Raising a healthy replacement heifer is a long, complicated process. According to Dr. David Carlson, technical services with Milk Products LLC, calf growth is influenced by many factors, including genetics, environment, health and nutrition. Understanding how all the factors work together can have a big impact on the management decisions you make to maximize performance.
Starting with genetics, breed traits influence a calf’s nutritional needs; for example, a Holstein calf may have very different nutritional demands versus a Jersey calf.
Environment also plays a big role. Air quality affects the animal’s respiratory health. When the air is dusty, the calf will inhale the polluted air, which could potentially cause respiratory issues. Remember that bedding and sanitation protocols greatly contribute to air quality and limit pathogen spread.
Overall health of the calf will also affect growth and vaccinations are a part of this equation. Carlson said a great vaccination program helps keep the calf healthy if any disease or viruses pose a threat. Colostrum quality also contributes to calf health. The four goals a manager should strive to reach for colostrum management are quality, quantity, quickness and cleanliness.
Colostrum quality, or the amount of immune factors present in the colostrum, can be measured with the use of a colostrometer. A concentration of 50 g per liter of IgG is considered good. As for quickness, the faster the calf is fed the colostrum, the more IgG absorption takes place. That’s because the intestinal wall closes once the calf is born, decreasing the ability for nutrients and proteins to be absorbed. If the calf is fed six hours after birth, the IgG absorption drops by about 20 percent.
Not only does a calf need to receive quality colostrum quickly, but it also needs to receive adequate amounts. Carlson said the recommended colostrum feeding should be about 10 percent of the calf’s birthweight. This equates to 3 quarts if the calf is fed by a bottle (if the colostrum is of good quality, this would amount to about 150 g of IgG intake) or 4 quarts if fed by tube (about 200 g of IgG intake).
Next comes cleanliness. High bacterial loads in the colostrum introduce disease to the calf, increasing the chances of it getting sick. With high bacteria counts, the overall IgG absorption can be affected when the calf is fed colostrum. It is important for any items such as buckets and milking units be cleaned, disinfected and dried to limit bacteria growth. Finally, stored colostrum should be kept at a steady, cool temperature. It should also be properly covered to prevent contamination.
Proper nutrition is the next step. Carlson reminded producers that calf nutrition has three components: liquid feed, starter and water. The liquid feed – whether it’s whole milk or milk replacer – is the major source of nutrition for the first three weeks of a calf’s life. According to Carlson, whole milk provides more protein and fat compared to milk replacer. However, milk replacer can be used with additional protein additives, such as milk proteins or animal plasma as the most ideal sources of protein. Other additives include soy protein isolate, soy protein concentrate, modified soy flour and wheat gluten. Carlson said soy flour and egg protein are less-than-ideal protein sources.
Calf starter is also essential as it stimulates rumen growth and development. Carlson reminded producers that water is necessary to this process as it promotes starter intakes. Remember, the milk replacer feeding program will influence starter intake patterns, especially near weaning. A calf receiving many calories through milk replacer will not take in as much starter. Producers need to keep this in mind as they use intensified milk replacer feeding programs.
Also included in the nutrition program is the consideration of added trace minerals, amino acids, medications and other additives. The value of these products varies greatly depending on the calf’s environment and nutrition program. Work with you nutritionist to decide the right program for your farm.
Investing in quality calf nutrition and health leads to high quality heifers entering the milking herd. Starting at birth with the colostrum feeding and continuing through the calf’s life, managers need to find the right balance between the environment, health protocols and nutrition programs to ensure optimum performance.