Mycoplasma species in vaginas of dairy cows before and after exposure to bulls and their association with conception

Abstract

Mycoplasma species can colonize the urogenital tract of dairy cattle. However, interrelationships between Mycoplasma spp. and reproductive performance in dairy herds are unclear. In this study, we measured apparent prevalences of Mycoplasma spp. in the vaginas of dairy cows (n = 629) pre-and post-bull exposure in dairy herds with and without Mycoplasma bovis clinical disease (n = 5 herds), and assessed associations between variables describing reproductive performance and consequent Mycoplasma spp. isolation. Mycoplasma spp. were infrequently isolated from the vagina pre-(1.9%; 12/629) and post-bull (3.2%; 20/629) exposure. Of the mycoplasmas isolated, Mycoplasma bovigenitalium was isolated most frequently (87.5%; 28/32), followed by Mycoplasma californicum (9.3%; 3/32). Mycoplasma bovis was only isolated from one cow. We were unable to provide any evidence of venereal transmission of M. bovis in cows in M. bovis-infected herds that use natural service bulls. There was an insufficient number of cows with Mycoplasma spp. in the vagina pre-bull exposure to assess effects on subsequent reproductive performance. Cows that had not conceived before post-bull exposure sampling had much greater odds (odds ratio 14.8; 95% confidence interval 4.2 to 52.3) of having a Mycoplasma sp. isolated from the vagina at this time compared with those that had conceived. Also, within those that had conceived, delayed conception increased the odds of having a Mycoplasma spp. isolated from the vagina at the post-bull exposure sampling by a factor of 1.62 for every additional week not pregnant. The likely cause of these findings is that cows that remain not pregnant for longer are more likely to be served by a bull (likely repeatedly) and subsequently become colonized with a Mycoplasma sp. (mostly M. bovigeni-talium) through venereal transmission. In dairy herds that use bulls, there is a greater chance of isolating a Mycoplasma sp. (mostly M. bovigenitalium) after a period of bull breedings from the vaginas of cows that have remained nonpregnant for longer during the bull breeding period.

Retained Placenta as a Potential Source of Mastitis Pathogens in Dairy Cows

“…However, environmental spread also occurs, and these pathogens can be classified as both environmental and contagious pathogens (see the review by Cobirka et al [29]). Mycoplasma spp., e.g., M. bovigenitalium and M. californicum (9.3%; 3/32), have also been detected previously in vaginal [30] and milk samples [31] from dairy cows.…”

Liver fatty acid metabolism associations with reproductive performance of dairy cattle

“…y otros agentes retardan este período. Se ha encontrado que existe una asociación entre la presencia de este patógeno y el incremento de los días abiertos (15). Así mismo, el déficit de energía que se presenta luego del parto aumenta los días abiertos, principalmente en novillas (16).…”

Survey of beef bulls in Brazil to assess their role as source of infectious agents related to cow infertility

“…Even though M. bovis has been demonstrated to colonize the reproductive tract of cows, venereal transmission of M. bovis has not been defined. 17 As well, the reproductive consequences of M. bovis and other Mycoplasma spp. are poorly studied in cattle.…”