Comparison of ultrasonographic measures of reproductive tract in Thai swamp buffalo heifers and cows

Abstract

Although artificial insemination (AI) technology is widely used in buffalo breeding in Thailand, AI in buffaloes has a lower conception rate compared to AI in beef cattle. It is crucial to understand the development of the ovary and reproductive system of buffalo heifers and cows. The objective of the present study was to evaluate the reproductive tract characteristic using ultrasound measurements during the luteal and follicular phases in Thai swamp buffalo heifers and cows. The studies of reproductive tract were conducted in buffalo cows (n=8; BCS=3.38) and heifers (n=8; BCS=3.25). The reproductive tract was evaluated by measuring the size of the ovary, dominant follicle, CL, uterine horn, cervix, and vulva. The buffalo cows had larger diameter of the cervix and vulvar width (P<0.05) compared with those of heifers. In the follicular phase, buffalo cows had a mean ovarian diameter (ipsilateral POF) of 2.35 cm, and heifers had a mean ovarian diameter of 2.24 cm (P>0.05). The average preovulatory follicle diameter was 1.29 cm in buffalo cows and 1.18 cm in heifers (P>0.05). In the luteal phase, the mean ovarian diameter (ipsilateral CL) of buffalo cows was significantly larger than heifers (P<0.05; 2.46 vs. 2.09 cm, respectively). The diameters of the CL in buffalo heifers and cows were 1.27 and 1.47 cm, respectively (P>0.05). Buffalo cows and heifers have no differences in ovarian components in the follicular and luteal phases, but there are differences in the size of the reproductive tract, which reproductive tract of buffalo cows is larger than heifers.