CO-Synch as a cheap fixed-time artificial insemination protocol to improve pregnancy rate in cow-calf production systems

Salomón Vázquez-López; Cyndi Gabriela Hernández-Coronado; Rene Carlos Calderón-Robles; Ana María Rosales-Torres; Ricardo Faustino-Carmona; Fredi Sánchez-Hernández; María Angelica Jáimez-Vázquez; Adrian Guzmán

Salomón Vázquez-López, Ms Universidad Autónoma Metropolitana Unidad Xochimilco. Maestría en Ciencias Agropecuarias. Calzada del Hueso 1100, CP 04960, México D.F., México
Cyndi Gabriela Hernández-Coronado, PhD Universidad Autónoma Metropolitana-Xochimilco, Departamento Producción Agrícola y Animal. Calzada del Hueso 1100, CP 04960, México D.F., México
Rene Carlos Calderón-Robles, Dr. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Campo experimental Las Margaritas. Hueytamalco Puebla 73580, México
Ana María Rosales-Torres, PhD Universidad Autónoma Metropolitana-Xochimilco, Departamento de Producción Agrícola y Animal. Calzada del Hueso 1100, CP 04960, Ciudad de México, México 3 Federación Canofila Mexicana, México
Ricardo Faustino-Carmona, MVZ Private practice
Fredi Sánchez-Hernández Private practice
María Angelica Jáimez-Vázquez, MVZ Private practice
Adrian Guzmán Universidad Autónoma Metropolitana-Xochimilco, Departamento de Producción Agrícola y Animal. Calzada del Hueso 1100, CP 04960, Ciudad de México, México 3 Federación Canofila Mexicana, México

Keywords: Beef cattle; FTAI protocols; economic evaluation.

Abstract

Fixed-time artificial insemination (FTAI) protocols are a tool to increase the reproductive efficiency in beef herds, however their use in Mexico and worldwide is limited. The aim of this experiment was to compare the pregnancy per artificial insemination (P/AI), overall pregnancy rate (PR), follicular dynamics, and cost among beef cattle treated with three different FTAI protocols. A total of 191 females were assigned to CO-Synch (n=63), CO-Synch+CIDR (n=60) and estradiol/progesterone (n=68) protocols balanced by BCS. Females treated with the estradiol/progesterone protocol had higher (P<0.05) estrus presentation than females in the CO-Synch and the CO-Synch+CIDR protocol. P/AI tend to be higher (P<0.10) in cattle treated with the estradiol/progesterone protocol than females in the CO-Synch protocol, however overall pregnancy rate (PR) was similar among protocols (P>0.05). Diameter of largest follicle, number of dominant follicles (≥ 6 mm) and percentage of females with a dominant follicle at PGF2- α injection were higher (P<0.05) in females of the CO-Synch protocol than females in the estradiol/progesterone protocol. Number of follicles from 2 to 5 mm was higher (P<0.05) in females treated with the estradiol/progesterone protocol than females in the CO-Synch protocol. Cost of treatment in relation to total calves born, was higher in estradiol/progesterone and in the CO-Synch+CIDR protocols than the CO-Synch protocol.