Effect of intra-follicular luteinizing hormone and human chorionic gonadotropin administration in dairy heifers

The aim of this study was to evaluate the effect of intra-follicular treatment (IFT) with luteinizing hormone (LH) and human chorionic gonadotropin (hCG) in dairy heifers. Intra-follicular treatment with LH (2 µg, 0.2 ml, LH group), hCG (10 IU, 0.2 ml, hCG group) or saline (0.2 ml, S group) was done into the dominant follicle on the seventh day of a synchronized oestrous cycle. A response of the follicles subjected to IFT on D7 as well as plasma progesterone concentration on the day of IFT (D0) and seven days later (D7) were evaluated. Ovulation and development of a new corpus luteum occurred in 89.3%, 92.9%, and 3.7% of treated heifers in the LH, hCG, and S group, respectively. Plasma progesterone concentration was greater on D7 in comparison to D0 in the LH and hCG group (6.31 vs. 11.31 and 6.68 vs. 9.56, respectively). Intra-follicular treatment with LH and hCG had similar effects. The results can be used in research or in practice to treat persistent cases of ovarian dysfunction in cattle.