Detailed Explanation of Key Points in Calf Rearing and Management Techniques

A calf refers to a young bovine from birth to 3 months of age, or up to 4-6 months of age. Proper rearing of calves is crucial for improving calf survival rates.

1. Feeding Colostrum

The milk secreted by a cow during the 5-7 days after calving is called colostrum. Colostrum also contains lysozyme and antibodies, which can kill various pathogenic microorganisms. After colostrum enters the calf's stomach, it can stimulate the digestive glands to secrete large amounts of digestive enzymes, promoting early activity of gastrointestinal function.

To make calves robust and grow and develop rapidly, the sooner they receive colostrum after birth, the better, and the more they eat, the better. Generally, the first colostrum feeding should be given when the calf can stand on its own, 30-60 minutes after birth. Do not delay without reason, and never discard the colostrum. The amount of colostrum fed depends on the calf's body weight and health condition. For a calf weighing about 35 kg with a healthy constitution, the first feeding should be as much as it will take, generally 1-1.5 kg. Afterwards, it can be fed at 1/6-1/7 of its body weight.

Colostrum is fed for 5-7 days, 4 times a day. The timing of colostrum feeding is best aligned with the milking time of the calf's mother, so that it can be fed immediately after milking. If the colostrum temperature is low, it should be heated to 37-38°C before feeding to avoid causing indigestion. However, the heating temperature must not be too high; if it exceeds 40°C, the colostrum will coagulate and become difficult to digest.

????2. Feeding Whole Milk

After being fed colostrum for 1 week, the calf can be switched to whole milk. At present, most dairy farms in China feed calves 300-400 kg of milk, with a nursing period of 2-3 months. However, a few large-bodied or high-yielding herds can be fed 600-800 kg, with a nursing period of 3-4 months. Specifically, during the 1-month-old stage when whole milk is the main source of nutrition, the daily feeding amount is about 1/10 of the calf's weight. At 2-3 months of age, the transitional stage, as the intake of forage and feed increases, the whole milk feeding amount decreases week by week, gradually transitioning from milk feeding to plant-based feed.

????3. Feeding Plant-Based Feed Early

Starting from 1 week after birth, calves can be given high-quality hay to train them to eat, allowing them to chew freely. This can prevent calves from licking dirty objects or contaminated hay and can promote early stomach development. Starting from 10 days after birth, begin training calves to eat concentrated feed. Mix wheat bran, soybean cake, cornmeal, etc., with a small amount of fish meal, salt, and bone meal into a dry powder feed, feeding about 15-25 g per day, placed in a trough for the calf to lick freely. Generally, starting 20 days after birth, add chopped carrots or beets at 20-30 g to the mixed concentrated feed. By 2 months of age, the daily feeding amount reaches 1-1.5 kg, and by 3 months of age it can be increased to 2-3 kg to promote digestive organ development.

????4. Early Weaning

The so-called early weaning is to reduce the previous 5-6 month nursing period, which consumes 800-1,200 kg of milk, to 2-3 months, consuming 300-400 kg of milk, by using nutritionally rich, highly refined artificial milk or milk replacer to raise calves. This can save a large amount of "feed-grade milk" and reduce production costs.

The key to successful early weaning, besides early supplementary feeding of hay, is mainly to formulate a good weaning plan.

1) Within 1 week after birth, feed colostrum three times a day, 2 kg each time.

2) From 8-20 days of age, feed whole milk twice a day, 2 kg each time, and train the calf to eat milk replacer and high-quality hay.

3) From 21-60 days of age, feed whole milk twice a day. For the first 35 days, feed 2 kg per day, and for the last 5 days, feed 1 kg each time. The daily amount of milk replacer is gradually increased to 1.2 kg. At the same time, train the calf to eat silage.

4) From 1-180 days of age, the milk replacer is gradually increased from 1.2 kg to 3.4 kg per day. Allow free access to hay and silage.

5) Milk replacer formula: soybean cake 40%, wheat bran 20-10%, cornmeal 40-25%, sorghum meal 20-10%, additives 1%, salt 1%, bone meal 1%.

5. Providing Sufficient Drinking Water

Starting 1 week after birth, provide water separately every day, or add an appropriate amount of milk to the water to entice the calf to drink. Tap water must be boiled and cooled to 37-38°C, then provided separately after milk feeding. After 10-15 days, clean cool water can be provided for drinking. In warm seasons, set up a water trough in the exercise yard filled with clean water for calves to drink freely.