SYNCHRONIZATION OF ESTRUS IN COWS WITH TWO NORGESTOMET LEVELS IN TWO CLASSES OF BODY CONDITION

Abstract

Objective: To determine the effect of two doses of norgestomet in the presentation of estrus in cows with two levels of BC.
Design/methodology/approximation: Twenty-four Holstein cows were evaluated by BC to create two groups, cows with normal BC (normalBC) and cows in low BC (lowBC). The treatments to be evaluated resulted from the combination of the two levels of BC with the two doses of norgestomet: 1) cows in normal BC received 1 norgestomet implant; 2) cows in normal BC received 1.5 norgestomet implants; 3) cows in low BC with 1 norgestomet implant; 4) cows in low BC with 1.5 norgestomet implants.
Results: Estrous presentation was 50% for the normalBC 1N and normalBC 1.5N groups and 66.6% for the lowBC 1N and lowBC 1.5N groups, without differences between treatments.
Limitations/implications: The use of progestogens allows to imitate the function of the corpus luteum, which is the basis for estrus synchronization.
Findings/conclusions: Under the conditions of this study it is concluded that the application of 1 or 1.5 implants of norgestomet to cows with different class of CC have the same probability of response to estrus synchronization