A Mathematical Model of Estradiol Production from Ultrasound Data for Bovine Ovarian Follicles

Abstract

In this paper, we present a new way to assess the concentration of estradiol (E2) and Insulin Growth Factor-1 (IGF) based on the results from ultrasound scans combined with mathematical models. The IGF1 model is based on the progesterone (P4) concentration, which can be estimated with models calculating P4 level based on the size/volume of corpus luteum (CL) measured during ultrasound scans. At this moment little is known about the underlying reasons for double ovulation and silent heat occurrences. Both of these are linked to the level of IGF1: double ovulations are linked to higher IGF1 levels and and silent heat is linked to lower E2 to P4 ratio. These models can help to improve understanding of the related concentrations of E2 and IGF1. Currently, it is known that diet and genetic factors have an impact on ovulation rates and silent heat. In this study, we also examine the decline of the production of E2 in vivo by atretic follicles throughout the process of atresia. This is the first recorded quantitative description of this decline.

Immunization against inhibin DNA vaccine as an alternative therapeutic for improving follicle development and reproductive performance in beef cattle

“…It has been reported that INH is able to inhibit FSH-induced E 2 production in granulosa cells ( 25 ). E 2 produced by ovarian follicles plays an important role in governing the estrous cycle and has a direct effect on the reproductive capability of cattle ( 26 ). Elevated level of E 2 and low concentration of P 4 can promote the estrus expression, follicle maturation and ovulation ( 27 , 28 ).…”

“…It has been reported that INH is able to inhibit FSH-induced E 2 production in granulosa cells (25). E 2 produced by ovarian follicles plays an important role in governing the estrous cycle and has a direct effect on the reproductive capability of cattle (26).…”