Calves and Heifers

Dairymen with successful calf rearing facilities have three primary housing management objectives:

• reduce calf stress
• reduce exposure to disease
• prepare the calf for its new environment

Let's briefly review these objectives.

Reduce calf stress

The infectious agents that can cause diarrhea and respiratory diseases in calves exist on nearly all farms. Disease incidence increases rapidly when calves become stressed. Dairy farms or calf ranches with a sudden increase in disease or a high on-going prevalence should look carefully for stressors that may be affecting the calf. Frequently cited calf stressors include:

• heat stress
• cold stress
• drafts in the calf facility
• improper ventilation
• wet bedding
• overcrowding
• variable feeding times or quantities
• inadequate water
• flies

Reduce exposure to disease organisms

Reducing exposure to infectious organisms goes a long way in preventing calf disease. Common practices which reduce exposure are:

• individual housing for milk fed calves
• cleaning and sanitizing housing between calves
• allowing housing to dry out between calves
• maintaining proper ventilation
• removing soiled bedding
• frequently adding fresh bedding

Prepare the calf for its new environment

Preparations for newborn calves include:

• adequate intake of colostrum
• navels dipped in iodine
• calves dried off by the dam or manually
• calves up and standing before moving from the maternity pen
• calves moved into a freshly bedded, cleaned pen

During the winter months, some dairymen keep their calves in a calf incubator with a heat lamp for 24 hours before moving into hutches or individual pens. Preparations for weaned calves include:

• weaning one week before moving the calf
• grouping five to ten recently weaned calves into freshly bedded pens
• feeding a properly formulated calf grower ration

Select well-designed calf hutches

Multiple plans are available for “build your own” hutches plus many commercially available finished hutches. Look for designs that have:

• adequate ventilation vents
• translucent material to minimize heat stress
• adequate size openings and adequate height for ease in accessing/treating calves
• reinforced hooks for lifting/moving hutches
• painted or plastic surface for ease in cleaning

Provide adequate natural drainage around the hutch

If the calf raising area is level ground, then build up a base of gravel or sand and place the hutches on top of this elevated base to keep bedding dry.

Proper hutch orientation

Season of year and prevailing winds influence hutch orientation. Facing the calf hutch to the south maximizes sun penetration in the winter for warming the calf and maximizes shade during the summer to keep the calf cool. Facing hutches away from prevailing winds is important for keeping bedding dry during rain or snowstorms and preventing the hutch from moving due to strong winds.

Calf restraint

Hutch design influences the method of calf restraint. The preferred methods are: wire panel fencing or tethering systems. Both methods allow calves freedom to lie outside in the sun or lie inside the hutch during inclement weather. These restraint methods also provide easy access for treating calves.

Feeding rack

The feed rack should have a slot for the starter pail, another slot for the water pail and an optional hay-rack. There should be a divider between the two buckets and the hay-rack to prevent hay or starter from falling into the water bucket. Bedding tends to stays drier and cleaner if the feeding rack is positioned outside the hutch on the wire panel fencing.

Position hutches so calves cannot touch

Isolating calves is an important strategy for minimizing disease transfer between calves. Isolation can be achieved by setting each hutch six feet apart. Some dairies/ranches achieve isolation by placing hutches side by side but varying the location of the hutch opening. For example, the first hutch opens to the south, second hutch opens to the north, third to the south, and so on down the line.

Use ample bedding

It is very important to keep the calf dry. Start each calf with a freshly bedded pack and add straw frequently to keep the bedding dry. Ammonia is released from urine in wet bedding. Reducing ammonia levels is important for preventing respiratory disease.

Ventilation vents

Proper use of ventilation vents are important for keeping calves cool in the summer and warm in the winter. Vents in the back wall and on top the hutch should be completely open during the summer to enhance cooling from breezes and reduce heat load. The vents in the back wall should be closed in the winter to prevent cold drafts and to keep the bedding dry.

Hutch management between calves

Tilt the hutch up on end and wash with a pressure sprayer to remove dried manure on the inside walls. Allow the hutch to dry out with direct sunlight on the inside walls. The old straw pack should be removed between calves and fresh bedding added. Hutches should be moved to a new location at least twice a year.

Barn orientation

Mono-slope roof facilities should open to the south to provide maximum sun penetration in the winter and maximize shade in the summer. Gable roof buildings should have the length of the run perpendicular to prevailing winds on the farm site.

Ventilation

Mono-slope barns should have at least a 2 to 4 inch continuous opening along the eaves. Gable roof buildings should have the same size opening in the eaves plus an open ridge for winter ventilation. The sidewalls should have windows or vents that can be opened for further increase air flow during the summer months.

Pen size

Recommended pen dimensions are 4 feet wide by 8 feet long. Sidewalls should be 4 feet high and constructed with solid plywood or other solid materials. The front wall is partially open and has a feeding rack. The back of the pen may be a barn wall or solid wood. The solid walls prevent nose-to-nose contact between calves and reduce draft conditions.

Feed rack

The feed rack should have a slot for the starter pail, another slot for the water pail and an optional hay-rack. There should be a divider between the hay-rack and the water bucket to prevent hay from falling into the water bucket. Dividers should be installed on both sides of the front wall to prevent calves from making nose-to-nose contact.

Pen cover

During the winter months, some producers/calf ranchers cover the back 4 feet of the pen with a sheet of plywood. Heat losses from the calf are reduced with this cover.

Bedding

Each pen should have a deep bed of straw or other type bedding. Wet, soiled straw should be removed frequently and fresh bedding added as needed.

Cleaning between calves

The old bedded pack should be removed between calves. The sidewalls should be cleaned and lime applied to the floor. The pen should be left vacant for a few days before introducing the next calf.

Weaning and moving to group housing are two major stresses on the dairy calf. Poorly managed transitions can result in poor calf growth, rough appearance, potbellied calves and outbreaks of disease (pneumonia, coccidiosis and others). Management practices that reduce the impact on these stresses are discussed below.

Avoid multiple stresses at one time

Wean calves in individual housing but do not move to a group pen for one week post weaning.

Monitor starter intake and calf performance

Starter intake should increase rapidly once the calf is weaned. An adequate supply of clean water is very important in this transition period. Weaned calves will consume 5 to 7 quarts of water per day, especially in heat of the summer.

Limit group size in first pen

The transition to group housing is less stressful when group sizes are small (five to 10 calves) and all calves are similar in size and age. Small groups also make it easier for the calf manager to identify poor doing calves.

Provide adequate bunk space

Transition calves are learning to compete for food. Make sure the pen has enough bunk space so that all calves can eat starter and hay at the same time. If bunk space is inadequate, timid heifers tend to have inadequate starter consumption and consume a mostly hay ration. Potbellied calves are a common occurrence in this situation.

Provide adequate water

The first pen for weaned calves should have its own water that is easy to find and easy to access by calves. Bucket feeding water is not a good practice since water intakes can vary tremendously between calves. Inadequate water intake is significant health issue for heat stressed calves and significant factor influencing feed intake.

Provide adequate ventilation

A variety of facilities are used for just weaned calves: including wooden super hutches, commercial polypropylene super hutches, and wooden frame structures. Properly ventilated housing reduces stress due to excessive humidity, ammonia fumes from bedded pack and aerosolized pathogens. Facilities for weaned calves should not be located close to older heifers or mature cows. Pathogens can be carried by the wind from nearby older animal facilities.

Provide adequate resting space

Facilities for transition calves usually include a bedded pack area for resting and an exercise area. The facility should provide at least 25 square feet of resting space per calf and the resting area should be well bedded with straw or other bedding. The exercise area should provide another 35 square feet of area per calf.

The “gold standard” liquid feed is whole milk, nature’s intended food for the calf. Young calves perform very well on an adequate diet of milk and calf starter. However, salable milk is more expensive than other liquid diets and is less commonly used than the alternatives.

Excess colostrum is an excellent feed for calves. The first priority use of colostrum is to feed the newborn calf. The second priority use should be to feed to calves under four days of age. Surplus colostrum is what remains after meeting the two priority uses. 

Colostrum is higher in solids and protein than whole milk. The higher solids content tends to cause the calf to have softer than normal feces. This is generally not a problem and can be overcome by diluting colostrum at 3 or 4 parts colostrum to 1-part water.

Improper handling can lead to poor quality feed. Surplus colostrum that have not been refrigerated can have very high bacteria counts and can become contaminated by flies if left uncovered. Colostrum should be fed shortly after milking or refrigerated.

The protein and solids concentration of colostrum declines over the first four milkings post-calving. This transition milk is an excellent feed for calves under four days of age. Proper handling is a concern to prevent high bacteria counts and contamination by flies.

