Endocrine Profiles of Oestrous Cycle in Buffalo: A Meta-analysis

Abstract

A meta-analysis was conducted to summarize the results of studies which have described the profiles of hormones during the oestrous cycle in buffalo using a fixed effect model and a random effect model. Plasma progesterone concentrations were lowest (0.30±0.06 ng/ml) during the peri-oestrous phase and increased (p = 0.067) through the early luteal phase to a maximum concentration (1.94±0.03 ng/ml) during the mid-luteal phase. Circulating plasma inhibin and estradiol concentrations were lowest (0.31±0.01 and 11.04±0.13 ng/ml) during the mid-luteal phase, increased through the late luteal phase to maximum concentrations (0.44±0.02 and 22.48±0.32 ng/ml) during the peri-oestrous phase. Plasma FSH concentrations were lowest during the early luteal phase and increased through the mid-luteal phase to a maximum concentration during the peri-oestrous phase. Peripheral prolactin concentrations were lowest during the late luteal phase and increased to a maximum concentration during the peri-oestrous phase which then declined (p = 0.716) during the early luteal phase. Peripheral plasma cortisol concentrations decreased from 2.68±0.14 ng/ml during the early luteal phase to 1.43±0.27 ng/ml during the mid-luteal phase (p<0.001) which then increased to 2.06±0.17 ng/ml during the late luteal phase. Plasma T 3 concentrations decreased from the late luteal phase to the peri-oestrous phase (p<0.001) which then increased during the early luteal phase. T 4 concentrations increased from the late luteal phase to the peri-oestrous phase which then decreased during the early luteal phase.