MANAGEMENT COMPONENTS

SECTION 1. CALF CARE FROM BIRTH TO WEANING

Heifer calves are raised as replacements for lactating cows and are essential to the successful future of the dairy. The greatest mortality and morbidity period for dairy cattle is from birth to weaning. Management goals for the first 6 to 8 weeks of a calf's life should be to minimize disease and mortality by providing a suitable environment, establishing a quality nutritional program, and implementing a preventive health care plan.

Health and survival of the newborn calf depend on its care and environment. Designs for calf-rearing facilities range from complete barn enclosures to minimum shelters. A wide range of acceptable housing facilities exists within California. Calf housing should provide an environment that is clean and dry and will minimize stress. Protection from heat, cold, wind, and rain is important. Adequate space, animal comfort, and proper ventilation are important in designing a facility. Facilities should be accessible for thorough cleaning and disinfecting on a regular basis to reduce the number of pathogens.

Placing the facility upwind from corrals and cow traffic decreases dust problems. Housing calves between hay stacks, barns, or other large structures that impede air movement should be avoided. This is especially critical during the summer.

Facility features which are desirable but do not necessarily influence calf health include: design for labor efficiency, conservation of space, esthetics, and location for easy access by dairy personnel but not the public. Calf theft is common, and easy public access enhances rustling potential. Storage facilities for supplies, equipment, and sanitizing materials as well as access to refrigeration for milk and health care products are also important considerations in calf housing design. These features assist in developing and maintaining a successful calf raising program.

Individual Pens

Individual pens separate calves and reduce the spread of communicable diseases and make it easier to observe behavior, feed consumption, and fecal and urine production. Changes in feed consumption and fecal consistency can be early indicators of disease.

Many calves are successfully raised in 2-foot by 4-foot expanded metal or slatted wood, elevated pens. More hock, leg, and joint problems are associated with expanded metal floor pens than with other systems. Plastic coated expanded metal may reduce these problems. Calves may suffer

from cold stress in elevated pens because they provide little shelter from drafts and cold in the winter. Pneumonia may also be associated with these pens when they are placed over a flush system for cleaning since pathogens can be aerosolized during the flushing procedure. Recommended modifications of the elevated pen are to double the pen size and include a bedding box filled with straw or other materials to allow for more comfort and fewer leg and foot problems (University of California, Cooperative Extension Leaflet #2327).

Hutches

Individual, outside hutches predominate in California. Most are approximately 4-foot by 8-foot wooden hutches, although other materials are used. Slightly smaller individual hutches grouped in units of three are commonly used in southern California. Hutches are more labor intensive than elevated metal pens, but they allow for complete separation of unweaned calves. Because hutches rest on the ground, calves are better insulated from drafts than in elevated pens. Hutches can be moved and modified to adjust for temperature, sunlight, predominating winds, and direction of inclement weather. Hutches are easy to move or lift for cleaning. Fiberglass and polyethylene hutches are easier to sanitize than wooden hutches or metal pens, but these should be opaque to reduce heat from the sun.

Cold Housing

Open-sided pole barns containing individual pens are referred to as "cold housing." Cold housing is adequate in most California conditions. Wind barriers, such as plywood or roll-up snow fencing material, can be used during the winter.

Closed Housing

Closed housing consists of an enclosed barn containing individual pens. The most critical aspect of closed housing is adequate ventilation. Accumulation of moisture and manure gases, such as methane, carbon dioxide, hydrogen sulfide, and ammonia, increase the potential for respiratory disease. Environmentally controlled, closed housing is expensive to construct and operate and is difficult to manage.

Colostrum Management

Colostrum is the milk produced by the cow prior to and during the first few days after calving. Colostrum obtained from the first milking after calving contains more protein, particularly immunoglobulins, fat, minerals, and vitamins than milk produced later. Immunoglobulins, or proteins produced by the cow's immune system, are secreted into the colostrum around the time of calving. For approximately 4-6 weeks after birth,

calves depend on the immunoglobulins absorbed from colostrum for protection from infectious agents in their environment. Proper selection, collection, storage, and feeding of colostrum are essential to a successful calf raising program. Colostrometers are used to select the highest quality colostrum for storage and subsequent feeding. Colostrometers are available to measure the specific gravity of colostrum, which should be greater than 1.106. This helps to ensure that the calf receives immunoglobulins.