Discard or waste milk is milk that cannot be sold for human consumption because it comes from cows treated with antibiotics for mastitis or other illnesses. Calf performance is generally similar between waste milk and whole milk. However, there are general precautions for feeding waste milk:

• Before using as a calf feed, pasteurize waste milk to reduce bacteria count.
• Do not feed waste milk to newborn calves.
• Use caution when feeding waste milk to calves destined for beef production. Antibiotic residues are a potential problem if the bull calf is raised for veal.
• Do not feed waste milk if milk fed calves are raised in groups. Waste milk can be high in mastitis causing bacteria. Teats can become infected if suckled by herd mates, particularly when fed waste milk.
• Don’t allow waste milk to sit for extended periods of time without refrigeration or a cover for the container.
• Discard waste milk that is excessively bloody, watery or unusual in appearance.
• Know the health status of cows producing waste milk. Do not feed unpasteurized milk from cows that are shedding BVD, Johne’s, and salmonella or from cows infected with E.coli, Pasteurella or BLV. 
• Pasteurization of waste milk decreases illnesses compared with no pasteurization. To be effective, pasteurization requires heating milk to a specific temperature for a specific amount of the time. The milk must be cooled and fed soon or refrigerated. The pasteurizer must be cleaned properly and sanitized between uses.

More than 70 percent of U.S. dairy calves are fed milk replacer during the liquid feeding period. Milk replacer typically costs less to feed than whole milk. Milk replacers are made from pasteurized ingredients and are an effective biosecurity tool for preventing spread of Johne’s, salmonella, BVD, Pasteurella and mycoplasma. Milk replacer can be introduced to the calf at four to six days of age. Key emphasis areas for success when feeding milk replacer include:

• Purchase a quality milk replacer and store it properly. Opened bags should be kept closed to prevent contamination. 
• Pay attention to quality of the milk replacer, looking for product that is off color or has an abnormal smell. Avoid feeding out of condition milk replacers to dairy calves.
• Check the feed tag to determine the recommended feeding rate. It is important to mix the correct amount of powder with water. Weighing the powder is more reliable than using the scoops provided in the bag of milk replacer.
• Check the feed tag to find out the recommended mixing temperatures. Use a thermometer to measure water temperature. Most milk replacers are mixed at 110 degrees Fahrenheit. If the water is too cool, the replacer will not go into solution very well and results in a colder diet being fed to the calf. If the water is too hot, fat will separate and float to the top or adhere to the calf bottle.
• The ideal temperature to feed milk replacer is just above normal calf body temperature (102 degrees Fahrenheit). A slightly hotter water temperature may be needed in the winter months to ensure the replacer is at the proper temperature when fed.
• Larger batches of milk replacer can be mixed in 5-gallon buckets or in 30-gallon garbage cans. Putting a mark on the bucket at the appropriate water level saves time in mixing replacer. 
• Getting a good mix is important to ensure the calf receives the proper nutrition. Evaluate mixing by looking for powder residues at the bottom of bucket or a fatty film. Longer mixing times and more effective mixing are indicated by powder residues in the bucket. 
• Proper sanitation of all feeding equipment is important for minimizing calf disease.

A wide variety of feeding rates are used across the dairy industry. Milk or milk replacer feeding rates differ due to breed, size of calf and calf rearing goals. The conventional feeding rate for Holstein calves is 10 percent of bodyweight. 

With this thumb rule, an 86-pound heifer calf should receive 8.6 pounds of milk per day. Since milk weighs 8.6 pounds per gallon or 2.15 pounds per quart, this calf would receive 1 gallon of milk or 4 quarts per day. 

A 100-pound calf would receive 10 pounds or 4.6 quarts per day (10 pounds divided by 2.15 pounds/quart = 4.6 quarts).

Calf size should be considered when feeding the liquid diet. Large calves at birth need more liquid diet than smaller calves. Pennsylvania State University sells a heart girth tape specially designed for estimating calf body weight. It is a very useful tool for establishing how much milk to feed the calf.

Conventional feeding rates provide enough energy from milk solids to maintain the calf plus provide some additional energy for growth under warm weather conditions. Growth rates are low until the calf consumes significant amounts of starter grain. Conventional feeding programs emphasize reducing feed cost with moderate growth during the milk feeding phase. 

Recent research has documented superior calf growth in body size and weight with higher milk replacer feeding rates. Conventional feeding programs call for feeding 1 to 1.25 pounds of milk replacer powder per day. Intensive calf-feeding programs call for 2 or more pounds of milk replacer powder. To achieve this level of intake, intensive programs call for mixing a higher percent solid (16 to 18 percent versus conventional 12.5 percent) and feeding more total volume of mixed milk replacer. Crude protein contents are higher (28 to 30 percent versus 20 to 22 percent) in specially formulated milk replacers intended for intensive feeding program. Calves fed high levels of 20 to 22 percent crude protein milk replacer tend to have more body fat and less muscle growth than calves fed the milk replacers designed for intensive feeding.

