Digestibility, methane production and chewing activity of steers fed whole-crop round bale corn silage preserved at three maturities

Farmyard manure application and associated root proliferation improve the net greenhouse gas balance of Italian ryegrass - Maize double-cropping field in Nasu, Japan

In Japan, most cows are fed indoors, so cow manure must be carefully treated and used to manage soil fertility. The objective of this study was to compare the net greenhouse gas (GHG) balance (NGHGB) of Italian ryegrass - corn (maize) double-cropping fields receiving farmyard manure (FYM), slurry, or methane fermentation digestion liquid (MFDL). FYM, Slurry, MFDL, mineral fertilizer only (Fert.), and no-N control (Cont.) plots were set up in a randomized block design (n = 3). FYM, slurry, or MFDL was applied to meet the K requirement for forage production, and then mineral fertilizers were supplemented to meet the N and P requirements. From September 2017 to September 2020, C inputs as manure and crop residue, heterotrophic respiration (R_H), and emissions of methane (CH₄) and nitrous oxide (N₂O) from soil were determined. The similarity of the total yields in FYM, Slurry, MFDL, and Fert. plots reflected judicious fertility management. However, the residue-C input of Italian ryegrass was 38% greater in FYM plots than in the other plots. Manure-C input decreased in the order of FYM > Slurry > MFDL plots. R_H was greater in FYM and Slurry plots than in MFDL plots. Net ecosystem C balance (NECB) ([residue-C + manure-C] - [R_H-C + CH₄-C]) decreased in the order of FYM > Slurry > MFDL plots. N₂O emission was greater in Slurry and MFDL plots than in FYM plots. Consequently, NGHGB ([CH₄ and N₂O emissions] - NECB) in terms of CO₂ equivalent decreased in the order of MFDL > Slurry > FYM plots, so FYM application contributed most to GHG mitigation. Yield-scaled NGHGB was smallest in FYM plots owing to the synergy of the greatest residue-C and manure-C inputs, less N₂O emission, and the achievement of a high enough yield, reflecting judicious fertility management based on manure and mineral fertilizer.

Effect of Different Silage Storing Conditions on the Oxygen Concentration in the Silo and Fermentation Quality of Rice

We investigated the effects of different silage storing conditions on the oxygen concentration in the silo and fermentation quality of rice (Oryza sativa L.). Forage rice was ensiled in bottles (with or without space at the bottlemouth, with solid or pinhole cap, and with oxygen scavenger, ethanol transpiration agent, oxygen scavenger and ethanol transpiration agent, or no adjuvant) and stored for 57 days. The oxygen concentration decreased with the addition of the oxygen scavenger and increased with that of the ethanol transpiration agent. The oxygen scavenger facilitated silage fermentation and fungus generation, whereas the ethanol transpiration agent suppressed silage fermentation and fungus generation. However, the combined use of the oxygen scavenger and ethanol transpiration agent facilitated silage fermentation and also suppressed fungus generation. Overall, this study revealed the negative effects of oxygen on the internal silo and the positive effects of the combined use of the oxygen scavenger and ethanol transpiration agent on silage fermentation quality.

Effect of feeding whole-crop corn silage as dietary roughage on physiological and digestive response of sheep under heat exposure

The present study was conducted to investigate the effect of feeding whole-crop corn silage (WCS) compared with mixed hay (MH) or grass silage (GS) on physiological and digestive responses of sheep at thermoneutral temperature (20°C) or exposed to heat (30°C). Six sheep were fed ad libitum with one of three diets in a replicated 3 × 3 Latin square design for 24 days. After 14 days’ adaptation, they were exposed to thermoneutral (20°C) and then heat exposure (30°C) for 5 days each. Rumen sample was collected on Day 4, whereas physiological response and nitrogen (N) balance were carried-out for three successive days in each exposure period. Respiration rate and rectal temperature of WCS-fed sheep were lower (P < 0.05) than of MH and GS fed sheep and both were higher (P < 0.01) during heat exposure. The intakes of dry matter (DM) and N and the digestibilities of N and neutral detergent fibre were lower (P < 0.05) for the WCS diet than for MH and GS diets and they did not differ between two temperature exposures. However, WCS-fed sheep had higher (P < 0.05) digestibilities of DM and organic matter, as well as metabolisable energy intake (M/D) than the sheep fed MH or GS diet, and there was no temperature effect on them. As DM and N intakes were lower for the WCS diet, the variables of rumen fermentation were also lower (P < 0.05) than the other two diets except propionate and butyrate concentrations, and they did not differ between temperature exposures except NH3 concentration. In conclusion, physiological responses were improved in the WCS diet and this approach thus shows promise for feeding heat-exposed animals. However, as results were inconsistent in terms of nutrient intake and digestibility, further work is needed and we suggest investigating the effect of feeding WCS with supplemented N.

