What principles should be followed when supplementing fat to dairy cows?

1. The amount of oil fed must be appropriate. The oil content in the dairy cow's diet must not exceed 7% of the diet's dry matter at most. Under normal circumstances, the dairy cow's basal diet itself contains about 3% oil, so the supplemental amount should be 3%-4%.

2. The amount of oil added must be calculated accurately. The amount of oil a dairy cow needs depends on the milk fat amount. If a dairy cow produces 36 kg of fresh milk per day with a milk fat rate of 3.5%, then the milk fat amount for 1 day is 1.26 kg. If the dairy cow's normal body condition and sustained production level are to be maintained, 1.26 kg of oil should be added to the diet.

3. Feed oils from different sources and types. The effect of adding oil to dairy cow feed depends on the source and type of the oil, so only one kind of oil should not be used in production. At the same time, liquid oil is not suitable for adding to the feed of lactating cows.

4. Pay attention to the interaction between oil and roughage. When adding oil, the type of roughage composing the diet should be considered. When corn silage is used as the main forage, only the addition of sheep fat or beef tallow can increase milk production. With alfalfa as the main forage, cottonseed cake can be added to the feed.

5. Feed oil gradually. Gradually increasing the amount of oil fed can avoid the problem of poor palatability. At the beginning, feed 1/3 first, and feed up to the full amount in 3 stages, which takes 3-4 weeks.