Investigation On The Incidence Of Foot And Limb Disease In Dairy Cows And Analysis Of Related Factors Of Lameness In A Large-scale Farm In Heilongjiang Province

Foot and limb disease seriously harms the health of dairy cows,resulting in an increase in dairy farming and medical costs.At the same time,the reduction of milk production and the early elimination of disease seriously affect and restrict the economic benefits of the dairy industrial intensive development.Therefore,this study investigated the status of foot and limb disease and lameness in a large-scale farm in Heilongjiang Province,and analyzed the possible risk factors,and proposed prevention and control measures for dairy cow foot and limb disease.In this study,the relationship between the temperature of the cows and the hardness of the hooves the horns was studied.The feasibility of the hoof temperature and the hardness of the horns was applied to the diagnosis of dairy cows,which provided an early and practical clinical diagnosis for dairy cows.We investigated the incidence and cause of foot and limb disease in dairy cows.At the same time,the dairy cows were scored by body condition,hock injury and hind limb cleanliness,and the individual information of the cows such as age and daily lactation was collected.The data were analyzed by one-way ANOVA to explore relationships between various factors and lameness.The temperature of the hoof of the right hind hoof is measured by using an infrared thermometer when the cow’s hoof was repairing,the horn hardness of the right hind hoof is measured using a handheld Shore hardness tester,which drawed the ROC curve,and the relationship with the degree of lameness is determined with the optimum threshold.By collecting data from 505 cows,tthe incidence of foot and limb disease in dairy cows was 28.91% and the incidence of arthropathy and foot and limb disease was 7.13% and 25.54%.There were seventeen kinds of foot and limb diseases were found in the pasture.The top three diseases with highest incidence rates were foot diseases,which were foot contusion(incidence 8.91%),deformed foot(incidence 8.32%)and white line disease(incidence 8.12%).The forth disease of the highest incidence of limb arthropathy is the joint swelling(incidence 7.13%).After that we collected data on 631 cows for related risk factors.The results of investigations on the status and related factors of lactating cows shows that the situation in there kind of serious,there were 272 cows walking without limp(score 1)accounting for 41.9% of the whole survey,meanwhile there were obvious claudication symptoms(the claudication score ≥ 3 points),which are 216 cows accounting for 34.3% of the survey.There were 57 cows with severe claudication symptoms(minimum score ≥ 4 points),accounting for 9.1%of the survey.And the average degree of calf in cows with moderate body weight was significantly higher than that in normal and obese cows(P<0.05).The higher the cow’s hock damage score,the cows are getting limp heavier.As the number and age of dairy cows increase,the more cows are getting limp,and more badly they are.In different lactation periods,the average claudication score of perinatal dairy cows was 2.08±0.86,which slightly higher than other periods.The difference between the perinatal cows’ perinatal scores and the late lactation cows was significant(P<0.05).The milk production of cows decreased with the increase of the degree of limp.Compared with the cows who scored 1 point,the average daily lactation of cows who had 5 points decreased by more than 40%.On the daily basis,the average number of cows’ walking decreased with the increase of the degree of limp.The difference between the daily number of 1 minute cows and the daily number of 3,4,and 5 cows was significant(P <0.05).There was no significant difference in the degree of milking between the different hindlimb cleanliness scores.The effect of dairy cows on hoof temperature and hoof horn hardness showed that the temperature of the cow’s line,the far side hoof wall and the hoof bottom triangle were increased compared with healthy cows,and there was a significant difference(P<0.01);the horn hardness of the far side hoof wall,the hoof tip white line area and the far axis side white line area decreased,and there was a significant difference(P<0.01).By plotting the ROC curve,it was found that the AUC of the temperature of the mooring,the temperature of the far side hoof wall and the hardness of the white line of the hoof tip were all bigger than 0.70,which determined that it had good performance for the diagnosis of cows,and established an optimal threshold for 25.30℃(SP 74.7 %,SE 61.3%),18.75℃(SP 82.7%,SE 57.3%)and 46.5 HD(SP 51.1%,SE 83.8%).