ARS = 250 g/kg of AFEX rice straw; 4) ARSW = ARS withdrawn from the diet 7 d before slaughter. Blood samples were collected biweekly and after ARSW on d 1, 3, 5 and 7 and at slaughter, the diaphragm muscle was used for measurement of acetamide. Alfalfa had greater Kd and A fraction (P < 0.05), whereas ARS had higher (P < 0.05) B and A + B fractions. Alfalfa DM and NDF degradability was greater at 12 h, but lower than ARS thereafter. Effective ruminal degradability (Ed) at 0.02, 0.04 and 0.06/h was greater (P < 0.05) for ARS than other forages. Digestion of ALF and ARS plateaued after 48 h, while RS continued to be degraded. Compared to other forages, alpha and beta microbial diversity of ARS was reduced (P < 0.05). The phylogenetic profile of initial colonizers of ARS was more similar to ALF than RS and was dominated by Bacteroidetes. Lambs fed RS exhibited similar growth to those fed ALF, while the DMI of ARS lambs was similar, but ADG and feed efficiency were reduced (P < 0.05). ALF exhibited greater (P < 0.05) DM, OM, CP, NDF, ADF and starch digestibility than ARS. ARS exhibited lower CP, but higher NDF and ADF digestibility than RS. A strong correlation (R² = 0.81) was observed between blood and muscle acetamide levels in lambs fed ARS. Withdrawal of ARSW reduced (P < 0.05) blood acetamide levels after 3 d, but levels in the diaphragm remained similar to ARS lambs at slaughter. Although AFEX improved the NDF and DM digestibility of RS and altered the phylogenetic profile of primary colonizers, it did not improve the growth of ewe lambs, likely as a result of reduced intake.

Ruminal degradation of dry matter and fibrous fraction of high-tannin grain sorghum

The present study aimed to evaluate the effect of replacing corn with high-tannin sorghum grain in the diet of steers on ruminal degradation of dry matter and fibrous fraction. Four rumen-fistulated cattle with a mean body weight of 519 ± 31 kg were used in this study. These animals were divided into groups using a 4 ´ 4 Latin square experimental design. Animals received four different diets in which increasing levels of ground corn were replaced with high-tannin sorghum grain in the proportions of 0%, 33%, 67% and 100% in the concentrate. Dry matter (DM) and neutral detergent fiber (NDF) were measured by in situ incubation of sorghum grain samples. Rumen residue was analysed for DM and NDF disappearance at incubation times of 0, 6, 12, 24, 48, 72, 96, 120 and 144 h. A quadratic behavior was observed in the fraction €œc€ of the DM and soluble fraction "a" of the NDF of the sorghum grain in function of the replacement levels of corn for high-grain tannin sorghum. Rumen DM and NDF degradability of sorghum grains with high tannin content up to 144 h showed an increasing behavior for all levels of inclusion of sorghum in the diet. The replacement level 67 showed the maximum DM and fibrous fraction disappearance of sorghum grain up to 144 h of incubation. Sorghum grain achieved maximum ruminal dry matter degradation and the fibrous fraction at the 67% replacement level of ground corn by high-tannin sorghum grain in the diet of steers.

Effect of xylanase, cellulase and natural maguey extract on the chemical composition of corn silage and in vitro rumen gas production

This study considered the application of two exogenous enzymes, xylanase (XYL) and cellulase (CELL), and maguey extract (ME), (applying 1 ml per kg as fresh matter) and a control (without additive) in four maize silage varieties (San Diego, Cacahuacintle, P-1832 and Victoria), to investigate their effect on the chemical composition (CC), gas production (GP) and in vitro ruminal fermentation. The GP was measured at 0, 3, 6, 9, 12, 24, 36, 48, 72 and 96 hours of incubation. Dry matter disappearance (DMD), organic matter disappearance (OMD), metabolizable energy (ME), and short chain fatty acids (SCFAs) were determined after 96 h of incubation. Data were analyzed using a completely randomized design with a 4×4 factorial arrangement with three replications. The CC showed a significant effect (P<0.05) for varieties with the exception of organic matter (OM), and the inclusion of additives increased the dry matter (DM) and crude protein (CP). A significant effect (P<0.01) was observed for the varieties in the GP parameters and ruminal fermentation. The addition of XYL, CEL and ME promoted dry matter degradation and increased energy availability, with increased in vitro gas production.

