Effects of Equine Chorionic Gonadotropin on Follicular, Luteal and Conceptus Development of Non-Lactating Bos Indicus Beef Cows Subjected to a Progesterone Plus Estradiol-Based Timed Artificial Insemination Protocol

Figures & data

Figure 1. Schematic diagram of the experimental design. Control and equine chorionic gonadotropin groups were equal, except for the administration of 300 U of equine chorionic gonadotropin on day 8 in the treatment group.

Figure 2. Bos indicus conceptuses recovered on day 16 after timed artificial insemination from equine chorionic gonadotropin (A) and control (B) groups.

Table 1. Follicular dynamics, CL development, P4 plasma levels and conceptus length in Bos indicus cows submitted to a timed artificial insemination protocol in equine chorionic gonadotropin and control groups.

	Control	eCG	P
Number of animals	64	60	-
Largest follicle diameter at day 8, mm	9.4±0.43	9.6±0.39	0.70
Largest follicle diameter at day 10, mm	11.0±0.41	12.2±0.44	0.06
Follicular growth rate (day 8 to 10), mm	2.6±0.24	3.5±0.32	0.03
Occurrence of oestrus, %	68.7 (44/64)	66.7 (40/60)	0.99
Ovulation rate %	78.13 (50/64)	86.7 (52/60)	0.23
CL diameter at day 15, mm	14.7±0.49	16.3±0.53	0.03
CL diameter at day 26, mm	17.9±0.42	19.6±0.32	0.003
Weight of the CL at day 26, g	2.4±0.11	2.8±0.12	0.04
Concentration of P4 plasma at day 15, ng/mL	1.5±0.34	1.4±0.20	0.82
Concentration of P4 plasma at day 26, ng/mL	5.5±0.83	5.5±0.76	0.94
Conceptus recovered, %	29.7 (19/64)	30.0 (18/60)	0.97
Conceptus length, mm	98.1±17.24	118.5±21.78	0.23

eCG, equine chorionic gonadotropin; CL, corpus luteum.