Effects of Neospora caninum on reproductive parameters in dairy cows from a closed herd in Brazil.

Autor: de Barros LD; Department of Preventive Veterinary Medicine, Laboratory of Animal Protozoology, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, Pr 445 km 380, 86057-970 Londrina, PR, Brazil. Electronic address: ldbarros@uel.br., Bogado ALG; Universidade Norte do Paraná, Arapongas, Brazil., Furlan D; Universidade Norte do Paraná, Arapongas, Brazil., de Melo Jardim A; Universidade Norte do Paraná, Arapongas, Brazil., Okano W; Universidade Norte do Paraná, Arapongas, Brazil., da Silva LC; Universidade Norte do Paraná, Arapongas, Brazil., Pereira CES; Universidade Norte do Paraná, Arapongas, Brazil., Bronkhorst DE; Universidade Norte do Paraná, Arapongas, Brazil., Cardim ST; Universidade Norte do Paraná, Arapongas, Brazil., Garcia JL; Department of Preventive Veterinary Medicine, Laboratory of Animal Protozoology, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, Pr 445 km 380, 86057-970 Londrina, PR, Brazil.
Jazyk: angličtina
Zdroj: Veterinary parasitology, regional studies and reports [Vet Parasitol Reg Stud Reports] 2021 Jan; Vol. 23, pp. 100524. Date of Electronic Publication: 2020 Dec 24.
DOI: 10.1016/j.vprsr.2020.100524
Abstrakt: Dairy production and cattle reproductive parameters exhibit a strong relationship, which can be disrupted by infectious agents, such as Neospora caninum, that affect the reproductive tract of these animals. Neosporosis is a major cause of abortion in cattle worldwide and is responsible for substantial economic losses. We evaluated the impact of N. caninum infection on the reproductive parameters of 434 Holstein dairy cows from a herd in Brazil that had been closed for 4 years through the assessment of serological testing and reproductive parameters. Dairy cows older than 24 months and that required at least 2.2 inseminations to become pregnant had a higher frequency of seropositive results. Analysis of the medians of positive and negative cows revealed that seropositive cows tended to require more insemination efforts to achieve pregnancy and showed a 2-month increase in age at first calving. According to the reproductive parameters, the correlation coefficient was higher in seronegative animals, while no such correlation was detected in seropositive cows. Thus, we concluded that N. caninum negatively affects the reproductive parameters of dairy cows kept in a closed herd.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE