Use of prostaglandin F2α in oestrus and ovulation synchronization programs in beff cattle

a critic discussion

Abstract

This study describes three methods of oestrus synchronization using PGF2a. Method I consisted of 2 PGF2a injectons 11 days apart, followed by artificial insemination (AI) AM/PM. Method II consisted of oestrus detection during 4 days and on the fifth day a luteolytic dose of PGF2a is given and followed by convencional AI for 6 days. Method III consisted of rectal palpation of a corpus luteum, a PGF2a injection and conventional AI for 6 days. The advantages and disadvantages of each one are analysed. A fourth method is described wich avoids some of the disavantages the above mentioned methods. This biological and economical evaluation of three of the fourth methods was performed. The biological evaluation suggests that a difference in percentage of oestrus and fertility between the methods. The economical evaluation is highly dependent on the assumptions used in the analysis.