Reduction of methane and nitrogen emission and improvement of feed efficiency, rumen fermentation, and milk production through strategic supplementation of eucalyptus (Eucalyptus citriodora) leaf meal in the diet of lactating buffalo (Bubalus bubalis)

Buffalo plays a compelling role in reducing malnutrition and ensuring food to the people of Asian countries by its major contribution to milk and meat pool of the livestock agriculture farming system in the region. As Asia is the home for more than 90% of world buffalo population, they are also one of the largest emitters of greenhouse gasses. Eucalyptus (Eucalyptus sp.) leaves are rich sources of naturally occurring essential oils and phenolic compounds, which could modulate rumen fermentation through mitigation of methanogenesis and nitrogen excretion along with stimulation of immune system and production performances of animals. Therefore, the present study investigated the impact of dietary inclusion of eucalyptus (Eucalyptus citriodora) leaf meal (ELM) on voluntary feed intake, rumen functions, methane emission, nutrient utilization, milk yield and fatty acids profile, and immune response in lactating buffalo (Bubalus bubalis). An in vitro experiment conducted with graded dose (10-40 g/kg) inclusion of ELM into the total mixed ration to select ideal level for feeding to lactating buffaloes, an improvement (P < 0.05) in feed degradability (IVDMD), microbial biomass and ruminal volatile fatty acids concentration with reduced (P < 0.05) methane and ammonia-N production were evidenced when ELM was added at 10-20 g/kg DM, beyond which negative effects on rumen fermentation were pronounced. An in vivo experimentation was conducted with sixteen Murrah (Bubalus bubalis) buffaloes of mean live weight, 544.23 ± 10.02 kg; parity, 2-4 at initial stage (~60 days) of lactation with average milk yield of 11.43 ± 1.32 kg and were divided into two groups (CON, ELM) of eight each in a completely randomized design. All the animals were kept individually on wheat straw-based diet with required quantity of concentrate mixture and green fodder. The control group buffaloes were fed a total mixed ration; however, the treatment group (ELM) was supplemented with 10 g/kg DM diet of dry grounded eucalyptus (Eucalyptus citriodora) leaves by mixing with the concentrate mixture. The feeding experiment was conducted for 120 days, including 15 days for adaptation to the experimental diets and 105 days for data recording. The nutrient digestibility (DM, OM, CP, and EE) was improved (P < 0.05) without affecting feed intake (P > 0.05) and fiber digestibility (NDF and ADF) in ELM supplemented buffaloes. Increased (P < 0.05) milk production and rumenic acid concentration (cis 9 trans 11 C18:2 CLA) were demonstrated with comparable (P > 0.05) milk composition and major fatty acids profile of milk in the supplemented buffaloes. Dietary inclusion of ELM reduced (P < 0.05) enteric methane production and fecal excretion of nitrogen. The health status of buffaloes fed ELM improved throughout the experimental period was improved by enhancing cell mediated (P = 0.09) and humoral (P < 0.01) immune responses without affecting (P > 0.05) major blood metabolites. The study described feeding ELM at 10 g/kg diet to lactating Murrah buffaloes as a natural source of phenols and essential oils to increase milk production and CLA content, reduce methane and nitrogen emissions, and improve health status. Thus, feeding of ELM could be beneficial for climate smart buffalo production system for enhancing milk production with lesser impact on environment.

Comparison of Black Tea Waste and Legume Roughages: Methane Mitigation and Rumen Fermentation Parameters

The chemical composition, in vitro total gas and CH₄ production and performance of cattle fed on factory black tea waste (Camellia sinensis) (BTW), alfalfa (Medicago Sativa), sainfoin (Onobrychis sativa) and white clover (Trifolium repens) was investigated. The gas production was quantified at the 24th hour of the incubation process. BTW was found to vary from roughages in chemical composition (p < 0.05). In addition, the roughages differed in terms of nutrient composition and gas production (p < 0.05). In legume roughages, acetic acid (AA), propionic acid (PA), butyric acid (BA), and total volatile fatty acids (TVFA) values ranged from 52.36-57.00 mmol/L, 13.46-17.20 mmol/L, 9.79-12.43 mmol/L, and 79.71-89.05 mmol/L, respectively. In comparison with black tea waste, legume roughages had higher values of AA, PA, BA, and TVFA. Black tea waste contained a higher acetic acid ratio than legume roughages when compared as a percentage. There was a similar ratio of propionic acid to the rate calculated for sainfoin (Onobrychis sativa) and clover (Trifolium repens), and a similar ratio of butyric acid to the ratio determined for alfalfa (Medicago Sativa). The current study shows that the 5.7-6.3% tannin content of black tea waste can be used in ruminant rations with high-quality roughages. Due to the fact that BTW reduces methane emissions from ruminants and eliminates energy waste from them, the environment can be improved. To obtain more reliable results, further animal feeding experiments on legume roughages and BTW are required.

