Enhancing reproductive performance in domestic dairy water buffalo (Bubalus bubalis).

The purpose of the review is to describe the factors that affect fertility in domestic water buffalo (Bubalus bubalis) and the techniques that enable an improvement in reproductive performance. On Italian and Latin American farms where natural mating is practiced and bulls are always present in the herd, the inter-calving interval is approximately 400 days and the culling rate is lower than 15%. The buffalo has a tendency for seasonal reproductive activity. Reproduction is favoured when there is a decrease in day length. Ovarian activity stops if conception does not occur within 3 to 5 ovarian cycles. It is important, therefore, that appropriate management of the transition period is practiced, particularly with respect to the hygienic conditions of the uterus. In tropical countries located north of the equator, feed deficiencies and heat stress are considered the main factors that lead to poor fertility in the summer. In Pakistan, for example, the increase in body condition score during the autumn was associated with the commencement of the breeding season in buffaloes. Anoestrus is observed also in Italy, however, where the average daily temperature during the same period is 13.5 to 23.5 degrees C and feeding is constant throughout the year. The only common element between the two areas is the progressive increase in daylight hours between April and June and the day length greater than 12 hours up to September. In Italian herds that apply an out-of-season breeding strategy, an improvement in fertility (measured as the percentage of corpora lutea corresponding to subsequent pregnancy) is observed when water pools are present on the farm. This demonstrates that an improvement in environmental conditions reduces the incidence of embryonic mortality and/or abnormal cycles. To summarize, in the absence of serious nutritional problems, an improvement in environmental conditions increases fertility in buffalo.