Lutropin (r-hLH) administration and its response on ovulation rate and viable embryos in Pelibuey sheep

Objective. To evaluate the influence of lutropin alfa (recombinant human LH, r-hLH) administered at 12 and 24 h post progesterone device withdrawal (CIDR) on the response of hours to onset of estrus (OE), ovulatory rate (OR), unfertilized oocytes (UNO), transferable embryos (TE), quality 1 embryos (Q1E) and plasma LH levels, in a pFSH-based superovulation protocol in Pelibuey sheep. Materials and methods. Eighteen Pelibuey sheep were used and randomly distributed into three groups (n=6): T1 (200 mg FSHp-Folltropin (R)); T2 (200 mg FSHp + 75 IU r-hLH at 12 h post CIDR withdrawal) and T3 (200 mg pFSH + 75 IU r-hLH at 24 h post CIDR withdrawal). Results. No significant differences were found between OE and OR. UNO was higher (p<0.05) in T2 (5.0 +/- 2.3) compared to T1 (0.8 +/- 0.6) and T3 (1.3 +/- 0.7). The number of Q1E was higher (p<0.05) in T3 (3.1 +/- 1.1) compared to T1 (1.1 +/- 0.3) and T2 (0.6 +/- 0.5) and for TE was higher (p<0.05) for T3 (6.6 +/- 0.9) relative to T2 (2.0 +/- 1) and T1 (4.0 +/- 0.6). Conclusions. The application of r-hLH 24 h after removal of CIDR increases plasma LH levels, in effect, decreasing the amount of UNO, improving the quantity and quality of TE in Pelibuey sheep.