Calf rearing: It’s more than the milk

Cathy Williams

Young heifers represent the future of your dairy operation, so proper feeding and care of these animals is essential for success. Great emphasis is placed on feeding plenty of high-quality colostrum as soon as possible after birth for passive transfer of immunity and for providing nutrients to the newborn calf.

After colostrum feeding, emphasis is placed on selecting the type of liquid feed to be given to the calves. Feeding whole milk or a high-quality milk replacer are excellent sources of nutrition for the young calf through weaning.

While colostrum feeding is the most important management practice in getting calves off to a good start in life and milk or milk replacer feeding follows closely behind, there are two other management practices often overlooked. These include feeding calf starter and providing water.

Calf starter is the first dry feed given to a young calf. It should be very palatable to encourage intake. Quality of the calf starter should be the number one factor in selecting a calf starter, not the cost. The starter must contain adequate amounts of readily digestible energy and should be low in fiber. Young calves lack the ability to digest fiber at this early age and filling them up with indigestible fiber will limit their intake of the nutrients they need to continue to grow and develop.

Good-quality calf starters contain no forage and usually contain no more than 7 percent fiber. Calf starters must also contain sufficient (16 to 20 percent) crude protein to meet the demands for growth. On average, most nutritionists recommend selecting a calf starter that contains 18 percent crude protein. If calves are weaned early or raised on an accelerated growth program, the starter should contain higher levels of protein.

Other additives to consider include antibiotics, coccidiostats and ionophores. Some calf starters do contain antibiotics; however, if the milk replacer contains antibiotics, then the calf starter must be free of them. A coccidiostat is commonly included in calf starters as a means of preventing coccidiosis. Ionophores are also very common as additives in calf starter. These ionophores not only aid in the prevention of coccidiosis but also have been proven to improve bodyweight gain and feed efficiency in growing calves.

Starter feeds should be offered to the calf in the first three to five days of life, and they should begin eating small amounts by day seven to 10. If calves do not begin “nibbling” on starter during the second week, starter consumption should be encouraged by placing some in the milk bucket or on the calf’s muzzle after she has finished her milk. Once the calf is consuming starter, feed as much as she will eat until intake reaches 6 pounds per day.

Early consumption of a good-quality calf starter is important for two reasons. First of all, starter consumption is the primary basis for determining when a calf should be weaned, not days or weeks of age or bodyweight gain. As soon as a young calf is consuming 1.5 pounds of starter per day for three consecutive days, then she can be weaned. The earlier calves can be weaned from the more expensive liquid feeds onto the less expensive starter feeds, provided the calves are gaining well, the sooner these economic advantages will be seen.

The second reason for encouraging early consumption of calf starter is rumen development. Intake of highly digestible calf starter stimulates rumen development by promoting proliferation of the rumen microbial population and growth of the tissues, primarily the papillae, which line the rumen. Microorganisms grow rapidly and ferment the readily digestible carbohydrates in calf starter to produce volatile fatty acids (VFA). These VFA stimulate the growth and development of the rumen papillae which are the sites of absorption of nutrients in the calf.

The population of microbes must be established prior to weaning, so starter consumption is critical for proper development of the rumen as the calf transitions into becoming a fully functional ruminant animal.

In feeding young calves it is important to note that forages should not be fed until calves are weaned. Once calves are weaned high-quality hay can and should be provided, but early consumption of hay prior to weaning will limit intake of the more nutrient-dense calf starter. While the growth and development of the rumen depend primarily on grain, the papillae may become too well developed if no forage (or roughage) is fed after the calf is weaned.

Additionally, adequate particle size of the starter is important in proper development of these papillae. The papillae could mat together which may result in decreased absorptive capacity.

As the calf is transitioning to becoming a fully functional ruminant, incorporation of forages or roughages into the diet will also help promote development of the rumen musculature. However, it is important to remember that calf starter is by far the most vital feed for rumen development in the young neonatal calf.

The selection of high-quality liquid and dry feeds for calves is certainly the basis for a sound calf nutrition program. As previously discussed, these feeds are necessary for growth of the calf and development of the rumen. However, providing plenty of fresh, clean water is extremely important for ensuring proper growth and development. Water is the most important nutrient and is required in greater quantities than any other ingested substance. Animals will consume more dry feed when water is available, and this will help young calves begin eating starter at an earlier age.

Calves should be offered water as soon as they are offered starter, typically on day 3 to 5. The water provided by the milk or milk replacer is not enough because milk is 87 percent water, and milk replacer, when mixed according to label directions, is approximately 88 percent water. A calf fed milk or milk replacer may only receive about 0.88 gallons of water per day and only at feeding time.

Besides promoting feed intake, water has many functions in the body. In times of heat stress, water intake will increase as the calf is trying to regulate its body temperature. Water is also important for proper rumen function. Clean drinking water is vital to the overall health and well-being of the young neonatal calf, just as much as a good-quality calf starter.

A successful heifer-rearing program begins with the proper management of the newborn calf. After initial colostrum feeding, a sound nutritional program is the key to success. In addition to milk or milk replacer, feeding high-quality calf starter and water are very important components of the nutritional management plan. The heifers are the future, so make sure they are off to a good start in life. PD

—From Louisiana Dairy Digest, December 2006