Effect of galectin-1 administration on pregnancy rate and its economic viability in TAI procedures in beef cattle

The purpose of this work is to demonstrate the reproductive effectiveness and the economic impact of a complementary tool to the TAI (timed artificial insemination) protocols - the administration of a single dose of recombinant human galectin-1 (rHGAL1) during the insemination procedure. GAL-1 can be considered as a modulator of the pregnancy development process. Reproductive efficacy was verified through the pregnancy rate in the first service, by ultrasonography (at 28-35 days) in contemporary groups (YG) of cows multiparous and with calf at the foot (from 60 to 100 days old) subdivided into 02 experimental groups. Ninety YG were formed, grouping cows under identical conditions (inseminator, farm/lot, breed, animal category, semen/bull variables). The experiment was conducted on 15 farms, with 3,125 cows (Nellore and crossbred), all of which maintained a body score (BSC) between 3.5 and 2.5 in the act of the TAI protocol and the pregnancy diagnosis. It was demonstrated, by the proposed statistical method (Generalized Linear Model assuming a binomial distribution “pregnant” or “not pregnant”) for residual effect under logarithmic function, PROBIT, which model included the “fixed effect” of YGs and treatments, that the “rhGAL-1 dose” effect was significant, increasing the probability of obtaining pregnancy by 8.38 percentage points (p < 0.0001). Based on the construction of a hypothetical model, economic profitability that can be obtained was compared. Using the average increase obtained by 8.38 percentage points more in the pregnancy rate, it was possible to increase productivity, adding, almost U$2 thousand to profitability for every 100 cows worked.