Vinod Kumar, Mayank Tandon and M.P. Verma. 2008. ENVIRONMENT FRIENDLY DAIRY FARMING: Nutritional Techniques for Mitigating Methane Production from Ruminants. Dairy Planner. Vol.4, Issue 11, (June). pp: 12-14

ENVIRONMENT FRIENDLY DAIRY FARMING:Nutritional Techniques for Mitigating Methane Production from Ruminants Vinod Kumar1, Mayank Tandon1 and M.P. Verma2

1 PhD Students, 2 Research Fellow, Division of Dairy Cattle Nutrition, N.D.R.I., Karnalemail: mpverma_78@rediffmail.com

Introduction

The global warming and ozone layer depletion due to increased emission of green house gases in the atmosphere have drawn world wide attention with a alarming stage of iceberg melting, increased ocean level, local and global eco-system upsets, changes in the rainfall patterns, changes in pathogenesis of plants, animals and human beings and alteration in life of the people. Several reports of the United Nations inter-governmental panels on climate changes (IPPC, 1994 & 1996) indicated the urgency of the problem. IPPC (2001) has warned that by the mid of this century the globe’s temperature will rise just like anything up to 5.80 C.

Methane as a Green House Gas Methane is second major gas after CO2 responsible for the warming of environment and ozone layer depletion. Its present concentration 1800 ppbv in atmosphere which is more than double of about 750 ppbv estimated 100 years ago (Khalil et al. 1993). Estimates of global methane production ranged between 350-820 T g/year (Khan et al 2001)

Table 1. Estimate of CH4 released into the Atmosphere

Source CH4 emission T g/ Year Percent of total A. Biogenic Ruminants 80-100 12-22 % Termites 25-150 Paddy fields 70-120 Natural wetlands 120-200 Land fills 5-70 Oceans and lakes 1-20 Tundra 1-5 Total Biogenic 302-665 81-86 B. A-biogenic Coal mining 10-35 Natural gas flaring & venting 10-30Industrial & pipeline losses 15-45Biomass burning 10-40Methane hydrates 2-4Volcanoes 0.5

Automobiles 0.5Total A-biogenic 48-155 13-19 % Total 350-820

Source: Khan, et al 2001

Methane by livestock The comparison of methane production by livestock of developed vs. developing countries and India is presented in Table 2. Singh (1997) arrived at the figure of 8.82-9.023 T g/ year of methane production from Indian ruminant livestock. Respiration calorimetric studies at the IVRI, Izatnagar, India and In-vivo methane measured using SF6 at the NDRI, Karnal showed that similar levels of methane was produced from adult cattle and buffaloes.

Table 2. Methane Emission from Livestock, T g(x1012 g) per year Species Develop Country Developing

Countries Total India

Ruminants Cattle 31.8 22.8 54.6 5.69-5.8Buffaloes -- -- 6.2 2.4-2.735Sheep 3.2 3.7 6.9 0.2- 0.388Goats -- -- 2.4 0.388-0.5Subtotal 35 26.5 70.1 8.67-9.42B. Other Animals Pig 0.5 0.4 0.9 --Horses, Mules, Ass -- -- 1.7 --Camel -- -- 1.0 --Wild Ruminants & other Herbivores

-- -- 2.6 --

Human -- - 0.3 --Subtotal 6-10Grand total 76-80 Source: Singh, (1997); Khan, et al. (2001)

Methanogensis in Ruminants

Rumen microbial utilization of carbohydrates in the gut of animals results in the production of volatile fatty acids, microbial protein, CO2 and Methane with little H2. Methane generation should be viewed as an every sink where H from all rumen microorganisms drains, allowing a greater total yield of ATPs.

Reaction; 4H2 + CO2 ----- CH4 + 2H2O is the most common mode of methane production in the rumen by methanogens like Methanobacterium formicicum, M. ruminantium, M. bryanti; Methanobrevibacter ruminantium; Mrthanosarcina barkeri; Methanomicrobium mobile and Methanoculleus olentangyi etc. Methanogenes are present in the rumen in a large number varying from 107 to 109 cells/ml of rumen liquor depending upon the type of diet given to

animals, especially the fibre content in the ration. On a fibre rich diet production of acetic acid is more coupled with more production of methane.

Nutritional Techniques to Reduce Methane Production

Environment concerns have stimulated efforts to develop techniques for increasing the utilization of diet and reducing environmental pollution, which referred to as Green Nutritional Techniques (Lu, 2001 & Singh, et. al 2003) are given hereunder.

1. Feed Processing Technologies The processing can improve the feeding value by increasing its digestible energy content and / or by increasing feed intake. Therefore, an attempt to increase feed intake may reduce methane emission. These techniques are chopping and grinding of straws, alkali/ammonia treatment of straws and feed residues, urea-molasses blocks. These processing techniques resulted in 15-25 percent increase in feed intake and 10- 20 percent increase in digestibility as compared to unprocessed straw and feed residues (high in fibre). Most of all are reported to depress the methane emission from rumen by 10 percent (Johnson & Johnson, 1995). Moreover, the processing altered the rumen pH, type of fermentation, more exposer for microbial activity, increase passage rate, and propionic acid production etc. Reduction in methane is associated with increased propionate production.

