Evaluating and monitoring dehydration in dairy calves is an important task for good calf performance and survivability.  This requires good management – careful observation, attention to individual calves and the ability to monitor dehydration.  Sick calves may lose up to 10% of their bodyweight in a single day when they are scouring.  When a calf losses 14% of its bodyweight, death occurs and it is the dehydration, not microorganisms, that typically kills these scouring calves (Table 1).  Early identification and treatment of dehydrated calves will help increase calf survival rates.

Steps to Evaluate Dehydration:

1. The first step is to evaluate the fecal scores of your calves.  Calves with very loose or runny feces are at a high risk of being dehydrated.
2. Inspect those calves that are at risk for the classic signs of dehydration:

a.   Sunken eyes

b.   Dry mouth and nose

c.   Weight loss

d.   Fast or very slow pulse

e.   Cold ears and/or cold legs

Tenting Test for Dehydration:

A good test for dehydration is the skin tenting check.  To conduct a tenting test:

1. Firmly pinch the loose folds of skin on the neck of the calf and check to see how long the skin remains tented.
2. If the skin remains tented for 2 to 6 seconds, the calf is moderately dehydrated.  Start oral feeding of a good electrolyte like Kentrol to assist rehydration.
3. If the skin remains tented longer than 6 seconds, it is an indication that the calf is severely dehydrated (10% dehydrated).  Calves observed in this state of dehydration need professional veterinary interventions with intravenous fluid administration.  Following the intravenous therapy, oral electrolyte therapy should be continued to maintain proper hydration.

Treating Dehydrated or Scouring Calves:

At the first signs of dehydration (section 2 above and tenting of 2-3 seconds), the easiest way to treat is oral feeding calves an electrolyte solution like Kentrol.  If the calf is exhibiting moderate to severe dehydration or not consuming liquids orally, the Kentrol should be given via an esophageal feeder.

Kent Kentrol contains dextrose and other energy sources; alkalinizing agents to treat acidosis; and sodium, potassium, and chloride to replenish lost electrolytes.  Kentrol also contains a gelling agent to aid absorption and reduce scouring.  Feed moderately dehydrated calves 2 quarts of Kentrol electrolyte solution, mixed according to the label recommendations twice daily until calves recover.  During this period, continue feeding dehydrated calves milk or Milk Replacer to ensure nutrient intake.  Kentrol (100 grams per 2 qt. water) and Milk Replacer (10 oz. per 2 qt. water) should be mixed separately per directions and fed to achieve recommended intakes.  The Kentrol mixture should be fed before or after Milk Replacer for 2 to 4 days or until the calf is no longer scouring and does not appear to be dehydrated based on skin tenting and observation.  When properly mixed separately, the Kentrol and Milk Replacer can be fed at the same time as long as recommended daily intakes are achieved.  However, never mix the recommended amount of Kent Kentrol and Milk Replacer in only two quarts of water as the resulting mixture is too high in osmolarity and may cause additional scouring.  When feeding waste milk, wait at least 30 minutes after milk feeding before feeding electrolytes, since most electrolytes contain bicarbonate or citrate, which can prevent milk clotting in the abomasum.

Why should milk replacer be mixed and fed according to directions? 

Nutrients are absorbed by osmosis.  In mammalian physiology, all body fluid compartments contain 300 milliosmols of osmolarity.  So for optimal absorption (osmosis) of nutrients by the calf, the milk replacer should be around 300 milliosmols.  Properly mixed calf milk replacer will contain 260-280 milliosmols of osmolarity, which is ideal for best absorption and digestion of the milk replacer. 

What occurs if calf milk replacer is mixed too concentrated? 

• If calf milk replacer is mixed more concentrated than labeled mixing directions (for example 10 oz. in 1 quart of water instead of 2 quarts), the resulting mix will be too concentrated (500-520 milliosmols, well above 300 milliosmols).
• To be absorbed, the concentrated solution must be held in the lumen of the intestinal tract until enough water can be secreted into the intestinal tract to dilute the concentrated milk replacer solution down to 300 milliosmols or below.
• This can take considerable time and may stall out the intestines and can result in dehydration and the growth of pathogenic bacteria.

 Can milk replacer and electrolytes be combined in one feeding? 

 No.