The ability of the calf's intestine to absorb immunoglobulins declines within hours after birth. The newborn calf can absorb the large immunoglobulins as intact proteins which impart passive immunity. However, within 24 hours of birth, intestinal closure occurs and intact proteins cannot be absorbed. Consequently, timing is important when feeding colostrum the first time following birth to ensure absorption of intact immunoglobulins. Calves, heifer and bull, should be fed 2 to 4 quarts of high quality colostrum by bottle or esophageal tube within the first few hours after birth.

Continued feeding of colostrum from the first through the third or fourth day of life is important because immunoglobulins in colostrum vary greatly in type, size, and complexity. Each type reacts differently with the absorptive capacity of the intestinal wall. Although most immunoglobulins are absorbed only in the first few hours of the calf's life, others may be available for absorption up to 72 hours. The immunoglobulins also may have beneficial local effects in the lumen of the intestine. If there is an ample supply of colostrum, it should be mixed with whole milk and fed during the first 3 to 4 days of the newborn's life.

If a cow "leaks" milk from her udder prior to first milking after calving, much of the colostrum may be lost. Colostrum from cows that "leak" should not be used for the first feeding of a calf.

Specific immunoglobulins are produced in colostrum in response to disease or other organisms prevalent in the herd. Cows are normally vaccinated or immunized against specific diseases to produce a higher level of specific immunoglobulins in their colostrum. Such programs are best established with the assistance of a veterinarian.

If colostrum is not fed immediately after collection, it should be stored frozen or refrigerated for later use. Freezing does not destroy immunoglobulins and other nutrients in the colostrum, but does prevent bacterial growth and deterioration of the colostrum. Frozen colostrum can be thawed slowly in warm water. The microwave can lead to uneven heating and may effect immunoglobulin quality. Temperatures over 111^oF can destroy the immunoglobulins. If colostrum is allowed to stand in a container, it should be gently stirred before feeding since the heavier and lighter particles may have separated. Once thawed, this colostrum can be fed to the calf following birth as an alternative to feeding the dam's colostrum.

Calf Nutrition

Colostrum feeding usually ends by the fourth day, after which fresh whole milk or an excellent quality milk replacer should be fed. Milk replacers are powdered products which contain predominately dry milk ingredients. These products are mixed with water and are formulated to provide proper nutrition for the growing calf.

On some dairies, milk from medicated or "hospital" cows is fed to calves. This is not a recommended practice due to the potential transfer of disease to calves. Caution should be taken if calves destined for sale or slaughter are fed a medicated milk replacer or milk from cows treated with antibiotics. This will prevent problems associated with antibiotic residues in the meat of slaughtered calves. All withdrawal times for medicated feeds should be followed.

Milk replacers with protein derived from dairy products are the most easily digested. Other protein sources (fish protein, cereal flours, unprocessed soy, or meat protein) are not as easily digested. Some milk replacers are being developed that contain vegetable protein with improved digestibility.

A milk replacer should contain a minimum of 20 percent crude protein and 20 percent fat on a dry matter basis. Acid detergent fiber should be a maximum of 1 percent. The milk replacer should mix easily in water and stay in solution after mixing. Water used with milk replacers should be fresh and clean. Employees should take care to use the appropriate volume and temperature of water to ensure consistency when mixing milk replacers.

In addition to milk, dry concentrate feed (calf starter) and good quality hay (e.g. alfalfa) can be offered free choice once the calf is a few days old. These feeds should be palatable, easily digested, and high in digestible protein. Similar to water provided, these feeds should be clean and fresh.

The calf's diet should contain all known nutritional components necessary for normal growth and health relative to the calf's age, environment, and physiological requirements. Rations for calves between birth and weaning should meet or exceed recommendations of the National Research Council's Nutrient Requirements for Dairy Cattle (1989) and allow body weight gains between 1.5 to 1.7 pounds per day.

Water

Water is an essential nutrient. It is necessary for various metabolic activities, such as digestion, hydrolysis of carbohydrates and proteins, excretion of waste products, nutrient transport, lubrication of joints, electrolyte balance, body temperature control, and development of rumen function. Dairy calves initially receive most of their water from colostrum, milk, or milk replacer, and all calves should have access to clean, fresh water. The water should be free of particulate matter and low in salt and bacterial content. It should be free of pesticide residues and

other toxic substances. Water troughs and pails should be cleaned thoroughly, and water should be changed when it becomes dirty. Changing the water frequently during hot summer months provides the calf with cool, fresh drinking water and promotes water intake and the intake of calf starter and hay when fed. Consumption of starter is necessary for rumen development and weaning of the calf.

The amount of water consumed depends on the calf's age, the amount and type of feed consumed, ambient temperature, amount of exercise, and water cleanliness and temperature. Calves up to 6 months of age drink 2 to 5 gallons per day.

