Morfofisiologia Do Dossel E Desempenho Bioeconômico De Ovinos Em Panicum Maximum Cv. Tanzânia Sob Lotação Rotativa Com Quatro Níveis De Suplementação Concentrada

Abstract

To evaluate the canopy morphophysiology and bioeconomic performance of sheep s on Tanzania pasture with four concentrate supplementation levels (0.0; 0.6; 1.2 e 1.8% of live weight), from September to December 2004, this research was undertaken. The research was conducted at the Vale of Curu Experimental Farm, belonging to the Federal University of Ceara and located at the city of Pentecoste CE. The grazing method was the intermittent stocking, adopting variable stocking rate, with three grazing periods and 21 rest periods. The residual condition adopted consisted of a height of 28.0 cm. A split plot design, with supplementation level being parcels and cycles sub-parcels, with three or four replicates (paddocks) by treatment, respectively was utilized to morphogenesis and canopy structure. To the animal behavior it was utilized a entirely randomized design in a factorial system (4 x 8) with six replicates (sheeps). To the animal performance, a completely randomized design with eigth replicates (sheeps) was used. There was no effect between supplementation levels (P>.10) and cycles (P>.05) to F1/2, averaging 0.69. There was a square effect (P<.10) of supplementation level on the TAlF, estimating 5.04 and 5.70 cm/tiller x day to the 0.0 and 1.8% LW levels. There were not effect (P>.10) supplementation levels on the TAlH and Pseud, averaging 0.10 cm/tiller x day and 18.31 cm, respectively. In relation to the cycles, it were not observed differences (P>.05) between cycles 4 and 3, however the TAlH of the last cycle was highest than the cycles 1 and 2. The same behavior ocurred with Pseud. The supplementation levels and cycles did not affect (P>.10) the TSFa, TSFp and TST. It was not observed effect of supplementation levels (P>.10) and cycles (P>.05) on the PHYL, with an average of 11.5 days. There was no effect between supplementation levels (P>.10) and cycles (P>.05) to TCC and TAC averaging 153.8 and 128.7 kg/ha, respectively. To the biomass components before grazing, it were observed effects between supplementation levels (P>.10) and cycles (P>.05) to the F/P, MSFM, MSFV, MV/MM, MSLV and MSCV. To variable ALT, it was observed difference (P<.05) between cycle 4 in relation the others. The MSFT was affected (P<.05) by supplementation levels, where the sheeps supplemented to the 0.6% LW was similar (P>.05) to the 0.0 and 1.8% LW levels, however the 0.6%LW was highest (P<.05) than 1.2%LW. It was not observed effect of supplementation levels (P>.10) and cycles (P>.05) on the residual height, with an average of 28.42 cm. There were no effects (P>.10) supplementation levels and cycles (P>.05) on the MSFTres and MSFMres, averaging 6121 and 2411 kg/ha, respectively. In relation to supplementation levels on MSFTres, it were not observed differences (P>.05) between 0.0, 0.6 and 1.8% levels, however the 0.6%LW was highest (P<.05) than 1.2%LW. The same ocurred with MSFMres. There was a square effect (P<.10) of supplementation level on the MSFVres, however there was not observed effect (P>.05) of cycles. It was not observed effect of supplementation levels (P>.10) and cycles (P>.05) on the MV/MMres relation. It was estimated MSLVres of 1429 and 1637 kg/ha to 0.0 and 1.8% LW levels. The same ocurred to the residual LAI. There was a square effect (P<.10) of supplementation level on the MSCVres, with a minimum estimated of 1789 kg/ha, with 1.2% LW level. The addition of supplementation level caused increase (P<.10) in F/Cres. It was not observed effects between supplementation levels (P>.10) about DPP. In relation to the cycles, the cycle 4 was biggest than cycle 2, however the cycle 4 was similar in relation the others. The biggest time grazing occurred in 0.0% supplementation level, decreasing gradually and raising back only in the 1.8% supplementation level. The time ruminating was superior in 0.6% LW supplementation level, mainly in pleasant temperature. The idleness time was superior in 1.2% supplementation level, mainly after the supplementation (periods of 14-20h). The number of supplement/salt ingestions was raised with the increase in the supplementation level from 11 to 14h periods. In it was raised with the increase in the supplementation level up to 1.2% PV and was concentrated from 11 to 14h periods. The water ingestion raised with the increase in the supplementation level up to 1.2% LW and it was concentrated from 11 to 14h. The urination was superior in 1.8% LW supplementation level from 5 to 8h. The gradual rise in the bite rate until 1.2% LW from 8 to 20h periods, with posterior fall suggests an additive effect of the supplement on the grass until such level, and a substitutive effect beyond this level. The total time under shade was concentrated in the hottest periods of day and was reduced with the supplementation level up to 1,2%. It was observed square effects of supplementation levels about GMD, estimated in 65.87 e 113.15 g/day from male sheep s not supplemented and receiving 1.8% LW supplement. The same occurred with GPT. The D12 to 0.0% LW level was estimated in 204 days, decreasing to 113 days when the sheep s received 1.8% LW supplement. It was observed square effects of supplementation levels about TLUA, with a minimum estimated in 63 sheep s/ha, with 0.39% LW of supplement. It was observed square effects of supplementation levels about TLUA, estimated in 7.67 and 8.98 AU/ha from male sheep s not supplemented and receiving 1.8% LW supplement, respectively. It was observed square effects of supplementation levels about RPV, estimated in 1538 e 3264 kg LW/ha x year from sheep s not supplemented and receiving 1.8% LW supplement, respectively. It was observed linear reduction (P<.10) on CAC when increased the supplementation levels. The economic analysis showed the highest profitable to the 0.6% LW supplementation level, with electrical fence, three hectares (minimum) and sale price above of R$ 3,00/kg LW.