Neutral Detergent Fiber Degradability Research Articles

Silage additives improve fermentation quality, aerobic stability and rumen degradation in mixed silage composed of amaranth and corn straw.

The objective of this research was to investigate effects of different additives on the fermentation quality, aerobic stability and rumen degradation of mixed silage composed of amaranth and corn straw. The mixture ratio of amaranth to corn straw was 78%: 22%. Three additives were selected in this study and five groups were as follows: control group (CON, without additive), lactic acid bacteria group (LAB, 5 mg/kg, Lactobacillus plantarum ≥ 1.6×1010 CFU/g and L. buchneri ≥ 4.0×109 CFU/g), glucose group (GLU, 30 g/kg), cellulase group (CEL, 2 mg/kg) and lactic acid bacteria, glucose and cellulase group (LGC, added at the same levels as in individual group). The period of ensiling was 60 days. Fermentation quality, chemical composition and aerobic stability of mixed silage were analyzed. Four cows with permanent ruminal fistula were selected as experimental animals. Nylon bag technique was used to study rumen degradation characteristic of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of mixed silage. Compared with CON group, the addition of different silage additives could improve mixed silage quality of amaranth and corn straw to some extent. Combining three additives significantly increased (P < 0.05) the DM, CP and lactic acid contents, whereas decreased (P < 0.05) the ADF and NDF contents as well as pH and ammonia nitrogen/total nitrogen. Moreover, the aerobic stability and rumen degradation of DM, CP and NDF were significantly improved (P < 0.05) in LGC group when compared to other groups. In conclusion, the combined addition of lactic acid bacteria, glucose and cellulase increased DM, CP and lactic acid contents as well as lactic acid bacteria count, decreased NDF and ADF contents and aerobic bacteria and mold counts, improved aerobic stability and rumen degradation of amaranth and corn straw mixed silage.

Evaluation of Rumen Fermentation and Microbial Adaptation to Three Red Seaweeds Using the Rumen Simulation Technique.

Several red seaweeds have been shown to inhibit enteric CH4 production; however, the adaptation of fermentation parameters to their presence is not well understood. The objective of this study was to examine the effect of three red seaweeds (Asparargopsis taxiformis, Mazzaella japonica, and Palmaria mollis) on in vitro fermentation, CH4 production, and adaptation using the rumen simulation technique (RUSITEC). The experiment was conducted as a completely randomized design with four treatments, duplicated in two identical RUSITEC apparatus equipped with eight fermenter vessels each. The four treatments included the control and the three red seaweeds added to the control diet at 2% diet DM. The experimental period was divided into four phases including a baseline phase (d 0-7; no seaweed included), an adaptation phase (d 8-11; seaweed included in treatment vessels), an intermediate phase (d 12-16), and a stable phase (d 17-21). The degradability of organic matter (p = 0.04) and neutral detergent fibre (p = 0.05) was decreased by A. taxiformis during the adaptation phase, but returned to control levels in the stable phase. A. taxiformis supplementation resulted in a decrease (p < 0.001) in the molar proportions of acetate, propionate, and total volatile fatty acid (VFA) production, with an increase in the molar proportions of butyrate, caproate, and valerate; the other seaweeds had no effect (p > 0.05) on the molar proportions or production of individual VFA. A. taxiformis was the only seaweed to suppress CH4 production (p < 0.001), with the suppressive effect increasing (p < 0.001) across phases. Similarly, A. taxiformis increased (p < 0.001) the production of hydrogen (H2, %, mL/d) across the adaptation, intermediate, and stable phases, with the intermediate and stable phases having greater H2 production than the adaptation phase. In conclusion, M. japonica and P. mollis did not impact rumen fermentation or inhibit CH4 production within the RUSITEC. In contrast, we conclude that A. taxiformis is an effective CH4 inhibitor and its introduction to the ruminal environment requires a period of adaptation; however, the large magnitude of CH4 suppression by A. taxiformis inhibits VFA synthesis, which may restrict the production performance in vivo.

25 Effect of Cyclic Monensin Feeding onin Situ Degradability of Low-Quality Forage Fed to Ruminally Cannulated Beef Steers

