Valor de hormonas estrogénicas y progesterona en ceba de novillos

Abstract

Data are presented on two experiments carried out at Turrialba, Costa Rica, on the effect of hormone implants on the rate of pasture fattening in steers. The main grass species available was molasses grass (Melinis minutiflora). In both experiments a control non implanted group was compared with two implanted groups. One of these received natural hormones Progesterone and Estradiol. The other treated group received Diethylstilbestrol. The difference between treated and untreated groups was significant with a 21% increase in daily gains. There was no difference between the two types of hormones in the benefits obtained. Some data from the monthly weights indicates that when pasture conditions are such that less than 300 grams daily gain per head is obtained, hormone treatment might be detrimental. The local price of the natural hormones is such that they cannot be recommended as an economical treatment for pasture fed steers