Effect Of Alfalfa Hay Substituting Part Of Concentrate On The Production Of Dairy Cows And Economic Profit

This paper was conducted to investigate the effect of alfalfa hay substituting partof the concentrate on production performance, milk quality of dairy cows, nutrientapparent digestibility, blood serum biochemical parameters and economic benefits. Allthe results are as follows.Twenty-four multiparous Holstein Lactation cows in mid lactation were selected,which had the similar body weight and milk production. They were randomly dividedinto four groups. The control group diet included corn silage, peanut vine andconcentrate, the concentrate: roughage ratio of all the mixed diet is52:48based onDM, the test groups A、B and C were used3kg of alfalfa hay substituting1.5kg,2kgand3kg concentrate,respectively, for70days of the feeding trial. The results showedthat:The milk yield of the experimental groups were significantly higher than thecontrol group (P<0.01), that of the group A was significantly higher than those ofgroup B and group C (P<0.05), there was no significant difference for the milk yieldbetween group B and group C (P>0.05).There were significant difference among experimental groups and control group inmilk protein (P<0.05), and those of group B and group C were significantly higherthan that of group A in milk protein (P<0.05). Compared to the control group, trueprotein, calcium and phosphorus in milk of the test groups improved, but thedifference among the four groups were not significant (P>0.05).Compared with thecontrol group, fat percentage (P<0.01), lactose and dry matter (P<0.05) of the testgroups were significantly increased, but those were not significant among three testgroups (P>0.05). Compared to the control group, somatic cell count of the test groupsreduced, but the difference among the four groups were not significant (P>0.05).Dry matter intake of group A was the highest, and those of the A and B groupswere significantly higher than (P<0.01) those of group C and the control group, however, the difference was not significant between group C and the control group(P>0.05).The apparent digestibility of crude protein (P<0.05) and neutral detergent fiber(P<0.01) of the group A and group B were significantly higher than that of the controlgroup, but the difference was not significant between the group A and the controlgroup (P>0.05). Compared to the control group, apparent digestibility of calcium ofthe test groups reduced, but the difference among the four groups were not significant(P>0.05). The apparent digestibility of phosphorus of the test group A，group C andthe control group significantly higher than that of the test group B（p<0.05）, but thedifference was not significant among the group A, group B and the control group(P>0.05).The test treatments had effect on blood urea nitrogen significantly, and blood ureanitrogen in group A（p<0.01） and group C（p<0.05） was lower significantly than thecontrol group, blood urea nitrogen in test group B reduced by6.63%than the controlgroup, through there were no significant difference between test group B and thecontrol group. Total protein, albumin, blood glucose, carbon dioxide combining powerand ALT showed no significant difference among the four groups（P>0.05）.The profit of group A was the greatest, which was7.92yuan/d.The above results showed3kg alfalfa hay substituting different ration ofconcentrate can improve the milk yield, the quality of milk and profit. So3kg alfalfahay substituting1.5kg concentrate was suggested.