Effect of fertilization with fluid swine slurry on production and nutritive value of Tifton 85

The objective of this study was to evaluate the effect of different doses of liquid swine slurry on dry matter accumulation rate and nutritive values (crude proten and neutral detergent fiber) of Tifton 85 grass pasture cultivated in southwestern Parana from October 2005 to March 2006. It was used a complete random experimental design in a 4 x 4 factorial scheme composed of four doses of swine slurry in the plots (0, 80, 160 and 320 m(3)/ha) and four consecutive cuts in the subplots of the pasture. It was carried out two applications, one in the beginning of the experiment and other after 80 days. Cuts were performed every time pasture height was 40 cm. There was a dose versus cut interaction for all variables. Swine slurry promoted increase on dry matter accumulation rate only on the first cut after its application (cuts 1 and 3). Dry matter maximal yield (24.2 t/ha) was obtained at 249 m(3)/ha of swine slurry manure (143 and 106 m(3)/ha, respectively for applications 1 and 2), corresponding to 450 kg of N/ha. Percentage of crude protein increases and neutral detergent fiber of Tifton 85 grass decreases as dose of swine slurry increases, improving forage nutritive value. Use efficiency and nitrogen recovery rate decrease with addition of swine slurry doses.