Study On Influence Of Cow Bunching Induced By Diptera For Enzyme Activity,Heart Rate,Body Temperature And Performance

Recently, the rapid development of Chinese Dairy Industry is expanding. However, environment was damaged from regulation and ranch facilities can not keep up the pace of development. It caused a serious impact for cow health and production performance. It led to a large number of Diptera breeding because of Pasture environmental degradation. Diptera transmit disease, while influence cow's normal behavior, physical index. In order to study the effect of cow's bunching induced by Diptera on physiological parameters and performance. XuRi ranch was selected as the experiment place on Hohhot, Inner Mongolia. Nine health cows were selected for the study from 300 lactating Holstein cows. Diptera month's activities was investigated in 2009.4～10. meanwhile change of serum enzymes, heart rate, body temperature and production performance were researched.(1)There were house fly, stable fly, flesh fly, Anthomyiidae, Hypoderma bovis and other Diptera in the pasture. But one activity is a greater density of house fly and stable fly. The activities of house fly reached the maximum density of 694.28±38.77 per hour in August, which compared with the other months significant difference (P <0.05). The activity density of stable fly reached 102.88±68.47 per hour in September, significantly higher than other months (P <0.05).(2) Cow aggregation happened in September 18～October 2, when the head inward together and dairy cattle close to each other to form a roughly circular aggregates. during the aggregation The number of house fly were 15.7±3.34 per head﹑per 20min on the cattle, there were significantly reduced from the previous few months (P <0.05). while the number of stable fly were significantly higher than before and after aggregation (P <0.05), there were 22.44±4.95 per head,per 20min. So stable fly was the key reason of cows aggregation behavior, but the house fly has some stimulating effect. The number of tail switching,ear twitching,skin twitching and leg stamping were increase during the aggregation, the number of ear twitching and leg stamping were significant difference (P <0.05). (3) Compared with the other months,γ-GT activity, GPT activity and LDH activity during aggregation behavior showed no significant change (P >0.05). So cows' liver was not damaged during aggregation, normal liver function. The experimental cows'ALD activity and CPK activity were significantly higher (P <0.05), it was considered that the invasion of Diptera made cardiac and muscle some damage.(4) Autonomic nervous system was more sensitive about invasion of the Diptera. Insect attack triggered cows'defensive behaviour in a quiet state, when heart rate was significantly increased 23 bpm ~ 26 bpm (P <0.05). Cows'heart rate only change with the axis of 65 bpm between at 55bpm ~ 83bpm during aggregation, lower than in other months significantly (P <0.05). So aggregation caused by Diptera insects induced heart rate slowing.(5) Diptera activities affected on Cow's average body temperature in the pasture. During the aggregation, the average body temperature of cow was 38.71±0.75℃, higher than in August and October were increased by 1.61℃and 2.24℃, significant difference (P <0.05). According to results, the invasion of Diptera destroyed body thermal regulation mechanism, thereby affected the health of dairy cows.(6) The average milk yield of cows was 594.25±102.51kg during the aggregation, significantly lower than in other months (P <0.05); milk content was also less than in other months. Milk fat content was 2.56±0.74%, reduced than in other months significantly (P<0.05); Milk somatic cells was increased to 603.4±87.8 thousand / ml. These results show that aggregation induced by Diptera activity produce negative effect on the cow's Enzyme Activity, heart rate, body temperature and performance. Normal behavior and physiological activity are disrupted, thus productive potential is interfered.