IMPACT OF LIVESTOCK FARMING ON THE ENVIRONMENT & STRATEGIES TO MITIGATE THE THREATS

June 4, 2020

3144

Compiled & shared by-DR. RAJESH KUMAR SINGH, (LIVESTOCK & POULTRY CONSULTANT), JAMSHEDPUR, JHARKHAND,INDIA 9431309542, rajeshsinghvet@gmail.com

Globally, we eat more meat now than ever before. Cultures that traditionally held vegetarian diets have become steadily more meat-oriented. In many areas, meat is seen not only as a delicacy but also as a luxury expense and a symbol of status. As the production of meat has gone up in recent decades and the cost has steadily dropped, meat is now much more affordable than ever before. This has led to what is referred to as a “global meatification of our diets.”
However, this new trend carries with it a series of environmental burdens. The livestock industry creates enormous amounts of waste, generates pollution, and also releases large amounts of methane into the atmosphere.
livestock producers and environmentalists have their share responsibility for the public safety and the protection of the environment. Therefore, urgent and decisive action is needed to conserve and maintain the ecosystem with a view to the sustainable management and the use of biological resources. Formulating and enforcing some of the needful policies and management would mean more than fighting pollution and degradation but unconsciously engaging in the use of cheap alternative resources for human development. An objective, consistent and continuous maintained environment-livestock management is the only answer to our problem of environmental protection for us today and for our children tomorrow.
The world’s growing population is constantly demanding higher levels of livestock products—meat, milk, and eggs—to satisfy an increasing appetite. As people become wealthier, they tend to eat more animal products, and researchers have dubbed the rapidly growing demand for meat and milk the Livestock Revolution.
The raising of livestock and the eating of animal products has social, cultural, and economic benefits, but also come at a cost to the environment. Livestock are produced in many ways. A pastoralist in India might have a mixed herd of cattle, sheep, and goats grazing across a wide swath of semi-arid land, a smallholder farmer in Vietnam might have some pigs and chickens integrated with her crops, or a major corporation might have an intensive meat production factory in the United States. Around the world, in all of these systems combined, raising livestock accounts for about 80% of all agricultural land and 25-32% of agricultural water use.
When it comes to climate change, livestock contribute to the problem and are also affected by it. An estimated 8-18% of human-caused greenhouse gas (GHG) emissions come from livestock. And as the climate shifts and average temperatures continue to rise, animals will suffer from heat stress, more parasites and diseases, and reduced quality and availability of feed.
Some of the techniques that scientists already know will help reduce GHG emissions from livestock include more digestible feed, better manure management, and avoiding deforestation by raising livestock in a more intense but sustainable manner.
A new report from FAO says livestock production contributes to the world’s most pressing environmental problems, including global warming, land degradation, air and water pollution, and loss of biodiversity. Using a methodology that considers the entire commodity chain, it estimates that livestock are responsible for 18 percent of greenhouse gas emissions, a bigger share than that of transport. However, the report says, the livestock sector’s potential contribution to solving environmental problems is equally large, and major improvements could be achieved at reasonable cost.
Some adverse effect of livestock farming on environment—-

Air pollution ———–

Air is one of the major livestock related environmental problems under industrial system. Air pollution has serious repercussions and damage to health occurs as pollutants molecules interact unfavourably with the intricate molecules and fluids of the human body (Ademoroti, 1996). Air pollution and global warming are produced by livestock directly and indirectly. The production of livestock has significantly contributed to the increase levels of CO2 and other greenhouse gases during the past 250 years (Darwin, 2001). About 40% of emitted methane is produced by agriculture predominantly by ruminant animals (Rosenzweig & Hillel, 1998).

Land degradation —————

Land degradation such as deforestation, soil quality and desertification are excessive global problems. The global assessment of soil degradation, Oldeman, et al. (1991) estimates that 680 hectares of rangeland have become degraded. In Nigeria, prolong heavy grazing contributes to the disappearance of edible plant species and subsequent dominance by either inedible, herbaceous plants or bushes. Excessive grazing has also caused soil compaction and erosion, decrease soil fertility and water infiltration and the loss of organic matter content. The recent increase in the rate of desertification may not be unconnected with excessive grazing in Northern Nigeria. Livestock impact on the soil can be classified into two broad categories as reported by Whitmore (2001); physical impact of the animal on the soil as it moves around and secondly, the chemical and biological impact of the feaces and urine that the animal deposits on the soil

Physical impact—————

Heavy livestock, such as cattle compact soil structures and destroy vegetation on which they graze. Destruction of soil structure and vegetation is harmful because restoration does not occur immediately the grazing animals are withdrawn. The problems with soil structure are not limited to cattle farming. Pig production is notorious for its destructive effects on vegetation as part of the pig’s behaviour to dig into the soil in extensive system common among rural farmers.

