Abstract
The in vitro true dry matter digestibility (IVTDMD) of rhizoma perennial peanut (RPP) forage was evaluated in trials at Lajas (PI no. 276233, 262826, 262833, 262839, and cvs Florigraze and Arbrook) and Juana Díaz (PI no. 276233, 262839, and cv Florigraze), Puerto Rico. At both sites, the forage was cut at six-, nine-, and 12-wk harvest intervals (HI) in each of the four seasons of the year. The digestibility of the forage was not influenced by genotype. Mean IVTDMD across HI and season of growth was 64.3 and 62.5% in the Lajas and Juana Díaz trials, respectively. The IVTDMD decreased in a quadratic manner (P < 0.01) as HI increased from six to 12 weeks. The digestibility of forage harvested at six and nine weeks was similar, with a relative decline of 6.6 and 10.6% as HI increased from nine to 12 weeks in Lajas and Juana Díaz, respectively. Season of growth influenced IVTDMD (P < 0.01). In both trials, the highest digestibility was obtained in forage grown in summer. The effect of season of growth on IVTDMD was greatest in forage harvested at 12 weeks, and least in forage harvested at six weeks. The high digestibility reported among genotypes evaluated suggests they are a viable alternative for the production of high quality hay in the Caribbean tropics.