Desempenho de bovinos em pastejo submetidos a duas frequências de suplementação no período da seca

This work was carried out to evaluate different frequencies of supplementation during the dry season. Forty-eight Nellore steers with 320 kg of initial live weight were fed with Brachiaria brizantha cv. Marandu pasture on a continuous stocking rate. The animals were submitted to following treatments: Daily supplementation and supplementation three times a week. The animals in both treatments received 7 kg of supplementation animal -1 weekly, and were weighted at 28-day intervals. The data were analyzed by the MIXED procedure in SAS (2004), with measurements repeated over time. The study observed average forage allowance of 4.2 tons of DM ha-1, with 3.5% CP, 82.24% NDF and 64.97% ADF. There was no difference (p < 0.01) among daily weight gains of animals who received daily supplementation and those received supplementation three times a week (0.23 and 0.13 kg day -1, respectively). Therefore, the supplementation intervals did not influence steer performance during the dry season.

Crescimento, comportamento ingestivo e desempenho reprodutivo de novilhas mestiças holandês x zebu, em pastejo, submetidas à suplementação protéica durante a época das águas

The objective of this study was to evaluate the effect of supplemental protein during the rainy season on body growth, ingestive behavior and reproductive performance of crossbred Gir x Holstein dairy heifers, with mean age of 21 ± 4.1 months and average initial body weight of 296.7 ± 57.3 kg, distributed in a completely randomized design with four treatments and six replicates per treatment. Heifers remained on Brachiaria brizantha cv. Marandu pasture, managed according to a rotational grazing system and, as treatment, it was supplemented with protein concentrate (34%, 43%, 56% and 66% BW) and level of supply of 0.30% body weight (BW). The animals were weighed and the mean weight of the lot was used for the calculation of adjustment of the amount of concentrate offered. Heifers that reached 330.0 kg of live weight were artificially inseminated and, 45 days after insemination, pregnancy diagnosis was performed for the calculation of pregnancy rate and age at conception. No significant difference of protein levels was observed on grazing, eating behavior, productive performance and age at conception of dairy heifers on pasture. The average daily weight gain of BW and age at conception were, on average, 0.907 kg/animal and 24.03 months, respectively.

Comportamento ingestivo de novilhos de corte sob diferentes alturas de pastejo do capim Tanzânia1

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Viabilidade econômica de quatro intensidades de pastejo do capim Tanzânia na pecuária de corte1

Were evaluated the economic effects of four grazing heights (20, 40, 60 and 80 cm) of Tanzânia grass for beef cattle. The total area was 12 acres divided into paddocks of one hectare, with three replications. We used three animals, males, Nelore per paddock, as more animals need additional adjustment to the height you want. The reduction in sward height allowed higher stocking rate, which, even with a reduction in individual performance, there was more beef production per area. The interest rate on capital given the property represented the largest share in the final cost of production. The participation of fixed variables showed a positive linear function of the increase in height from grazing, showing significant reduction of the production scale. A reduction in cost of production per hectare per year with increasing grazing height. No differences were found in certain economic indicators, and the four systems remunerate the capital invested.

Déficit hídrico na eficiência de herbicidas e nas características bioquímicas de Euphorbia heterophylla

The objective of this work was to evaluate conditions the effectiveness of acetolactate synthase (ALS) and protoporphyrinogen oxidase (PROTOX) inhibitors in the Bidens pilosa control under two water deficit conditions, as well as to determine the action under the content of soluble carbohydrates and protein and free amino acids of weed. The experimental design was randomized completely design, with four replications, with the treatments setup in a factorial scheme 4x2, with four herbicides (fomesafen lactofen, chlorimuron-ethyl and imazethapyr), and two soil water conditions (-0.5 MPa and -0.01MPa). At 7, 14, 21 and 28 days after application (DAA), was assessed visually control efficiency of herbicides. For the determination of organic solutes plants were collected at 24, 48, 72 and 96 hours after application (HAA), except for the amino acids were analyzed 48, 72 e 96 HAA. Herbicides fomesafen and lactofen were efficient to control E. heterophylla, while the ALS inhibitors (chlorimuron-ethyl e imazethapyr) provided an unsatisfactory control. Water deficit altered the efficiency of herbicides, mainly chlorimuronethyl. Lactofen provided a smaller content of soluble carbohydrates, in the same way, the protein ranged in the 72 HAA, the lower value observed for imazethapyr e lactofen respectively. Herbicide lactofen increased the concentration of free amino acids, while the imposition of water deficit caused an increase in soluble carbohydrate content.