Effect of supplementing sulphate-reducing bacteria along with sulphur on growth performance, nutrient utilization and methane emission in goats

A competitive relationship exists between sulphate-reducing bacteria and methanogens in the anaerobic environment including rumen for hydrogen where sulphate is not limiting growth and consequently inhibit enteric methane emission as thermodynamically energetic sulphate reduction (∆G^o =  - 21.1 kJ/mole of H₂) is more favourable than methanogenesis (∆G^o =  - 16.9 kJ/mole H₂). To validate this hypothesis, a study was designed to investigate the effect of supplementation of sulphate-reducing bacteria (SRB) identified as Streptococcus caviae RM296 as microbial feed additives alone or along with sulphur (as sodium sulphate) on methane production, live weight gain, feed intake, nutrient digestibility and energy metabolism in goats. The experiment was conducted on growing kids (n = 36, 5-6 months of age) with average body weight of 10.08 ± 0.21 kg, divided into six groups (n = 6). The duration of the feeding trial was of 150 days. The six treatments were control fed a basal diet (T1), SRB 0.5 ml/kg BW (T2), sulphur (as sodium sulphate) 0.095% of DMI (total sulphur level in the diet 1.5 times the requirement) (T3), sulphur (as sodium sulphate) 0.095% of DMI + SRB 0.5 ml/kg BW (T4), sulphur (as sodium sulphate) 0.19% of DMI (total sulphur level in the diet 2 times the requirement) (T5) and sulphur (as sodium sulphate) 0.19% of DMI + SRB 0.5 ml/kg BW (T6). Duration of study was 150 days and goats were fed as per ICAR (2013) feeding standard. Methane (CH₄) production (l/kg DMI) was reduced by 11.8% (P = 0.052) in T6 where sulphur (0.19% DMI) was supplemented along with SRB4 (at the rate 0.5 ml/kg BW) as compared to T1 (un-supplemented group). However, the dry matter intake (DM), total weight gain (TG), average daily gain (ADG), feed conversion ratio (FCR), excretion of purine derivatives (allantoin, uric acid, xanthine and hypoxanthine) and digestibility of organic matter (OM), dry matter (DM), ether extract (EE), crude protein (CP), acid detergent fibre (ADF) and neutral detergent fibre (NDF) were similar (P > 0.05) among all the groups. The experimental data revealed that feeding of SRB as a microbial feed additive along with sulphur (as sodium sulphate) is capable of reducing enteric CH₄ emission without any adverse effect on rumen fermentation and digestibility of the nutrients.

Garlic and Its Bioactive Compounds: Implications for Methane Emissions and Ruminant Nutrition

Methane (CH4) emission from enteric fermentation of ruminant livestock is a source of greenhouse gases (GHG) and has become a significant concern for global warming. Enteric methane emission is also associated with poor feed efficiency. Therefore, research has focused on identifying dietary mitigation strategies to decrease CH4 emissions from ruminants. In recent years, plant-derived bioactive compounds have been investigated for their potential to reduce CH4 emissions from ruminant livestock. The organosulphur compounds of garlic have been observed to decrease CH4 emission and increase propionate concentration in anaerobic fermentations (in vitro) and in the rumen (in vivo). However, the mode of action of CH4 reduction is not completely clear, and the response in vivo is inconsistent. It might be affected by variations in the concentration and effect of individual substances in garlic. The composition of the diet that is being fed to the animal may also contribute to these differences. This review provides a summary of the effect of garlic and its bioactive compounds on CH4 emissions by ruminants. Additionally, this review aims to provide insight into garlic and its bioactive compounds in terms of enteric CH4 mitigation efficacy, consistency in afficacy, possible mode of action, and safety deriving data from both in vivo and in vitro studies.

Nutritional Interventions to Reduce Methane Emissions in Ruminants

Methane is the single largest source of anthropogenic greenhouse gases produced in ruminants. As global warming is a main concern, the interest in mitigation strategies for ruminant derived methane has strongly increased over the last years. Methane is a natural by-product of anaerobic microbial (bacteria, archaea, protozoa, and fungi) fermentation of carbohydrates and, to a lesser extent, amino acids in the rumen. This gaseous compound is the most prominent hydrogen sink product synthesized in the rumen. It is formed by the archaea, the so-called methanogens, which utilize excessive ruminal hydrogen. Different nutritional strategies to reduce methane production in ruminants have been investigated such as dietary manipulations, plant extracts, lipids and lipid by-products, plant secondary metabolites, flavonoids, phenolic acid, statins, prebiotics, probiotics, etc. With the range of technical options suggested above, it is possible to develop best nutritional strategies to reduce the ill effects of livestock on global warming. These nutritional strategies seem to be the most developed means in mitigating methane from enteric fermentation in ruminants and some are ready to be applied in the field at the moment.