2. Animal Species and Ration

It was observed that methane energy losses as percent of gross energy intake which were higher in crossbred cattle than in exotic cattle/ buffaloes (Lal et al., 1987). Singh (2001) reported that methane production by cattle and buffaloes were 76.74 and 97.01 g/ head/ day respectively. This difference among species was probably due to the difference in feed intake and utilization efficiency. The quantity and quality of ration consumed by ruminants have a major influence on the proportion of energy lost as methane since acetate: propionate ratio is influenced by feed quality and quantity as well as with roughage: concentrate ratio. Methane emission would be less when high grains are fed as a result of higher production of propionic acid. Methane emission fall down drastically to as low as 2-3 percent. (Johnoson and Johnoson, 1995).

3. Defaunation

Removal of protozoa from the rumen microbial population is defaunation. The methanogenic bacteria have an eco-symbiotic relationship with ciliate protozoa and remain attached to the outer surface of the protozoa. In defaunated ruminants, the methanogenic bacteria do not get the symbiotic partner and methane synthesis is partially inhibited. On defaunation the methane production is reduced by 30-35 percent depending on the various factors in the diet of the animal. The various methods for defaunation are, feeding of high grain, anti-protozoal drug, isolation of animal from other animals from birth, etc.

4. Supplementation of Unsaturated Fatty Acids

As methane is produced in the rumen to act as a hydrogen sink during the fermentation of carbohydrate, So Polly Unsaturated Fatty acids having double or triple bonds have potential to be used as Hydrogen sinks, because these bonds will get saturated by hydrogen and less hydrogen will be available for methane production. Various trials have shown the potential of feeding PUFA rich diet such as vegetables oils for methane reduction.

5. Organic Acids

Dietary supplementation of dicarboxylic organic acids such as malate, fumarate, aspartate etc. reduces methane production (Martin, 1998). Malate, a potent methane inhibitor, present in animal feeds like alfalfa (2.9-7.5% of DM) and Bermuda grass (1.9-4.5%) and its level varies with Varity and stage of maturity. These organic acids are converted to succcinate or propionate by reduction process and less hydrogen will be available for methane production.

6. Haloginated Methane Analogues

Various haloginated methane analogues so far tried as methane inhibitors are such as carbon tetrachloride, chloral hydrus, trichloroacetamide, DDT, trichloacetaldehyde, bromochloromethane, chloroform, methylene chloride, methylene bromide, nitrapyrin, hemiacetyl of chloral and starch etc. ( Haque, 2001) generally inhibit methanogens. Favourable effects of these had been reported only in those animals fed on high roughage diets, as prevalent in Indian livestock. Chloral hydrate is converted in the rumen to chloroform prior to inhibiting methanogens. Bromo chloromethane is belived to inhibit methane production by reacting with reduced form of Vit. B12 which inhibits cobamide dependent Methanogenesis.

7. Ionophores

Ionophores are generally used as feed additives in order to improve the efficiency of digestion in ruminants, such as tetronasin, monensin, lasalocid, salinomycine, narasin, lysocellin etc. These ionophores antibiotics are carboxylic polyether compounds produced by various strains of Streptomyces eg. Monensin by S. cinnamonensis and lasalocid by S. lasoliensis. Monensin is moderately active against gram positive bacteria, certain myobacteria and coccidian, while lasalocid is specifically against hydrogen producing bacteria and results in higher propionate production which is in turn related with low methane production (Kobayashi et al, 1992).

8. Microbial Feed Additives, Probiotics and Prebiotics The use of acetogenic bacteria as microbial feed additive along with some anti-methanogenic compound may be effective in methane inhibition, as acetogenic bacteria may not be able to compete with methanogenic bacteria due to poor affinity with hydrogen. Probiotics such as yeast cultures are used to stimulate bacterial activity in the rumen. The probiotics have been shown to stabilize rumen pH, increase propionate levels and decrease the amount of acetate, methane and ammonia production.

Fuller (1989) defined probiotics as “A live microbial feed supplement which beneficially affect the host animals by improving its intestinal microbial balance. In 1989, US Food and Drug Administration (FDA) termed them as direct fed microbe (DFM). The commonly used culture includes Aspergillus orygae, Sacchromyces cerevisiae, Lactobacillus spp. Bifidobacterium spp.

and Streptococcus spp. Recently strains of orpinomyces and piromyces isolated , have been shown to have good affect on rumen digestion. Addition of Sacchromyces cerevisiae reduced methane production in vitro. (Mutsvangwa et al., 1992). Galacto oligosaccharide (GOS), Fructo oligosaccharide (FOS), Mannan oligosaccharide (MOS), Galactosyl lactose, etc. are few pre-biotics, which are non digestible and help in the proliferation of beneficial microorganism, can be used as propionate enhancer thereby decreasing methane production.

