Composition and quality of red clover (Trifolium pratense L.) with seasons and growth stage

Abstract

Forage quality usually improves output per head and efficiency of converting forage to animal products. Thus, an experiment with red clover was designed to investigate in vitro dry matter digestibility (IVDMD) and total nonstructural carbohydrates (TNC) of herbage components along with forage yields as influenced by stages of growth during various seasons to obtain information that may be implemented into forage-management systems.

Red clover yields generally increased with successive advances in growth stage - early vegetative, vegetative, early bloom and full bloom; however, leafiness which is associated with forage quality peaked during vegetative to early bloom stages.

All plant components (leaves, petioles and stems) were higher in TNC during spring than in summer. After the early vegetative growth, the TNC increased and then declined at full bloom. Stems were generally higher in TNC than leaflets, petioles and flowers. Young stems were around 48% higher in TNC and 44% higher in IVDMD than old ones. Plant components were higher in digestibility during spring than in summer. Petioles were higher in TNC than leaflets.

Leaflets and petioles were higher in digestibility after as compared to before frost. For vegetative forage, the digestibility was higher during spring; values for summer and in fall before frost were similar but lower than after frost harvests.

Stages of growth influenced IVDMD more than TNC. During vegetative but not for full bloom stages, TNC was positively associated with digestibility.

Dead forage made up about 23% of the forage dry matter during full bloom stages and as much as 50% of the dry matter after frost. Dead material was associated with poor digestibility in spring and summer but not in fall.