Swati Thakur*, Ruokuobeinuo Houzha1, Sunil kr. Rastogi2 and Jyoti Palod3
College of Veterinary and Animal Science,
G. B. Pant University of Agriculture & Technology,
Pantnagar-263145, Uttarakhand
Introduction
Water is the most important in animal nutrition as it is one of the largest single constituents of body fluid that maintains the body homeostasis. Younger animals contain a higher percentage of body water in relation to their body weight than the older animals. Obese animals contain a lower water percent than lean animals, as fat replaces the body water content. Water percent present in different body wise as in newborn calf70%, obese dairy cow 50%, and lean dairy cow 70% and in small ruminants is 60 to 76%.
Provision of clean water to domestic animals at all time is necessary. Since water is the most essential nutrient that requires for various physiological functions in the body. These includes –
1.Involved in all the biochemical reactions of digestion and metabolism in body
2.Act as solvent for a wide variety of compounds. It transportsdissolved nutrients and helps in the excretion of end waste products in the body
3.Major factor in regulation of body temperature
4. Serves as a medium for transportation of semisolid digesta after absorption in the alimentary tract i.e. blood, tissue fluids and cell secretion and excretory fluids (urine, sweat)
4.It provides cell rigidity, fluidity and elasticity tothe texture ofbody cells
5.Form major constituent of body fluids and provides lubrication in the synovial fluid
6. It maintainsmilk volume duringlactation
7. Life sustainer
Domestic animals met their daily water requirement and maintains their body homeostasis mostly from three different sources such as –
• Water consumed voluntarily ad libitum
• Water contained in feed or as bound water
• Water from metabolismor oxidation of nutrients. Metabolic water produced by oxidation of fat, carbohydrate and proteins produce approximately 100%, 60% and 42% of body waterrespectively. This water acts as important water source to animals under certain physiological conditions i.e. deserts environment, scarcity of water.
Quality water and its requirements
Quantity of water consumed by the animal depends upon the quality of water consumed. Foul odour and taste may affect water intake. Toxicand impure water quality can affect herd health and cause enormous health hazards. This may cause production loss due to consumption of suchimpure water containing variety of micro-organisms such as bacteria, virus, protozoa and parasitic eggs. Water containing Coliform bacterial count of more than 1 in 100 ml water can cause calf scour and bacterial count above 20 in 100 ml water can cause diarrhea in cows. This is taken care by water chlorination method that helps to remove harmful bacteria and other microbes. Protozoa and enterovirus are more resistant to water chlorination.Dissolved substances such as inorganic salts; calcium, magnesium, sodium chloride, sulfates and bicarbonates are often present in water. Various levels of these salts in water cause osmotic effect leading to poor performance of animals. Sulfates and magnesium salts are less effective than calcium and sodium salts whereas sulfates in water have laxative effect in the body causingdiarrhea.
Table 1: Water requirements by different domestic animals
Domestic animals Water requirement (L/day)
Dairy cattle:
Calves (1-4 M)
Heifers (5-24 M)
Milking cows
Dry cows
9
25
115
41
Beef cattle 22-66
Sheep:
Lamb
Gestating meat ewe/ram
Lactating meat ewe
Gestating dairy ewe/ram
Lactating dairy ewe
4.4
5.25
10
5.75
10.4
Goat 4-5
Swine:
Weaner
Feeder pig
Gestating sow/boar
Lactating sow
2.0
6.7
15
20
Horses 30-45
Chickens 0.2-0.4
Turkey 0.4-0.6
Water deprivation and its consequences
Animals have capacity to tolerate dehydration and efficiency to utilize water in order to rectify body imbalances. This capacity is varied among domestic animals. Cattle have limited capacity in this aspect than heat tolerant camel. Total water deprivation causes no significant reduction in milk yield up to24 hours, but beyond which it effectsmilk composition. The reduction in milk yield is partly associated with decline in feed and water intake. Cattle try to compensate reduced water intake by reducing more excretory water than milk yield.
