Supplementing previously treated anestrous dairy cows with progesterone does not increase first-service conception rate.
Theriogenology
; 63(1): 239-45, 2005 Jan 01.
Article
en En
| MEDLINE
| ID: mdl-15589287
ABSTRACT
The objective of this study was to investigate the effect of supplementing previously treated anovulatory anestrous (AA) dairy cows with progesterone delivered intra-vaginally for 7 days, commencing 4 or 5 days after insemination, on first-service conception rate. A clinical trial, involving 990 AA dairy cows in 14 dairy herds, was conducted during the 2002/2003 breeding season. On Day -8, all cows were treated with a progesterone-containing intravaginal device (Cue-Mate). The devices were removed on Day -2; on Day -1, all cows were given 1mg of estradiol benzoate im. Cows in the control group (n = 499) received no further treatments. Cows in the treatment group (n = 491) that had been inseminated on Day 0 or 1 had a new device inserted (on Day 4 or 5), with removal of the device after 7 days. First-service conception rates for the control and treatment groups were not different (35.0% versus 36.7% respectively; P = 0.41). Furthermore, there was no difference in conception rates between cows that had devices inserted on Day 4 or 5 (31.3% versus 37.2% respectively; P = 0.45). In conclusion, supplementation of previously treated AA dairy cows with an intravaginal progesterone-releasing device for 7 days (commencing 4 or 5 days after insemination) did not significantly improve first-service conception rate.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Progesterona
/
Anestro
/
Bovinos
/
Estradiol
/
Fertilización
Límite:
Animals
Idioma:
En
Revista:
Theriogenology
Año:
2005
Tipo del documento:
Article
País de afiliación:
Nueva Zelanda