Estrous synchronization in cattle, sheep and goat

Abstract

The basic approaches for controlling estrous cycle length are: administration of prostaglandin for the corpus luteum (CL) regression before natural luteolysis in animals; administration of progesterone or, more commonly, synthetic progestins to temporarily suppress ovarian activity in animals; and another way of creating estrous synchrony is by using gonadotropinreleasing hormone (GnRH) or an analogue, either alone or in combination with other hormones, which causes the ovulation of a large follicle.An estrous synchronization protocol has several advantages, such as a short calving interval allows females (especially heifers) to conceive earlier; artificial insemination and embryo transfer technique to reduce time and labor detecting estrous; and uniform calf crop production, i.e., of a similar age group. Methods Prostaglandin treatmentIt is possible to synchronise estrous by administering a luteolytic drug that induces the corpus luteum to regress, such as prostaglandin F2alpha or its analogue. When a functional corpus luteum is present in one of the ovaries, PGF2alpha administration is only effective from days 8 to 17 of the estrous cycle.

In Vitro, In Compost, and In Vivo Assessment of Chitosan-Polyethylene Glycol as an Intravaginal Insert for Progesterone Delivery in Sheep

“…Oral progesterone supplementation with melengestrol acetate (MGA) was added to the feed (Arya et al, 2023). Feeding duration may vary between protocols, but feeding rates are consistent and critical to success.…”

“…Estrus synchronization is a technique for causing female herds to go into estrus at a predetermined time. In sheep, estrus synchronization can be done by manipulating hormones (Biehl et al, 2019;Arya et al, 2023). The administration of progesterone hormone is one of the most relevant steps in synchronization protocols.…”