Calves cannot obtain immunoglobulins through the placenta. They must obtain antibodies through colostrum to establish a passive immune system. Therefore, calves should be fed high-quality colostrum within 1 hour after birth, with a feeding amount of 4 kg and a temperature of (38 ± 1) ° C. If the calf does not consume a sufficient amount of colostrum, it can be forcibly administered with a clean esophagus feeder. It is best to feed breast milk within 3 days after birth. If the quality of the colostrum of the cow is poor, it can be fed with the high-quality milk of the calving cow on the same day, or frozen colostrum (ie, the remaining high-quality colostrum frozen), It can be taken by heating in a 50 ° C water immersion bath to about 38 ° C. After 3 days, it gradually transitions to feeding regular milk.
Management of lactation
Normal milk should be pasteurized by heating at 60 ° C for 1 hour to effectively kill paratuberculosis bacteria and other pathogenic microorganisms and maintain the nutrition of milk. Feed after the temperature of the milk has cooled to about 38 ° C (the temperature difference is controlled within 1 ° C). It is strictly forbidden to adjust the temperature of the milk with hot or cold water. It is very important to control the temperature of the milk fed by the calves within a few weeks after birth. The temperature of the milk will affect the sealing of the esophagus. Cold milk is more likely to enter the rumen than hot milk, so feeding cold milk is more likely to cause calf digestive disorders . The calf lactation period is generally 50 days and fed 3 times a day. The specific feeding amount is shown in Table 1. The total feeding amount during the whole period is 265.0 kg.
The consumption of rough appetizers is the main method to promote calf rumen development. The calf can start training on the fourth day after birth. In order to make the calves familiar with the food as soon as possible, they can be mixed into the milk to induce the calves to eat. Before the calf is 90 days old, the calf starter should be mainly fed. From 90 to 120 days old, based on the 3 kg calf starter daily, add 0.5 kg of the calf late-stage mixture for transition and then re-feed Give 0.5 kg of quality alfalfa. The recommended nutritional concentration of the late calf mix is: net energy 1.62 megacalories / kg, 20% crude protein, 5.3% crude fat, 1.6% calcium, 0.9% phosphorus, 17% NDF, 7.5% ADF. For calves under 120 days of age, it is strictly forbidden to feed silage fermented feed. After 120 days of age, feed the calf with 1.5 kg of starter feed, 1 kg of late mix, 1 kg of high-quality alfalfa (late mix and alfalfa are evenly mixed), and supplement 4 kg of pre-lactating TMR.
Beginning at 36 days of age, further reduce the amount of milk fed and increase the amount of food to prepare for weaning and minimize stress. Calves are completely weaned around 50 days of age, but do not wean in extreme weather or sudden changes in temperature. After weaning, ensure that the calf has access to the mix and clean drinking water at all times.