The effect of rectal palpation on the fertility of cyclic mares

The effect of rectal palpation of fertility of non-lactating, normal cyclic mares was studied over 3 years. During the first year (1971), the conception rates in mares after daily paplaption during oestrus only, and during oestrus and the first 50 days of pregnancy, were not significantly lower (P greater than 0-05) than the conception rates recorded in mares not palpated. No abortions could be attributed to palpation. Oestrus lasted longer (P less than 0-05) in non-palpated than palpated mares. During the second year (1972), first-cycle pregnancy rates in two groups of mares palpated daily during oestrus were lower (P less than 0-05) than those of mares not palpated. Daily palpation and insemination on the palpator's recommendation resulted in fewer (P less than 0-05) inseminations per cycle than in mares inseminated every other day of oestrus. During the third year (1973), the difference of first-cycle conception rates between mares palpated on alternate days of oestrus and those not palpated was not significant. Throughout the three years of the study, first-cycle conception rates following insemination with undiluted semen were higher (P less than 0-025) in non-palpated mares than in palpated mares (45-7 versus 79-2%).