Features of Uterine Involution in Dairy Animals: A Review

Uterine involution is the process of resumption of pregnant uterus to non pregnant state along with restoration of ovarian function which occurs during puerperium/post-partum period. Estrogen and progesterone hormones are responsible for changes in shape and size of uterus during pregnancy whereas, release of fetus, reduced oxytocin and increased PGF_2α help uterus to resume normal state. Fast involution of uterus is essential in order to make cow receptive and conceive again. Though rectal palpation is most commonly used technique for assessing uterine involution in cows but it is less accurate than trans-rectal ultrasonography. Annual incidence of uterine infection in herd has been recorded by different scientists to the extent of 10–50% in cows and 20–75% in buffaloes whereas an anatomical, physiological and phagocytic barriers prevents the uterus from getting infection. Purulent discharge and its odour indicate severity of infection due to pathogenic bacteria under field condition. pH of secretions act as first line defense preventing infection through tract. Poor and delayed uterine involution contributes to poor reproductive efficiency in dairy cattle and it is affected by age, nutritional status, suckling by calves and milk yield of the individual cows, respectively. Rate of uterine involution can be accelerated by using PGF_2α, methylergometrine maleate, Vitamin E, selenium and cloprostenol injection, respectively. Intrauterine lactobacilli application puts a very positive effect of on involution.