Factors associated with rectovaginal injuries in Holstein dairy cows in a herd in Tehran, Iran

Rectovaginal injuries can result in subsequent infertility in cows. In a retrospective study, records of 147 Holstein cows with evidence of rectovaginal injuries were reviewed to determine the odds ratio (OR) of these injuries and their related risk factors. The study was conducted in a large dairy (typical herd size 1420 cows) in Tehran between the years 1993 and 1996. Period prevalences were 0.4% fistula, 1.9% laceration (third degree), 5.7% pneumovagina, 1.5% urovagina and 0.8% mixed injuries. The highest risk occurred among first-calf heifers. Animals with dystocia, first-calf heifers and male calves were at higher risk for rectovaginal injuries. We concluded that (1) handling dystocia with care might have a substantial role in reducing rectovaginal injuries, (2) first-calf heifers are to be under close observation and care during calving, and (3) because rectovaginal injuries reoccur in the next calving, cows with the history of these injuries should be monitored at the next labor.