Assessment of Seasonal Variations in Plasma Progesterone Concentrations and the Morphometry of Corpus luteum and Ovary during Estrous in Nili-Ravi Buffalo

The influence of season on the plasma progesterone concentrations and morphometric values of corpus luteum and ovary was studied through ultrasonography in spring (n=10) and dry hot (n=10) seasons on alternate days during the estrous cycle regardless of estrous phases in Nili-Ravi buffaloes. The mean morphometric values of length and width of ovary and the diameter and area of corpus luteum were higher in spring than those in dry hot seasons. The plasma progesterone concentrations were determined by ELISA (Enzyme Linked Immuno Sorbent Assay) technique and influence of seasons was found significant (P<0.05) between two seasons. The traditional method of rectal palpation for detection of corpus luteum and ovary results in heavy economic losses. Due to silent estrous of buffaloes, most of the animals are misdiagnosed by rectal palpation. Adoption of transrectal ultrasonography in buffalo breeding can overcome the problem of misdiagnosis of actual size and presence of corpus luteum, especially during dry hot season. It was concluded that the size of corpus luteum and ovary along with plasma progesterone levels changed between the two seasons and these parameters could be effectively employed to detect the true anestrous animals for improvement in milk production.