Supplementation based on protein or energy ingredients to beef cattle consuming low-quality cool-season forages: I. Forage disappearance parameters in rumen-fistulated steers and physiological responses in pregnant heifers

Two experiments evaluated the influence of supplement composition on ruminal forage disappearance, performance, and physiological responses of Angus x Hereford cattle consuming a low-quality cool-season forage (8.7% CP and 57% TDN). In Exp. 1, 6 rumen-fistulated steers housed in individual pens were assigned to an incomplete 3 x 2 Latin square design containing 2 periods of 11 d each and the following treatments: 1) supplementation with soybean meal (PROT), 2) supplementation with a mixture of cracked corn, soybean meal, and urea (68:22:10 ratio, DM basis; ENER), or 3) no supplementation (CON). Steers were offered meadow foxtail (Alopecurus pratensis L.) hay for ad libitum consumption. Treatments were provided daily at 0.50 and 0.54% of shrunk BW/steer for PROT and ENER, respectively, to ensure that PROT and ENER intakes were isocaloric and isonitrogenous. No treatment effects were detected on rumen disappearance parameters of forage DM (P >= 0.33) and NDF (P >= 0.66). In Exp. 2, 35 pregnant heifers were ranked by initial BW on d -7 of the study, allocated into 12 feedlot pens (4 pens/treatment), and assigned to the same treatments and forage intake regimen as in Exp. 1 for 19 d. Treatments were fed once daily at 1.77 and 1.92 kg of DM/heifer for PROT and ENER, respectively, to achieve the same treatment intake as percent of initial BW used in Exp. 1 (0.50 and 0.54% for PROT and ENER, respectively). No treatment effects (P = 0.17) were detected on forage DMI. Total DMI was greater (P < 0.01) for PROT and ENER compared with CON and similar between PROT and ENER (P = 0.36). Accordingly, ADG was greater (P = 0.01) for PROT compared with CON, tended to be greater for ENER compared with CON (P = 0.08), and was similar between ENER and PROT (P = 0.28). Heifers receiving PROT and ENER had greater mean concentrations of plasma glucose (P = 0.03), insulin (P <= 0.09), IGF-I (P <= 0.04), and progesterone (P = 0.01) compared to CON, whereas ENER and PROT had similar concentrations of these variables (P >= 0.15). A treatment x hour interaction was detected (P < 0.01) for plasma urea N (PUN), given that PUN concentrations increased after supplementation for ENER and PROT (time effect, P < 0.01) but did not change for CON (time effect, P = 0.62). In conclusion, beef cattle consuming low-quality cool-season forages had similar ruminal forage disappearance and intake, performance, and physiological status if offered supplements based on soybean meal or corn at 0.5% of BW.

Demanda energética na colheita de híbridos de milho para silagem em função do estádio de maturidade e tamanho de partícula

Corn is the crop most used for making silage. The efficiency of the process should also be evaluated by cost per kg of dry matter harvested (kgDM). The objective of this study was to evaluate energy consumption in the harvest of corn hybrids for silage depending on the texture of the hybrid, four and three harvest maturities of particle sizes - Tp was used a tractor Massey Ferguson MF 610 model 86 cv. Cutting and harvesting the forage harvester is used model JF92 Z10. To obtain data on fuel consumption (CC) and time spent for each plot, we used a flow meter, installed near the fuel filter of the tractor. The experimental design was completely randomized in a split plot. The interaction between factors triple stage hybrid * Harvest * Tp. The velocity and displacement of the tractor were different for the maturities for hybrid hard texture. The CC schedule for hybrid dent increased harvest maturity earlier and at lower Tp. Consumption was lower by kgDM later maturity, hard texture and bite respectively. The theoretical power was higher in earlier maturity and yield were higher for hybrid hard texture in the most advanced. The CC was lower in late maturity and the hybrid hard texture can be used for silage in relation to the Cc and income in later maturity in higher Tp.

Functional Morphology of the Crop and Proventriculus of Sitophilus zeamais (Coleoptera: Curculionidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chemical composition, in vitro digestibility and gas production of Brachiaria managed under different forage allowances

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Absence of detection of xanthomonas axonopodis pv. malvacearum in cotton seeds used in the Northeast Region of Mato Grosso do Sul in a three-based crop season study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Intercropping soybean and palisade grass for enhanced land use efficiency and revenue in a no till system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dry matter yield and tillering of brachiarias sown at depths intercropped with corn

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produção de forragem de Tifton 85 adubado com nitrogênio e submetido à lotação contínua

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Correlação entre condição da superfície do solo agrícola e o coeficiente de absorção acústica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitrogen fertilization (15NH4NO3) of palisadegrass and residual effect on subsequent no-tillage corn

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Humic fractions of forest, pasture and maize crop soils resulting from microbial activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

NUTRITIONAL STATUS AND DRY MASS PRODUCTION OF ALFALFA IN FUNCTION OF POTASSIUM RATES IN TWO SOILS

Potassium fertilization is very important to alfalfa crop in terms of yield, quality and persistence of forage, especially on soils naturally poor K. Thus, to assess the effects of K fertilization in alfalfa production and nutritional status, was carried out an experiment in a greenhouse using samples of a Dystrophic Oxisol medium texture (LV) (0.6 mmol(c) dm(-3) K) and a Dystrophic Ultisol sandy/medium texture (PVA) (2.2 mmol(c) dm(-3) K). A completely randomized design in a factorial arrangement 6 x 2 (six K rates and two soils) was used, with four replications. The K rates used were: 0, 25, 50, 100, 150 and 200 mg kg(-1) K. Potassium fertilization increased K content in soil and shoots. Dry matter production was increased with the K addition. However, in the PVA, this occurred only in the second cut. In LV, potassium fertilization increased N concentration in alfalfa shoots in both cuts. Plants with K concentration around 10 g kg(-1) had typical symptoms of this nutrient deficiency. The K critical levels of K in soil and shoots were 1.8 mmolc dm(-3) and 16.7 g kg(-1), respectively.

POTASSIC FERTILIZATION FOR CRAMBE CROP

There are few studies for the crambe crop (Crambe abyssinica Hochst), and studies that characterize the sufficiency level of K in the soil and leaves are indispensable to support future programs potassium fertilization for this crop of fall/winter. An experiment was carried out to investigate the response of crambe to K soil. The experiment was carried out on a clayey Red Latossol under no-till in Botucatu, S (a) over tildeo Paulo State, Brazil. Treatments consisted of seven K levels in the soil, resulting from the application year (2000 to 2010), the summer crop (soybean), 0, 30, 60, 90, 120, 150 and 180 kg ha(-1) K2O. Before starting the experiment, soil samples were collected at depths of 0-20 cm and soil K contents determined by the resin and Mehlich-1 method. The sufficiency levels of K in soil and leaves were obtained considering the relative yield of 90%. When the levels of soil K extracted by resin and Mehlich-1, are above 88 and 94 mg dm(-3), respectively, equivalent to 26 g kg(-1) K in the leaves, the increase in crop yield of crambe is unlikely. These values should match the sufficiency level of crop and are sufficient to achieve relative grain yield of 90%.

SIMULATION OF USE AND MANAGEMENT EFFECTS ON THE SOIL ORGANIC MATTER POOLS OF THE ATLANTIC FOREST BIOME, BRAZIL

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Manejo da adubação nitrogenada na cultura do milho pelo uso da inoculação com azospirillum brasilense em consórcio com capim xaraés

Pós-graduação em Agronomia - FEIS