Reproductive efficiency is the primary factor affecting productivity of
farm animals. Among the various causes of subfertility, anoestrus is the
major reproductive disorders (Pandya et al., 1989). Prolonged postpartum
acyclicity and anestrum are major sources of economic loss to buffalo
breeders (El-Wishy, 2007). Postpartum ovarian activity and subsequent
pregnancy may be affected by several factors such as breed, nutrition
plan, milk yield, suckling, uterine involution, season of calving (Arya
and Madan, 2001; Baruselli et al., 2001; Campo et al., 2002). The
present study was conducted to explore the cyclical status of apparent
anoestrus postpartum buffaloes and to test the effectiveness of oestrus
induction in cyclic and non-cyclic buffaloes at 60 or more days
post-partum. Pre-ovulatory follicle (POF) is the prime structure behind
the endocrinology of oestrus in buffaloes which produces substantial
amounts of estradiol. The present study was conducted to investigate the
relationship of pre-ovulatory follicular (POF) diameter at estrus with
subsequent luteal size and pregnancy in buffaloes.