•  Milk replacer should be mixed according to correct mixing directions and fed separate from electrolytes.
•   An electrolyte like Kentrol should be mixed according to its correct mixing directions and fed at least 30 minutes after the milk replacer feeding.
•   Combining both milk replacer and electrolytes into 2 quarts of water will produce a mixture that is high in osmolarity (500 milliosmols or higher) and will be held in to the lumen of the intestinal tract until water can be drawn into the gut to dilute the mixture.  This can actually increase the scours that may be occurring.

What occurs if calf milk replacer is mixed too diluted?  (Sometimes done to provide water in the same feeding so water does not have to be fed separately.) 

The calf’s absorption and digestion processes work best if milk replacer is fed at recommended rates (260-280 milliosmols and then offered water about 30 minutes afterwards.  If calf milk replacer is diluted more than labeled mixing directions (for example, 10 oz. in three quarts of water instead of two quarts), the resulting mix will be too diluted (less than 300 milliosmols) and will not be absorbed and digested as well.  Having access to water too soon will even further dilute the milk replacer and further reduce absorption and digestion. 

When is best time to provide water? 

Ideally, water should be offered 30 minutes after milk replacer is fed for several reasons:

•   Milk replacer should be fed at 100ºF in order for the esophageal groove to close so milk goes directly to the abomasum instead of the rumen.
•   Allows time for the suckling and drinking reflex to subside.
•   Allows the initial digestive processes to begin.
•   Water can then pass into the rumen and does not dilute the processes in the abomasums.

We are getting close to the end of a long, hard winter that has tested all of us in some way.  With that being said, I thought it would be beneficial to discuss some basic care recommendations that help maintain healthy calves.

Bed calves for comfort – Calves need help staying warm with good bedding such as small grain straw.  Because of the hollow stem and other characteristics of straw, it has better insulation potential for calves than sawdust or corn stalks.  A calf that is wet or covered in mud and manure gets cold quicker because the matted hair provides less insulation.  Also, when the calf’s bedding is clean and dry, the calf is clean.  When dirty, the calf licks itself and ingests the mud and manure on its hair coat; we all know about the resulting health problems that could occur.

Provide clean, fresh water.  Water is very critical for growth and the health of calves and steers.  As a rule of thumb for calves, it takes four pounds of water for every one pound of feed.  Calves consuming 1.25 pounds of Milk Replacer in four quarts of water and one pound of starter is short of water.  This will reduce gain and open the possibility of health issues.  Water weighs eight pounds per gallon or four quarts; 2.25 pounds with only eight pounds of water instead of nine pounds.  Providing clean, fresh water at all times during the cold winter months is difficult, but don’t under or over mix Milk Replacer with water to get more or less water in the calves as this can cause digestive problems.  Always mix and feed the Milk Replacer as recommended.

Provide adequate shelter and feeding areas.  Calves require adequate shelter from the elements to maintain their performance during inclement weather.  Shelters should have good air quality – air high in humidity increases the potential of pneumonia.  Wet bedding decreases air quality so it is imperative that calf pens be cleaned and rebedded on a regular schedule.  Facility design should allow livestock to be comfortable and easily allow calves to access feed and water.  The water and feed should be clean and free of foreign material.  Also, it should be readily accessible, which means calves can eat comfortably without having to reach up or down.  Locate feeders and waterers so they are not too high or low for animals to find or eat from it.  Keep waterers clean of any manure or bedding.  Remove any leftover feed daily from the feeding bucket or trough.

Provide the proper nutrition.  It is fun because it is easily solved with the Kent Calf Feeding program.  A calf has a very low feed intake of 1-2 pounds per day so it is very critical to have all the proper nutrition in a very dense balanced package – Kent calf starters do that.  Cost per ton or pound is not as big a concern as to what is in it and the resulting performance.

The list could go on with more, but these are basic, but very critical recommendations for getting the best performance from Kent Feeds’ Calf feeds.  Most times, when you focus on basic animal husbandry skills and proper nutrition, you will minimize the health concerns in dairy-beef calves.  So, walk your customers’ calf facilities and help them fine-tune their calf management for maximum profits.

Water quality is becoming a greater issue for dairy producers as they continue to grow and put additional stress on their water resources.  Water quality within a water source is not necessarily a constant over time.  Pulling additional water from a well, weather patterns and fertilizer application are all items that can influence water quality within a well.  Some producers have found that managing water quality is better left to local municipalities and have started purchasing water for their cattle rather than pulling water from a private well.  For producers using a private well, a water quality control program should be in place.

