ABSTRACT.
SEXUAL CYCLE AND LENGTH OF THE REPRODUCTIVE SEASON ON TWO TEETH EWES, MAGALLANES

Etel Latorre V.1 y Sergio Cvitanic M.2
 

An essay on reproductive behavior on Corriedale hoggets was carried out at the experimental station "Kampenaike", on the shrubb-steppe transition site of the region of Magallanes, Chile.
Length of the reproductive season, frecuency of oestrus through it, and length of sexual cycles during the breeding season were determined. Daily controls through deferectomized marking rams were taken from December 14 th, 1974, to September, 15 th, 1975.
Observations pointed out that 24% of hoggets started their reproductive season on March, 66% on April, and 9% on May, and 17% of animals finished it on June, 55% on July, and 27% on August. Main oestrus concentrations were noticed on April (86%), May (99%), June (96%) and July (81%). A 6.4 heat average was established, with a 3 - 10 rank, and a seven heats mode.
As for sexual cycles, 88.7% proved to last from 14 to 19 days; 9.5% were 27-51 days; 0.9% 20-26 days; and 0.9% were 11-13 days. Normal cycles (14-19 days) had an average length of 17.13 days (S=0.91 and C.V.=5.33), with a 17 days mode.
A 5.44 average on sexual cycles was established for the whole reproductive season.

Keywords:
1Méd. Vet., Estación Experimental Kampenaike, Instituto de Investigaciones Agropecuarias (INIA), Casilla 616, Punta Arenas, Chile.
2Ing. Agr., Servicio Agrícola y Ganadero (SAG), Casilla 323, Punta Arenas, Chile.