Effect of blocking vision and olfaction on sexual responses of haltered or loose stallions

Summary Ten stallions were used in a modified split-plot design involving four treatments and two handling methods. Treatments were: a) vision and olfaction not blocked; b) vision blocked, olfaction not blocked; c) vision not blocked, olfaction blocked; and d) vision and olfaction blocked. The methods of handling were: a) stallions turned loose in teasing area, and b) stallions handled on a lead shank. Stallions teased four estrous mares, four diestrous mares and four geldings. Criteria for evaluation of stallion behavior was duration of investigation (sec), of area as well as various portions of the stimulus animal's anatomy, and other pre-copulatory sexual behaviors (Table 1) in duration and frequency. Except for area investigation and no investigation, there were more frequent or longer responses when vision was not blocked compared to blocked (P 0.05) in the time spent inyestigating estrous mares, diestrous mares or geldings, except for number of flehmen responses. Number of flehmen responses to estrous mares was higher (P