Chemical and biological impacts of manure and urine —————–

Although impacts of livestock manure has been seen to have impact on water and the atmosphere, soil is an intermediary. The amount of urine declared by a grazing cow is of the order 2 liters applied to an area of about 0.4m2 (Addiscoth et al. 1991). This represents an instantaneous application of 400 to 1,200kg N per hectare. Such an amount burns vegetation and is often toxic to plant roots which cannot immediately recover to take the nitrogen (full recovery can take up to 12 months) and the problem worse in areas where animals congregate

Heavy metals———————

Copper and zinc which are essential minerals for livestock diets are deliberately added to concentrate feeds whereas other heavy metals in particular cadmium, are introduced involuntarily via feed phosphates. Only 5 to 15% of metals additive are absorbed by animals, the rest are excreted. Soils on which pig and poultry manures are continuously applied at high rates accumulate heavy metals jeopardizing the good functioning of the soil, contaminating crops and posing human health risk

Socio-economic problems ———-

The extensive system of animal production especially by rural poor community in India which houses over 90% of the ruminant animals has continued to pose serious threat to crop farming in India. The migration system imposed upon this ruminant production by climatic factors results in animals trampling and eating existing or growing crops on the field. Some herdsmen most often sent the bush on fire destroying crops and damaging the ecosystem. There have been several reports of clashes between the herdsmen and the crop farmers leading to loss of lives, displacement of settlements and destruction of valuable property.

ENVIRONMENTAL AND LIVESTOCK MANAGEMENT STRATEGIES TO MITIGATE THE PROBLEMS—–

Haphazard livestock management is synonymous with hazardous environment and hazardous economy and society. Many production systems had been at a sustainable equilibrium with livestock being produced in harmony with nature and environmentally sound systems. However, over the last decade, several production systems and growing concern for increase livestock production have lost this equilibrium because of the pressure caused by growing human population and increased demand for animal products. To get this right, the appropriate environmental friendly livestock management must be inculcated in the production system.