Abstract Effects of cyclic monensin feeding on in situ disappearance kinetics of low-quality forage (LQF; 4.9% CP) were evaluated. Ruminally cannulated steers (n = 12; Bos taurus; 260 kg BW) consuming LQF were randomly assigned to of 3 treatments in a completely randomized design: CON (0 mg∙animal-1∙day-1 monensin; Rumensin 90, Elanco Animal Health, Greenfield, IN), 2) MON (200 mg∙animal-1∙day-1 monensin), or 3) CYC (200 mg∙animal-1∙day-1 monensin for 4 d and 0 mg∙animal-1∙day-1 monensin for subsequent 4 d). Steers were fed dried distillers’ grains with solubles (1 kg∙animal-1∙day-1) for monensin inclusion. Four 28-d replicated cycles were used allowing 9 days for treatment adaptation, 4 days for sampling, and 4 days for withdrawal of monensin within the CYC treatment group. Low-quality forage samples were weighed into 0 × 20 cm polyester bags in replicates of four for each sampling hour. On d 0, all replicates were placed into the ventral area of the rumen and replicates were removed 0, 4, 8,6, 24, 48, and 72 hours post feeding. Upon removal, bags were rinsed in ice water, and frozen until final replicates were removed. Subsequently, bags were washed utilizing a commercial washing machine, dried at 55°C to a constant weight and dried residues were analyzed for DM. Ruminal in situ DM degradation data over time were fitted to the first-order exponential model with discrete lag using the NLIN procedure of SAS 9.4, then model parameters were compared with PROC GLIMMIX model to compare dietary treatments with period included as a random variable. There was no effect of treatment (P ≥ 0.22) on potentially degradable DM, rate of DM degradation, DM residue, DM lag, or wash loss of DM. Results are consistent with findings in the concurrent in vivo study conducted by Hook et al. (2022). Further evaluation of NDF degradability is required to determine a clear effect of cyclic monensin feeding on steers consuming an LQF.

In-Situ Digestibility of Selected Fibrous Feedstuffs at Varying Levels of Concentrate Supplementation in Rumen-fistulated Brahman Bull

A series of experiments were done to determine the effects of 20% and 40% levels of concentrate supplementation on the in-situ degradability of dry matter (DMD), organic matter (OMD), and neutral detergent fibre (NDFD) in a rumen-fistulated Brahman bull. Treatment diets included: T1—untreated rice straw, T2 – urea-treated rice straw, T3 – Napier soilage, T4 – Napier silage, T5 – sugarcane tops, and T6 – dried cogon grass. The nylon bags containing the treatment diets were incubated in the rumen at two periods: first at a 20% concentrate (20% of total diet D.M.) level, and second at a 40% concentrate (40% of total diet D.M.) level in a bull-fed Napier grass as basal diet. There were significant differencesin DMD and OMD among feedstuffs tested at a 20% level of concentrate supplementation; the highest was with Napier silage. Neutral detergent fibre (NDF) digestibility was highest with urea-treated rice straw (UTRS) and lowest in Napier silage and sugarcane tops. At a 40% level, in situ DMD, OMD, and NDFD decreased significantly with Napier silage, UTRS, and Cogon, respectively, which were associated with a drop in rumen pH. Most significant drop in NDF digestibility was with rice straw, Napier soilage, and Cogon. Hence, further study is recommended on evaluating fibre degradability and incubation.

In situ ruminal degradability of forage cactus-based diets associated with pornunça silage

The knowledge of ruminal degradation kinetics of forage cactus-based diets associated with Euphorbiaceae species of the genus Manihot assist in understanding nutrient quality and use, contributing to the indication of combinations of these ingredients in ruminant diets. This study aimed to evaluate the in situ ruminal degradability of diets with increasing association of forage cactus Elephant Ear (MEE) and pornunça (Manihot sp.) silage, as well as to analyze and evaluate the indigestible neutral detergent fiber (FDNi) content of forage cactus MEE and pornunça silage. The treatments consisted of diets with cactus pear associated with pornunça silage in the roughage portion in the proportions of 375, 250, 125 and 0 g kg-1 of DM. The feed was composed of 50% roughage and 50% concentrate of dry matter. Incubation times of 0, 6, 12, 24, 48, 96, and 144 hours were evaluated for the ingredients and 0, 2, 4, 6, 8, 12, 24, 48, 72, and 96 hours for the diets. Incubation to obtain the iNDF was given for 288 hours. The experimental design consisted of randomized blocks, with three replications. Regarding roughage ingredients, MEE showed higher average disappearance, potential degradability (PD), and effective degradability (ED) in relation to pornunça silage, as well as lower NDFi content. The proportion of 375 g kg-1 MEE and 125 g kg-1 pornunça silage provided higher fractions a, b, and c, increasing ED considering the three passage rates, with higher PD. In conclusion, the association between MEE and pornunça silage at a proportion of 375 g kg-1 MEE and125g kg-1 pornunça silage of the roughage portion increases the in situ degradability of dry matter, crude protein, and neutral detergent fiber.

Effect of waste mango silage on the in vitro gas production, in situ digestibility, intake, apparent digestibility, and ruminal characteristics in calf diets.

