Factors Affecting Culling Decision And Methods For Assessing Of Optimal Production Life In Dairy Cow

There are mainly two reasons of culling cow. one is active culling which older or low production cows were culled, the other is positive culling which incurable deases or some kind of defective cows were culled. Because of feeding and management is poor in Chinese dairy farm, too many cows were positive culled and average productive life was no more than4 years, which seriously affected the economic benefits of farm. So it is urgent and helpful to investigate how to decrease positive culling rate and plan active culling in Chinese dairy farm.A total of 14.7 million cows are raised in China, with a cow culling rate of 15% to 20%.Most of the culled cows and finishing bull calves are sold to slaughter house and individuals,and then are processed to meat products which have become a great supplement to the beef m arket in China. Two sides avoid frequently the supervision of sanitary authority during the tra ding of culling cows. Most of them were finally passed into slaughter house under the conditi on of lack of the obligatory inspection and quarantine, causing a potential risk of the beef pro duction.This research of dairy farm size from 120 to 13500, cattle structure is difference, the smallest percentage of the total cattle is 38.08%, the highest is 80.35%, average 55.7%, this is mainly related to dairy cow elimination rate, cow elimination rate of 10-30% of survey dairy farms is the 49%. Cause analysis showed that breeding disease is a major disease causes eliminated cow, accounted for 49% of the total elimination causes, limb hoof disease and metabolic disease accounted for 21% and 27% respectively, infectious diseases only 3%.Culling time statistics show that cows are culled when the 1-4 parity, mainly concentrated in accounted for 84% of the total number out, 1-2 parity elimination rate as high as 51%, which shows our country dairy farms are widespread elimination cow premature problem, use fixed number of year of the cow is short, with foreign eliminated a cow’s age gap is too big.Generally, the 20% culling rate of cow is feasible. It is necessary to make up the reasona ble culling plan of cow because cow is common culled out for the passive reasons that are arb itrary. Moreover, the culling occurs at the crucial first-lactating stage due to reproductive diseasesin which the potential of milk production has not been effectively exhibited. Therefore,it is necessary to strengthen the management of primiparous cow and to reduce the incidence of reproductive disorder diseases. The total income of dairy farm is mainly composed of sales income of fresh raw milk. Of which, the average milk yield of individuals is an important influence factor, which is one of the key factors to determine the economic benefits of dairy farm s. Therefore, by strengthening the progress of genetic improvement to increase milk yield per cow is one of important breeding projects in dairy farm.