The Effect Of Different Ratio Forages On Digestion Metabolism And Performance Of Dairy Cattle

Corn stover and alfalfa hay are main forage and widely used in dairy production, In order toproduce a marked synergistic action, and enhance their utilization efficiency, the optimization ratio ofcorn stover and alfalfa hay should be studied. Under the condition of the same addition ofconcentration and corn silage, the experiment researched the effect of different ratio of corn stoverand alfalfa hay on digestibility and nitrogen metabolism of cow, and determine dairy cattleperformance of the forage optimization ratio. Accordingly, we can obtain eligible ratio of corn stoverand alfalfa hay, which can reduce the value of rear and raise profits. The study provided theories ofutilization and generalization of corn stover and alfalfa hay in cow production.Experiment one:Twenty-four Heifers were allocated to six dietary treatments according to theprinciple of body weight and birth similarity.The diets consisted of six forage mixtures of alfalfa hayand corn stover (dry matter basis).The six forage mixtures treatments: A: alfalfa hay and corn stover(1:1); B: alfalfa hay and corn stover (1:1.2);C: alfalfa hay and corn stover (1:1.4);D: alfalfa hayand corn stover (1:3);E: alfalfa hay and corn stover (1:3.5);F: alfalfa hay and corn stover (1:4).(1) The trial results showed that DM apparent digestibilities of Heifers fed C and D ration werehigher than others, but difference were not identical (p＞0.05).CP apparent digestibilities between Dgroup and F group were different (p＜0.05),but difference were not significant between the twogroups and these four (p＞0.05).NDF apparent digestibilities were significant between D group andA group, F group(p＜0.05), but difference were not identical to these three(p＞0.05). ADF apparentdigestibilities were not significant between the six groups(p＞0.05);(2)The trial results also showedthat N metabolism is not significant between A, B, and C, D groups (p＞0.05),but difference wassignificant between F group and these four (p＜0.05).Difference was identical between E group andB group, C group. According indexes determined from the experiment, the C group and D groupwere optimization.Experiment two:Thirty healthy dairy cattle were allocated to three diets according to milkyield, lactation and body weight.Each group was ten dairy cows. Dairy cattle ofⅠgroup andⅡgroup were fed forage ratio of C group and D group optimized from trial one, their performanceswere compared with that of dairy farm (as the control).The trial group and the control group wereoffered TMR. (1) The trial results indicated that dairy yield was significant between the trial group and the control (p＜0.05),dairy yield ofⅠgroup andⅡgroup were respectively higher 17.0% and21.7% than that of the control. (2) Milk indexes such as milk fat, milk protein and lactose were notsignificant between the trial group and the control (p＞0.05), but these of the trial were higher thanthese of the control. (3) Profits ofⅠgroup andⅡgroup were higher than these of the control, andforage ratio of D group was better than that of C group.According to the results from the experiment, when the ratio of alfalfa hay and corn stover is25%, positive associative effects is highest;the ratio is 25%～50%, there exists negative associativeeffect, but it is not significant.When the ratio is 50%, negative associative effect is special significant.Performances and profits of C group and D group were better than these of the control.