Water quantity and quality for dairy cattle By Virginia Ishler Dairy Alliance Nutrient Management

Water – an important nutrient Total body water content of dairy cattle is 56-81% of their body weight.  Transport nutrients to and from cells  Nutrient digestion and metabolism  Elimination of waste material  Excess heat (perspiration)  Proper fluid and ion balance  Fluid environment for the fetus

Water – an important nutrient Loss of water from the body occurs via:  Milk production (25-35% of total water intake)  Fecal (30-35% of total water intake)  Urine (15-21% of total water intake)  Sweat  Vapor loss from the lungs

Water Quantity 80-90% of the cows water needs comes from drinking water. Amount of water consumed depends on  Body weight  Age  Milk yield  Dry matter intake  Temperature  Relative humidity  Water temperature, quality, and availability  Moisture content of the feed

Predicting water intake Equation 1  Total water intake (lbs./day) = (4 x DMI ) + 4%FCM  Drinking water intake (lbs./day) = Total water intake – ration water intake* *Ration water intake =DMI/%DM - DMI 4%FCM = (0.4 x lbs. milk) + [15 x (% fat/100) x lbs. milk]

Predicting water intake Equation 2  Water intake (lbs./day) = x DMI (lbs./day) x milk yield (lbs./day) x sodium intake (grams/day) x weekly min temp o C What is the difference in predicted water intake using these 2 equations?

Example: How much H 2 O will this cow consume? Information needed  Milk production = 80 lbs. of 4% FCM  Dry matter intake = 54 lbs.  Ration dry matter content = 45%  Sodium intake = 44 grams  Mean temperature = 70 o F or 21 o C o F to o C = ( o F – 32) x

Equation 1 – Includes ration water content Total water intake (lbs./day) =  (4 x 54 lbs ) + 80 lbs = lbs. of water Drinking water intake (lbs./day) =  lbs. – 66 lbs.* = lbs or 30.7 gallons. * 54 lbs. DMI/0.45 – 54 lbs = 66 lbs. of ration water.

Equation 2 – Includes Na and Temperature Water intake (lbs./day) =  (1.58 x 54 lbs./day)  x 80 (lbs./day)  x 44 (grams/day)  x 21 o C lbs or 30.4 gallons

Estimated water intake for a 1,350 lb. lactating cow producing 40 – 100 lbs. Milk prod.DMIMean Min. Temp. a lbs./daylbs./day 40 o F50 o F 60 o F 70 o F 80 o F Source: Water for Dairy Cattle. Guide D-107. New Mexico and Oklahoma Cooperative Extension. a Mean min. temp. is 10 to 15 o F lower than mean daytime temp. b One gallon of water weighs 8.34 lbs. gallons per day b

Additional comments on factors affecting water intake… What about diets containing very high moisture ingredients, i.e. wet brewers, high moisture silages?  Decreased drinking water is affected more by the decline in DMI than the moisture content per se. Metabolic water  During metabolic oxidation, water yields (ml/g tissue) are 1.07 from fat, 0.40 from protein, and 0.50 from carbohydrates. Metabolic oxidation contributes metabolic water, however, this is an insignificant source.

What about non- lactating animals? Dry cows  7 to 13 gallons per day. Calves and heifers  1 mo – 1 to 2 gal.  2 mo – 1.5 to 2.4 gal.  3 mo – 2.1 to 2.8 gal.  4 mo – 3.0 to 3.5 gal.  5 mo – 3.8 to 4.6 gal.  15 – 18 mo – 5.9 to 7.1 gal.  18 – 24 mo – 7.3 to 9.6 gal.

Drinking Behavior Water consumption is usually associated with feeding or milking.  Cows may consume 30-50% of the drinking water intake within 1 hour after milking.  Rates of 1 to 4 gallons per minute (higher value in free-stall barns)  One watering device for every cows or 2 feet of tank space per 20 cows.  Ideally, waterers should be located at milking parlor exit and within 50 feet of the feed bunk (or at every crossover in freestall barns).

Drinking Behavior Research at MSU – pattern and quantity of water consumed.  First calf heifers- avg. 63 lbs milk 16.7 gallons of water in 13 drinks daily 17.7 minutes spent drinking, avg. drink was 1.4 gal and the rate was 1 gal/min.  Older cows – avg. 83 lbs milk 23.6 gallons of water in 14.9 drinks per day minutes spent drinking, avg. drink was 1.9 gal and the rate was 1.2 gal/min.

Drinking behavior – Heat Stress USDA research showed total water loss from the body increased by 58% in non-lactating cows at 86 o F vs. 68 o F. (sweat)  Loss of water in feces decreased 25%, but increased 54% & 26% via respiration and urine. Lactating cows increased drinking water consumption 29% in warmer temp.  Fecal water loss dropped 33%, but loss of water via urine, skin surface and respiratory evaporation increased 15%, 59% and 50%, respectively.

