Recria de bezerras de corte em alternativas de uso da pastagem de azevém(Lolium multiflorum Lam.)

Abstract

The performance of beef heifers from eight until twelve months, grazing exclusively Italian ryegrass (Loluim multiflorum Lam.) pasture, ryegrass plus red clover (Trifolium pratense LE 116) and ryegrass plus 1% LW supplement, was evaluated. The grazing period was within July, 27th until October, 14th and a continuous variable stocking was used. A commercial ration (14% CP; 21.6% NDF and 59.6% TDN) daily supplied at 2 pm, was utilized as supplement. The studied variables were average daily gain (ADG), body condition (BC), stocking rate (SR), per area weight gain (AWG), daily accumulation rate of DM (DMAR), forage on offer (FO), green leaf on offer (GLO), green forage mass (GFM) and leaf: stem relationship (LSR). In the botanical composition of the pasture was evaluated: clover leaf, clover stem, ryegrass leaf, ryegrass stem and dead material components percentile in forage mass. The nutritive value apparently ingested by the animals was evaluated through crude protein (CP), in vitro organic matter digestibility (IVOMD), total digestible nutrients (TDN), neutral detergent fiber (NDF) and metabolizable energy (ME). The supplementation didn t affect studied variables (P>0.05). However, there was interference of pasture cycle (P<0.05). Animals were submitted to average values of forage mass of 1327.2 kg/ha of DM, forage offer of 10.5 kg de DM/100 of BW and leaf offer of 3.7 kg DM/100 kg of BW. Daily body weight gain of heifers varied with different alternative of pasture utilization. Stocking rate (SR) and body gain per area (ABG) were greater (P<0.05) for supplemented animals, compared with animals exclusively on pasture. The use of supplementation provides an additive and replacement effect in the intake of dry matter of the grazing heifers.