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ABSTRACT: This trial evaluated the production performance, gastrointestinal nematode infection (GIN), and selected blood analytes, in Corriedale lambs during the finishing phase in an integrated crop-livestock system (ICLS) with 2 stocking rates. Fifty-two Corriedale lambs were divided into 4 groups: a semi confinement system with a low stocking rate (T1) for 70 days; a semi confinement system with a high stocking rate (T2) for 70 days; confinement for 28 days, followed by semi confinement with a low stocking rate (T3) for 42 days; and confinement for 28 days, followed by semi confinement with a high stocking rate (T4) for 42 days. Body weight, dry matter intake, blood collection, and faecal analysis of nematode eggs were performed for each animal. The stocking rates did not influence body weight gain for the semiconfined lambs (T1 and T2) or for the confined/semiconfined lambs (T3 and T4). All treatments had lower EPG counts at the end of the experimental period. The nematode genera identified during the experiment trial were Haemonchus and Trichostrongylus. There were no significant differences (P > 0.05) for packed cell volume, total plasma protein, and eosinophil means between treatments. These results suggested that the confinement followed by semi confinement in an ICLS, was an option for lamb production during the finishing phase which could be useful in reducing GIN without affecting the production performance.

The Pantanal has been facing consecutive years of extreme drought, with an impact on the quantity and quality of available pasture. However, little is known about how locally adapted breeds respond to the distribution of forage resources in this extreme drought scenario. This study aimed to evaluate the movement of free-grazing Pantaneiro sheep using a low-cost GPS to assess the main grazing sites, measure the daily distance traveled, and determine the energy requirements for walking with body weight monitoring. In a herd of 100 animals, 31 were selected for weighing, and six ewes were outfitted with GPS collars. GPS data collected on these animals every 10 m from August 2020 to May 2021 was analyzed using the Python programming language. The traveled distance and activity energy requirements (ACT) for horizontal walking (Mcal/d of NEm) were determined. The 31 ewes were weighed at the beginning and end of each season. The available dry matter (DM) and floristic composition of the grazing sites were estimated at the peak of the drought. DM was predicted using power regression with NDVI (normalized difference vegetation index) (R2 = 0.94). DM estimates averaged 450 kg/ha, ranging from traces to 3830 kg/ha, indicating overall very low values. Individual variation in the frequency of use of grazing sites was observed (p < 0.05), reflecting the distances traveled and the energetic cost of the activity. The range of distances traveled by the animals varied from 3.3 to 17.7 km/d, with an average of 5.9 km/d, indicating low energy for walking. However, the traveled distance and ACT remained consistent over time; there were no significant differences observed between seasons (p > 0.05). On average, the ewes’ initial weight did not differ from the weight at the drought peak (p > 0.05), indicating that they maintained their initial weight, which is important for locally adapted breeds as it confers robustness and resilience. This study also highlighted the importance of the breed’s biodiverse diet during extreme drought, which enabled the selection of forage for energy and nutrient supplementation. The results demonstrated that precision tools such as GPS and satellite imagery enabled the study of animals in extensive systems, thereby contributing to decision-making within the production system.

As countries prioritize climate action under the Paris Agreement, determining the overlap in agricultural areas requiring both adaptation and mitigation (A&M) interventions could lead to more efficient use of resources and support for farmers. Here, we identify global priorities for A&M by evaluating global datasets on greenhouse gas (GHG) emissions and climate hazards related to agriculture. We show that joint A&M hotspots cover

Abstract Food systems (FSs) emit ~ 20 GtCO2e/y (~ 35% of global greenhouse gas emissions). This level tends to raise given the expected increases in food demands, which may threaten global climate targets. Through a rapid assessment, evaluating 60+ scenarios based on existing low-emission and carbon sequestration practices, we estimate that intensifying FSs could reduce its emissions from 21.4 to − 2.0 GtCO2e/y and address increasing food demands without relying on carbon offsets (e.g., related to afforestation and reforestation programs). However, given historical trends and regional contexts, a more diverse portfolio of practices, including diet shifts and new-horizon technologies, will be needed to increase the feasibility of achieving net-zero FSs. One likely pathway consists of implementing practices that shift food production to the 30th-percentile of least emission-intensive FSs (~ 45% emissions reduction), sequester carbon at 50% of its potential (~ 5 GtCO2e/y) and adopt diet shifts and new-horizon technologies (~ 6 GtCO2e/y). For a successful transition to happen, the global FSs would, in the next decade (2020s), need to implement cost-effective mitigation practices and technologies, supported by improvements in countries’ governance and technical assistance, innovative financial mechanisms and research focused on making affordable technologies in the following two decades (2030–2050). This work provides options and a vision to guide global FSs to achieving net-zero by 2050.