Energy partitioning and methane emission by sheep fed sorghum silages at different maturation stages

Energy partitioning and methane production by sheep fed silages of three commercially available sorghum hybrids (BRS 610, BR 700 and BRS 655) harvested at three maturation stages (milk, soft dough and floury) were evaluated in open circuit respiration chambers. A complete randomized design was used in a 3 × 3 (hybrids × maturity stages) factorial arrangement, and the means were compared by the Student-Newman-Keuls (SNK) test (P<0.05). The intake of dry matter, digestible dry matter, gross energy, digestible energy and metabolizable energy were not affected by maturation stage, but were influenced by hybrid. The net energy intake was influenced by maturity and sorghum genetics. The fecal output represented the main source of energy loss, as percentage of gross energy intake (48% to 52%), followed by heat increment (10% to 19%), methane emissions (4% to 6%) and urine (1% to 2%). There were no differences (P>0.10) among the treatments for the apparent digestibility of gross energy and metabolizability (qm). An interaction (P<0.05) between sorghum hybrid and maturation stages was observed for the efficiency of metabolizable energy utilization for maintenance (km), which ranged between 0.53 and 0.78. No differences (P>0.10) among treatments occurred in the daily methane production. There is substantial genetic diversity within sorghum species, determining different nutritional values. Sorghum genetics and maturity at harvest should not be an opportunity to reduce the contribution of agriculture to methane emissions.

Methane production and energy partitioning in sheep fedAndropogon gayanusgrass ensiled at three regrowth stages

Ribeiro Jr., G. A., Teixeira, A. M., Velasco, F. O., Faria Jr., W. G., Jayme, D. G., Maurício, R. M., Gonçalves, L. C. and McAllister, T. A. 2015. Methane production and energy partitioning in sheep fed Andropogon gayanus grass ensiled at three regrowth stages. Can. J. Anim. Sci. 95: 103–110. This study was undertaken to evaluate the effect of harvesting Andropogon gayanus at different regrowth stages (56, 84 and 112 d) on the nutritional value of silage and CH4emissions from sheep. Rams (n=18) were adapted to silages for 21 d after which intake and digestibility were measured over 5 d in a completely randomized design (six rams/treatment). Heat production and methane emissions from each ram were measured in a respiration chamber over 24 h. Silage dry matter (DM; 54.4 g kg−1BW0.75d−1) intake was not influenced (P>0.05) by silage regrowth stage, but apparent DM digestibility linearly decreased (P<0.05) from 526 to 380 g kg−1with increasing regrowth. Energy lost as a percent of gross energy intake (GEI) linearly increased with longer regrowth, yet no effect on CH4losses (as% GEI; g kg−1DM; g kg−1digestible DM) or heat production were observed. Ensiling A. gayanus grass at an earlier regrowth stage (56 d) will improve silage quality, but improvements in the energetic value are not due to a reduction in enteric CH4emissions as a% GEI.

Special topics--Mitigation of methane and nitrous oxide emissions from animal operations: I. A review of enteric methane mitigation options

The goal of this review was to analyze published data related to mitigation of enteric methane (CH4) emissions from ruminant animals to document the most effective and sustainable strategies. Increasing forage digestibility and digestible forage intake was one of the major recommended CH4 mitigation practices. Although responses vary, CH4 emissions can be reduced when corn silage replaces grass silage in the diet. Feeding legume silages could also lower CH4 emissions compared to grass silage due to their lower fiber concentration. Dietary lipids can be effective in reducing CH4 emissions, but their applicability will depend on effects on feed intake, fiber digestibility, production, and milk composition. Inclusion of concentrate feeds in the diet of ruminants will likely decrease CH4 emission intensity (Ei; CH4 per unit animal product), particularly when inclusion is above 40% of dietary dry matter and rumen function is not impaired. Supplementation of diets containing medium to poor quality forages with small amounts of concentrate feed will typically decrease CH4 Ei. Nitrates show promise as CH4 mitigation agents, but more studies are needed to fully understand their impact on whole-farm greenhouse gas emissions, animal productivity, and animal health. Through their effect on feed efficiency and rumen stoichiometry, ionophores are likely to have a moderate CH4 mitigating effect in ruminants fed high-grain or mixed grain-forage diets. Tannins may also reduce CH4 emissions although in some situations intake and milk production may be compromised. Some direct-fed microbials, such as yeast-based products, might have a moderate CH4-mitigating effect through increasing animal productivity and feed efficiency, but the effect is likely to be inconsistent. Vaccines against rumen archaea may offer mitigation opportunities in the future although the extent of CH4 reduction is likely to be small and adaptation by ruminal microbes and persistence of the effect is unknown. Overall, improving forage quality and the overall efficiency of dietary nutrient use is an effective way of decreasing CH4 Ei. Several feed supplements have a potential to reduce CH4 emission from ruminants although their long-term effect has not been well established and some are toxic or may not be economically feasible.