Disease affecting the pre-weaned calf may compromise her ability to mature and produce milk. A calf treatment protocol should be established, and calf personnel trained to recognize disease early and to promptly initiate treatment. Well managed calf operations can keep death loss prior to weaning below 5%. Death losses greater than 5% indicate management should be improved. Failure in any of the following areas can contribute to increased calf illness and death: colostrum management, facility, design, sanitation, disease recognition and treatment, preventive health care, and quality nutritional programs.

Umbilical Cord

If the umbilical cord is not severed immediately after birth, it can be cut 2 to 3 inches from the calf's body. The belly area (including the cord) should be dipped in a 2 to 7 percent tincture of iodine or other approved disinfectant. The tincture of iodine will dry the cord and prevent pathogens from entering the calf's body through the cord.

Sanitation

The calf should be born in a dry, clean environment regardless of the type of housing or bedding used. Hospital pens for sick cows should not be used as maternity pens. All sick animals should be isolated from the maternity and calf areas. Pathogen exposure from accumulations of feces, urine, and spoiled feed can cause digestive and respiratory diseases. Even calves that have been fed ample colostrum may become ill if housed in an unsanitary environment.

Utensils used in feeding should be cleaned and sanitized after use.

This will reduce the growth of pathogens and stimulate feed intake.

Preventive Health Care Programs

Most health problems can be minimized with proper management, including adequate nutrition, clean and dry housing, low-stress handling, prompt treatment, and vaccination. The vaccination program depends on the disease problems prevalent within a given area and herd. Common diseases of calves are associated with the digestive and respiratory tracts. In most cases, vaccines are an essential part of a total health maintenance program that should be developed with the assistance of a veterinarian.

It is recommended that calves be vaccinated at least once prior to weaning for Infectious Bovine Rhinotracheitis (IBR), Bovine Respiratory Syncytial Virus (BRSV), and Bovine Viral Diarrhea (BVD). Vaccines must be used according to the manufacturer's specifications.

Extra Teat Removal

Extra teats (more than four) can interfere with milking and may leak, which increases the possibility of mastitis. If desired, extra teat removal should be performed as soon as possible after birth to ensure a quick recovery. Precaution should be taken to avoid unnecessary pain or distress during the procedure and recovery.

Dehorning

Animals are dehorned primarily to avoid injury to personnel or other animals, reduce feeder space requirements, and increase handling ease. It is recommended that dehorning be performed when calves are 2 to 10 weeks old. Older calves are more difficult to restrain and handle, and risk of blood loss, infection, and fly infestation increases.

A hot dehorning iron is the simplest and fastest way to kill the horn-producing cells. Caustic pastes and scoops are alternative methods, but these generally cause the animal more prolonged discomfort. A local anesthetic is recommended for animals older than 10 weeks.

Regardless of the dehorning method, a fly repellant should be sprayed on the dehorned area during fly season. Newly dehorned calves should be isolated (e.g. individual housing) from other calves to avoid licking, and be kept out of the rain until the dehorned area is scabbed over and dry.

Parasites

Some parasitic infections, such as coccidiosis, can cause serious health problems. It is recommended that a regular parasite control program be developed with a veterinarian's assistance. A clean environment is the best tool for combating parasite infections. Coccidiostats may be included in calf starter to prevent coccidiosis. As with vaccinations, products to control parasites should be used according to the manufacturer's instructions and, if necessary, under supervision of a veterinarian. All guidelines for use and withdrawal times should be carefully followed.

Identification

Animal identification is critical for making important management decisions, such as feeding, selection, medicating, breeding, and culling; for official production testing systems; and for registering animals with purebred cattle organizations. Dairy cattle improvement depends on identifying and breeding animals with superior phenotypic and genotypic traits. This requires accurate records on each animal. Some breed associations require that each animal be tattooed before leaving its pen or hutch.

Animal identification may be either temporary or permanent. Temporary identification methods include ear tags, neckchains, neck straps, ankle straps, and marking crayons or paints. Permanent identification methods include ear tattoos, hide brands (hot iron brands, freeze brands, and liquid/chemical brands) computer chips implanted subcutaneously, and photographs.

The most popular type of animal identification is the plastic ear tag which is easily applied by trained personnel. An additional identification is the metal ear tag the veterinarian attaches following brucellosis vaccination. More recently, electronic identification systems have been developed that use a combination of "readers" or "decoders." Electronic identification systems may involve neck collars or subcutaneous implants which interface with milking parlor computers and are gaining popularity.

Calves should be fed colostrum within the first few hours of birth.