Dr. Banarsi Lal
Livestock is a significant sector of the Indian economy. This sector plays a major role in the agricultural sector in the developing nations by contributing 40 per cent in the agricultural GDP. This sector provides livelihood support to the rural population. This sector provides necessary proteins and nutritious diet to the human beings through milk, meat, eggs etc. Livestock also provides raw material such as skins, blood, bone etc. This sector contributes about 12.9 per cent of global calories and 27.9 per cent of proteins and also contributes in the crop production through manure, ploughing and transport.
The livestock sector employs at least 1.3 billion people across the globe and supports the livelihoods of about 600 million small farmers in the developing countries. Climate change impacts livestock directly and indirectly. Climate change has a global occurrence with the negative impacts. The IPCC predicts that by 2100 the increase in global average surface temperature may be between 1.8-4 degree C .It is predicted that with the increase of 1.5 degree C to 2.5 degree C ,about 20-30 per cent of plants and animal species are expected to be at risk of extinction. Climate change is caused by the various factors.
Some human activities have also been identified as the significant causes of climate change often referred to as the global warming. The three major Green House Gases (CGGs) are Carbon Dioxide, Methane and Nitrous Oxide.
Livestock production is associated with the carbon dioxide, methane and nitrous oxide emissions. Climate change impacts livestock production. Climate change can impact the fodder crops and grazing system. Herbage growth is brought about by the changes in the atmospheric CO2 concentrations and temperature.
It has been observed by the research studies that climate change impacts on the yield, biomass and photosynthesis of field crops. Climate change also affects the genetic and cultural diversity in agriculture.
Animal and plant genetic resources are the non-renewable resources, once gone, are gone forever. Pastoralists and smallholders are the guardians of much of the world’s livestock genetic resources. According to FAO about 20 per cent of the animal genetic resource breeds are now at risk and almost one breed per month is becoming extinct. The drivers of these changes in developing countries depend on the system.
Climate change is the major threat to the sustainability of livestock systems globally. Climate change strongly affects the production performance of farm animals and this has been observed across the globe.
It has been observed through the research studies that milk yield of crossbred cows in India has been negatively correlated with temperature humidity index. Glaciers retreat, polar bears, penguins and other livestock species struggle to survive.
Research depicts that productivity of crossbred animals is lower in areas where the annual temperature is higher. It has been reported that over 50 per cent of the bovine population is located in the tropics and it is estimated that heat stress may cause economic losses in about 60 per cent of the dairy farms around the world. Exposure to elevated temperature decreases fertility rate even in poultry, rabbits and horses. High temperature has a greater impact on semen quality. Climate change is providing the atmosphere for infectious diseases allowing disease causing bacteria, viruses and fungi to move in the new areas where they may harm the wild life, domestic species and even to the human beings. Diseases initially found in the tropical and sub-tropical areas are now moving towards temperate areas.
It has been observed that the increasing occurrence of tropical infectious diseases in the mid latitudes is linked to the global warming. Insect-borne diseases are now present in temperate areas where the vector insects were non-existent in the past. The increased respiration rate results in enhanced carbon dioxide being exhaled.
Heat stress may be responsible for the impairment for the protective value of colostrums in animals and for alteration of the passive transfer of immunoglobulin in neonatal calves.
Ruminants such as buffalo, sheep, goat and cattle produce nitrous oxide, carbon dioxide and methane through belching. According to the Food and Agriculture Organization (FAO) livestock are responsible for about 14.5 per cent of greenhouse gases emissions. This puts the livestock sector on par with the transport.
According to the Intergovernmental Panel on Climate Change transport is responsible for 14 per cent of greenhouse gases emission. Throughout the world the scientists are on the mission to reduce the greenhouse gases emissions from the livestock.
They are working on the technologies to reduce these emissions by breeding the animals that burp less, by altering their diet and by planting trees in the pastures so that green house gases emissions can be reduced.
According to the studies, methane is the main greenhouse gas which is more harmful as it traps 28 times more heat. Scientists have also developed certain probiotic- helpful bacteria or yeasts in the digestive system which reduce 50 per cent of methane emission in cattle.
Some scientists have bred sheep that produce 10 per cent less methane. Reduction of 10 per cent methane in a single sheep may not have significant impact on the environment but when there are millions of sheep in the world, it will have a huge impact.
The less methane producer sheep breed is lean and produces more wool. In India, National Dairy Development Board (NDDB) has launched a programme to boost the milk production of cows and buffaloes by improving their diet and thus helping to keep a healthy environment.
The NDDB uses software to assess the ideal diet for an animal. Changes are made in the diet of the animals by adjusting the feed quantity and adding locally available mineral supplements. The tailored diet reduces 12-15 per cent of methane production in the animals. In some countries scientists are testing the grasses which can increase the milk, meat or eggs per kg of the livestock and reduce the methane gas production. Cows are kept in the respiration chambers where the scientists measure the methane chambers from different feeds.
Scientists are convincing the farmers to change the diets of their animals to mitigate the problem of global warming.
In some countries, scientists are studying the issue of global warming by strapping plastic tanks to the back of the cows to collect their burps. According to the studies, 30 per cent of methane emission by the livestock can be reduced globally by applying different technologies.
Scientists have developed the web applications by which the effect of diet on the methane emission by the livestock can be calculated. Scientists are also experimenting with silvopastoralism-planting trees in pastures where they absorb the greenhouse gases and offset emissions.
Livestock production system is sensitive to climate change. There is need to counter the adverse effect of climate change on animals by the new interventions. During the period of heat stress it is essential to maintain a continuous supply of fresh diet for the animals and it should be provided in the coolest part of the feeding area.
There is need to give the high quality forages that contain high concentration of digestible NDF. Fat sources like oilseeds and rumen inert fats may be included. In summers, water can serve as an effective cooling agent for farm animals. Overcrowding of animals should be avoided. Cooling in the farm of fans and sprinklers are usually beneficial for the animals.
There is need to develop the livestock development strategy. The integration of new technologies into the research and technology transfer systems potentially offers many opportunities to develop the climate adaptation strategies.
Epigenetic regulation of gene expression and thermal imprinting of the genome could also be an efficient method to improve thermal tolerance.
(The writer is Chief Scientist & Head of KVK, Reasi SKUAST-J)