Improving grassland conditions under grazing has the potential not only to accumulate carbon in soils, but also to reduce nitrous oxide (N2O) emissions from animal urine deposition. However, measurements in developing countries are still scarce. In the Orinoquia region, permanent grasslands (PG; this unimproved, native pasture is considered as at some state of degradation) based on unimproved grasses are found due to extensive, inefficient grazing combined with annual burning of pastures. We hypothesized that, compared to PG, improved grasslands (IG) managed through rotational grazing of introduced, productive and deep-rooted pasture grass species promote soil organic carbon (SOC) accumulation and reduce N2O emission from urine deposited by grazing cattle. We determined SOC and N2O emissions from urine deposited on soils in an area of PG and in a 6.5 year-old IG area of Urochloa (Syn. Brachiaria) humidicola grass pasture in a beef cattle ranch in Orinoquía region (Colombia). In both areas, we sampled soil for chemical/physical analysis, and measured N2O emissions by simulating urine deposition over 21 days. We applied two-way analysis of variance considering pasture type and soil depth as fixed factors. Estimated SOC stocks (0–100 cm) were in the range of 224.8 Mg C ha−1 for the PG and 259.0 Mg C ha−1 for the IG, with a significant (p < 0.05) average accumulation of 2.0 Mg C ha−1 y−1 (0–20 cm) in the IG area. N2O emissions were 10 times lower in the IG compared to the PG. The introduction of U. humidicola grass influenced SOC accumulation probably through its more abundant root system and greater turnover together with higher (14%) forage dry matter production compared to PG. The reduced N2O emissions observed from urine patches in IG were attributed to biological nitrification inhibition ability and greater nitrogen uptake of U. humidicola grass. Compared to the reference default value of IPCC for, the SOC stock found in PG was almost 40% higher, whereas the N2O emission factor (5%) was within the uncertainty range (0.7–6%). The Orinoquía region shows significant potential for SOC storage and reduced N2O emissions in improved pastures with deep root systems. Thus, scaling the implementation of land-based SOC storage practices/projects could significantly contribute to reducing net emissions from beef production from this region.

The present study aimed to evaluate the application of shear strength and its correlations with leaf blade morphological and chemical variables as a tool capable of detecting differences between species and accessions of the genus Paspalum in the early stages of a forage plant breeding programme. A total of 13 Paspalum accessions from two species (Paspalum atratum and Paspalum regnellii) were subjected to analyses of shear strength, which also analysed the neutral detergent fibre, acid detergent fibre, lignin, and digestibility. Morphological measurements were also performed to standardize the shear strength per unit of leaf tissue. The experimental design consisted of complete randomized blocks, with four replications and eight cuts performed over 2 years. Shear strength was evaluated for its potential usefulness for detecting differences between accessions of the same species and the correlations of accessions. It was possible to use the shear strength measured with the texturometer to detect differences between species and accessions of the Paspalum genus. The results showed significant correlations of shear strength and neutral detergent fibre (r = 0.49), and negative correlations were found between digestibility and shear strength (r = -0.55). These correlations were maintained when the strength variables were standardized according to the morphological variables. Thus, shear strength can be used in the initial stages of the selection of species of the genus Paspalum.

The purpose of this trial was to evaluate serum levels of oxidative stress biomarkers and biochemical analytes in crossbred lambs during the rearing phase in an integrated crop-livestock system (ICLS) to control gastrointestinal parasites. The experiment used 36 crossbred lambs (cross: Ile de France × White Dorper × Texel) divided into two groups. The WCS group was supplemented with whole cottonseed (WCS), and controls had no supplementation. Body weight, blood collection, and fecal analysis of nematode eggs and Eimeria oocysts counting per gram of feces were performed for each animal within 84 days of experiment. The following serum analytes were determined: total protein, albumin, globulin, cholesterol, haptoglobin, and 10 oxidative stress biomarkers: cupric reducing antioxidant capacity, ferric reducing ability of plasma, trolox equivalent antioxidant capacity, thiol, uric acid, paraoxonase-1, total oxidant status, ferric-xylenol orange, advanced oxidation protein products, and reactive oxygen metabolites derived compounds. The inclusion of WCS suggested the benefit in controlling infection as well as inducing an increase in antioxidants and a decrease in oxidants in lambs naturally infected by gastrointestinal parasites. The combination of WCS and ICLS could be a useful tool in controlling gastrointestinal parasite infection without affecting the production performance.

Nitrogen (N) fertilizer use is rapidly intensifying on tropical croplands and has the potential to increase emissions of the greenhouse gas, nitrous oxide (N2O). Since about 2005 Mato Grosso (MT), Brazil has shifted from single-cropped soybeans to double-cropping soybeans with maize, and now produces 1.5% of the world's maize. This production shift required an increase in N fertilization, but the effects on N2O emissions are poorly known. We calibrated the process-oriented biogeochemical DeNitrification-DeComposition (DNDC) model to simulate N2O emissions and crop production from soybean and soybean-maize cropping systems in MT. After model validation with field measurements and adjustments for hydrological properties of tropical soils, regional simulations suggested N2O emissions from soybean-maize cropland increased almost fourfold during 2001–2010, from 1.1 ± 1.1 to 4.1 ± 3.2 Gg 1014 N-N2O. Model sensitivity tests showed that emissions were spatially and seasonably variable and especially sensitive to soil bulk density and carbon content. Meeting future demand for maize using current soybean area in MT might require either (a) intensifying 3.0 million ha of existing single soybean to soybean-maize or (b) increasing N fertilization to ~180 kg N ha−1 on existing 2.3 million ha of soybean-maize area. The latter strategy would release ~35% more N2O than the first. Our modifications of the DNDC model will improve estimates of N2O emissions from agricultural production in MT and other tropical areas, but narrowing model uncertainty will depend on more detailed field measurements and spatial data on soil and cropping management.

