Administration of testosterone in alpacas with penile-preputial adhesions

© 2002 Universidad Nacional Mayor de San Marcos. All rights reserved. In order to study the effect of testosterone on penis-prepucial adherences, twenty alpacas were selected from a flock ofmale tuis. Fourteen and six ofthe selected animáis were one and two years oídrespectively, from which 90% showed almostcomplete penis-prepucial adherence (0 and 1 grade) and the remaining showed a grade 2 adherence. Animáis were randomly assigned to two treatment groups (Tfl and T2) according to age and adherence grade inorderto achieveexperimental equilibrium. Each T2 animal received 327 mg oftestosterone i.m. distributed in three doses, on a two-week interval. Both body weight and adherence releasing grade were evaluated fortnightly; testicular size and sexual behaviour were recorded weekly. A larger releasing adherence was observed in one-year-old alpacas in T2, specially between weeks sixth and ninth, after treatment (P<0.08). There was a treatment-age interaction (P<0.05) in body weight, in which one-year-old alpacas from T2 had higher body weight gain than those from To (P<0.05), and than those oftwo-year-old alpacas from TQ and T2 (P<0.01). Treatment-age interaction was also significative on testicular size (P<0.05) becauseofa larger increase in length and width in one-year-old males from To than in the other animáis (P<0.01), while the smallest increase (P<0.01) was showed by one-year-old males from To and Tr Sexual behaviour was absent in almost all males exposed to females in heat.