Abstract

ARBUES, R.; F.QUINTANA, C.; YANEZ, E.  and  FERNANDEZ, J.. Ciclicidad en ovejas Santa Inês e Ideal en el subtrópico argentino. Rev. vet. [online]. 2018, vol.29, n.1, pp.3-8. ISSN 1669-6840.  http://dx.doi.org/10.30972/vet.2912778.

Whit the aim of characterize the annual cyclicity of Santa Inês ewes in subtropical environment, the trial was developed in the department of Monte Caseros, Corrientes, Argentina. Ten Santa Inês ewes and ten controls Ideal race blood samples were taken every ten days during autumn, winter and spring to determine serum progesterone levels and classify them in cyclic ewes and anestrous ewes. During the first twenty days of trial they received food supplementation. Live weight was recorded twice in each season. Data were analyzed using frequency tables and chi-square test with significance level with 0.5. The 70% of Santa Inês ewes presented estrous cycles in autumn and winter. This percentage fell to 60% in spring. Ideal ewes had a percentage of cyclicity 80, 10 and 20 in autumn, winter and spring respectively. It was associatedto the absence of cyclicity and live weight. During the period of food supplementation all Santa Inês females gained weight. All ewes that cyclized in the 3 seasons studied had no large variations in live weight. Although there was decrease in weight this was not enough to change the body condition. Among females who presented some period of anoestrus greater weight decreases they were recorded. Although weight loss could determine the anestro, time signaling for the resumption of estrous activity could be variable. Statistical analysis showed no significant differences in Santa Inês ewes but it did on Ideal ewes. In conclusion, tropical ewes in subtropicals environments maintain the annual cyclicity and the time of year does not influence the presentation of estrous cycles in the Santa Inês race

Keywords : ewes; progesterone; live weight; reproductive seasonality; anestrous.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )