Dr. Anshul Gautam1, Dr. Nistha Yadav1 and Dr. D.Sreekumar2
- Assistant Professor, 2- Professor
Arawali Veterinary College, Sikar, Rajasthan
*Corresponding author-anshulgautam789@gmail.com
India, a country with a large population, has had impressive economic growth in the past decades. The thriving economy is causing a change in people’s income, expenditure patterns, and lifestyles. Consequently, there is a shift in food consumption patterns toward wealthier diets that include more animal products. The continuous transition from traditional, extensive, and mixed farming systems to industrial farming systems is expected to continue in order to supply the growing demand for animal products. For rural residents to be secure in their food and means of subsistence, milk is essential. The demand for milk is rising in India, and producing milk demands a lot of water because it is required to produce feed, used as drinking water, and used as fuel for the animals. The global livestock business accounts for around 8% of all water use. Approximately one-third of the water used in agriculture worldwide is either directly or indirectly used by animals. The world’s fresh water supplies are probably going to be under much more stress as a result of the rising consumption of animal products. The depletion of water resources, both in quantity and quality, has drawn concern from all around the world. The public’s attention is focused more on ruminants in particular because of their comparatively high water use per unit of meat or milk generated. One indicator of water use that was suggested was the water footprint (WF) indicator. An indicator of water use in connection to consumer products is the “water footprint” concept. A product’s water footprint is the total amount of freshwater utilized during its production process, as assessed at different stages. Any product derived from animals has a greater water footprint than a carefully selected crop product of comparable nutritional content. Reducing milk’s water footprint is critical for sustainable dairy farming, as milk production is becoming more and more water-intensive and demanding. Improved measurement and examination of the relationship between water and milk production are necessary for our nation’s nutritional security and means of subsistence.
Methods to measure water footprint-
The evaluation of Water Footprint uses two well-known methodologies. These are the life cycle assessment (LCA) approach and the volumetric water footprint approach. Throughout a product’s life cycle, the LCA technique allows for a thorough impact assessment of freshwater consumption at both the mid-point and endpoint levels. The LCA incorporates water footprints through the utilization of the water stress index (WSI). The whole volumetric WF divided by the catchment’s water availability yields the WSI. Water shortage is taken into account in LCA studies in order to modify the volumetric water usage for potential local environmental implications. Water consumption can be represented in litres of water equivalents by multiplying each litre of water consumed by a local WSI factor ranging from zero to one.
The volumetric water foot (WF) technique is becoming more and more popular since it provides a thorough evaluation of water use and measures pollution and water consumption in connection to productivity or consumption. Its definition is the total amount of freshwater consumed across a product’s whole supply chain, both directly and indirectly. In its computation, three important water components are monitored. The use of water from green water resources—rainwater retained in the soil—is referred to as the “green WF.” The use of blue water resources (net abstraction from surface and groundwater) is referred to as the “blue WF.” The gray WF, which denotes water pollution, is the amount of freshwater needed to absorb a load of contaminants given ambient water quality standards currently in place as well as natural background concentrations.
A live animal’s water footprint is made up of two parts: the direct water footprint associated with the drinking and service water consumed, and the indirect water footprint of the feed. The term “service water” describes the water used for farmyard cleaning, animal washing, and other tasks that help to keep the environment in good condition. When summed over the course of the animal’s life, the water footprint of an animal and its three components can be stated in terms of m3/y/animal or m3/animal. When analyzing dairy cattle, it is easiest to focus on the animal’s yearly water footprint (averaged over its life), as this can be easily connected to the animal’s average annual milk production. Growing the feed is by far the first stage that contributes the most to the overall water footprint of all final animal products. We must first examine the water footprint of feed crops in order to gain a better understanding of the water footprint of an animal product. Obviously, the type of crop and climate have an impact.