Effect of treated Conocarpus erectus L. leaves with Klebsiella pneumoniae and Acinetobacter as tannin-degrading bacteria on digestion activity of rumen microorganisms

The current research focuses on the effect of Conocarpus erectus L. leaves (CL) processed with two tannin-degrading bacteria Klebsiella pneumoniae (K. p) and Acinetobacter (A. b) on digestion activity and fermentation parameters of rumen bacteria and fungi in Arabian sheep. These isolates capable of utilizing tannic acid as sole carbon and energy source. Eight species of Klebsiella pneumoniae (A1, A2, A3, A4, A5, A7, A8, A9) follow by an Acinobacter sp. were used for biological treatment of CL for ten days. Then, digestion activity and some rumen fermentation parameters of ruminal bacteria and fungi in specific culture medium (SCM) were determined in Arabian sheep. Treated CL by bacterial isolates, reduced total tannin (TT) compared with unprocessed groups (P &lt; 0.05). Dry matter disappearance (DMD) was affected by biological treatment for both rumen bacteria and fungi in different incubation times, except for 3 and 6 h of incubation in SCM of mixed rumen fungi, which indicated same pattern with untreated CON group (P &gt; 0.05). The NDF disappearance (NDFD) and CP disappearance (CPD) in SCM of mixed rumen bacteria and fungi were increased during all incubation times (P &lt; 0.05) due to biological prosses of CL compared to CON treatment. Biologically treated CL increased gas production from the fermentable fraction (b) pattern in both SCM of mixed rumen bacteria and fungi during all incubation times (P &lt; 0.05), but, the gas production rate constant (c) was increased only at SCM of mixed rumen fungi (P &lt; 0.05). Overall, the data indicated that bacterial inoculation of K. p and A. b. sp. could improve digestion activity and some fermentation parameters of rumen bacteria and fungi in Arabian sheep.

Dry matter yield and nutritive value of early‐ or late‐maturing spring wheat, spring barley, and oat cultivars planted in late summer

AbstractThe objectives of this experiment were to evaluate early‐ and late‐maturing cultivars of oat (Avena sativa L.), spring wheat (Triticum aestivum L.), and spring barley (Hordeum vulgare L.) for autumn forage production and nutritive value. Early‐ and late‐maturing cultivars evaluated were ‘Newport’ and ‘Hays’ barley, ‘Select’ and ‘Iguacu’ wheat, and ‘Ogle’ and ‘ForagePlus’ oat. Field plots were arranged in a randomized complete block design with six replications (blocks) each year for 72 plots across the 2‐yr trial. For 2016, yields of dry matter (DM) were greatest for the barley cultivars (mean = 6,828 lb DM acre–1); all the other cultivars exhibited similar yields (P &gt; 0.05; mean = 5,597 lb DM acre–1). For 2017, the yield responses for Newport barley (4,422 lb DM acre–1) were greater than all other cultivars, which did not differ from each other (P &gt; 0.05; mean = 2,712 lb DM acre–1). Generally, wheat and oat cultivars differed by early‐ or late‐maturing designation for most measures of nutritive value; however, barley cultivars differed only for whole‐plant ash. Total digestible nutrients were similar (P &gt; 0.05) for early‐maturing Newport barley and all late‐maturing cultivars (mean = 66.0%); collectively, their energy densities were greater than those observed for early‐maturing Select wheat (62.8%) or Ogle oat (61.3%). Within species, in vitro disappearance of DM and fiber were greatest for the late‐maturing cultivars, with ForagePlus exhibiting the greatest disappearance. Spring wheat or barley are viable choices for emergency autumn forage in the north‐central United States.