9. Non-Ionic surfactant (NIS)

Tween 80, a non ionic surfactant , given at a concentration of 0.05 percent (v/v) in (in vitro expt.) in growth medium, increase growth rate of rumen bacteria and fungi and rate of cereal digestion, succcinate and lactate dehydrogenase activities and polysaccharides degrading enzymes activities (Lee and Ha, 2003). Tween 80 at 0.10 percent of diet significantly decreased cummmulative gas production with enhanced efficiency of dry matter digestion.

10. Bacteriocines

Many bacteria produce Bacteriocines (specific proteins with anti microbial activity) which have a range of activity that mimic the ionophore antibiotics. Therefore, they would be effective alternative to the ionophore antibiotics for the modification of rumen microbial population and fermentation products. Bacteriocines also have many advantages over existing ionophore like their complete digestibility (as these are proteins), prevent accumulation of residues and their ability to be produced indigenously by the resident bacteria of the rumen and their better specification than the ionophores, which promises, better ability to target specific rumen microorganisms that are responsible for such undesirable rumen function as feed protein degradation and methane production. 11. Plant Secondary Compounds

Majority of there plant secondary compounds fall in the category of lignin’s, tannins, terpenenoids, volatile essential oils, alkaloids, etc.; have anti-microbial activity, but their mechanism of action and inhibition of microbial growth is very specific and therefore these are active against a specific group of microbes, and can be used for selective amelioration of rumen fermentation.

a- Saponin

These are high molecular weight glycosides in which sugars are linked to a triterpene or steroidaql aglycone moiety. A large number of saponins could be possible depending upon the modification of the ring structure of aglycone moieties and the number of sugars attached to it. There are some feeds or forages plants which contain saponins such as Alfalfa (3-5%), Sapindus rarak, Sapindus mokorossi, Yucca schidigera (4%), Quillaja saponaria (10%), Acocia concinna, Emblica officinalis etc. These caused a decrease in methane production from 20-60 percent on different substrate accompanied with a decrease in a ammonia N and the numbers of protozoa. The molar proportion of acetate was decreased and that of propionate was increased. Saponins, reduces the protozoal population which reduces the inter species hydrogen transfer to the methanogenic Bacteria attached to the protozoa, thereby decreases the H availability to the methanogens.

b- Tannins

These are the second most abundant group of plant phenolics after lignin. Tannins are widely distributed in plant kingdom including forage trees, shrubs, legumes, cereals and grains. These are complex phenolic organic molecules with molecular weight ranging from 500 to 3000 Kda. Based on their structure and properties they are divided in two groups’ Hydrolysable tannin and Condensed tannins. These have been found to be toxic for many of the rumen microbes, especially ciliate protozoa, fibre degrading microbes and methanogenic bacteria. As a result of this property the Methanogenesis in the rumen is also reduced (Kamra, 2006).

12. Sulphate Supplementation

In the rumen fermentation three H2 utilizing microbes are the sulphate reducing bacteria, methanogens and carbon dioxide reducing acetogens, which have a threshold value of H2 (m mole/ liter) as 0.0013, 0.067 and 1.26 respectively at which these bacteria act as the dominant electron acceptors. Thus it appears that sulphate-reducing bacteria have the highest affinity to utilize H in the rumen, even better than methanogens, but the availability of sulphate in the rumen appears to be a limitation. Kamra et al, (2004) observed that sulphate supplementation helps in increasing the production of fibre degrading enzymes and fibre degradation in the rumen. As sulphate / sulphite have high affinity for utilization of H for its reduction to sulphide, therefore, a fibre diet, as prevalent in Indian livestock sulphate/ sulphite supplementation can be a good mode of rumen amelioration for improving fibre degradability and inhibiting methanogensis, but a proper dose will have to be optimized, keeping in view the toxic levels of sulphide generated on sulphate reduction.

13. Protected Protein/ Amino Acids

The ruminants derive their required amount of protein and amino acids mainly from microbial proteins synthesized in the rumen and the dietary protein, which escape degradation in the rumen. If degradation of the dietary protein in the rumen is controlled, it results in better utilization of protein by the ruminant and ultimately improves their performance. The protection of protein by various techniques as treatment with heat, formaldehyde and tannic acid and feeding of encapsulated protein, few proteins are naturally more un-degradable then the others such as cotton seed cake etc.; produced a significant improvement in productivity and caused depression in methane production (Johnson & Johnson, 1995).

Conclusion

Environmental problems related to animal production mainly originate due to low efficiency of nutrient utilization, low availability of cereal grains, less awareness about environment protection, increasing human and animal population, extensive industrialization and due to unlimited utilization of natural resources. The genuine application of science and technology in animal nutrition/ farming is one of the important tools to check the environmental concerns. To make livestock production economically, environmentally and socially sound the above green nutritional technologies/ management strategies can be adopted.

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