A compromise feeding program is to simply increase feeding rate from 10 percent of bodyweight to 12 or 14 percent of bodyweight. Feeding a higher level of milk or milk replacer increases growth rate and feed efficiency during the first four weeks of life but tends to delay or reduce starter intake.

The calf requires more energy to maintain body functions, to stay warm and to grow during the winter months. Feeding milk/milk replacer at 10 percent of bodyweight does not provide sufficient energy for body maintenance and growth in young dairy calves (less than 4 weeks of age). Feeding rate should be increased by 25 to 50 percent, especially during periods of extreme cold (see below). If feeding milk, increase the volume fed to an 86-pound Holstein calf from 4 quarts to 5 quarts (25 percent increase) or 6 quarts (50 percent increase). If feeding a milk replacer, increase both the amount of milk replacer powder and volume of water per feeding. Use a milk replacer with 20 percent fat during the winter months.

Winter feeding adjustments for an 86 pound Holstein calf

Milk

• 10 percent — 2 quarts
• 12.5 percent — 2.5 quarts
• 15 percent — 3 quarts

Replacer powder

• 10 percent — 8 ounces
• 12.5 percent — 10 ounces
• 15 percent — 12 ounces

Volume

• 10 percent — 2 mixed replacer
• 12.5 percent — 2.5 mixed replacer
• 15 percent — 3 mixed replacer

An alternative method is to increase the solids concentration by mixing more milk replacer powder in two quarts of water. It is possible to mix up to 1.5 pounds of milk replacer per gallon of water.

The two most common liquid feeding methods are nipple bottles and buckets. Calf performance tends to be similar with either feeding method. However, bacterial growth within the feeding utensil can be very high if not cleaned frequently. 

Bottles are nearly always washed between feedings, but many calf feeders do not wash the milk buckets. Residual milk in the bucket is an excellent growth medium for bacteria. High bacteria counts can occur in the residual milk and can contribute to scours outbreaks. From a disease control standpoint, it is very important to properly wash bottles or buckets after every feeding.

Do not use the same bottle to feed more than one calf. If there are not enough bottles available, replace the nipple with a clean one before feeding the next calf. Disease can be transmitted between calves by reusing nipples for several animals.

Pay attention to opening size of the nipples. Many calves are aggressive nursers and can handle the large volume of liquid delivered by wide openings. Other calves are not as aggressive. In this case, some milk can end up in the lungs leading to a case of pneumonia.

The main reason for washing calf-feeding equipment is to minimize bacteria and other pathogens present at the next feeding. Proper cleaning procedures include: rinsing, washing, rinsing and allowing to completely air dry. 

Rinse in lukewarm water. Rinsing can be accomplished by spraying or by immersing in water. Make sure you rinse both the inside and outside of calf buckets, bottles, nipples and other feeding equipment. Water temperature is very important. If too hot, protein from milk or milk replacer will adhere to the side of the feeding utensil, forming a film and potential growth medium for bacteria.

Wash in hot, soapy water. Wear gloves and wash feeding equipment with hot water (approximately 140 degrees Fahrenheit). Use a chlorinated cleaner or a combination of detergent plus bleach. Brushing and wiping action removes the soil from the surface while soap and chlorine kill bacteria. Milk solids are suspended in hot water but will reattach to feeding utensils if water temperature falls below 120 degrees Fahrenheit. Make sure your water temperature does not fall below 120 degrees Fahrenheit when washing feeding equipment.

Rinse with acid sanitizer. Many operations rinse calf bottles with warm water to remove soap residues. The preferred method is to use a warm water rinse with acid sanitizer. The hot water removes soap and the acid sanitizer lowers pH on the surface of the feeding utensil. Most bacteria do not grow well under acidic conditions. Bacteria counts would be much lower when rinsed with an acid sanitizer over a simple warm water rinse. Acid sanitizers should be diluted in water following label directions. Acid sanitizers designed for manual cleaning of bulk tanks work well in this application.

Allow to air dry. Bacteria require moisture to grow. Arrange calf bottles and/or buckets on racks where they can dry out before the next feeding. Do not stack buckets together before they are dry. Do not set a freshly cleaned bucket upside down on the floor.

Water is very important for attaining desirable growth and proper rumen development. Failing to provide water reduces starter intake which in turn delays rumen development. The amount of water consumed by the calf varies due to age, starter intake and temperature. Calves will consume small amounts of water during the first few weeks of life, but intake increases dramatically with higher starter intakes. 

