-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 Paraná from October 2005 to March 2006. It was used a complete random experimental design in a 4 × 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.

Structure and milk production in Mombaça Grass

-Nitrogen (N) at 100, 200, 300, and 400 kg ha -1 was applied to Tanzania grass swards to evaluate the animal response and relationships between sward characteristics and the performance of young Nellore bulls (Bos indicus) under continuous stocking. A completely randomized experimental design was used with two replications between 11 November 2001 and 15 April 2002 when the sward heights were maintained at 60 cm by using different stocking rates. The average daily gain (ADG) (0.73 kg d -1 ) was not affected by N doses while the number of animal days ha -1 increased linearly from 515 to 1267. On the other hand, the linear increase in the animal yield was 399, 653, 755, and 895 kg ha -1 for N at 100, 200, 300, and 400 kg ha -1 , respectively, while the ratio between the liveweight gain (kg) and N (kg ha -1 ) decreased. Correlation coefficients between ADG and herbage mass, green leaf mass, green herbage mass, proportion of green leaf and leaf:culm ratio were low and nonsignificant. Under the conditions in Northwestern Paraná, the application of N to swards of Tanzania grass is a management option for increasing beef cattle production.

No abstract

O experimento de pastejo foi conduzido na Fazenda Nossa Senhora Aparecida, situada no município de Astorga, região Noroeste do Paraná, Brasil. O experimento visou avaliar quatro doses de nitrogênio (N) aplicadas ao solo de pastagens de capim Tanzânia-1 (Panicum maximum Jacq.). As doses avaliadas de N foram 100, 200, 300 e 400 kg ha-1 e o delineamento experimental utilizado foi o inteiramente casualizado com duas repetições. O período experimental foi de 10/11/2001 a 15/04/2002. Os animais usados foram machos inteiros da raça Nelore e o método de pastejo empregado foi o de lotação contínua e taxa de lotação variável. A altura do pasto foi mantida o mais próximo possível de 60 cm em todas as unidades experimentais. A taxa de acúmulo de massa seca (MS) apresentou resposta linear positiva (P<0,0112) com o aumento da quantidade de N aplicada. As taxas de acúmulo foram de 76, 113, 138 e 152 kg de MS ha-1 dia-1, respectivamente para as doses de N de 100, 200, 300 e 400 kg ha-1. A produção de forragem aumentou linearmente (P<0,03) com o aumento da quantidade de N aplicada. A análise estatística revelou aumento linear (P<0,05) da massa individual por perfilho com o aumento da dose de N. A densidade populacional de perfilhos vegetativos apresentou comportamento quadrático (P<0,003) com a elevação das doses de adubo nitrogenado.