The Effect Of Different Coated Methionine On Milk Performance And Blood Indices In The Mid-lactation Diary Cows

Objective:Utilized gelatinizing technology to disposed Met and hydroxymethyl-Met-Ca (HMB-Ca) ,through feeding experiment(detect milk yield,milk composition , blood indices and so on), use rumen degradation experiment to evaluate the manufacture value and stability of gelatinizing Met and gelatinizing HMB-Ca,to determine its effect on milk performance and cross rumen property. Method:Feeding experiment:selected 25 Holstein diary cow, divided into 5 groups, feeding with basic daily diet(BDD)(control), BDD+400 gelatinizing Met (group 1), BDD+20g Met(group 2),BDD+400g gelatinizing HMB-Ca (group 3), BDD+20g HMB-Ca (group 4),respectively. Determined the digestive condition, milk quantity and ingredient, and blood index of the feeding of different treatments.Rumen degradation experiment:selected 3 diary cow which with rumen fistula,through rumen nylon bag way to determined the stability and degradation rate gelatinizing Met.Result:The result showed:1) The apparent digestibility of DM,NDF and ADF of group 4 had improved 1.91%(P<0.05), 20.98%(P<0.01), 11.4%(P<0.05) compared to control;the CP apparent digestibility of group 4 had improved 3.06% (P<0.05) compared;the NDF apparent digestibility of group 3 improved 15.73% (P<0.05) compared to control.2) The difference of dry matter foraging amout between each groups were not significant (P>0.05),but each group has a tend of increase;the milk quantity of group 4 was very significantly higher than control (P<0.01),the milk quantity of group 3 was significantly higher than control(P<0.05),improved for 6.93% and 4.95% compared to control,respectively;the butterfat rate of group 3 improved 2.31% compared to control (P=0.086);the milk protein quantity of group 4 significantly higher than group 2(P<0.05),improved 2.15%.3) The level of plasma-albumin of group 3 was significantly higher than control (P<0.05),increased 6.39%;the whole plasma-protein quantity of group 4 and 3 were significantly higher than control(P<0.05),increased 8.48% and 7.07%,respectively; plasma urea nitrogen(PUN) of group 4 was lower than control that decreased 6.98% (P<0.05).The result showed Met can decreased PUN,increased plasma protein(PP) contents,enhance the ability to digest and absorb protein.4) After 5 different fine forage incubated in rumen for 12h, the DM and CP of gelatinizing-HMC all lower than other groups.After incubated for 24h, elimination coefficient of gelatinizing-Met and gelatinizing-HMC were 62.81% and 62.85,respectively,pass rumen quantity were 54.41 and 69.20,but mixture of Met-corn basically disposed in 24h(91.44),it showed gelatinization can protect Met and HMC very well.Conclusion: Gelatinizing Met can increase apparent digestibility of DM,CP,NDF and ADF. Gelatinizing-HMC and gelatinizing-Met can increased milk output and milk composition of intermediate stage lacting cow,decreased UN,increased PP,thereby increased the exploitation and protein content,but gelatinizing-Met have no significant effect on milk cow.After incubated in rumen for 12h, degradation rate of DM,CP of gelatinizing HMC and gelatinizing Met were all about 50%,it showed that gelatinization have acceptive protection to Met and HMC,but the effect was not good enough.