Unveiling the Hoof Print: “Analysing India’s Carbon Footprint in Animal Husbandry”

Vimla Saran¹, Harideep Verma², Salam Prabex Kumar Singh³ and Uttam Kumar Sahu⁴

^1&3 Ph.D. Research Scholars, ²M.V.Sc. Research Scholar, Division of Extension Education,

⁴M.V.Sc. Scholar, Division of Animal Reproduction

 ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh – 243122

Global warming is the rise in an average temperature of earth’s atmosphere and oceans. Warming of the climate system is unequivocal and scientists are more than 90% certain that it is primarily caused by increasing concentration of greenhouse gases produce by human activities such as burning of fossil fuel and deforestation. Naturally occurring amount of greenhouse gases have a mean warming effect of about 33°C. The major greenhouse gases are water vapour, carbon dioxide which cause 9-26 %, methane which cause 4-9 %, ozone which cause 3-7 % of the greenhouse effects. Greenhouse gases can be emitted through transport, land clearance, production and consumption of food, fuels, manufactured goods, materials, wood, roads, buildings and services.

Carbon Footprint

Product carbon Footprint is the total amount of GHG emissions associated with a product, along its supply-chain, and sometimes includes emissions from consumption, end-of-life recovery and disposal (IPCC 4th Annual Report, 2007). It is usually expressed in kilograms or tonnes of carbon dioxide equivalent (CO2-eq.). A carbon footprint has historically been defined as “the total set of greenhouse gases emissions caused by an organization, event, product or person”.

CO2-equivalent emission

CO2-equivalent emission: is the amount of CO2 emissions that would cause the same time integrated radiative forcing, over a given time horizon, as an emitted amount of a long-lived GHG or a mixture of GHGs.

Statistics

Livestock production is a significant contributor to the world’s total greenhouse gas (GHG) emissions. Within the livestock sector, 20% of total emissions comes from milk production which is increased by almost 40% in the last 30 years and is anticipated to increase (IPCC 4th Annual report,2007). The GHG’s emission is multiplied by its Global Warming Potential (GWP) during the specified time horizon to determine its CO2 equivalent emission. A typical and helpful measure for evaluating the emissions of various GHGs is the CO2 equivalent emission (IPCC, 4th Annual report 2007). According to the IPCC Third Annual Report (2001), global warming potential is an indicator that shows how much of an impact a greenhouse gas (GHG) has on climate change over a given period of time, such as 100 years, when compared to the same mass of carbon. The most potent greenhouse gas is Methane has a half-life of 9.1 years and one kg equals 25 kilograms of CO2 eq. (EPA, 2020). It is estimated that 2.7% of all anthropogenic emissions come from the production, processing, and transportation of milk worldwide. At present, methane contributes about 20% of anthropogenic radiative forces, only after carbon dioxide at 60% (Lassey, 2007). It is about 25 times more potent in trapping atmospheric heat than the CO2; it has perceived greater concern over these years (IPCC 3rd Annual report, 2001). Low persistence period of about 10 years, compared to hundreds of years in case of CO2 in the atmosphere, has led to increased global attention for implementing the emission reduction programmes for the methane. 61% of the total methane emissions in India contributed by the agriculture sector, 40% coming from enteric fermentation, 17% from paddy cultivation and 4% from farm waste management.  A cow emits 500 litres of methane per day, equivalent to 10% of the energy she would otherwise use for performance and milk production (Royal DSM, 2016).

Sources of Greenhouse gases:

Methanogenesis, which goes by the name “bio methanation,” is a microbial metabolic anaerobic respiration process. It is the process by which methanogenic microorganisms, such as bacteria, viruses, fungi, protozoa, and others, reduce carbon dioxide (CO2) by hydrogen (H2) produce methane. As a byproduct of the feed digestion system, methane is continuously fermented in the rumen, a large fore stomach, in anaerobic circumstances (Richard et al., 2009). Methane is also released by a process similar to enteric fermentation that occurs in manure (Richard et al., 2009). The cellulose content of the manure is degraded by the microbes in the process of methanogens (Richard et.al, 2009). Annual methane emissions from manure management from Indian livestock were estimated through several studies: 0.91 Tg/yr in 1997 and 1.13 Tg/yr in 2010 (Australasians Journal of Animal Sciences, 2014).

