Quality Water for Dairy Cattle
by Jim Linn, Dept of Animal Science 
University of Minnesota

Water is the most important nutrient for lactating dairy cattle. It is required in a larger quantity than all other nutrients combined. We know that without an adequate clean, fresh supply of water everyday, milk production will be severely compromised. Ensuring dairy cattle will consume adequate quantities of water
requires adequate drinking space, clean water supplies and water sources that are good quality.

Water Intake
Factors effecting water intake include: dry matter intake, percent dry matter of the diet, milk production, environmental conditions and sodium intake. Milk
production and temperature are the two major factors affecting water intake.
Table 1 shows the increase in water intake per day with increasing milk production and temperatures.

Table 1. Impact of milk production and temperature on water intake of dairy cattle.

Drinking Rates and Water Access
The average cow will drink 3 to 5 gallons of water per minute from an open tank.  Cows will normally drink about 10 minutes per day. This is true drinking time.  They may lap and play in the water with their tongue much longer.
     Cows prefer to drink with their head down similar to a grazing position. The muzzle will be 1 to 2 inches below the water surface. The size of drinking area for a cow to comfortably fit her muzzle into and drink from is about 100 square inches (McFarland, Penn State, 1998). The general recommendation for water space in loose housing is 2 linear feet per 15 to 20 cows. Fifteen percent of the cows in a group should be able to drink at the same time. Two or even three locations of water in a pen or group are preferred over one large single location.

On Farm Water Tests
How do you know if there is a water quality or quantity problem on the farm?
Here are a few quick assessments to help you evaluate.

1. Low water intake will result in low milk production, but low milk production is not always a result of a water problem. Cows will drink water according to their needs. Therefore, when low milk production is a problem on the farm, low water consumption is usually observed. Therefore, the cause of low milk production can be something other than poor water quality or limited quantity.
2. Is there a water flow problem? Use of water meters on farms is encouraged and the only true way to know how much water cows are consuming. In tie-stall barns with drinking cups, press the lever or button and check flow. If cows are aggressive to drink the water coming into the cup, this is a sign of either low water flow or cows do not know how to operate the drinking cup.
3. Do people and cattle drink the same water? If people are drinking the same water as cattle and are not complaining about water quality, bad taste or experiencing any health problems, it is highly unlikely the water adversely affects the cows.
4. Check the taste and smell of the water. What is your assessment?
5. Are calves fed milk replacer using the same water cows are drinking? If yes, how is the calf health and growth? These young animals should be some of the most sensitive to poor quality water.
6. Check pH of the water. This is a very quick screening test. Most water should be between 6 and 8.5. If it is outside this range, a water quality test for contaminates should be conducted to determine why. However, just because it is between 6 and 8.5 doesn't mean water quality is always good

Beth Fox presented Outstanding New Field Representative

DHIA service is as good as the person who shows up on your farm each sample day.  Each year Minnesota DHIA recognizes the very best Field Representatives. They represent the top 6% of the DHIA field staff.
     Beth Fox is a new Field Representative serving herds in the Glencoe and Hutchinson areas. Beth started testing on July 10th of last year and has been an inspiration. She came from a dairy background, so knew what the hours could be like.
     Since starting in July, Beth has already taken the initiative to add 3 new herds, for a total of 43 herds that are in her testing unit. She has been up to the challenge of testing small herds as well as larger herds, which can sometimes be intimidating as a new Field Representative. Her testing interval is at 33 days, so she is making the rounds and getting herds tested regularly. Beth has improved test to process timing in her unit from 3.21 days to 2.10 days.
     Beth has what it takes to make a great Field Representative. She has the understanding of why herds are on test and why it is important to offer the services that are needed to manage dairy herds in the 21st century. 
     We hope Beth agrees to stay around for quite some time and be a part of what is happening in dairy in MN. Thank You Beth!

