Effect of Intrauterine Infusion of Chitosan Acetic Acid Solution on Conception Rate after Synchronization of Estrus or Ovulation in Dairy Cows with Anestrus

Abstract

We performed two experiments to determine the effect of intrauterine administration of chitosan acetic acid solution (chitosan solution) on the conception rate after synchronization of estrus-ovulation. In the first experiment, the cows were given intrauterine administration of chitosan solution at a dose of 200 mg/50 ml. Seven days after the chitosan solution administration, the cows were given variant CIDR-synch (chitosan CIDR group: n=106). The conception rate of cows with CIDR-synch only (control group: n=101) was 44.5%, whereas the rate for chitosan-treated cows was 59.4% (P<0.05). In the second experiment, the subjects were postpartum Holstein cows, which showed no clear estrus until after parturition. The cows were given intrauterine administration of a chitosan solution. Rectal examinations were performed 7-14 days after administration, and cows with corpus luteum were given intramuscular injections of PGF2α (PG) to induce estrus, and were artificially inseminated (chitosan group: n=27). The conception rate of cows with PG only (n=29) was 37.9%, whereas the rate for chitosan-treated cows was 74.1%. The rate for chitosan-treated cows was thus significantly higher than that for cows with PG only (P<0.01). These findings suggest that with intrauterine administration of the chitosan solution before synchronization of estrus-ovulation, conception rates improved.