Efecto de la mastitis subclínica sobre la fertilidad en vacas de leche en los cantones: Cuenca, Girón, San Fernando de la provincia del Azuay y Déleg de la provincia del Cañar

Abstract

The effect of subclinical mastitis (MSC) on fertility in Holstein mestizo cows, in Azuay and Cañar was determined. Three trials were performed; the first one evaluated the effect of MSC on the percentage of pregnancy, 60 cows were sampled with MSC and 60 healthy, the diagnosis of MSC was made by somatic cell count, to determine the percentage of pregnancy the information of the first post-diagnosis insemination was used of MSC. The second experiment evaluated the size of the preovulatory follicle (TFPO) and the% of ovulation by ultrasound, 54-56h post-implant removal; % ovulation 48 h after day zero. Two treatments were evaluated: T1 (n = 40) cows with MSC and T2 (n = 40) healthy cows; To homogenize the day of ovulation, a conventional IATF was performed. The third trial determined the relationship between estrogen in blood and follicular fluid, two treatments were used: T1 (n = 10) cows with MSC and T2 (n = 10) healthy cows; The hormonal evaluation was performed by electrochemiluminescence. The statistical analysis was performed in SPSS version 25. It was established that cows with MSC had a lower percentage of pregnancy (48.3%), versus healthy ones (68.3%) (P <0.05). The FPO and% ovulation were similar between treatments (P> 0.05). Regarding estrogen levels in blood serum, cows with MSC had higher values (73.9 pg / ml) vs 37.4 pg / ml (healthy cows) (P <0.05), but not in follicular fluid (P> 0.05). It is concluded that MSC negatively impacts on pregnancy