Analysis For Linear Type Traits Of Holstein Dairy Cows In Beijing

28In this experiment,1391 Holstein dairy cows in Diyi,Chunyan,Runfa,Yuanhe and Jianguang dairyfarms in Beijing area were selected as the research object,and 23 linear type traits were identified by the9-point scale method.Identification was performed to weight the traits as structural capacity,rump,limb hoof,breast and breast characteristics to obtain the total type score.The one-way ANOVA was used to analyze the significant difference of total type scores among the five farms.The development of dairy cows in the area was observed in six levels,i.e.“EX”,“VG”,“GP”,“G”,“F” and “P”.The basic parameters of dairy cows were analyzed by the average,standard deviation and the difference with the theoretical optimal score.The correlation between the traits and the total scores of each part were analyzed using SPSS 22.0.The aim is to provide some references and bases for the improvement of body traits and the management in Holstein dairy cows in Beijing.The results are as follows:1.The ANOVA results showed that the differences of the total scores between Diyi dairy farm and the other four farms were highly significant(P < 0.01),and that between Jianguang and other three farms were also significant(P < 0.01).There was no significant difference among Chunyan,Runfa and Yuanhe dairy farms(P > 0.05).The average value of the total score of Diyi farm was the highest,followed by the Jianguang farm,and the averages of the other three farms were similar.2 The cattle in Diyi and Jianguang dairy farms were relatively stable.Most of the cows were distributed in the “G” grade,and the development degree was better,but in the “EX” grade was 0,and the proportion of the “VG” was very low,so there was still much room for improvement.The score distribution of other three farms was scattered.The overall development of Holstein dairy cows in Beijing was relatively stable.From the average level,the average score of each trait ranged from 3.28 to 6.68,and the average valueof structure capacity and breast shape was about 6.68.The dairy cows in this area were larger,and the breasts were well developed.Overall,the difference between the structural capacity,the body shape of the breast and the theoretical optimal score was relatively small.The development of these traits was significantly improved,while the suspensory ligament(5.72)and the hind limb posterior(3.16),breast texture(3.73),anterior breast attachment(3.82),waist strength(3.90)and heel depth(4.32)were significantly different from the optimal score,which still need further improved.3 The structural capacity,rump,limb hoof,breast and milk characteristics of the Holstein dairy cows in Beijing were positively correlated with the overall type score,and there was a significant difference(P <0.01).The correlation between the structural capacity and the total type score was the smallest(0.157),and that between the structural capacity and breast(0.865)was the largest.There was a strong correlation among body depth and chest width and structural capacity.There was a significant positive correlation among heel depth,lateral vision of hind limb,limb hoof traits,and nipple position.In addition,there was a strong correlation among body depth,chest width and structural capacity.The anterior breast attachment and the posterior nipple were positively correlated with the breast traits.