It is difficult to establish a water quality program and determine it’s effectiveness if you do not establish a way to measure water intake.  This can be done relatively easily with in-line water meters that measure only the water supplied for drinking.  Measurements should be taken for at least 7 to 10 days to account for day-to-day variation.  Once water intake is established, it should be compared with expected intake and factors limiting intake evaluated.  Keep in mind that there are many factors other than water quality that can limit intake.  Although these are not the focus of this Nutrition Note, some factors include cleanliness of water tanks, water supply (gallons delivered per minute), stray voltage and water space/accessibility.

Cows can display several signs of inadequate water intake including:

1. Sudden drop in milk production (if the factor limiting water intake occurs suddenly).  Problems that arise slowly over time do not cause this sudden drop; therefore, you do not need to see this symptom to have a water quality issue.
2. Infrequent drinking.
3. Firm manure.
4. Low urine output.
5. Drinking urine.
6. High blood packed cell volume (PCV) – over 38% average PCV in a group of cows.  This is an indicator of dehydration.

Water analysis and evaluation can become quite complex.  There are many elements that can be tested for in water (e.g., total dissolved solids (TDS), sodium, calcium, magnesium, chloride, sulfates, nitrates, iron, manganese, copper, hardness, total coliforms, arsenic, barium, cadmium, cobalt, lead, mercury, aluminum, fluorine, & pesticides).  However, an initial water analysis does not need to be this complicated and should focus on a few key components that are the most common factors causing decreased water quality. 

Many certified water testing laboratories offer a “livestock suitability” package that includes TDS, sodium, calcium, magnesium, chloride sulfate, nitrate, iron, manganese, copper and hardness.  The key components to monitor routinely will be addressed below:

1. Total Dissolved Solids (TDS):  This is a measure of the sum of all the inorganic material that is in the solution within the water.  High TDS does not always indicate the water is not suitable for livestock.  There are some solids (i.e., calcium and magnesium) that can be high in the water without detrimental effects on livestock.  Target levels for TDS are 500 – 1000 ppm.
2. Hardness:  This is a measure of the amount of calcium and magnesium dissolved in the water.  Hard water is often a problem when cleaning milking equipment, but it does not appear to impact performance in dairy cattle.
3. Sulfate:  High sulfate levels will cause decreased water intake and decreased milk production.  Also, because sulfur is an anion, high levels will reduce overall cation-anion difference.  This will have a negative impact, particularly in fresh cows, resulting in increased metabolic disease.  Target levels for sulfate are 250 – 500 ppm.  A thumb of rule for anions in the water is to keep the sulfate + chloride concentration below 1000 ppm.
4. Chloride:  See sulfate (above).  Target levels of chloride are 250 – 500 ppm.
5. Iron:  Importance is secondary only to sulfate and chloride.  It causes reduced water palatability and promotes growth of black slime in water tanks (this is the result of bacterial growth).  Iron in water is nearly 100% available to the animal (iron in feed is generally only about 10% available).  High iron can bind copper and zinc, making them unavailable to the animal.  Once absorbed, high iron levels promote free radical production, decreased immunity and increases the incidence of infection, particularly in fresh cows.  Target levels for iron are 0.3 ppm or less.
6. Manganese:  It causes off flavor and decreased water intake.  Target levels for manganese are 0.05 ppm or less.
7. Nitrate:  The most common source of nitrate in water is fertilizer run-off.  High nitrates do not appear to impact milk production, but decreased reproductive performance has been reported.  Target levels for nitrate nitrogen are 20 to 25 ppm or less.
8. Copper:  High copper levels in water can cause liver damage.  Target levels for copper are 0.3 ppm or less.

Water quality at a dairy farm is a dynamic component of the operation, much in the same way as forage quality.  To monitor and manage this, water samples should be analyzed quarterly and kept as part of the herd record.  When water quality is identified as a limiting factor, there are many options to help “clean” the water (e.g., carbon filtration, air stripping, chlorination, distillation, cation-anion exchange, filtration, reverse osmosis).  These are all generally quite expensive.  Before considering these options, a reputable supplier should be identified who will guarantee that their system will remove the unwanted components from the water (as measured by an independent laboratory).  Maintenance cost should also be considered.  Finally, the return on investment should be estimated before spending large sums of money to manipulate water quality.

Kent Kafnurs® Gold is a premium milk replacer containing milk and animal (bovine) plasma protein (16% crude protein from milk protein and 4% crude protein from bovine plasma).  The primary benefits of Kent Kafnurs Gold are better performance under stress conditions and a slight cost savings compared to an all-milk protein milk replacer.  The benefits of bovine plasma protein in calf milk replacers are most often observed in stressed calves and calves facing a greater pathogen load and include increased gains, fewer scour days, better fecal scores, less dehydration, and reduced mortality.

