Harit Dhara

Harit Dhara

Subject: Environment

Context: Indian Council of Agricultural Research (ICAR) institute has developed an anti-methanogenic feed supplement ‘Harit Dhara’

Concept:

Methane in cattle

• Methane is produced by animals having rumen, the first of their four stomachs where the plant material they eat – cellulose, fibre, starch and sugars – gets fermented or broken down by microorganisms prior to further digestion and nutrient absorption.
• Carbohydrate fermentation leads to production of CO2 and hydrogen. These are used as substrate by archaea microbes in the rumen with structure similar to bacteria to producemethane, which the animals then expel through burping.
• Belching cattle, buffaloes, sheep and goats in India emit an estimated 9.25 million tonnes (mt) to 14.2 mt of methane annually, out of a global total of 90 mt-plus from livestock
• Methane’s global warming potential – 25 times of carbon dioxide (CO2) over 100 years, making it a more potent greenhouse gas – that’s cause for concern.
• Indian livestock largely fed on agricultural residues wheat/paddy straw and maize, sorghum or bajra stover – ruminants in India tend to produce 50-100% higher methane than their industrialised country counterparts that are given more easily fermentable/digestible concentrates, silages and green fodder

Harit Dhara has been prepared using condensed and hydrolysable tannin-rich plant-based sources abundantly available in the country. It roughly costs Rs 6/kg and it is to be fed only to animals aged above three months having fully functional rumen. It was developed by ICAR

Advantages

• it not only cuts down their methane emissions by 17-20%, but also results in higher milk production and body weight gain.
• Fermentation continues and more production of propionic acid now in proportion to acetic and butyric acid, provides much of the energy for lactose (milk sugar) production and body weight gain, from feeding of Harit Dhara.
• Harit Dhara acts by decreasing the population of protozoa microbes in the rumen, responsible for hydrogen production and making it available to the archaea for reduction of CO2 to methane.

• The benefit-cost ratio for the dairy farmer works out to 3:1.