Water footprint (m3/ton) of milk production is given as-
Water footprint of milk (m3 /ton) = Total CWU/ daily milk yield
In order to estimate the water footprint of milk production, CWU (Consumptive Water Use) of milk production needs to be calculated first which is given as-
CWU milk = Direct CWU + Indirect CWU
Direct CWU comprises water required for bathing, drinking and servicing purpose of milch animals where as indirect CWU consists of calculation of water use of feed and fodder crops
Indirect CWU= CWU (Dry fodder) +CWU (green fodder) +CWU (concentrates)
CWU of crop is the actual evapotranspiration (ETp) in four crop growth periods (initial, development, mid and late stage)
ETp = 4∑i=1 ki x ∑ dij ET0ij
Where,
Ki = crop coefficient of ith growth period
dij = no. of days of the jth month in the ith crop growth period
ET0ij =reference evapotranspiration of the jth month in the Ith crop growth period
Factors affecting water footprint-
The primary determinants of an animal product’s water footprint are its feed conversion efficiency, composition, origin, and livestock production system. From grazing systems to mixed systems to industrial systems, the feed conversion efficiency increases and results in a reduced water footprint in the latter. The type of feed works against grazing systems since roughages (grass, agricultural residues, and fodder crops) have a very small water footprint whereas concentrates have a relatively large one. The water footprint of concentrates is typically five times greater than that of roughages. All three dairy production technologies have similar total water footprints per unit of product. When dairy products are obtained from a mixed system, their water footprint is the least; when they are obtained from an industrial or grazing system, it is slightly bigger but still comparable.
In general, arid regions have higher WF of livestock products than humid ones. The main components of the WF of animal products, feed production productivity and evapotranspiration variability, account for the variation in WF between agro-ecological zones. In arid climates, low agricultural and pasture yields combined with high evapotranspiration lead to increased water usage and WF. While the blue water fraction (WF) is larger than the green component in semiarid and arid locations, the green WF is significantly larger in humid regions. While having access to sufficient drinking water is essential for any livestock business, the manufacturing of feed is said to require 100 times more water than drinking.
Strategies to reduce water footprint-
Governments prioritize reducing the water footprint of livestock production systems as a means of addressing the issue of water scarcity. With 98% of the overall water footprint for animal production coming from the feed they eat, this is where the biggest water footprint for animal production is found. Within the grazing system, fodder crops and grazing account for approximately 97% of the water footprint associated with feed, with 94% of the water footprint being green. The green water footprint accounts for 87% and 82% of the total footprint in the mixed and industrial production systems, respectively. The grazing system’s blue water footprint makes up 3.6% of the overall water footprint, of which 33% is derived from the usage of drinking and service water. The blue water footprint makes for 8% of the overall water footprint in the industrial system. By not using chemicals in the field, the gray water footprint in agriculture can be completely eliminated. It can also be significantly reduced by using fewer pesticides, better application methods, and time of application (such that fewer chemicals enter the water system through leaching or runoff from the field). By raising water productivity (ton/m3), green and blue water footprints (m3/ton) in agriculture may typically be significantly decreased. A common goal in agriculture is to maximize land productivity (ton/ha), which makes sense in situations when freshwater is plentiful and land is rare. However, when water is scarcer than land, it is more crucial to maximize water productivity. This means that a higher yield per cubic meter of water evaporated can be achieved by strategically using less irrigation water. Reducing the food footprint can be achieved by substituting animal products with locally grown crops that are nutritionally similar. It is advised to choose feed that uses less water, trade virtual water wisely, manage servicing water, integrating crops with cattle and allowing them to consume crop byproducts and improve irrigation efficiency in order to maximize the dairy industry’s potential for water savings and lessen water scarcity. By using these methods, runoff can be reduced and soil percolation or recycling increased. Reducing the quantity of irrigated feed and the amount of water that animals consume are the two primary solutions. Reducing irrigation of feeds grown in regions with little rainfall to prevent freshwater depletion could be the most effective approach, at least in specific seasons. The total water intake of ruminants ranges from 3.5 to 5.5 L/kg of dry matter intake; dairy cows require more water than developing animals or animals kept at maintenance. Thus, consuming less drinking water is achieved by increasing the amount of fresh grass or silage in the diet. Eating salty foods also increases the intake of water. The usage of shelters lowers heat stress and decreases water intake in hotter areas.
Conclusion-
Estimating the WF of livestock production and economic analysis of water use at different stages of production will help farmers and other stakeholders to identify the most demanding activities in term of water use, and implement strategies to improve water-use efficiency. Sustainable consumption rather than sustainable production can be the main goal of water policy. Finding areas with high agricultural output, low water consumption, high nutrition feed crops, appropriate feeding schedules, water-saving methods, and raising milk productivity all require attention. Teaching dairy producers about the drawbacks of excessive consumptive water usage is a crucial step toward lowering the water footprint of milk production. As a result, everyone has a stake in the topic of prudent water governance, including investors, companies, governments, and consumers.