Bovine plasma is a concentrated source of protein obtained by removing the red and white blood cells from fresh whole blood.  The bovine plasma used in Kent Kafnurs Gold is NutraPro^TM (American Proteins Corporation).  It is a straw colored, freely flowable, soluble powder that is properly processed to retain plasma biological functions.  The proteins (e.g., tansferrin, loctoferrin, immunoglobulins and others) in plasma have been shown to inhibit bacterial growth, reduce the severity of diarrhea and improve overall animal performance.

Although the specific interactions of bovine plasma protein in calves are uncertain there are two apparent benefits.  First, some of the immunoglobulin G (IgG) in the plasma escapes gastric and intestinal degradation and remains in the digestive tract to help fight bugs such as salmonella, corona virus and E. coli.  Second, use of plasma protein in pig prestarter diets has indicated the plasma promotes intestinal growth resulting in improved digestion and overall animal growth (animal plasma protein has been used in baby pig diets for years to improve performance).

Tests with calves that are not stressed generally indicate bovine plasma protein is well utilized by the calf (similar to all-milk protein).  The responses vary from similar performance (similar gains, fecal scores, scouring, and mortality) to improved performance compared to a standard whey protein based milk replacer.  In addition to being an excellent quality protein that is highly digestible with excellent amino acid profile, bovine plasma also provides immunoglobulin and other beneficial (functional) factors.

An early research study (Morrill et al, 1995) with 40 calves per treatment indicated improved performance in calves receiving bovine plasma in milk replacer compared to a 20/20 all-milk protein milk replacer:

• 4.2 lb more body weight gains by 6 weeks of age…the difference in gains occurred after 3 weeks of age.
• 5 lb more starter intake by the end of 6 weeks.
• Fecal scores did not differ.
• Mortality was similar (2 deaths in control and 3 deaths in bovine plasma group).

A 2002 study (Quigley et al, 2002) was conducted with barn sale calves that blood IgG test indicated the majority had not received an adequate colostrial feeding.  The results indicated calves on a 20/20 milk replacer containing bovine plasma protein had:

• 4.9 lb more body weight gains by 56 days.
• Less mortality, no mortality in plasma fed calves versus 3.3% mortality on all-milk fed calves.
• A 25% reduction in number of day calves had diarrhea.

A more recent study (Quigley et al, 2003) with barn sale calves (blood test indicated that the majority had received adequate colostrum) indicated calves on a 20/20 milk replacer containing bovine plasma protein had:

• 3.0 lb more body weight gains by 42 days.
• 7.5% mortality in plasma fed calves versus 25% mortality on all-milk fed calves.
• A 30% reduction in the number of day calves had diarrhea.

Reduction in mortality has been observed in at least seven reported studies where a standard milk replacer was compared to one containing bovine plasma:

Table 1

Effect of Bovine Plasma on Mortality

A trial reported in 2000 (Quigley et al) looked at challenging calves with E. coli.  Calves were fed one of three 20/20 all-milk protein milk replacers (unmedicated; medicated with 400/800NT; or unmedicated with bovine plasma).  At 3 days of age calves were challenged with E. coli and observed for the next three weeks.  Results were as follows:

Table 2

Effect of E. Coli Challenge During 3-Week Observation

The use of bovine plasma protein has been exempt from the government ban on use of ruminant products associated with the BSE concerns.  Bovine plasma products carry little or no risk to cattle due the aseptic environment in which blood is collected from slaughter facilities (at slaughter the blood does not come in contact with the brains of the animal-thought to be the source of BSE transmissions).

Kent Kafnurs Gold looks and mixes well (very similar to Milk Formula™ 1).  Kafnurs Gold should be mixed in 110-120 degree water and fed soon after mixing to avoid possible coagulation of the bovine plasma protein.

Kent Kafnurs Gold is a premium quality milk replacer providing highly digestive sources of protein with additional nutritional factors that can assist with raising health calves.

References:

Morrill et al. 1995.  Journal of Dairy Science. 78:902-907.

Quigley et al. 2003.  Journal of Daily Science.  86:586-592.

Quigley et al. 2000.  Food and Agricultural Immunology.  12:311-318.

Quigley et al. 2002.  Journal of Dairy Science.  85:413-421.