Comparison of Milk Production Performance of Cows at Different Feeding Levels during Early Lactation
[Objective]To investigate the difference of milk production performance of dairy cows at different feeding levels during early lactation.[Methods]In this experiment,45 healthy Holstein cattle in early lactation period with similar body condition and parity were selected according to low feed intake group,medium feed intake group and high feed intake group for 7 days of pre-test and 28 days of formal test.[Results]Compared with low feed intake group,the average daily feed intake of cows in medium feed intake group and high feed intake group was significantly increased(P<0.05).The feeding speed,milk yield and 4%standard milk yield of dairy cows in high feed intake group were significantly increased(P<0.05),and the milk urea nitrogen content was significantly decreased(P<0.05).Rumen pH,ammonia nitrogen,acetic acid,propionic acid and total volatile fatty acid contents of cows in medium feed intake group and high feed intake group were significantly increased(P<0.05).Serum albumin and total protein contents in medium feed intake group and high feed intake group were significantly increased(P<0.05);Serum urea nitrogen content in high feed intake group was significantly increased(P<0.05).[Conclusion]Dairy cows in the early lactation period have different milk production performance under different feeding levels.The higher the feed intake,the better the milk production performance,the stronger the rumen fermentation function and the better body condition.
prelactationcowsfeeding levelmilk production performanceserum biochemical index
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