Ovarian length and persistence in cattle dominant follicle nellore chelate supplemented with chrome

The objective determine the length and diameter of ovarian follicular Nellore heifers supplemented with chelate of chromium in the rearing. We used 80 (eighty) Nellore heifers at 12 months of age with an average live weight of 220 kg, under to rotational grazing with Brachiaria brizantha Marandu, where they received mineral supplements with or without the chromium chelate. The animals were divided into two experimental groups: chromium treatment - 40 Nellore heifers subjected to supplementation with chromium chelate and control treatment - 40 Nellore heifers without chromium chelate. Ultrasound examination was performed in two experimental moments at the beginning (D0) and end (D200) of the experiment, to evaluate the chromium effect on ovarian activity; twenty animals were selected from each treatment according to the inclusion of chrome in the diet. Data were subjected to analysis of variance (ANOVA) at 5% significance level. The results showed that there was no difference in body weight, and 330.4 kg for the control group and 325.5 kg for the group chrome. There was no difference between the length of the ovaries, the evaluation of the control group was 17.9 mm and 20.0 mm for group chrome in the rights ovaries, and in left ovaries 19.4 mm in the control group, and 20.7 mm in group chrome. There was a difference in the diameter of the largest follicle, with 8.9 mm for the control group, and 11.0 mm for group chrome. There were also differences between groups in the percentage of animals with corpus luteum, being 100% in control group, and 68% in the chrome. The mineral supplementation associated with chromium in the growing phase was a decrease in the percentage of females with corpus luteum, and was able to increase the presence of persistent dominant follicles in Nellore heifers.