Eficiência de utilização de nutrientes por cultivares de batata

The use of cultivars efficient in nutrient use is essential to increase yield and reduce production costs. The objective of this study was to evaluate absorption and nutrients use efficiency on five potato cultivars. The experiment was conduced in Itaí, São Paulo State, Brazil, in winter cropping season of 2008 on Oxisol. The experimental design was randomized blocks with split-plots and four replications. Plots comprised the five potato cultivars and subplots were established by sampling times, performed at planting and every seven days after emergence. At 97 DAP was calculated the nutrients use efficiency for dry matter production and at 122 DAP were calculated the nutrients use efficiency for fresh tuber and tuber dry matter yield. Mondial and Asterix cultivars showed greater dry matter production, higher fresh tubers yield and nutrients accumulation. Nutrients use efficiency for total dry matter and tubers dry matter, was similar among cultivars, but Ágata was more efficient in nutrients use efficiency for fresh tubers yield.

Características morfogênicas e estruturais do capim-xaraés submetido a intesidades de pastejo

The aim of this study was to evaluate the effects of residual leaf area index (rLAI), years of evaluation and grazing cycles on the morphogenetic and structural characteristics of xaraés palisadegrass subjected to grazing intensities in two summers (years of evaluation). The experiment was carried out at the Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP, Campus de Jaboticabal, São Paulo, Brasil and the intensities of grazing were defined by four rLAI: 0.8, 1.3, 1.8 and 2.3. When the canopy intercepted 95% of incident light, the animals were placed on the pasture for grazing and kept until the rLAI target has been reached. Pastures were grazed by non-lactating Holstein cows (Bos Taurus Taurus L.), using the technique of mob-stocking. The morphogenetic and structural characteristics of xaraés palisadegrass respond effectively to weather conditions. There is variability in morphogenetic and structural characteristics in response to years and grazing cycles within years.

Desenvolvimento corporal de novilhas leiteiras suplementadas com minerais inorgânicos e orgânicos em pastejo na época das águas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficiência de escórias de siderurgia na cultura do feijoeiro em sistema de semeadura direta

In the no till system, soil acidity correction practice is restricted to limestone use and there is little information regarding slag. The study aimed to evaluate the amendments in soil chemical properties, yield and bean nutrient uptake according to the application forms of slags, compared to limestone, in the implantation of no till system. The experiment was conducted in the field at College of Agricultural Sciences, Botucatu (SP) from December 2010 to May2011. The treatments consisted of two application ways of seven soil acidity correctives: steel slag, blast furnace slag, ladle furnace slag, stainless steel slag (agrosilício), wollastonite, lime and calcined dolomite lime, plus one control without corrective application. Each material dose was calculated to raise the base saturation to 70%. Soil acidity was neutralized down to 20cm with limestones, whereas for wollastonite and ladle furnace slag those effects occurred down to 10cm, for steel slag, blast furnace slag and agrosilício the corrective effect was restricted to the first 5cm. The bean yield increased by application of correctives in soil acidity, without differences between the application ways.

Eficiência de herbicidas inibidores da ALS e PROTOX sob condições de déficit hídrico no comportamento bioquímico de plantas daninhas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Intervalos de chuva na eficiência de herbicidas aplicados em pós-emergência

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

Eficiência da seleção recorrente para redução da altura de plantas em mamoneira (Ricinus communis L

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação de eficiência relativa para a reatividade em silicatos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficiência agronômica de fertilizantes organominerais sólidos e fluidos em relação à disponibilidade de fósforo

Pós-graduação em Agronomia (Agricultura) - FCA

Eficiência da azospirillum brasilense na fixação de nitrogênio em milho

Pós-graduação em Agronomia (Agricultura) - FCA