Abstract

Buffalo cows play a vital role in milk and meat production; however, they are characterised by several reproductive disorders. Feeding diets with high oestrogenic activity may be a disrupting factor. This study aimed to evaluate the effects of feeding roughages with different oestrogenic activity on the reproductive performance of early postpartum buffalo cows. A total of 30 buffalo cows were equally stratified into two experimental groups and fed either Trifolium alexandrinum (Berseem clover, phytoestrogenic roughage) or corn silage (nonoestrogenic roughage) for 90 consecutive days. After 35 days from the beginning of the feeding treatments, buffalo cows in both groups were synchronized for oestrus using a double i.m. injection of 2 mL prostaglandin F_2α, 11 days apart, subsequently, overt signs of oestrus were observed and recorded. Moreover, ovarian structures, numbers and sizes of follicles and corpora lutea, were ultrasonography examined at day—12 (represents Day 35 of feeding treatment), Day 0 (day of oestrus) and Day 11 after oestrous synchronization (mid-luteal phase). Pregnancy was diagnosed 35 days postinsemination. Blood serum samples were analysed for progesterone (P₄), estradiol (E₂), tumor necrosis factor (TNF-α), interlukein-1β (IL-1β) and nitric oxide (NO). The high performance liquid chromatography-analysis of roughages showed the abundance of isoflavones in Berseem clover, with about 58 times higher concentration than that in corn silage group. During the experimental period, the numbers of ovarian follicles of all size categories were higher in the Berseem clover group than that in the corn silage group. No significant difference in the numbers of corpora lutea was observed between both experimental groups, but lower (p < 0.05) diameter of corpus luteum was observed in the Berseem clover group than that in the corn silage group. The Berseem clover group had higher (p < 0.05) overall concentrations of blood serum E₂, IL-1β and TNF-α, but lower (p < 0.05) overall concentrations of blood serum P₄ than those recorded in the corn silage group. Oestrous rate, onset of oestrus time and oestrous duration were not significantly affected by the treatment. The conception rate was significantly (p < 0.05) reduced in the Berseem clover group compared with that in the corn silage group. In conclusion, feeding roughage with a high oestrogenic activity such as Berseem clover can negatively affect the conception rate of buffalo cows. This reproductive loss seems to be associated with inadequate luteal function and P₄ concentration during early pregnancy.