Cistanche deserticola Addition Improves Growth, Digestibility, and Metabolism of Sheep Fed on Fresh Forage from Alfalfa/Tall Fescue Pasture

Simple Summary

Cistanche deserticola is a functional plant which mainly grows in desert and is parasitic on roots of the host species Haloxylon ammodendron. It has advantages in improving bodily intestinal peristalsis, immunity, anti-aging, anti-oxidation, and liver health and was supplied for sheep in this experiment to study the effects of C. deserticola addition on nutrients digestion, nitrogen balance, energy utilization, and methane production. The results revealed that C. deserticola has good utilization value in animal nutrition. The data are useful for further research on this natural plant additive to improve the health and productivity of the sheep fed on fresh forage from alfalfa/tall fescue pastures.

Abstract

This study is targeted at evaluating whether C. deserticola addition promotes digestion, nitrogen and energy use, and methane production of sheep fed on fresh forage from alfalfa/tall fescue pastures. The sheep feeding trial was conducted with four addition levels with C. deserticola powder, and a basal diet of fresh alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea). Addition levels of 4% and 6% improved average body weight gain (BWG) by 215.71 and 142.86 g/d, and feed conversion ratio (FCR) by 0.20 and 0.14, respectively. Digestibility of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), and ether extract (EE) was 62.25%, 65.18%, 58.75%, and 47.25% under the addition level of 2%, which is greater than that in the control group. C. deserticola addition improved energy utilization efficiency, while addition levels of 2% and 4% increased nitrogen intake and deposited nitrogen. Overall, C. deserticola has the potential to improve growth performance, digestion of sheep, so it has suitability to be used as a feed additive.

Effect of feeding of blend of essential oils on methane production, growth, and nutrient utilization in growing buffaloes

Objective

An experiment was conducted to study the effect of a blend of essential oils (BEO) on enteric methane emission and growth performance of buffaloes (Bubalus bubalis).

Methods

Twenty one growing male buffaloes (average body weight of 279±9.3 kg) were divided in to three groups. The animals of all the three groups were fed on a ration consisting of wheat straw and concentrate mixture targeting 500 g daily live weight gain. The three dietary groups were; Group 1, control without additive; Group 2 and 3, supplemented with BEO at 0.15 and 0.30 mL/kg of dry matter intake (DMI), respectively.

Results

During six months feeding trial, the intake and digestibility of dry matter and nutrients (organic matter, crude protein, ether extract, neutral detergent fibre, and acid detergent fibre) were similar in all the groups. The average body weight gain was tended to improve (p = 0.084) in Group 2 and Group 3 as compared to control animals. Feeding of BEO did not affect feed conversion efficiency of the animals. The calves of all the three groups were in positive nitrogen balance with no difference in nitrogen metabolism. During respiration chamber studies the methane production (L/kg DMI and L/kg digestible dry matter intake was significantly (p<0.001) lower in Group 2 and Group 3 as compared to control animals.

Conclusion

The results indicated that the BEO tested in the present study have shown potential to reduce enteric methane production without compromising the nutrient utilization and animal performance and could be further explored for its use as feed additive to mitigate enteric methane production in livestock.

Effect of sulphate and blend of plant parts containing secondary metabolites on in vitro methanogenesis, digestibility and feed fermentation with buffalo rumen liquor

A blend of plant parts containing fruit of Phyllanthus emblica (amla), seed of Foeniculum vulgare (fennel) and seed of Trachyspermum ammi (ajwain) mixed in equal proportion (BP) was tested at 0, 10 and 20% of the substrate along with 0, 2.5 and 5% of sodium sulphate (S) for their effects on in vitro methane production and feed fermentation. Inclusion of combination of BP with S did not affect production of total gas, methane and feed digestibility. In vitro gas production was not influenced by any level of S, whereas, it increased linearly with increasing level of BP. Inhibition pattern of methane production (ml/g DM) was similar by inclusion of both S and BP and the inhibition was 21.3% by inclusion of BP20S5. In vitro true digestibility of feed was significantly increased by inclusion of both S and BP and was 10.9% higher with BP20S5 as compared to control (BP0S0). Total volatile fatty acids werenot affected by any of the treatments, whereas, acetate was increased and propionate and butyrate were significantly reduced resulting in increased acetate to propionate ratio. Ammonia production was not affected by inclusion of neither S nor BP. It may be summarized that the blend of amla, ajwain and fennel and sodium sulphate can be explored as feed additive to mitigate methane production with an additional benefit of improvement in feed digestibility.