title: Bovine viral diarrhea virus (BVDV) infection in dairy cattle herds in northeast Thailand.
abstract: Bovine viral diarrhea virus causes a wide range of clinical manifestation with subsequent economic losses in dairy production worldwide. Our study of a population of dairy cattle in Thailand based on 933 bulk tank milk samples from nine public milk collection centers aimed to monitor infective status and to evaluate the effect of the infection in cows as well as to examine the reproductive performance of heifers to provide effective recommendations for disease control in Thailand. The results showed a moderate antibody-positive prevalence in the herd (62.5 %), with the proportion of class-3 herd, actively infected stage, being 17.3 %. Fourteen persistently infected (PI) animals were identified among 1196 young animals from the class-3 herds. Most of the identified PI animals, 11/14, were born in one sub-area where bovine viral diarrhea virus (BVDV) investigation has not been performed to date. With respect to reproductive performance, class-3 herds also showed higher median values of reproductive indices than those of class-0 herds. Cows and heifers in class-3 herds had higher odds ratio of calving interval (CI) and age at first service (AFS) above the median, respectively, compared to class-0 herds (OR = 1.29; P = 0.02 and OR = 1.63; P = 0.02). Our study showed that PI animals were still in the area that was previously studied. Furthermore, a newly studied area had a high prevalence of BVDV infection and the infection affected the reproductive performance of cows and heifers. Although 37.5 % of the population was free of BVDV, the lack of official disease prevention and less awareness of herd biosecurity may have resulted in continuing viral spread and silent economic losses have potentially occurred due to BVDV. We found that BVDV is still circulating in the region and, hence, a national control program is required.
authors.affiliation: Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.|Faculty of Technology, Udon Thani Rajabhat University, Udon Thani, Thailand.
authors.forename: Theerakul
authors.initials: T
authors.lastname: Nilnont
authors.affiliation: Department of Surgery and Theriogenology, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
authors.forename: Suneerat
authors.initials: S
authors.lastname: Aiumlamai
authors.affiliation: Department of Veterinary Physiology, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
authors.forename: Kwankate
authors.initials: K
authors.lastname: Kanistanont
authors.affiliation: Epidemiology and Animal Health Economics Group, Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
authors.forename: Chaidate
authors.initials: C
authors.lastname: Inchaisri
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand. jarpat@kku.ac.th.|Research Group for Preventive Technology in Livestock, Khon Kaen University, Khon Kaen, 40002, Thailand. jarpat@kku.ac.th.
authors.forename: Jaruwan
authors.initials: J
authors.lastname: Kampa
mesh_terms: D000818:Animals; D000914:Antibodies, Viral; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000453:epidemiology*; D002417:Cattle; D003612:Dairying; D030241:Diarrhea Virus 1, Bovine Viral / Q000276:immunology / Q000302:isolation & purification; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology / Q000302:isolation & purification*; D005260:Female; D008892:Milk / Q000821:virology*; D015995:Prevalence; D012098:Reproduction; D013785:Thailand / Q000453:epidemiology
chemical_list: D000914:Antibodies, Viral
keywords: BVDV; Bulk tank milk; Dairy herd; Prevalence; Reproductive index; Thailand