EQUINE CHORIONIC GONADOTROPIN, A LOW-COST ALTERNATIVE IN EMBRYO TRANSFER IN COWS UNDER TROPICAL GRAZING

Abstract

Objective: To determine the efficiency and cost of dos superovulatory treatments in cows under tropical grazing and subjected to embryo transfer.

Design/methodology/approximation: Fifty-one cows randomly distributed in: First group synchronized and superovulated cows with FSH (200 mg, GFSH, n=9), second group superovulated with eCG (2000 IU, GeCG, n=9), third group (GA. n=16) embryo recipients of the GFSH and finally fourth group (GB, n=17) embryo recipients of the GeCG. The superovulatory efficiency, cost of the embryo transfer program, gestational cost, was determined through the relationship between response to treatment, inputs used and price of inputs. The data obtained were compared by means of Mann-Whitney test U, or t student for independent groups. The gestation rate was analyzed by a Chi square test.

Results: The cost of embryo transfer is lower superovulatory with ECG than using FSH (P=0.000). The number of embryos did not differ between cows from GFSH and GeCG (P?0.18). The cost/donor is 10.8% lower in GeCG vs. GFSH (P=0.000), the cost/viable embryo was 35.6% lower in GeCG (P=0.046) vs. GFSH. The gestation rate is similar in both groups (GA, 31.3% vs. GB, 35.3%, P=0.73).

Limitations/implications: The study shows that it is possible to replace the use of FSH with the ECG, obtaining the same efficiency at lower cost in cows under tropical grazing conditions.

Findings/conclusions: A superovulation with eCG decreases the cost of the embryo transfer program.