The effects of water deprivation to animals can be of two ways –
• Moderate water deprivation:
This effect will decrease feed intake, low productivity and more water excretion through urine, faeces, sweating
• Severe water deprivation:
This effect will lead to increase rapid weight loss, hemoconcentration, more renal excretion of electrolytes (Na, K), higher pulse rate and rectal temperature under high environment temperature, nausea, muscular immobility and death.
Factors affecting water intake in domestic animals
• Variation with different physiological status
Water intake varies with different physiological statussuch as for maintenance, growth, pregnancy, lactation and ageing. Growth, pregnant and lactation status ofanimals require more water than animals of other status. Lactating dairy cows requires more water intake proportion to their body weight. Dairy cows milk has85 to 87% of waterand requires average blood volume of 500 ml to passes through mammary gland to synthesize 1 ml of milk. Normal lactating ewes requires 50%morewater intake than dry ewes. The difference in water intake by lactating animal may be due to their high metabolic rate and more water loss through vaporization and excretion.
• Variations with climate
Increase in ambient air temperature above 4°C willincrease the water intake per unit of dry matter consumed by the cattle. The ratio of water intake and dry matter consumed remain constant when environmental temperature is between -12°C to +4°C and afterwhichit increases with increase in environmental temperature. Sheephaving well grown woolshowed less heat loss from skin and more heat loss through respiratory tract, involving greater vaporization of water and increased water intake. Relative humidity percent at comfort environmental temperature have little effect on water intake but increased water intake withhigh relative humidity
percentand environmental temperature. These changes in relative humidity percent is accompanied with lower feed intake and reduced vaporization of moisture.Increase in wind velocity up to 45m/s at ambient air temperature of 10°-26.7°C results into decreased water intake. Water consumption is considered to be same at 1.8 and 45m/s velocities at 33°C. Besides all these, the amount of rainfall per day also influences the water intake.
• Diurnal and season variations
Animal’s water intake varies in both diurnal and seasons such as during summer and winter seasons. Water intake during hot environment increases as much as up to 72%. Peak water demand in lactating dairy animals occurs between 1 to 3 hours after the evening milking and next smaller peak demand occurs 1 to 3 hours after morning milking or early afternoon.
• Quantity and composition of dry matter intake
Increased dry matter intake is positively correlated with increased water intake. Water intake per unit of dry matter feed consumed is higher for dry matter feeds than more water content feeds. Since water content in feeds is ranged from 10% in air dried feeds and more than 80% in fresh green forages.Large amount of salt in dry matter feed tends to increase the electrolyte concentration in body fluids. This increases the water intake to balance water with electrolytes.
Higherthe proportion of minerals in dry matter feedthere is greater excretion in urine and more water intake. Water requirement increases in high protein diet than low protein diet because nitrogenous end products require more water for excretion. However, chronically sodium-deficient dairy cows exhibit signs of intense polydipsia and polyuria. High level of pentosans and crude fiber in feed increasedmore water loss through feces. This stimulates the osmoregulatory center for more water intake. However domestic animals are more tolerant to salty dry feedthan in drinking water.
• Water rich in minerals
Water may contain salt, sulphates, nitrates or other minerals whose effectvaries with animal species. Salt concentration below 1000 ppm is generally safe for all livestock andabove 1000 to 5000 ppm may develop diarrhea. Though salt ranges 5000 to 7000 ppm is considered safe for dairy, beef and swine but not suggested for pregnant or lactating animals. Salt concentration of 7000 to 10000 ppm is considered unsafefor all livestock. Domestic animals can tolerate salt in water up to 1% and not more than 1.2%. It is observed that water intake is increased by 53% at 1% salt in water.Excessive level of nitrates or high alkalinitymakes waterunpalatable to animals. Waterintake during lactationis very important to maintain milk volume and irrespective to types of water either hard water (33ppm of calcium and magnesium) or soft water (1ppm of calcium and magnesium)it does notaffectmilk synthesis. The presence of other elements such as iron, aluminium, zinc, manganese and strontium increase the hardness of water and such water turn toxic if their amounts present is higher enough.
