Study On The Epidemiology Of Main Gastrointestinal Nematodes Of Drylot Feeding Sheep In Bayannur District

In nearly a decade, the method of drylot feeding mutton sheep is actively promoted in the Inner Mongolia Autonomous Region government, and make the rural area formed many intensive and formalized mutton sheep farms. This emerging breeding mode plays a important role in the development of mutton sheep production.By 2016, the total numbers of stall-feeding mutton sheep and the growth rate are in the first place in Bayannur city of Inner Mongolia. It is worth noting that the epidemic features of sheep gastrointestinal nematode disease in the whole barn feeding conditions are changing when compare to traditional model, however, the control and treatment systems of sheep gastrointestinal nematode disease do not be built and completed in the new breeding mode. In our study, the investigation of sheep gastrointestinal nematode disease in the whole barn feeding conditions, in order to provide a scientific basis for the preventive formulation of sheep gastrointestinal nematode disease in the whole barn feeding conditions.The research that the tracing and investigation of natural infection wi th gastrointestinal nematodes sheep from July 2013 to December 2015 i-n Fuchuan Mutton Sheep Farms, Linhe District, Bayannur City. The dy-namic Survey results of infected nematode species and ovulation show that before the stall-feeding mutton sheep, there are eight species of ne-matode infected in sheep farms, such as Haemonchus contortus, Trichost rongylus colubriformis, Nematodirus oiratianus,Chabertia ovina,Ostertagi-a circumcincta,Bunostomum trigonocephalum,Cooperia erschowi,Trichuris ovis. After 27 months of barn, feeding breeding, there are only three n-ematode species, such as Haemonchus contortus, Trichostrongylus Colub-riformis, Nematodirus oiratianus. The infection intensity of gastrointesti-nal nematodes of sheep is sharply declined, In 2015, the peak in 2015 was decreased 67.89% when compared with 2013. Ovulation seasonal dy namic presents a peak point and lowest point, which are from June to August and from January to March, respectively.The observation results which the developmental state of sheep gastrointestinal nematode larva in the whole barn feeding conditions show that the development of infective larvae is focused on June to October every year, and reached to a peak in July. The others time eggs of gastrointestinal nematode can not develop into infective larvae.The observation results which the first time of ovulation time in different date of birth lambs show that lamb borned in summer can not find the eggs eduction of gastrointestinal nematode before nine months; lamb borned in autumn can observe eggs of Nematodirus oiratianus in April of next year, the average ages are seven months, lamb borned in winter can first observe eggs of Nematodirus oiratianus in June of next year, the average ages are six months, the average ages are seven months, lamb borned in spring can firstly observe eggs of three species of gastrointestinal nematodes in September of next year. Nematodirus oiratianus is the highest percent of gastrointestinal nematodes in weaned lambs, then Haemonchus contortus is second.Before the lambs of five months can not find eggs of gastrointestinal nematodes, the earlyest time which observed the eggs is lambs of six months.The observation results which the infection situation of lambs gastroi ntestinalnematode in the whole barn feeding conditions show that the av erage infectiou-s rates are 39.42% for Haemonchus contortus,40.34% f-or Trichostrongylus colubriformis,51.59% for Nematodirus oiratianus; The seasonal dynamic of gastrointestinal nematodes in lamb barn feedin-g breeding is the same as the adult sheep:a peak period and a trough period in all year around.