 Summer Months and Somatic Cell Counts

As the weather gets warmer, SCC counts will likely climb, but there are management tools that can be implemented to help control it. Here are some ideas from mastitis experts:

1. Evaluate your current status.
   1. If a high percentage of animals < 30 DIM on the Yearly SCC Summary section of the Herd Summary Report are infected it would be a good idea to evaluate your dry cow treatment program and bedding conditions for dry and close-up animals.
   2. The Changes in SCC Status section shows the most recent test results. A good goal would be to have less than 10% new infections for fresh cows and less than 7% new infections for current vs. last test. Divide Fresh Infections by Fresh Cows in the Production Averages section to see what percent of animals in each test interval were infected on the first test.
   3. Use the Somatic Cell I. Herd Summary, or the Bulk tank analysis report in Scout or Dairy Comp 305, to determine the percentage of somatic cells individual cows are contributing to the tank.
   4. Use Bulk tank cultures to determine if you are dealing with contagious or environmental organisms. Individual Cow cultures help you to decide if you should treat, milk last, or cull. Use a high quality laboratory so you can be assured of the accuracy of the results. Many DHIA Field Representatives have had training to be able to take samples for you and have additional information on the value of doing cultures.
   
   
2. Check your milking procedure. Drs. Jeff Reneau and Ralph Farnsworth from the University of Minnesota observed thousands of milkings to develop the Minnesota Method of udder preparation.
   1. Brush off loose contamination and apply predip to cover the entire teat.
   2. Use milking gloves and clean teats with three to four vertical hand motions, and then use the thumb and first finger in one or two horizontal motions across the teat end to remove dirt and manure. Forestrip to check for clinical mastitis.
   3. Allow 30 seconds of contact time for the teat dip, then dry teats with a single service towel. Make a special effort to ensure the teat end is cleaned. (Most dairies omit this very important step).
   4. Attach the unit within 1 to 1.5 minutes from the start of udder prepping.
   5. Remove the unit as soon as the cow has completed milking to avoid overmilking which may cause teat end damage and subsequent increased susceptibility to mastitis. Cows should have up to 1.5 cups of milk left in the udder when the unit is removed. Strip the cow as soon as the unit is removed, taking milk that readily flows into the teats without massaging the udder, to determine how much milk is left.
   6. Apply post dip as soon as possible after removing the unit. Cover the entire area of the teat that had contact with the milking unit. Complete coverage of teats with pre and post teat dip is a significant factor in controlling contagious mastitis causing agents such as Staph aureus, Strep Ag. and mycoplasma.
   
   Bacterial contamination of the udder and teat is directly linked to milk quality and udder health. Good udder prepping techniques can cut bacteria by 75 percent.  For you, that means lower bacteria count in the bulk tank and better chances you can keep your cows free of mastitis. In addition, cows that have had good udder prepping often milk out faster and may produce more milk.
   
   
3. Maintain clean bedding.
   Many dairymen pull bedding from the front of stalls to the back and then put clean bedding in the front. University of Minnesota research shows that bacteria in that front bedding has already had a chance to multiply so counts can get extremely high in a relatively short time. The preferable method according to their research is to scrape the back of the stall clean and replace that bedding.  Keep enough bedding under the cow for good cows comfort and cleanliness.
   
   
4. Make sure milking equipment is working properly.  It is a good idea to have equipment checked on a semiannual or at least annual basis. Dirty or improperly functioning vacuum regulators and inaccurate vacuum gauges are common problems. Change inflations and hoses at recommended intervals.
   
   
5. Control Stress.
   Animals under stress are more susceptible to disease. Good ventilation, comfortable stalls, clean water and good nutrition will help cows resist mastitis infections as well as produce more milk.

Cows for Sale

1 Bred Holstein Heifer FOR SALE. If interested please call Rodney & Shirley Domjahn @ 952.955.1559 Montrose, MN. (5/31/02)

For Sale - 4 Bred Holstein Heifers. Herd located in Montrose.  If interested please call John & Lori Salonek 952.955.3207 (5/29/02).

FOR SALE: 3 Springing Heifers - full vaccination program, Level 2 Johne's tested herd, AI bred, AI sired, 22,500 RHA. Due to calve in June, August, September. Call Steve Hoffman - Brown County 507.354.7268 (5/1/02)

Cows For Sale is a service of Minnesota DHIA.  Members can advertise for just $2.50 per animal with a maximum of $50 per herd (good for 60 days).  For more information, talk to your Field Rep on sample day or call us at 800.827.3442.

 THANK YOU!