Nutritive value of forage of pastures managed during cool-season

This research aimed at evaluating the nutritive value by determining the organic matter (OM), in vitro OM digestibility (IVOMD), total digestibility nutrient (TDN), in vitro dry matter digestibility (IVDMD), crude protein (CP) and neutral detergent fiber (NDF) of four pasture-based system grazed by Holstein cows. The treatments were sod seeding of ryegrass (Lolium multiflorium Lam. cv. 'Common') over coastcross (Cynodon dactylon L. Pers.,); sod seeding of ryegrass plus white clover (Trifolium repens L., cv. 'Yi') over coastcross ryegrass plus white clover or ryegrass. From May 15(th) to October 24(th), 2006, in five grazing periods, the pregraze herbage mass (PM), botanical and structural compositions and stocking rate (SR) were evaluated. Hand-plucked samples were collected to analyze the nutritive value. The experimental design was completely randomized, with four treatments (pastures) and two replications (paddocks). Differences in PM and SR averages were not detected among treatments. Better results of nutritive value were associated of ryegrass leaf lamina biomass in all pastures. Small differences on nutritive value were observed on sod seeding 'coastcross' systems compared to ryegrass plus white clover or ryegrass pastures. The mean values of OM, IVOMD, TDN, IVDMD, CP and NDF of the pastures were 89.52; 69.50; 60.95; 70.96; 23.03 and 51.87%, respectively.