Water should be fed about 20 minutes after feeding milk or milk replacer. If it is fed too early, the water goes through the esophageal groove and ends up in the abomasum instead of the rumen. Delaying water feeding ensures that the water goes into the rumen where it provides moisture for bacterial growth and rumen fermentation, important factors in developing the rumen. 

Water intake increases with rising temperatures and is two to three times higher during the summer than in the winter. Pay attention to water intake by individual calves. Sudden increases or decreases can be an early sign of disease.

Several management factors affect the calf’s ability to consume water. Barriers to access include:

• No water in bucket.
• Calf can’t find the bucket or can’t reach it.
• Water is unpalatable due to urine or feces contamination.
• Water is contaminated with starter grain or hay.
• Water is frozen.

Management practices that enhance water intake include: 

• Provide high quality water to calves beginning at three to four days of age.
• Discard leftover water from previous feeding.
• Clean water bucket if contaminated with feces, urine or feed.
• Add more fresh water than the calf normally drinks at each feeding.
• Install a barrier between the starter bucket and water bucket to reduce contamination by starter.
• In summer months, use a larger container to handle the increased water intake or schedule an additional feeding to provide water.
• In winter months, provide warm water (approximately 105 degrees Fahrenheit) to prevent chilling the calf. Discard water one to two hours later to prevent ice formation in the water bucket.

Calf starters typically have 18 to 20 percent crude protein. The grains (corn, barley, oats) in the starter are usually processed or textured to improve acceptability by calves. Ground grains are not as palatable to young calves and are not recommended for calf starters. Molasses is usually added to enhance palatability and to prevent separation of ingredients. Commercial starters typically include pellets that include protein supplements, vitamins and minerals. 

Rumen development is largely driven by the consumption and digestion of calf starter dry feed consumption increases the number and variety of microflora in the rumen. These microorganisms grow rapidly on the carbohydrates from grain and produce volatile fatty acids. Volatile acids provide nutrients to the calf and stimulate growth of papillae on the rumen wall. Encouraging calves to consume starter is therefore a key component in successful calf-raising.

Several management factors can affect the calf’s ability or desire to consume starter. Barriers to access include: 

• Starter is not stored properly before feeding (wet, moldy, contaminated, “off odors”)
• No starter in bucket.
• Starter container/bucket is mounted incorrectly and is difficult for calf to use.
• Starter container/bucket smells bad due to manure, urine or mold. 
• Starter in container is unpalatable (may be contaminated, stale or contain excessive fines).
• Starter is packed down so hard the calf can’t eat it.
• Starter is frozen into a solid chunk.

Management practices that enhance starter intake include:

• Store starter properly to retain freshness and quality.
• Offer starter to young calves by putting some in their mouth with your hand or add a small amount into the milk bucket. Make sure you rinse out the milk bucket before the next milk feeding.
• Offer more starter than the calf normally consumes, allowing the calf to increase intake.
• Starter buckets should be emptied and refilled once or twice daily, especially during summer months.
• Clean starter buckets/containers when they become soiled or contaminated.
• Discard starter if it is frozen, packed together or forms clumps in the bucket.

Proper weaning strategy is important for minimizing the stresses associated with a change in diet and for minimizing the impact on growth during the first week post weaning. The critical factors that determine when to wean the calf are: starter intake, calf health and weather conditions. Calves are ready to be weaned when they are consuming 1.5 to 2 pounds of starter per day (1.5 to 2 cups). Avoid compounding stresses by only weaning healthy calves and avoid weaning calves during inclement weather or extreme cold.

There are two primary methods of weaning calves: abrupt cessation of milk feeding and gradual reduction in milk feeding. Starter intake increases rapidly post-weaning with both strategies. However, some research studies have noted that growth rates are higher during the first week post-weaning with gradual reduction (milk feeding reduced to half normal rate during last week). Gradual weaning is therefore recommended to prevent a drop in growth rate at weaning.

Do not move the calf into a group pen immediately after weaning. Keeping the calf in her hutch or individual pen allows the calf feeder to monitor increase in starter intake post weaning and prevents multiple stresses (weaning and moving into a group pen). This practice also tends to reduce suckling on other animals.

Hay is not required by calves during the milk-feeding period nor in the immediate post-weaning period. The goal is to increase starter intake up to 4-5 pounds per day post weaning. Hay can be introduced at this time but do not offer too much hay initially. Some calves consume too much hay if given liberal amounts and develop a “potbellied” appearance. The rumen in the just weaned calf is still developing and does not digest hay quickly. The “pot belly” occurs due to filling the rumen with hay. Inadequate bunk space in the first weaned pen can also contribute to potbellied calves. Timid animals do not consume their allotted amount of starter but still consume hay.