Mexico is the fifth largest producer of mangoes in the world. For the conservation of agro-industrial waste and crop residues, the ensiling technique has shown good results. This study aimed to evaluate the effect of increasing the level of mango silage (86% waste mango and 14% pangola grass hay) in calf diets on in vitro gas production, in situ digestibility, intake, apparent digestibility, and ruminal characteristics. The diets contained 0 (T0), 30 (T1), 45 (T2), and 60% (T3) mango silage. The partial (24, 48, and 72 h) and cumulative (72 h) biogas, CH4 production, and degradation were determined in the in vitro evaluation. In situ digestibility and estimators of fermentation kinetics of dry matter (DM) and organic matter (OM) were determined. Intake, apparent nutrient digestibility, and rumen parameters of calves (200 kg) were evaluated in a 4 × 4 Latin square design. Response to increased mango silage was calculated by linear and quadratic orthogonal contrasts. In vitro partial and cumulative biogas production decreased linearly (p < 0.05), and the partial and cumulative CH4 production did not show linear or quadratic contrast (p > 0.05); in vitro DM degradation, in vitro neutral detergent fiber degradation, and in vitro acid detergent fiber degradation showed a linear increase (p < 0.05). In situ dry matter digestibility (DMDis), in situ organic matter digestibility (OMDis), b, a + b, c, and effective digestibility (ED) of DMDis, a, a + b, c, and ED of OMDis increased linearly (p < 0.05). Dry matter intake, OM intake, and crude protein intake showed a linear increase (p < 0.05); NDF intake and ADF intake presented a quadratic behavior (p < 0.05). Apparent digestibility of DM, OM, CP, and hemicellulose, pH, N-NH3, total bacterial count, acetate, propionate, butyrate, volatile fatty acids, acetate: propionate ratio, cellulolytic bacteria, and protozoa did not present a linear or quadratic orthogonal effect (p > 0.05). The in vitro, in situ, and in vivo variables demonstrated that up to 60% mango silage can be used for the intensive fattening of calves in confinement.

Supplementing Proteolytic Enzymes Increased the In Vitro Nutrient Effective Degradability and Fermentation Characteristics of Pineapple Waste Silage

Pineapple waste silage (PAS) is an abundant agro-industrial by-product characterized by its high fiber content posing a high potential feed value as roughage for ruminants. Studies on its supplementation with proteolytic enzyme (PE) will help extend its utilization as an alternative nutritive feed source for cattle nutrition. Thus, this study aimed to determine the in vitro nutrient degradability and fermentation characteristics of fiber-rich but low-protein PAS supplemented with different levels of PE. Seven treatments were evaluated in this study: PAS without PE and PAS1 to PAS6, which corresponds to incremental levels of PAS supplementation as follows: 0.1%, 0.2%, 0.3%, 1%, 2%, and 4%. The nutrient disappearance, nutrient effective degradability, and fermentation characteristics such as total gas production, ammonia-nitrogen, and pH values were evaluated in vitro. PAS without added PE showed a comparably good nutritive value (dry matter: 94.30%, neutral detergent fiber: 63.66%, acid detergent fiber: 34.78%) to that of commonly used corn silage in South Korea. With the supplementation of PE in PAS, the PE increased the effective degradability of different nutrients such as dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), organic matter (OM), and crude protein (CP). The effect of PE supplementation on the degradation of nutrients was consistent with improvements in in vitro rumen fermentation characteristics. Supplementing PAS with PE increased the total gas production and decreased the pH values, which are characteristics of heightened fiber degradation and fermentation. The ammonia-N concentration of the in vitro-incubated PAS was moderated by the addition of PE, which is likely due to the decrease in pH or in vitro acidosis and has shown a synergistic protease activity effect on nutrient degradation. Overall, supplementing PAS with PE increased the effective degradability of DM, NDF, ADF, OM, and CP, with the most dramatic effects observed in PAS3 and PAS6 (0.3% and 4%, respectively).

The Effect of Combining Millet and Corn Straw as Source Forage for Beef Cattle Diets on Ruminal Degradability and Fungal Community

Three ruminal cannulated Simmental crossbreed bulls (approximately 3 years of age and with 380 ± 20 kg live weight at initiation of the experiment) were used in a 3 × 3 Latin square experiment in order to determine the effects of the treatments on ruminal pH and degradability of nutrients, as well as the rumen fungal community. The experimental periods were 21 d, with 18 d of adjustment to the respective dietary treatments and 3 d of sample collection. Treatments consisted of a basal diet containing a 47.11% composition of two sources of forage as follows: (1) 100% millet straw (MILLSTR), (2) 50:50 millet straw and corn straw (COMB), and (3) 100% corn straw (CORNSTR). Dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) were tested for ruminal degradability using the nylon bag method, which was incubated for 6, 12, 24, 36, 48, and 72 h, and rumen fungal community in rumen fluid was determined by high-throughput gene sequencing technology. Ruminal pH was not affected by treatments. At 72 h, compared to MILLSTR, DM degradability of CORNSTR was 4.8% greater (p < 0.05), but when corn was combined with millet straw, the difference in DM degradability was 9.4%. During the first 24 h, degradability of CP was lower for CORNSTR, intermediate for MILLSTR, and higher for COMB. However, at 72 h, MILLSTR and COMB had a similar CP degradability value, staying greater than the CP degradability value of the CORNSTR treatment. Compared to MILLSTR, the rumen degradability of NDF was greater for CORNSTR and intermediate for the COMB. There was a greater degradability for ADF in CORNSTR, intermediate for COMB, and lower for MILLSTR. In all treatments, Ascomycota and Basidiomycota were dominant flora. Abundance of Basidiomycota in the group COMB was higher (p < 0.05) than that in the group CORNSTR at 12 h. Relative to the fungal genus level, the Thelebolus, Cladosporium, and Meyerozyma were the dominant fungus, and the abundance of Meyerozyma in COMB and CORNSTR were greater (p < 0.05) than MILLSTR at 12, 24, and 36 h of incubation. In conclusion, it is suggested to feed beef cattle with different proportions of millet straw and corn straw combinations.

