Changes in the Productivity and the Percentage of Grasses Intake in Different Mixtures Grazed by Thoroughbred Horses

A study was conducted over two years to determine the temperate mixtures of grasses for grazing horses in Jeju, Korea. The experiment field located at 450 m altitude (Jeju Horse Training Center of Korea Racing Association) was divided into 3 different mixtures plots (3 replications) without a fence between treatments, and sown by three main grasses (orchardgrass, perennial ryegrass and timothy). Seven castrated adult horses were kept on pasture from the middle of April to the end of November without supplementary concentrates. The dry matter yield, percentage of grasses intake and botanical composition were determined during the grazing period. Nutrients in grasses and soils were analyzed. The dry matter yield during two-year experimental period was not different among mixtures (11,000-12,000 kg/ha/year). In botanical composition, perennial ryegrass was dominant in all mixtures during spring through early summer season, but faded away during hot summer season. Timothy seemed to be more resistant against a hot or dry weather than other grasses. The percentage of grasses intakes was higher in the mixture of timothy than those in other mixtures. The contents of NDF (neutral detergent fiber) and ADF (acid detergent fiber) were not different among different mixtures. These results indicate that the mixture of timothy, orchardgrass, perennial ryegrass and white clover (20, 5, 5, 2 kg/ha as a seeding rate) can be used for gazing pasture of horses in the high altitude of Jeju.

제주지역 말 방목 초지의 혼파조합별 생산성 및 채식율 변화

본 연구는 제주지역에서 말 방목에 적합한 혼파조합을 선발하기 위해 해발 450m에 위치한 한국마사회 경주마육성목장에서 티모시, 오차드그라슨 페레니얼 라이그라스 화본과 위주 초종으로 혼파 파종하여 2년 간 말(더러브렛)을 방목하면서 목초생산성, 식생변화 및 채식율 변화 등을 구명하기 위해 수행되었다. 연간 총 건물생산량은 1, 2차년도에 관계없이 혼파조합 간 유의적인 차이를 보이지 않았으나 시기별에 따라 생산량 차이를 보였다. 식생은 페레니얼 라이그라스가 봄철 크게 우점현상을 보였으나 여름철에는 하고 현상으로 식생구성이 낮게 나타났다. 방목 첫 해 티모시는 식생비율이 낮았으나, 그 후에는 연중 적절한 식생 구성을 보였다. 채식율은 티모시 주초종에서 높게 나타났다(P<0.05). 식물체 NDF, ADF, Ca 및 P 함량은 처리 간 차이를 보이지 않았다. 본 연구결과 제주지역(해발 400m 내외)애서 티모시 주초종(ha 당 티모시 20, 오차드그리스 5, 페레니얼 라이그라스 5, 화이트클로버 2kg)의 혼파조합은 시기별 생산성과 기호성을 고려할 때 말 방목초지로 활용할 수 있을 것으로 사료된다.