• Variation between species and individuals
The rate of water consumption varies with species and increase with high ambient air temperature. Water consumption increases more slowly with rising temperature in zebu than exotic cattle. The amount of water intake within same animals can be maintained by providingsame feed and environmental conditions. Water intake is significantly correlated with dry matter intake and milk yield. An individual variation of water intake is observedboth in the dry matter intake and milk yield.
• Temperature of drinking water
Decrease water intake when ambient air temperature falls below the freezing point and increaseswhen it is slightlywarmed above freezing temperature. Higher environmental temperature decreases the water intake and is reversed with cold environmental conditions.
• Frequency and periodicity of watering
There is more water intake (18%) and increased milk yield in cattle when ad libitum wateris provided rather than given once a day. Grazing cattle usually drink 2-5 times more water than stall fed animals. Frequency of watering to dairy animals affects the milk yield and composition i.e. increased water intake in the morning is associated with increased water content in evening milk. Both frequency and duration of drinking water are influenced by type of roughage feeding and availability of drinking water. Animals feeding on silage drink less frequently than those fed on dried grasses.
• pH and toxicity of water
Natural water has a pH range of 6 to 9. Water pH falling in these ranged is considered satisfactory for all domestic animals. Lake and other surface water may be mostly contaminated with blue-green algae that may lead totoxicity.Watertoxicity in animals may occur due to water containingsufficient concentrations of lead, cadmium and mercury. Such consumption of water allows these toxic substances to accumulate in livestock tissues and products such as milk, meat and eggs. These products are unfit for human consumption causinghealth hazards and economic loss. Pesticides of high organophosphorus(OP) compounds present in water give a major threat and are lethal even in low doses. Insecticides such as dichlorodiphenyltrichloroethane (DDT), methoxychlor, dilan, perthane and dichlorodiphenyldichloroethane(DDD) are dangerous and their lethal dose is slightly higher than OP compounds while pyrethrins and rotenones are non-toxic to livestock’s.
Table2: Recommended levels of some potentially toxic substances in drinking water for animals
Elements Safer upper limit of concentration(ppm)
Arsenic 0.2
Cadmium 0.05
Chromium 1.0
Cobalt 1.0
Copper 0.5
Fluoride 2.0
Lead 0.1
Mercury 0.01
Nickel 1.0
Nitrate-N 100
Nitrite-N 10
Vanadium 0.1
Zinc 25
Conclusion
Animals can survive longer without feed for several days but cannot thrive without water. Since water is essential most for all vital physiological functions in the body. Continuous availability of clean, fresh and quality water to domestic animals is necessary for quality production. Water requirements in lactating animals are higher than dry animals for maintaining milk volume. It is recommended that in a well-organized dairy farm, productive farmsalways provide ad libitum of clean drinking water at least once daily. Lactating and producing animals in tropical environments are recommended to supply adequate waterseveral times a day.
*Corresponding author and MVSC Scholar, Veterinary Physiology & Biochemistry, C.V.A.SC., G.B.P.U.A&T, Pantnagar E-mail:
1. Assistant professor, Deptt. of Veterinary Physiology & Biochemistry, C.V.A.SC., G.B.P.U.A&T, Pantnagar
2. MVSC Scholar, Deptt. of Veterinary Gynecology& Obstetrics, C.V.A.SC., G.B.P.U.A&T, Pantnagar
3. Professor, Deptt. of Livestock Production & Management, C.V.A.SC., G.B.P.U.A&T, Pantnagar
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James R. Gillespie. Animal nutrition and feeding.
Animal nutrition. 5th edition. P. McDonald.
Ward, D. and McKague, K. 2007. Water requirement of livestock.
Olkowski, A.A. Livestock water quality: A field guide for cattle, horse, poultry and swine.