Effect of drought stress on neutral detergent fiber degradation kinetics of corn for silage

The objective of this study was to determine the effect of irrigation on in situ neutral detergent fiber (NDF) degradability of corn tissues from plants grown under controlled conditions in a greenhouse. Five commercial corn hybrids were planted in 6 pots that were placed in a greenhouse. Pots were randomly subjected to 2 irrigation regimens, which consisted of either abundant (A; 598 mm) or restricted (R; 273 mm) irrigation. At harvesting, leaf blades and stem internodes were collected from the upper and bottom portion of the plants. Tissue samples were incubated in the rumen of 3 rumen-cannulated cows for 0, 3, 6, 12, 24, 48, 96, and 240 h to determine in situ NDF degradation kinetics. Drought stress did not affect the concentration of undegraded NDF (uNDF) in upper or bottom internodes but slightly decreased it in upper leaf blades (17.5 and 15.7% for A and R, respectively). The concentration of uNDF differed substantially among corn hybrids in upper internodes (13.4 to 28.3% uNDF), bottom internodes (21.5 to 42.3% uNDF), and upper leaf blades (11.6 to 20.1% uNDF). No interactions existed between irrigation treatment and corn hybrid for uNDF concentration. Drought stress did not affect the fractional degradation rate (kd) of NDF in upper internodes, bottom internodes, or upper leaf blades. The kd of NDF differed among corn hybrids in upper (3.8 to 6.6%/h) and bottom internodes (4.2 to 6.7%/h) but did not vary in upper leaf blades (3.8%/h). No interactions existed between irrigation treatment and corn hybrids for the kd of NDF. Significant interactions existed between irrigation treatment and corn hybrids for the effective ruminal degradation (ERD) of NDF in upper and bottom internodes. This interaction did not exist for upper leaf blades. The ERD of NDF differed substantially among corn hybrids in upper leaf blades (32.5 to 39.1%). In conclusion, drought-stressed corn had a marginal increase of NDF degradability of leaf blades but not in stem internodes, and drought stress had no effects on ERD of NDF. The effect of drought stress on NDF degradability of corn for silage is still inconclusive and deserves further investigation.

Balancing dairy cattle diets for rumen nitrogen and methionine or all essential amino acids relative to metabolizable energy

Improving the ability of diet formulation models to more accurately predict AA supply while appropriately describing requirements for lactating dairy cattle provides an opportunity to improve animal productivity, reduce feed costs, and reduce N intake. The goal of this study was to evaluate the sensitivity of a new version of the Cornell Net Carbohydrate and Protein System (CNCPS) to formulate diets for rumen N, Met, and all essential AA (EAA). Sixty-four high-producing dairy cattle were randomly assigned to 1 of the 4 following diets in a 14-wk longitudinal study: (1) limited metabolizable protein (MP), Met, and rumen N (Base), (2) adequate Met but limited MP and rumen N (Base + M), (3) adequate Met and rumen N, but limited MP (Base + MU), and (4) adequate MP, rumen N, and balanced for all EAA (Positive). All diets were balanced to exceed requirements for ME relative to maintenance and production, assuming a nonpregnant, 650-kg animal producing 40 kg of milk at 3.05% true protein and 4.0% fat. Dietary MP was 97.2, 97.5, 102.3, and 114.1 g/kg of dry matter intake for the Base, Base + M, Base + MU, and Positive diets, respectively. Differences were observed for dry matter intake and milk yield (24.1 to 24.7 and 39.4 to 41.1 kg/d, among treatments). Energy corrected milk, fat, and true protein yield were greater (2.9, 0.13, and 0.08 kg/d, respectively) in cows fed the Positive compared with the Base diet. Using the updated CNCPS, cattle fed the Base, Base + M, and Base + MU diets were predicted to have a negative MP balance (-231, -310, and -142 g/d, respectively), whereas cattle fed the Positive diet consumed 33 g of MP/d excess to ME supply. Bacterial growth was predicted to be depressed by 16 and 17% relative to adequate N supply for the Base and Base + M diets, respectively, which corresponded with the measured lower apparent total-tract NDF degradation. The study demonstrates that improvements in lactation performances can be achieved when rumen N and Met are properly supplied and further improved when EAA supply are balanced relative to requirements. Formulation using the revised CNCPS provided predictions for these diets, which were sensitive to changes in rumen N, Met, all EAA, and by extension MP supply.