Drinking behavior – Heat Stress Cows consume less water in high humidity vs. low humidity environments.  Water intake is very DMI driven. DMI decreases during hot, humid conditions.  Reduced ability by the animal to employ evaporative heat loss mechanisms.

Drinking behavior – Heat Stress NO STRESS MILD STRESS MEDIUM STRESS SEVERE STRESS

Water temps between 60 o -80 o F appear most acceptable to dairy cattle. Research studies conducted in Texas and Florida examining effects of chilled water (50 o F).  Variable milk production response.  Cows prefer warm water over chilled. Costs associated with chilling are not warranted. Chilled water has to be the only source if used. Drinking behavior – Water Temp.

Water Quality pH Total dissolved solids Sodium, potassium, sulfate, chloride  Affects on the dry cow ration Nitrates

Water pH - Acidosis Recommendations - pH 6.5 to 8.5 Lower and higher water pH has been blamed for acidosis problems.  Water may be a contributing factor, but the ration and the physical environment has a greater impact than water ever would. Focusing on water only will not solve an acidosis problem.

Total Dissolved Solids - Intake Salinity  Sodium, Chloride, Bicarbonate, Sulfate, Calcium, and Magnesium  No differences observed in drinking water intake on high saline water (TDS = 4,400 mg/L) vs. low saline water during cool temperatures. Differences observed during the summer months.  Higher water intakes observed on high saline water vs. normal.

How does water affect dry cow rations? Specifically – DCAD –  Dietary Cation Anion Difference Cations are Sodium and Potassium Anions are Chloride and Sulfur Example:  1400 lb dry cow  DMI is 30 lbs.  Water intake is 11 gallons or 92 lbs.

Water - DCAD Diet Avg. waterFarm A waterFarm B water Variable% of DMppm ppm ppm K Na Cl S DCAD, mEq/100g DM

Water - DCAD Diet + Water, mEq/100g DM Total meq/day Diet Avg. waterFarm A waterFarm B water Variable% of DMppm ppm ppm K Na Cl S DCAD, mEq/100g DM

How does water nitrate level affect dairy cattle?

Nitrate – General Information Nitrate  In the rumen – source of N for synthesis of bacterial protein Can be reduced to nitrite  Nitrites reduces oxygen-carrying capacity of hemoglobin  Symptoms of acute nitrate poisoning Asphyxiation and labored breathing Rapid pulse Frothing Blue muzzle/bluish tint around eyes Chocolate-brown blood

DMIFeed NO 3 -N FactorNO 3 -N intake lbs. ppm mg Corn silage Haylage Hay Shelled corn Canola Roasted beans Soybean meal (HT) Cottonseed hulls Cookie meal Sugar Min-vit mix ,272 Ration Nitrates

DMIFeed NO 3 -NFactorNO 3 -N intake lbs.ppm mg Corn silage Haylage Hay Shelled corn Canola Roasted beans Soybean meal (HT) Cottonseed hulls Cookie meal Sugar Min-vit mix ,272 Water Total 13,070 Nitrates: Ration + Water

Nitrates – Total Ration 13,070/454,000 / 54 x 100 = 0.053% NO 3 -N content of total diet as %DM (Reasonable level is 0.04 to 0.09%) Possible problemsTotal diet, ppm Noneup to 400 Impaired infertility Reduced gains1301 – 1700 Clinical symptomsover 1700 Convert % to ppm % X 10,000 = 530 ppm

Nitrates – Worse Case Scenario

DMIFeed NO 3 -NFactorNO 3 -N intake lbs.ppm mg Corn silage Haylage Hay Shelled corn Canola Roasted beans Soybean meal (HT) Cottonseed hulls Cookie meal Sugar Min-vit mix ,272 Water ,426 Total 33,698 Nitrates: Ration + Water

Nitrates – Total Ration 33,698 /454,000 / 54 x 100 = 0.14% NO 3 -N content of total diet as %DM (Reasonable level is 0.04 to 0.09%) Possible problemsTotal diet, ppm Noneup to 400 Impaired infertility Reduced gains1301 – 1700 Clinical symptomsover 1700 Convert % to ppm % X 10,000 = 1400 ppm

General Recommendations Test suspected forages/water Suspected or high nitrate forages  Introduce gradually -adaptation reduces risks  Limit meal size  Feed more frequently  Feed at least 3-5 pounds of grain  Limit dry matter intake/single meal if forage contains > 1100 ppm NO 3 -N.

Summary Water is important – both quantity and quality.  Very little research is available to define lower and upper limits of when problems will occur.  Rely on commonsense Handling problem herds  Water is unlikely the sole problem, but it may be a contributing factor.  Nutrition and feeding management affect cows more that water, under normal conditions.  If water quality is an issue, calves, young stock, and dry cows probably are experiencing problems as well as lactating cows.