300 CASE REPORT: MORE THAN ONE CALF PER WEEK PRODUCED BY NELORE DONOR
G. L. Santos A , L. T. S. Yamazaki A , E. C. D. Benzi A , D. P. Corneglian A , M. Romano A , F. J. Guidorizzi A , A. C. Netto A , L. P. Landim Junior A and W. Yamazaki ABioembryo - Animal Reproduction Biotechnology, Bauru, Sao Paulo, Brazil
Reproduction, Fertility and Development 22(1) 306-306 https://doi.org/10.1071/RDv22n1Ab300
Published: 8 December 2009
Abstract
According to the animal reproduction biotechnologies, in vitro fertilization is considered one of the most important tools to improve genetic gain as well as reduce bovine herd generations. Brazil is recognized as having the greatest commercial bovine herd in the world as well as by its use of IVP; however, this biotechnology needs more studies to improve not only the oocyte-embryo conversion rate but also the competent oocyte recovery from donor cows. Recently, one Nelore donor cow in 3 sessions was able to convert 233 (53.81%) embryos from 433 oocytes recovered, which resulted in 156 pregnancies (55.95%), which means one pregnancy per 2.7 oocytes or 3.05 pregnancies per week (when 51 weeks are admitted in one year). The COC obtained from this donor were matured (TCM-199, supplemented with FCS, LH, FSH, E2, pyruvate, and antibiotic) for 24 h and fertilized (Fert-TALP supplemented with BSA, PHE, and heparin) for 18 to 22 h (Day 0) in vitro. On Day 1, presumptive zygotes were transferred to development media (SOFaa supplemented with BSA and FCS) and on Day 7 the blastocyst production rate was evaluated. Following embryo transfer, the pregnancy diagnosis was performed at 30 days and confirmed at 60 days after ET. The possibility of identification of factors related to high performance and its selection could improve the formation of a homogeneous bovine herd, highly correlated with embryo production, which numerically could promote more than fifty calves per year (more than one calf per week). This case report refers to an animal highly superior to the average and therefore needs more investigation, mainly with molecular markers able to identify and select this class of high genetic animal.
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