Effects of different proportions of stevia stalk on nutrient utilization and rumen fermentation in ruminal fluid derived from sheep.

Stevia straw is a byproduct of sugar crop stevia. It is a good feed material because of richness in nutrients and active substances (steviosides and flavonoids). However, due to improper utilization such as piling, burning and so on, it became a large amount of wasted straw resources and lead to environmental pollution. We added 0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0% and 1.5% of stevia stalk to study the effects of different stevia stalk concentrations on nutrient utilization and rumen fermentation in sheep (based on sheep diet). In vitro fermentation method was used, with 17 repetitions for each treatment. All fermentation substrate based on sheep diet with different stevia stalk concentrations were fermented for 2 h, 6 h, 12 h, 24 h and 48 h, then the gas production, dry matter degradability (DMD), crude protein degradability (CPD), neutral detergent fiber degradability (NDFD), acid detergent fiber degradability (ADFD), pH, ammonia nitrogen (NH3-N) and volatile fatty acids (VFAs) were determined. The results showed that at different fermentation time, the change trend of gas production in each teatment was basically same, but the maximum occurred in 1.0% treatment at 48 h. The DMD, CPD, NDFD and ADFD of sheep diets increased with fermentation time increasing, especially the CPD48h, NDFD48h and ADFD48h of diets in 0.8%, 1.0% and 1.5% treatments were significantly higher than those in control (P < 0.05). The pH of fermentation substrate in each treatment remained within the normal range of 6.21∼7.25. NH3-N24h-48hin 0.8%, 1.0% and 1.5% treatments were higher than that in control. At 6 h-12 h, the total acid content of 0.8% and 1.0% treatments were significantly higher than those of other treatments (P < 0.05), it reached the highest in 1.0% treatment. According to overall evaluation, effect ranking of stevia stalk on sheep nutrient utilization was as follows: 1.0% >0.8% >1.5% >0.4% >0.6% >0.2%. Overall, 1.0% stevia stalk could promote nutrient degradation and sheep rumen fermentation.

Network analysis to evaluate complexities in relationships among fermentation variables measured within continuous culture experiments.

The objective of this study was to leverage a frequentist (ELN) and Bayesian learning (BLN) network analyses to summarize quantitative associations among variables measured in 4 previously published dual-flow continuous culture fermentation experiments. Experiments were originally designed to evaluate effects of nitrate, defaunation, yeast, and/or physiological shifts associated with pH or solids passage rates on rumen conditions. Measurements from these experiments that were used as nodes within the networks included concentrations of individual volatile fatty acids, mM and nitrate, NO3-,%; outflows of non-ammonia nitrogen (NAN, g/d), bacterial N (BN, g/d), residual N (RN, g/d), and ammonia N (NH3-N, mg/dL); degradability of neutral detergent fiber (NDFd, %) and degradability of organic matter (OMd, %); dry matter intake (DMI, kg/d); urea in buffer (%); fluid passage rate (FF, L/d); total protozoa count (PZ, cells/mL); and methane production (CH4, mmol/d). A frequentist network (ELN) derived using a graphical LASSO (least absolute shrinkage and selection operator) technique with tuning parameters selected by Extended Bayesian Information Criteria (EBIC) and a BLN were constructed from these data. The illustrated associations in the ELN were unidirectional yet assisted in identifying prominent relationships within the rumen that were largely consistent with current understanding of fermentation mechanisms. Another advantage of the ELN approach was that it focused on understanding the role of individual nodes within the network. Such understanding may be critical in exploring candidates for biomarkers, indicator variables, model targets, or other measurement-focused explorations. As an example, acetate was highly central in the network suggesting it may be a strong candidate as a rumen biomarker. Alternatively, the major advantage of the BLN was its unique ability to imply causal directionality in relationships. Because the BLN identified directional, cascading relationships, this analytics approach was uniquely suited to exploring the edges within the network as a strategy to direct future work researching mechanisms of fermentation. For example, in the BLN acetate responded to treatment conditions such as the source of N used and the quantity of substrate provided, while acetate drove changes in the protozoal populations, non-NH3-N and residual N flows. In conclusion, the analyses exhibit complementary strengths in supporting inference on the connectedness and directionality of quantitative associations among fermentation variables that may be useful in driving future studies.

