Possible factors affecting pregnancy rate of cows in the Amazon Ecuatorian

Abstract

The objective of this work was to assess how the cow pregnancy depends on the type of service as, race and follicular development in cattle with dual purpose in the Ecuadorian Amazon. The 341 records of the individual services were evaluated from January 2015 to December 2015 that corresponds to cows of different genotypes and cross: Brown Swiss (BS) n = 135, Charolais (Ch) n = 24, Holstein Friesian (HF) n = 104, Jersey (J) n = 12, Normando (N) n = 21, x Brown Swiss Holstein Friesian (HFxBS) n = 35 and Holstein Friesian x Normando (HFxN) n = 10. The work was conducted in the Cantons and Santa Clara which is located in the Pastaza Province (Ecuador). The Two insemination techniques were performed: a estrus detected (natural) 136 cows and a Insemination Time (TAI). The independent variables are "Race" (BS, CH, HF, J, HFxBS and HFxN), the "Technical Service" (N and IATF) and "Follicular Development" (DF). An additive model was adjusted and it was not significant for the interactions between independent variables and the result of the model. It was found that the variable DF is the only that contributes significantly to the model. That is, pregnancy is significantly affected by follicular development (p-value <0.0001), but is not related to the technical service and race. Maximum Credible estimates the coefficients model and calculated odds ratios. For every unit increase in the value of follicular development, the chance of "pregnant" is 14 times higher than "empty". Keeping fixed the categories for race and service. To conclude that there was no difference between races and insemination technique that was used, even if a relationship between follicular development in proestrus and pregnancy in the Ecuadorian Amazon.

Keywords

• Cows
• genotypes
• insemination techniques
• grazing systems