Effects of Different Dietary Crude Protein Levels on Lactation Performance of Binglangjiang Buffalo
This experiment was conducted to investigate the effects of different dietary crude protein levels on lactation performance of Bingangjiang buffalo.A single factor completely randomized block design was used in the experiment,and 21 healthy Bingangjiang buffalo with similar age[(6.33±2.75)years],parity[(3.14± 1.56)parities]and milk yield in upper parity were randomly divided into 3 groups(7 heads per group).They were fed total mixed rations with low crude protein level(9.5％),medium crude protein level(12.5％)and high crude protein level(14.8％),respectively.The pre-trial period lasted for 7 days and the experimental pe-riod lasted for 273 days.The results show that with the increase of dietary crude protein level,the relevant indi-ces of lactation performance of Bingangjiang buffalo had certain changes,among which the average daily milk yield,average milk yield and contents of milk protein,milk non-fat solids and milk urea nitrogen in 14.8％crude protein group were significantly higher than those in 9.5％crude protein group(P＜0.05),and the above indices were not significantly different between 9.5％and 12.5％crude protein groups(P＞0.05).With the in-crease of lactation time,the milk fat content in 12.5％and 14.8％crude protein groups basically showed a trend of first decreasing and then increasing,and the change in 9.5％crude protein group was not obvious,but the milk fat content in all three groups was higher at the end of lactation than at the beginning of lactation,and the milk fat content in 12.5％crude protein group was the highest(7.84％).There were no significant differ-ences in average lactation days,milk fat to protein ratio and contents of milk fat,milk lactose and milk total solids among the three groups(P＞0.05),and little changes in milk fat to protein ratio and contents of milk lactose and total solids were observed.The milk somatic cell count in 12.5％crude protein group was signifi-cantly higher than that in 9.5％and 14.8％crude protein groups(P＜0.05).In conclusion,increasing dietary crude protein level from 9.5％to 14.8％can significantly increase the milk yield and contents of milk protein,milk non-fat solids and milk urea nitrogen,but has no significant effects on lactation days and contents of milk fat,milk lactose and milk total solids as well as milk fat to protein ratio of Bingangjiang buffalo.[Chinese Journal of Animal Nutrition,2024,36(4):2457-2474]
lactation performanceBinglangjiang buffalocrude protein level
万方数据
维普