Optimisation of solid-state fermentation process of sunflower meal based on response-surface methodology

Context Some studies have investigated the application of sunflower meal (SFM) in feeding livestock and poultry. However, there have been few researches related to fermenting SFM. Aims In this experiment, the neutral detergent fibre degradability and increase rate of crude protein were used as rapid evaluation indicators of solid-state fermentation (SSF), and the response-surface methodology was used to optimise the process conditions for SSF of SFM with the mixed fermentation agent (Bacillus subtilis H-12, Saccharomyces cerevisiae Y-5 and Trichoderma longibrachiatum). Methods Box-Behnken design with three factors and three levels was adopted. The process conditions were fermentation temperature (28°C, 32°C, 36°C), duration of time (48 h, 72 h, 96 h), and moisture to substrate ratio (MSR; 50 %, 100%, 150 % (v/m)). The nutritional quality and feeding value of the original SFM and fermented SFM were evaluated under the optimal process conditions according to response-surface methodology. Key results The results showed that the optimal process conditions for SSF of SFM were as follows: fermentation temperature 31.7°C, duration of time 72.2 h, and MSR 106.4%; the contents of crude protein (44.82%), true protein (42.40%) and total amino acid (36.77%) in fermented SFM were significantly increased compared with those of original SFM (P &lt; 0.05); the neutral detergent fibre, crude fibre and chlorogenic acid contents were decreased significantly (P &lt; 0.05); the index values of metal elements, vomitoxin, aflatoxin and coliform were all lower than the national limit standards. Conclusion The nutritional quality and feeding value of SFM were improved by microbial SSF, while the potential risks of harmful toxins and microbial contamination were reduced. Implications The results of this study will contribute to the research on the development of protein-feed raw materials and explore the application of SFM in feed industry.

Effects of &amp;lt;i&amp;gt;Stylosanthes scabra&amp;lt;/i&amp;gt; Forage Supplementation on &amp;lt;i&amp;gt;in Vitro&amp;lt;/i&amp;gt; Gas Production and Fiber Degradation of &amp;lt;i&amp;gt;Eragrostis&amp;lt;/i&amp;gt; Grass Hay

Natural pastures constitute a major component of ruminant livestock feed, and are the most cost-effective feed resource available for smallholder subsistence farmers. However, this feed resource does not meet animal nutritional requirement due to deficiency in nitrogen, energy and minerals. In addition, at maturity lignification is the major concern since it reduces digestibility and contributes to methane emission. Thus, the objective of this study was to evaluate the effect of supplementing low-quality Eragrostis grass hay with five (9281, 11,252, 11,255, 11,595 and 11,604) selected Stylosanthes scabra accessions on in vitro ruminal fermentation and neutral detergent fiber degradation. Therefore, in vitro study was conducted on grass hay, accessions and the mixture of grass hay with each accession included at two (15%, 30%) levels. The substrates (grass hay, accessions and the mixtures) were incubated in separate serum bottles for 72 h. Neutral detergent fiber (NDF) of the accessions ranged from 300 to 350 g/kg DM with crude protein (CP) value ranging from 177.5 to 184.1 g/kg DM. Eragrostis grass hay had NDF value of 813 g/kg DM, with CP value of 34.3 g/kg DM. Grass hay fermented slowly, it took 30 h for grass hay to produce gas volume above 50 mL, while Stylosanthes scabra accessions took 12 h. Supplementing grass hay with accessions significantly improved fermentation. However, it was observed that 15% inclusion took 30 h to produce gas volume above 50 mL, whereas at 30% inclusions it took 24 h for accession 9281, 11,595 and 11,604. Accession 11,604 improve grass fermentation by almost three times the value of grass hay in 2 h. Grass hay supplemented with accession 11,604 at 30% had a positive associative effect and significantly improved NDF degradability. In conclusion, accession 11,604 may be fed strategically as forage supplement to low-quality forage for ruminants.

Fibrolytic Enzymes Increase Fermentation Losses and Reduce Fiber Content of Sorghum Silage

Abstract Fiber digestibility is a key-point of forage usage in ruminant production systems. The present study aimed to evaluate the effect of fibrolytic enzyme blend on whole-plant sorghum silage fermentation profile, fermentative losses, chemical composition, in vitro degradation, and aerobic stability. It used fifty experimental silos (plastic bucket, 28 cm i.d. and 25 cm in height) in a blocked randomized design to evaluate the following fibrolytic enzyme levels: 0, 150, 300, 450, and 600 mL per ton of dry matter (DM). Enzymes had 300 U/mL of xylanase and 300 U/mL of cellulase. Enzymes linearly increased acetic acid, branched-chain organic acids, and ethanol concentration of silage. Although there was no treatment effect on silage DM recovery over the ensiling process, enzyme levels linearly increased gas, effluent, and total losses. Intermediary levels of enzymes (from 312 to 342 mL/ton DM) decreased fiber content (NDF and ADF), whereas improved NFC silage content. Besides, enzymes did not affect DM and NDF degradation and tended to linearly reduce acid detergent fiber in vitro degradation. The enzymes addition linearly decreased silage temperature after aerobic exposure. However, there was no treatment effect on silage pH after aerobic exposure also during the time that silage remained with a temperature lower than 2°C above environmental temperature. Thus, fibrolytic enzymes reduce fiber content, promote a heterolactic fermentation, and reduce silage temperature after aerobic exposure. However, this increases fermentative losses and has no positive effect on in vitro degradation and the time of aerobic stability.