The potential nutritive value of Sargassum fulvellum as a feed ingredient for ruminants

The aim of present study was to evaluate the nutritional value of Sargassum fulvellum (S. fulvellum; gulfweed, mojaban, hondawara) as a feed ingredient and investigate whether its functional metabolites could be helpful for increasing rumen fermentation characteristics. Rumen contents were collected from two rumen-cannulated Hanwoo cows (BW = 450 ± 30 kg). The in vitro trial was performed after 3, 6, 9, 12, 24, 48, and 72 h with S. fulvellum inclusion at concentrations of 1, 3, 5 and 10% of total ration. Total gas emission indicated that each S. fulvellum dose was significantly higher at 3, 6 and 9 h of incubation compared with the 0% inclusion sample but did not affect methane and carbon dioxide emission. Supplementation with 10% S. fulvellum significantly increased total volatile fatty acid (VFA) concentrations over those without supplementation. The in situ trial was performed 6, 12, 24, 48 and 72 h, with 5 g S. fulvellum, to estimate the dry matter disappearance (DMD) from the bag in the rumen. The DMD of S. fulvellum was significantly higher than that of timothy hay at 6, 12 and 24 periods. Proton nuclear magnetic resonance (1H NMR) was used to identify and quantify functional metabolites in S. fulvellum. The most abundant metabolites were guanidoacetate, ethylene glycol and alanine. Although the level of arsenic (As) in S. fulvellum was high, it was still within the acceptable limit for ruminants, and was not likely to cause any health defects, especially as S. fulvellum also contained many beneficial minerals. Overall, the inclusion of S. fulvellum as an alternative feed ingredient in ruminant diet has many potential nutritional benefits. Nevertheless, further in vitro studies using S. fulvellum and different basal diets combinations and, ultimately, in vivo studies are necessary to determine its value.

Beneficial effect of Rhodopseudomonas palustris on in vitro rumen digestion and fermentation.

As a member of photosynthetic bacteria, Rhodopseudomonas palustris, which has extraordinary metabolic versatility, has been applied as one of potential probiotics in feed industry. To explore whether R. palustris can increase rumen microbial viability and thus improve microbial fermentation, a 2×5 factorial experiment was conducted to evaluate the effect of R. palustris at dose rates of 0, 1.3, 2.6, 3.9, 5.2×106 cfu/ml on ruminal fermentation of two representative total mixed rations (HY, a ration for high-yield (>32 kg/d) lactating cows; LY, a ration for low-yield (<25 kg/d) lactating cows). After a 48 h in vitro rumen incubation, both rations resulted in different fermentation characteristics. The HY in comparison with LY group presented greater in vitro dry matter disappearance (IVDMD), cumulative gas production (GP48) and total volatile fatty acids (VFA, P<0.01). Increasing R. palustris addition linearly increased IVDMD (P<0.01) and GP48 (P<0.05), and the IVDMD increment in response to R. palustris addition was greater in LY than HY group (6.4% vs 1.4%). Meanwhile, increasing R. palustris addition also linearly enhanced microbial protein synthesis and increased total VFA production (P<0.01), especially in LY group (up to 21.5% and 24.5% respectively). Unchanged acetate and declined propionate in molar percentage were observed in response to the R. palustris addition. Furthermore, increasing R. palustris addition altered fermentation gas composition in which molar O2 proportion in headspace of fermentation system was linearly reduced by 46.1% in LY and 32.9% in HY group, respectively (P<0.01), and methane production in both ration groups was enhanced by 1.9-4.1% (P=0.02). In summary, the R. palustris addition exhibited high potential for promoting the growth of rumen microorganism and enhancing microbial fermentation towards non-glucogenic energy supply by maintaining an anaerobic environment to microbe equilibrium.