The objective this study was to evaluate the growth rates of Tifton 85 bermudagrass under four nitrogen levels (0, 33, 66, 100, and 133 kg/ha N) and harvested at three plant heights (30, 40 and 50 cm). The experimental design was completely randomized in a split plot scheme with three replications. Nitrogen rates were set in the plots and plants heights in the subplots. For all variables, the interaction N rate × plant height was not significant. The net assimilatory […]

Climatic risk zoning allows the identification of areas of low risk of reduced crop productivity due to climatic events. In Brazil, losses to agriculture due to climate are mainly caused by drought. The objective of this research was to determine areas of low climatic risk for corn and palisade grass cultivated in integrated crop-livestock systems in Sao Paulo state. Corn varieties characterized by a 120-day growing cycle and soil with three different water holding capacities (sandy, medium and clayey soils) […]

The objective of this experiment was to establish different criteria for evaluation of the requirements of digestible threonine for broilers from 22 to 42 d of age, using different regression models (quadratic, exponential, and Linear Response Plateau). A total of 1,920 22-day-old male Cobb broilers were distributed in randomized experimental design, with six treatments (six threonine levels: 0.5904, 0.6441, 0.6977, 0.7514, 0.8051, and 0.8588%) and 8 replications containing 40 broilers each one. The level of 0.6977% digestible threonine was used […]

The study was conducted to determine the kinetic parameters of in situ DM and NDF and the passage of particles of forages produced from the intercropping of brachiaria grass with corn and soybean crops. Three experiments were performed, as follows: Experiment 1 – Brachiaria grass intercropped with corn at different plant ages; Experiment 2 – Cultivation of brachiaria grass intercropped with corn set in different sowing arrangements; and Experiment 3 – Intercropping of brachiaria grass and soybean. Passage kinetic of […]

The objective of this study was to evaluate the influence of two levels of digestible energy (3250 and 3500 kcal kg-1) in conjunction with three levels of crude protein (25, 30 and 35%) on the productive performance of catfish (Rhamdia voulezi) juveniles. Two-hundred and forty catfish juveniles with 95.55±6.70 g average weight and 20.43±1.13 cm total length were randomly assigned into twenty-four 370 L-cages, in a factorial arrangement with six treatments and four reptitions. Feeding was performed four times a […]

The objective of this study was to evaluate the daily intake and total apparent digestibility of dry matter, organic matter, crude protein, gross energy, ether extract, neutral detergent fiber, acid detergent fiber, total and non-fibrous carbohydrates, total digestible nutrients, energy intake and nitrogen balance of silages of six maize varieties with early or super early cycles recommended to Northeast Brazil. Twenty-four male castrated lambs were lodged in metabolic cages. A completely randomized design with six treatments and four replications was […]

This study aimed to evaluate the growth index of massai grass during two regrowth cycles in a greenhouse under five levels of nitrogen (0, 150, 300, 450 and 600 mg N/dm3 of soil) and eight growth ages (5, 8, 11, 14, 17, 20, 23 and 26 days) in a split-plot design with five replications. The following variables were evaluated: net assimilation rate, herbage growth rate, relative growth rate, leaf area ratio, leaf weight ratio and specific leaf area. The effect […]

The objective of this study was to evaluate the potassium requirement for laying Japanese quails. Two hundred and forty quails were distributed in a randomized block design, with five treatments and six replicates, with eight birds each. The treatments consisted of a basal diet deficient in potassium (K) (2.50 g/kg), supplemented with potassium carbonate, to replace the inert, to reach levels of 2.50, 3.50, 4.50, 5.50 and 6.50 (g/kg) of K in the diet. There was a quadratic effect of […]

The objective of this study was to evaluate the effect of different true protein:non-protein nitrogen ratios in supplements on digestibility, microbial protein synthesis and nitrogen balance in grazing cattle during rainy season. Five crossbred Holstein × Zebu steers, averaging 335±35 kg of body weight and fitted with rumen and abomasum canullae were used. The treatments were: control (only pasture), and supplements based on urea, 2/3 of nitrogenous compounds from urea and 1/3 of nitrogenous compounds from albumin, 1/3 of nitrogenous […]

The experiment was conducted to evaluate the effects of levels of neutral detergent fiber (NDF) of diets offered to the pullets between the 7th and 17th weeks of age on performance, development of the digestive and reproductive systems, as well as the effects on sexual maturity, performance and egg quality in laying phase, which was assessed until the 35th week. A total of 1,296 pullets were distributed in a completely randomized design in a 3 × 2 factorial arrangement with […]