Effects of Stocking Rates on Animal Performance and Herbage Responses of Mulato (Bracharia sp.) and Pensacola Bahiagrass (Paspalum notatum) Pastures.

  Brachiariagrasses are the most widely grown warm-season forage in tropical America. Mulato is the first hybrid in the Brachiaria genus and results from crossing ruzigrass (Brachiaria ruziziensis clone 44-6) and palisadegrass (Brachiaria brizantha CIAT 6297). The objective of this study was to test the effect of different stocking rates on animal performance and herbage production of Mulato and bahiagrass pastures. The experiment was conducted at the Range Cattle Research and Education Center – Ona, FL from May to September 2007. Treatments were the factorial arrangement of three stocking rates [4, 8, and 12 heifers (LW = 350 ± 21 kg) ha^-1] and two forage species (Mulato and bahiagrass), in a randomized incomplete block design. Pastures were 0.25 ha stocked on fixed and continuous stocking rates. Heifers were weighed every 28-d interval. Herbage mass was measured every 14 d using a disk plate meter and double sampling. Hand plucked samples were collected every 14 d and analyzed for IVOMD and CP. Treatments were considered different when P≤ 0.10. There was a linear increase in herbage mass (from 2.5 to 5.7 Mg ha^-1) and decrease in herbage allowance (3.2 to 0.6 kg DM kg^-1BW) with increasing stocking rates. Mulato had greater herbage mass (4.0 vs. 3.1 kg ha^-1), herbage mass accumulation (129 vs. 71 kg DM ha^-1 d^-1), CP (149 vs. 133 g kg^-1), and IVDOM (680 vs. 520 g kg^-1) than bahiagrass. Heifers grazing Mulato had greater ADG (0.49 vs. 0.35 kg d^-1) than heifers grazing bahiagrass pastures. There was a linear decrease in ADG (from 0.49 to 0.22 kg d^-1) as stocking rates increased. Gain per hectare was greater for pastures stocked at 8 (479 kg) than 4 (230 kg) and 12 heifers ha^-1 (320 kg). Mulato has potential to be a feasible forage option for livestock producers in south Florida.