MT制剂降低牛奶体细胞数初探

Preliminary Study of Melatonin Preparation on Reducing Somatic Cells Counts in Dairy Cows

试验旨在研究MT(褪黑素)制剂对牛奶体细胞数的影响。根据年龄、胎次、产奶量、泌乳期相近的原则,选取牛奶体细胞数(SCC)在20万~60万个/mL、60万~100万个/mL、100万个/mL以上的妊娠荷斯坦奶牛各30头,共90头。将SCC在20万~60万个/mL、60万~100万个/mL、100万个/mL以上水平的荷斯坦奶牛各随机分为3组,第1组为对照组不给药,第2组每天皮下注射4 mL MT制剂,第3组每天灌服24 mL MT制剂,连续给药4 d,试验期11 d,每天采集奶样测定牛奶体细胞数。结果表明:对体细胞数在20万~60万个/mL的各组奶牛,与对照组相比,皮下注射MT制剂可以显著地抑制体细胞数的上升(P<0.05),灌服MT制剂抑制体细胞数上升效果不显著(P>0.05);对体细胞数在60万~100万个/mL的各组奶牛,与对照组相比,皮下注射MT制剂极显著降低了牛奶中体细胞数(P<0.01),灌服MT制剂降低牛奶中体细胞数效果显著(P<0.05);对体细胞数在100万个/mL以上的各组奶牛,与对照组相比,皮下注射MT制剂和灌服MT制剂均能极显著地降低牛奶中的体细胞数(P<0.01)。综上,皮下注射MT制剂降低牛奶中的体细胞数效果显著;灌服MT制剂对降低60万个/mL以上高体细胞数水平的奶牛的体细胞数效果明显。

This test is to study the effect of melatonin preparation on somatic cells in dairy cows.Choose 30 Holstein cows each with somatic cell counts of 200 000 to 600 000/mL,600 000 to 1 million/mL and 1 million/mL above,90 in total.The cows were divided into three groups according to the principle of similar days of lactation and similar parity,group 1 as a control group was not administered,group 2 subcutaneous injection of 4 mL melatonin daily,group 3 was orally administrated 24 mL of melatonin daily.Continuous dosing for four days,the test period was 11 days,collection milk sample and detection somatic cells everyday.The results showed that the number of somatic cells increased each group of somatic cells in the range of 200 000 to 600 000/mL,compared with the control group,subcutaneous injection of melatonin could significantly inhibit the rise of somatic cell counts(P<0.05),the effect of oral administration melatonin preparation on inhibiting somatic cell counts was not obvious(P>0.05);the number of milk somatic cells of each group with somatic cell counted between 600 000 and 1 million/mL shows a downtrend,compared with the control group,subcutaneous injection melatonin preparationon could extremely significantly reduce the number of milk somatic cells(P<0.01).Oral administration melatonin preparation could significantly reduce the number of milk somatic cells(P<0.05);the number of milk somatic cells of each group with somatic cell counted above 1 million/mL shows a downtrend,compared with the control group,subcutaneous injection and oral administration melatonin preparationon could extremely significantly reduce the number of milk somatic cells(P<0.01).In summary,subcutaneous injection melatonin preparationon can significantly reduce the milk somatic cell counts in dairy cows.Melatonin preparationon can significantly reduce the number of somatic cells of high somatic cell level above 600 000/mL in dairy cows by orally administration.