SciELO - Scientific Electronic Library Online

 
vol.50 número4Supplementing diets for broilers that are low in crude protein and amino acids with proteaseEffect of including canola meal in diets of slaughter ostriches (Struthio camelus var. domesticus) índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Articulo

Indicadores

Links relacionados

  • En proceso de indezaciónCitado por Google
  • En proceso de indezaciónSimilares en Google

Compartir


South African Journal of Animal Science

versión On-line ISSN 2221-4062
versión impresa ISSN 0375-1589

Resumen

RODRIGUEZ-SANCHEZ, Y.I. et al. Reusing intravaginal progesterone releasing devices for oestrous synchoronization in ewes. S. Afr. j. anim. sci. [online]. 2020, vol.50, n.4, pp.529-536. ISSN 2221-4062.  http://dx.doi.org/10.4314/sajas.v50i4.5.

In this study, the second use of an intravaginal progesterone-releasing device or controlled intravaginal drug release device (CIDR) was evaluated. After a first use of 11 days, the CIDR was again used for either nine or 12 days with 200 or 300 IU equine chorionic gonadotropin (eCG) being injected on its removal. Sixty-four ewes were randomly distributed to four treatments (n=16/group): CIDR9+eCG200, CIDR9+eCG300, CIDR12+eCG200, and CIDR12+eCG300. The eCG was administered intramuscularly on withdrawal of the device. Thus, the experiment was a completely randomized design with a 2x2 factorial arrangement of treatments. Oestrus presentation did not differ between treatments (P =0.29). However, with the dose of 200 IU of eCG, oestrus presentation tended to increase (P =0.08). The onset and duration of oestrus, percentage of gestation, and return to oestrus did not differ between treatments (P >0.05). Progesterone concentration in serum was greater (P < 0.05) in ewes treated with CIDR12+eCG300. Prolificacy was greatest (1.44) with the CIDR12+eCG300 treatment and was different (P = 0.001) from the treatments CIDR9+eCG200 (1.21) and CIDR9+eCG300 (1.20), but not from the CIDR12+eCG200 treated ewes (1.31). The CIDR12+eCG300 treatement produced the highest percentage of twin births (45.8%) (P =0.001). Leaving the device in place for 12 days increased (P =0.001) the incidence of twin births. Use of the CIDR for a second time synchronized oestrus in ewes successfully with better fertility being obtained when the device was left in place for 12 days, and 300 IU of eCG was injected on its removal.

Palabras clave : gonadotropin; progesterone device; synchronization.

        · texto en Inglés     · Inglés ( pdf )

 

Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons