Studies On Mechanism And Harmfulness Of Holstein Dairy Social Bunching Behaviour Harassed By The Diptera

The study focus on the the harmfulness of diptera upon Holstein dairy in the extensive administration and the mechanism of the harmfulness from behaviour neuroendocrine and immunity the experiment divided into four partsThe first part of the experiment studied the variation of the species and number of the diptera with seasonal chang and the variation of the diptera of a day in prevelence. the experimental days was 6-15 days every month from 2009 April to Octomber and there were seven experimental periods in all.The environmental temperature and humidity of the farm was recorded eight times a day at different time and at the same time diptera were collected by the way of the same man collecting in the fixed location in Sunrise Ranch in the Inner Mongolia. The results show that the number and species of Diptera in the farm vary every month from Api to Oct and the species of diptera mainly included flies and mosquitoes, but flies were predominated and mainly consisted of house flies and stable flies .The number of Diptera and the house flies peaked in June August and September and the stable flies peaked in September. The Dipteta were active from 8:00 to 17:00 of a day in the prevalence.The second part of experiment studied dairy social bunching behaviour harassed by the diptera .This part of the experiment Synchronized with the first part of the experiment and adopted completely randomized experimental design influenced by the single factor. In terms of milk yield and parity being similar, 12 (about 4 years old) healthy lactating cows of different lactating stage were selected. The Diptera numbe invaded dairy and the defence behaviour of the dairy cow were observed though the method of the naked eye and the CameraThe results showed that the dairy cows were suffered seriously from diptera on June August and September and the number of diptera (number/20min) attacked dairy significantly higher than July and Octomber (P <0.05), highly significantly higher than May (P <0.01), the peak of the house number invaded dairy was in july June and August in that the number of the july was significantly higher than june (P <0.05) and not significantly higher than in August (P> 0.05). The number of stable flies peak in September, the number of stable fly in September were significantly higher than August October (P <0.05).When attached by the Diptera, the behavior of the dairy cows the change at first , constantly tail switching, head-tossing ,ear twitching ,skin twitching, leg stamping were used to shaking the invasion of the flies .the frequency of defence benaviour increased with the increasing of denisity of flies and in that the tail switching is the most frequently behaviour. When In late September the number of stable flies reached about 25 on the sunny sides of body of the dairy, the cows aggregate to fight against, the frequency and the duration of bunching behaviour are linear correlation with the the number of stable fly attacked the dairy.The design of the third part of the experiment was the same as the second part and aimed at the influence of the activities of Diptera on dairy performance. The milk samples were collected in the end of each experiment , the conclusion show that due to the harassment of the stable fly on September the average milk production, milkfat decreased significantly (P <0.05), meanwhile the number of somatic cells in milk was significantly increased (P <0.05).The desigh of the fourth part of the experiment was the same as the second part and aimed at the influence of the activities of Diptera on neuroendocrine and immune function of the dairy .The blood sample were collected in the end of the each experiment . The results showed that the response of heart rate of dairy is bradycardia and rectal temperature of each month was no significant difference (P> 0.05); when the dairy cows aggragate in late September. The content of ALD, CK, LDH, GPTin serum were not significantly difference (P> 0.05) each month,γ-GT of May was significantly higher than that of June, July, September and October (P <0.05), CPK of September were significantly higher than that of May, June and October (P <0.05 ). The content of NE and EPI in the serum of the dairy were not significantly higher than that of July (P> 0.05), significantly higher than that of the other months (P <0.05), when the dairy aggregate in September. CRH levels of September were significantly higher than that of October (P <0.05); ACTH levels was not significant diffence compared with other month except May (P> 0.05), the concentration of the COR is lowest in September, and significant lower than that of the other month (P <0.05). the concentration of TRH, T4 is no difference among experimental month (P> 0.05); the concentration of T3 of September highly significantly lower than of July (P <0.01), and made no significant difference with july and August (P> 0.05).The concentrations of TSH of September were significantly lower than that of October (P <0.05); PRL levels of September were significantly lower than that of June (P <0.05) and made no difference with June and Augest (P> 0.05). GH levels of September were significantly lower than that of July (P <0.05), and showed no difference with Augest and September (P> 0.05); the contents of INS was no significant difference among the experimental month (P> 0.05).The content of IL-1βof Sep was significantly higher than that of May (P <0.05); the content of IL-2 were not significantly different among experimental month (P> 0.05). IL-6 of September were significantly higher than that October and May (P <0.05).The contents of IL-8 in the serum of the dairy of September were the highest and significantly higher than that of the experimental month except August (P <0.05). TNF-αof September were significantly higher than that of the other experimental month (P <0.05). CD3+ T% in peripheral blood of September were significantly lower than that of the other experimental month except October (P <0.05), CD4+T% in peripheral blood was the lowest in September and significantly lower than tthat of July and august (P <0.05). CD8+T% in peripheral blood of September significantly lower than in July (P <0.05) and no significant difference compared with August (P> 0.05) but significantly higher than that of June and October (P <0.05). CD21+B% of September was significantly higher than that of July and August (P <0.05) but no difference with July Octobe (P> 0.05).When aggragating in september harassed by the diptera, the production and milkfat had decreased by 33% and 1.69% respectively compared with Juiy when the production of the dairy is the highest in the experimental month while the SCC/ml had rearched 660,000/ml, meanwhile, the neuroendocrine and immune sisytem of the dairy changed to address with the stress.This kind of the stress was belonging to severe stress that inflenced of not only well-being of the dairy cows but also security of the milk.