(i) Environmental awareness campaign

The level of environmental awareness among livestock farmers is low as majority of the people are environmentally illiterate. They have little or no regard to biodiversity and aesthetics. This has to be improved through publications, workshops, radio and television jingles and personal touch. It should be down to earth so that the people can understand and realize the need for action.
(ii) Environmental pollution laws
There is the need to widen the scope and review the dimensions of the responsibility of the national Environmental Protection Agency in line with what happens in other developed countries. Appropriate laws must be passed and measures put in place to punish erring farmers.
(iii) Livestock waste management financing
The problem of livestock waste is quite enormous. Much of the constraints is lack of Governmental involvement. Government’s assistance would serve as a good incentive to poor farmers and would further boost production efficiency thereby reducing the high cost of production. Substantial budget must therefore be allocated to livestock waste management and the implementation supervised by a nucleus of waste management experts.
(iv) Control of commercial/industrial livestock production
There should be laws strictly limiting commercial livestock production to rural or remote areas. Commercial livestock activities within urban areas constitute major environmental hazards. In most cases, rural farms are soon enveloped by residence through development and urbanization, Government must assist in relocating such farms.
(v) Livestock production system
In practice, close grazing system (under extensively system) where the waste products are used within the system and does not present a burden on the environment should be adopted by the farmers. Government should help to establish more functional ranches and monitor the activities of livestock in such establishments. Mixed farming which integrates crop and livestock production should be encouraged. According to FAO (1996), mixed farming is probably the most benign agricultural system from an environmental perspective because it is partially, at least, a closed system. This allows intensified farming with less dependence on natural resources and preserving more biodiversity.
(vi) Processing waste through the use of activated sludge
To prevent surface and underground water pollution, waste water treatment is essential. Such treatment using intermitted aeration process is efficient in removal of organic substances such as Biochemical Oxygen Demand (BOD), Total Organic Carbon (TOC), Total Nitrogen (TN) and Total Phosphorus (TP) and regulate the emission of nitrous oxide, a greenhouse gas (IPCC, 1995)
(vii) Proper animal waste management and disposal
Collection of animal wastes is the first step in waste disposal. The properties of collected wastes are determinants in the choice of disposal options. Most beef cattle and chicken waste is in solid or semi solid form, therefore, it can be removed easily. With pig and diary cattle raised on concrete floor, theirs has to be cleared out by water. There are a large number of ways for animal waste disposal. The choice is highly dependent on the housing design and ways of cleaning and some region, the religious taboo. Producers should therefore establish a right sense of taking up the responsibility for proper waste disposal.
(viii) Efficient livestock nutritional management
A valuable option in developing an environmentally sound waste management is through nutritional management. It includes proper feeding programmes and feeds which will result in less excreted nutrients that need to be managed. Critical components to be controlled are N, P and minerals that are used in supranutritional level. This can be achieved through amino acid supplementation and protein restriction that will reduce N excretion in monogastric animals. Supplementation of enzymes such as carbohydrates, phytase and protease can be used to reduce excretion of nutrients and feaces by improving digestibility. Use of growth promoting agents and deodorases are other available ways but this will increase costs of production.
(ix) Use of biological technology
The industrial scale implies large herd or flock sizes, large volume of waste and high concentration of environmental hazard with the biggest problem having to deal with the over-concentration of animals in areas of high human population density with little, viable opportunities to utilize waste products on land. This requires specialized technology such as:
Invertebrates
The biological digestion of livestock manure by invertebrates appears to be a solution to the accumulation of large amount of waste if reasonable technological processes can be developed in our country .Generally, during digestion of manure, the invertebrates convert the sticky mass of manure into an odourless loose crumbly products which can easily be disposed. The digestion of poultry manure by the larvae reduced the moisture content from 80% to 55% and removed about 80% of the organic matter resulting into odourless, loose and crumbly texture.
(b) Production of single call protein
Single call protein (SCP) can be obtained from microorganisms resulting from biosynthetic activities of these organisms. These microbial proteins can be cultivated on cheap agricultural byproducts, principally manure from livestock. The technologies are cheap and simple. The values of the chemical composition of these SCP like protein 23-65%, carbohydrate 4-33%, lipids i.i-308%, ash 4.2-9.0% and fibre 2.2-3.4% make them economically attractive for feed formulation
(c) Production of biogas
Biogas (domestic gas) can be produced anaerobically from livestock waste. A household biodigester (for biogas production), about 19kg of dung per day is required for the domestic energy consumption (Anyanzo, 2005). In the biodigester, the organic materials is fermented by bacteria, producing biogas and slurry. Biogas is seen as a good alternative source of energy for cooking and lighting. Since it was manure, it improves the sanitation of the homestead and saves time use in collecting scarce firewood. It is also safer than the commercial gases
(d) Biodigestion for the production of high quality fertilizer
In the past, biodigestion has been considered mainly as a way to produce combustible gas from waste organic matter. Because of increasing emphasis on the sustainable use of natural resources in farming system, it is now appreciated that biodigestion is considered in a much wider perspective and specifically, in the potential role for the recycling of plant nutrient (Preston, 2005). The by-products of the anaerobic decomposition that takes place in a digester occur in two fractions, the liquid fraction called the biol and the solid fraction or biosol. Both are excellent fertilizers for a variety of crops (Osorio, 2005). The biol contains many essential elements for plant growth such as nitrogen, phosphorus, potassium and calcium. It also offers additional benefits to plant because it contains plant growth regulators such as auxines and gibberelin, as well as other substances that stimulate plant development. The solid part, biosol has similar nutrient contents. Both fertilizers favour rooting, the development of the foliage and flowering and activate seed germination (Osorio, 2005). Farmers can easily modify the nutrient content of the liquid fertilizer, for example, by adding chopped alfalfa, fish entrails and marine seaweed to the digester. The ready made biol can also be enriched with mineral salts to provide additional nutrients to a crop or for other liquid fertilizer to control diseases such as leaf rust in coffee crops. Biol is easily applied to crops directly to the foliage as liquid fertilizer with a backpack sprayer or to the irrigation water. Biosol can be applied directly to the plant just as one would apply compost.