Source: Carbon footprint of Dairy Farming, Shivani Singh et al., Livestock production management division, Indian Veterinary Research Institute, Izatnagar, Bareilly.

Estimation of Carbon Footprint

Carbon footprint of a product is determined using the Life Cycle Assessment (LCA) approach. A dairy farm, dairy plant, and the full dairy production system are few examples for which LCA analysis used, that accounts for all inputs and outputs for a specific product and production system across a specified system boundary. Several agri-food studies have employed life cycle assessment (LCA) to pinpoint environmental hotspots and potential remedies to lessen environmental impacts (Roy et al, 2009). With the exception of the last stages of the product life (processing, shipping, and packing material disposal), the majority of these studies were carried out at the farm level (Tamburini et al, 2016).

Mitigation Strategies:

Nutritional Manipulations –

• Changes in diet of animal can lead to reduction in methane emission by 45- 75%.
• ICAR-NIANP, Bengaluru bags Indian Patent: Tamarind Seed Husk for Methane Amelioration in Ruminants. The tamarind seed husk contains 13% to 15% of tannins (a natural polyphenolic compound) modulates rumen fermentation.
• Tropical tree leaves reduce enteric methane emission: Selected tropical tree leaves from Azadirachta indica, Ficus religiosa and Artocarpus integrifolia were evaluated for their methane suppressing effect.
• Silkworm pupae oil – a potent inhibitor of rumen methanogenesis: silkworm (Bombyx mori) pupae oil was supplemented with graded levels of 2 to 20% in finger millet and concentrate based diet. Results indicated 15-50% reduction in methane production in vitro (ICAR-INANP).
• Plant secondary metabolites: The tannins exert their anti‐methanogenic activity and 55 % methane reduction was seen on feeding tannin rich diet like lucerne, red clover etc. (Barry et al., 2005).
• An in vitro study reported 29% reduction in methane production on the addition of 4% commercial grade saponin in wheat straw and concentrate based diet. 21% Reduction in enteric methane emission in Murrah buffalo calves due to the supplementation of saponin‐containing lucerne fodder (Patra et al., 2009).

Supplementation of unsaturated fatty acids –

• Various trials have shown potential of PUFA in diet and its associated effects in methane reduction.
• Addition of fat reduces methane emission by lowering fermentation in rumen (Johnson et al., 1995).
• Addition of 4.6% of canola to high forage diet reduces methane emission by 32% (Beuchemin et al., 2006).
• For every 1% (DMI basis) increase in dietary fat, methane emission (g/kg DMI) was reduced by 5.6 % (Beauchemin et al., 2008).
• Inclusion level should be < 7% (Hegarty, 1999).
• Methane emissions cut down to 80% in vitro and about 25% in vivo by adding oils in the diets of ruminant animals (Singh et al., 2010).

Altering Rumen Microflora –

• Methanogenic bacteria have an eco-symbiotic relationship with ciliate protozoa and remains attached to surface of protozoa (Newbold et al., 1995).
• Ethanol extracts of Sapindus mukorossi (a seed rich in saponin) showed 52% reduction in protozoa population and 96% reduction in methane emissions in buffalo (Agarwal et al., 2009).
• Defaunation can decrease methane production by 50 % (Hegary et al., 1999).

Conclusion:

Greenhouse gases emission has become a serious problem which needs to be focused on. Diet manipulations for greenhouse gas emission reduction in spite of being difficult and costly, are a most reliable way to minimize GHGs emissions. Incorporating high yielders’ animals with remarkable genetic selection leads to mitigation of greenhouse gases. Scientific mitigation strategies can reduce the overall greenhouse generation and also climate change impacts.