In sacco evaluation of ruminal degradability of waste vinegar residue as a feedstuff for ruminants

Waste vinegar residue (WVR) is a by-product of vinegar processing by solid-state fermentation. In this study, two experiments were conducted to determine chemical composition and ruminal degradability of WVR and whether WVR can be used as a feedstuff for ruminants. In Experiment 1, 14 WVR samples were incubated in the rumen of three Inner Mongolia White Cashmere Goats to determine the in sacco ruminal degradability parameters for DM, crude protein (CP) and neutral detergent fibre (NDF). The NDF, CP and ether extract (EE) contents of the WVR samples were 796.6, 125.2 and 93.3 g/kg, respectively. The greatest variation was observed for lactic acid, which ranged from 150.39 to 4391.12 mg/kg with an average of 1023.84 mg/kg. The average A, B and C fractions of DM for the 14 samples of WVR were 122, 350, and 528 g/kg, respectively. The effective degradability of DM, CP and NDF were 275, 550 and 211 g/kg, respectively. In Experiment 2, the in sacco degradation parameters for DM, CP and NDF of Chinese leymus, corn stalk and WVR were evaluated in a 3 × 3 Latin-square design. The rapidly degradable fraction of the DM and NDF for WVR was significantly (P < 0.01) greater than that of Chinese leymus and corn stalk. No difference in rumen-degraded DM, rumen-degraded CP and rumen-degraded NDF was found between Chinese leymus and WVR (P > 0.05). It is concluded that, WVR is not well digested ruminally but is a good source of protein for ruminants giving it value as an ingredient in ruminant diets.

Effect of anthocyanin-rich corn silage on digestibility, milk production and plasma enzyme activities in lactating dairy cows

Anthocyanin in purple corn (Zea mays L.) has been reported to show several functional and biological attributes, displaying antioxidant, antiobesity and antidiabetic effects in monogastric animals. The objective of this study was to investigate the effect of feeding anthocyanin-rich corn (Zea mays L., Choko C922) silage on digestibility, milk production and plasma enzyme activities in lactating dairy cows. The cows were fed diets based on the control corn or the anthocyanin-rich corn silage (AR treatment) in a crossover design. The anthocyanin-rich corn silage-based diet had a lower starch content, nutrient digestibility and total digestible nutrients content when compared to the control diet. The milk yield, lactose and solids-not-fat contents in the AR-treatment cows were lower than in the control cows. The feeding of the anthocyanin-rich corn silage led to a reduction in aspartate aminotransferase (AST) activity and an increase in superoxide dismutase (SOD) activity in the plasma. These data suggest that the anthocyanin-rich corn has a lowering effect on AST activity with concomitant enhancement of SOD activity in lactating dairy cows. However, a new variety of anthocyanin-rich corn with good nutritional value is needed for practical use as a ruminant feed.

Características de fermentação da silagem de seis variedades de milho indicadas para a região semiárida Brasileira

Avaliaram-se as características fermentativas e a qualidade das silagens de seis variedades de milho, de ciclos precoce e superprecoce - BRS Caatingueiro, BRS Assum Preto, BR 5033 Asa Branca, BR 5028 São Francisco, Gurutuba e BRS 4103 - indicadas para a região semiárida brasileira. Foram utilizados silos experimentais, em delineamento inteiramente ao acaso, com seis tratamentos (variedades) e quatro repetições. Avaliaram-se: matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), extrato etéreo (EE), carboidratos totais (CHO), carboidratos não fibrosos (CNF), pH, nitrogênio amoniacal como parte do nitrogênio total (N-NH3/NT), ácidos orgânicos e digestibilidade in vitro da matéria seca (DIVMS) das silagens. Os valores médios encontrados para a silagem foram: MS= 28,7%; MO= 94,9%; PB= 8,3%; FDN= 49,9%; FDA= 27,5%; EE= 3,8%; CHO= 82,7%; CNF= 32,8%; pH= 3,8; N-NH3/NT= 2,9%/NT; ácido láctico = 7,6%; ácido acético = 0,6%; ácido butírico = 0,3% e DIVMS= 57,9%. As variedades BR 5028 - São Francisco e Gurutuba destacaram-se das demais em relação ao teor de matéria seca. A variedade BRS Caatingueiro apresentou maior teor de carboidratos não fibrosos em relação às demais. As silagens de todas as variedades foram classificadas como de excelente qualidade, por apresentarem potencial para ensilagem no semiárido brasileiro