摘要：Ongole cattle in smallholder farms on Java, Indonesia, have been crossed with Limousin, which is not controlled repeatedly. The character of estrus affects the success of Artificial Insemination. This study aimed to determine the relationship between estrus characters before double dose artificial insemination using frozen semen sexing. The research was conducted in Senggreng Village, Sumber Pucung District, Malang Regency. The material was 45 head of Limousin crossbred cow inseminated using sexing semen produced by the Singosari National Artificial Insemination Center (SNAIC). The sexed semen processed with the Percoll Density Gradient Centrifugation (PDGC) method. The average body value of cows between 3-5 (scale 1-9) with an average age of 1.8-7 years, normal reproduction, clear signs of estrus. The reproductive organs were examined by rectal palpation to confirm that the cows are not pregnant. Parameters of estrus character were vulvar color, cervical mucus, vaginal temperature, pH, vulvar swelling, and heat detector value. The result showed that the estrus characters, including vulva color, vulva swelling, cervical mucus, vaginal temperature, cervical mucus pH, and heat detector score in the first and second artificial insemination have a low relationship. The regression models produced can be used but are less precise to estimate the relationship between estrus characters because the coefficient of determination shows a low influence.