Comparative Study of the Nutritional Value and Degradation Characteristics of Amaranth Hay in the Rumen of Goats at Different Growth Stages.

The objective of this study was to investigate the rumen degradation characteristics of grain amaranth hay (Amaranthus hypochondriacus) at four different growth stages. The aim of this study was to evaluate the nutritional value of grain amaranth hay at different growth stages by chemical composition, in vivo digestibility, and in situ degradability. Three Boer goats with permanent ruminal fistulas were selected in this study. Amaranthus hay at four different growth stages (squaring stage (SS), initial bloom stage (IS), full-bloom stage (FS) and mature stage (MS)) was crushed and placed into nylon bags. Each sample was set up with three replicates, and two parallel samples were set up in fistulas at each time point. The rumen degradation rates of dry matter (DM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF) were determined at 0, 6, 12, 24, 36, 48 and 72 h. The results were as follows: (1) The concentration of CP in SS was the highest and was significantly higher than that in other stages (p < 0.05), whereas the contents of NDF and ADF gradually increased with the extension of the growing period and reached a maximum in MS; (2)The degradation of CP in the rumen at 72 h of SS and IS was more than 80%. Compared with other stages, the effective degradability of CP was highest in SS (p < 0.05) and reached 87.05% at 72 h, and the degradation rate was the lowest in MS; and (3) The effective degradability of NDF in IS was the highest (p < 0.05) and reached 69.326% at 72 h. The effective degradability of ADF in MS was the highest (p < 0.05) and reached 65.728% at 72 h. The effective degradability of DM and CP in SS was the highest. In conclusion, among the four stages, IS was superior in chemical composition and rumen degradability characteristics.

Effects of exogenous amylolytic or fibrolytic enzymes inclusion on in vitro fermentation of lactating dairy cow diets in a dual-flow continuous-culture system

The objective of this study was to determine the effects of including exogenous amylolytic or fibrolytic enzymes in a diet for high-producing dairy cows on in vitro ruminal fermentation. Eight dual-flow continuous-culture fermentors were used in a replicated 4 × 4 Latin square. The treatments were control (CON), a xylanase and glucanase mixture (T1), an α-amylase mixture (T2), or a xylanase, glucanase, and α-amylase mixture (T3). Treatments were included at a rate of 0.008% of diet dry matter (DM) for T1 and T2 and at 0.02% for T3. All treatments replaced the equivalent amount of soybean meal in the diet compared with CON. All diets were balanced to have the same nutrient composition [30.2% neutral detergent fiber (NDF), 16.1% crude protein (CP), and 30% starch; DM basis], and fermentors were fed 106 g/d divided into 2 feedings. At each feeding, T2 was pipetted into the respective fermentor and an equivalent amount of deionized water was added to each fermentor to eliminate potential variation. Experimental periods were 10 d (7 d for adaptation and 3 d for sample collection). Composite samples of daily effluent were collected and analyzed for volatile fatty acids (VFA), NH3-N, and lactate concentrations, degradability of DM, organic matter, NDF, CP, and starch, and flow and metabolism of N. Samples of fermentor contents were collected from each fermentor at 0, 1, 2, 4, 6, and 8 h after feeding to determine kinetics of pH, NH3-N, lactate, and VFA concentrations over time. All data were analyzed using PROC GLIMMIX of SAS (SAS Institute Inc.), and the repeated variable of time was included for kinetics measurements. Treatment did not affect mean pH, degradability, N flow and metabolism, or the concentrations of VFA, NH3-N, or lactate in the effluent samples. Treatment did not affect pH, acetate:propionate ratio, or the concentrations of lactate, NH3-N, total VFA, acetate, propionate, butyrate, isobutyrate, valerate, or caproate. However, the concentration of total VFA tended to change at each time point depending upon the treatment, and T2 tended to have a greater proportion of 2-methylbutyrate and isovalerate than CON, T1, or T3. As 2-methylbutyrate and isovalerate are branched-chain VFA that are synthesized from branched-chain amino acids, T2 may have an increased fermentation of branched-chain amino acids or decreased uptake by fibrolytic microorganisms. Although we did not observe changes in N metabolism due to the enzymes, there could be changes in microbial populations that utilize branched-chain VFA. Overall, the tested enzymes did not improve in vitro ruminal fermentation in the diet of high-producing dairy cows.

Cactus Cladodes Opuntia or Nopalea and By-Product of Low Nutritional Value as Solutions to Forage Shortages in Semiarid Areas.

We aimed to evaluate the effect of the cactus cladodes Nopalea cochenillifera (L). Salm-Dyck. (NUB) and cactus cladodes Opuntia&amp;nbsp;stricta (Haw.) Haw. (OUB), both combined with sugarcane bagasse (SB) plus urea, Tifton hay (TH), corn silage (CS), and sorghum silage (SS) plus urea on nutrient intake and digestibility, ruminal dynamics, and parameters. Five male sheep, fistulated in the rumen, were assigned in a 5 × 5 Latin square design. The NUB provided a higher intake of dry matter (DM) and any nutrients than SS. TH provided larger pools of DM and iNDF. The OUB and CS provided a higher DM degradation. CS provided a higher NDF degradation rate. OUB provided a lower ruminal pH. Depending on the collection time, the lowest pH value was estimated at 3.79 h after the morning feeding. There was an interaction between treatments and collection time on VFA concentrations. Due to the high degradation rate, greater energy intake, less change in rumen pH, greater volatile fatty acid production, and feasibility, we recommend using cactus associated with sugarcane bagasse plus urea in sheep diets.

Rumen microbiota responses to the enzymatic hydrolyzed cottonseed peptide supplement under high-concentrate diet feeding process.

In current dairy production, dietary energy is always excessively provided with a high-concentrate diet feeding to improve milk production. However, this feeding practice disturbed the rumen microbial ecosystem and the balance between ruminal energy and nitrogen, resulting in decreased nutrient fermentability, which in turn declined the milk yield of dairy cows. Therefore, supplementation of dietary degradable nitrogen may be helpful for high dairy production. In this study, we evaluated the regulatory effects of easily utilized enzymatic hydrolyzed cottonseed peptide (EHP) supplements on rumen microbiota communities and rumen nutrient fermentability under high-concentrate feeding. For this purpose, a gradient concentrate of EHP (from 0.2 to 1.0%) was added to the high-concentrate basal substrates for an in vitro experiment. Each treatment contained three replicates, with three bottles in each replicate. Rumen fermentable parameters included microbial protein content, volatile fatty acids, and ammonia-N; the rumen nutrient degradability of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, ether extracts, calcium, and phosphorus were further investigated after in vitro fermentation for 72 h. Then, rumen microbiota communities and their correlation with ruminal fermentation parameters and rumen nutritional degradability were analyzed to understand the regulatory mechanism of the EHP supplements on rumen fermentability. Results indicate that treatment with 0.6% of EHP supplements had the highest content of acetate, butyrate, and neutral detergent fiber degradability among all treatments. Furthermore, EHP supplements significantly increased the relative abundance of rumen cellulose and starch-degrading bacteria such as Ruminococcus, Bifidobacterium, and Acetitomaculum, and the high nitrogen utilizing bacteria Butyrivibrio and Pseudobutyrivibrio, which may further promote the rumen carbohydrate and nitrogen metabolism. In summary, supplementation of easily degraded small peptides helps reestablish rumen energy and nitrogen balance to promote the rumen fermentable functions and nutritional degradability under high-concentrate diet feeding circumstances. These findings may further promote dairy production.

Ensiling of rice straw enhances the nutritive quality, improves average daily gain, reduces in vitro methane production and increases ruminal bacterial diversity in growing Hu lambs

To ensile rice straw (ENRS), a combination of lactic acid bacteria (LAB), consisting of Lactobacillus plantarum, L. buchneri and Pediococcus acidilactici at a ratio of 2:1:1 was added to rice straw (RS), and stored for 42 days at room temperature. We examined: 1) the nutritive quality of ENRS; 2) in vitro rumen fermentation parameters and microbiota composition with ENRS as substrate; and, 3) serum metabolites and average daily gain (ADG) of growing Hu lambs consuming ENRS. Ensiling of rice straw increased in vitro neutral detergent fiber (NDF) and acid detergent fiber (ADF) degradabilities (both P < 0.05), and total gas production (P < 0.05) but decreased (P < 0.05) methane (CH4) production. In addition, ensiling increased bacterial diversity and reduced the relative abundance of the methanogen Methanobrevibacter. Twelve male Hu lambs (initial live body weight = 25.2 ± 0.47 kg), aged 70 ( ± 6) days, were assigned randomly to one of two groups (n = 6) and offered a total mixed ration (TMR) that included 400 g/kg DM of either RS or ENRS for 4 weeks. Ensiling ruptured the physical structure of the RS, decreased (P < 0.05) dry matter and hemicellulose contents, and increased (P < 0.05) the concentrations of lactate, acetate and organic acids. Feeding ENRS up-regulated purine metabolism and improved ADG and gain to feed ratio of Hu lambs when compared to RS. In summary, ensiling was effective in improving both the nutritive quality of the feed and ADG of the lambs.