COMPARAISON DE DIVERSES METHODES DE CASTRATION ET DE STERILISATION DES AGNEAUX: I. INFLUENCE DE CES METHODES SUR LA CROISSANCE, L’EFFICIENCE ALIMENTAIRE, LE RENDEMENT A L’AHATTAGE ET LA RENTABILITE

Abstract

An experiment was conducted to compare various physical and chemical methods of castration of lambs at 15 and 60 days of age. Their effects on body growth, feed efficiency, dressing percentage and profitability were studied. At birth 100 lambs were divided among the 16 different treatments according to sex and the following breeding groups: Suffolk, North Country Cheviot, two-breed cross and three-breed cross. The different methods of castration were: complete removal of the testicles, Burdizzo, elastrator and partial castration. The sterilization methods consisted of intramuscular, intratesticular and intraveinous injection of cadmium chloride. All lambs were weaned at 30 days of age and placed in individual pens. They were subjected to similar environmental conditions and shipped to slaughter at approximately 45 kg body weight. Significant differences were observed among breeds, sexes and the various castration methods for daily gain, feed efficiency, days required to reach market and profitability. Age at castration did not have any important effect ort the variables measured. Superior gains, feed efficiency and profitability were observed for the partially castrated group, for the lambs that received an intramuscular injection of cadmium chloride and for the non-castrated males. All treatment groups involving males were superior to the females for the characters studied except for dressing percentage.