This study characterizes the changes in leaf mass, morphological composition and nutritional value of leaf blades of palisadegrass (Urochloa brizantha cv. Marandu) under continuous grazing in the first year of implementation of pasture and after second year of the eucalyptus planting in an Integrated Crop-Livestock System and Integrated Crop-Livestock-Forest, which were tested in the four seasons. The experimental design was in random blocks, with three treatments: Crop-Livestock System (ICL) and Integrated Crop-Livestock-Forest with two eucalyptus tree densities (ICLF-1L, 196 eucalyptus trees ha-1 and ICLF-3L, 448 eucalyptus trees ha-1) and four replicates. Sixty castrated Nellore cattle with initial weight of 235.43 ± 25.46 kg and mean age of 16 ± 2.81 months were used during the growing phase under continuous grazing. The agronomic variables were: total dry mass of forage, leaves, stem and dead material; leaf:stem and live:senescent material ratios; and accumulation rate. The leaf:stem and live: senescent material relation did not obtain any difference between the evaluated systems. Dry matter, crude protein, fiber fractions and digestibility of leaf blades were evaluated. Dry mass of the forage (6775 kg ha-1), stem (2175 kg ha-1), senescent material (3175 kg ha-1) and dry matter content (28.6%) were greater in the ICL, whereas crude protein (11.3%) was greater in the ICLFs. On the other hand, accumulation rate and dry mass of leaf blades did not change between systems. Thus, until the first year of grazing, tree systems have advantages, because the forage production (accumulation rate) and leaf mass are similar to those of plants in full sun, besides showing higher nutritional value.

The economic losses caused by gastrointestinal nematodes are one of the biggest obstacles in the small ruminants production. Understanding the population dynamics of the infective larvae (L3) in the pasture is the key point to develop control programs, and reliable results depend on the used methodology to quantify L3 numbers. The use of the sampling directly from the pasture appears as a viable option, since it is not required the use of animals with an esophageal fistula or tracer animals, decreasing the costs involved in the study. Therefore, the present project, which had as objective evaluate the efficiency of two collection methods for quantification of L3 in the pasture, utilized 64 lambs (n = 16) allocated to four integrated crop-livestock systems (treatments) with 12 paddocks each. Pasture samples were collected every nine days. The W method consists in traversing the area in the form of a W and again an inverted W, forage samples being collected every 10 steps, and the Square method, in tossing a 0.16 m2 square to four random points within the area, the forage within the square being collected after each toss. After the forage samples had been processed, the L3 were recovered and identified. Cohen’s Kappa coefficient (k) was determined. The W-transect and Random-plot methods did not differ (p ? 0.05) with respect to the number of L3 recovered from the pasture, and a positive correlation was found between them, suggesting agreement with one another, being that when the number of L3 recovered by the W-transect method increases, the same occurs in the Random-plot technique. The Random-plot method, which is already used to collect samples of forage for chemical analyses, can also be employed to estimate the pasture contamination by L3. The W-transect and Random-plot methods showed to be important in the epidemiological study of gastrointestinal nematodes in sheep. Therefore, the use of both on the same occasions and with different purposes, with one complementing the information that is not provided by the other, may be more effective in the investigation of environmental contamination by L3 of gastrointestinal nematodes.

O objetivo deste trabalho foi avaliar a produtividade e valor nutritivo de silagens de milho em consórcio com Urochloa brizantha cv. Marandu (capim-marandu) em sistema integrado de produção agropecuária colhidas em diferentes maturidades, alturas de corte e submetidas ou não a processamento mecânico antes da ensilagem. O delineamento experimental foi o de blocos casualizados, com quatro repetições, em esquema fatorial 2x2x2+1, sendo os tratamentos compostos por silagem de milho em consórcio com o capim-marandu, em duas alturas de corte (20 e 45 cm), dois estádios de colheita (1/4 do grão leitoso e maturidade fisiológica) e duas formas de processamento da massa antes da ensilagem (esmagado e não esmagado) e o cultivo exclusivo do milho como testemunha. A produtividade de massa seca das plantas não diferiu estatisticamente entre os tratamentos, demonstrando a viabilidade do consórcio entre as culturas. Embora o teor de matéria seca das plantas de milho no momento da ensilagem ter sido superior ao recomendado, não houve comprometimento da qualidade das silagens. A elevação da altura de corte do milho causa incremento na proporção de grãos na massa ensilada, além de não comprometer o desenvolvimento subsequente do capim em consórcio. As silagens oriundas de plantas colhidas no ponto de maturidade fisiológica e as submetidas ao processamento mecânico foram as que apresentaram melhor qualidade fermentativa e nutritiva.

Objetiva-se avaliar o milho em consórcio com forrageiras em sistema integrado de produção agropecuária para produção de silagem, com posterior formação da pastagem. O delineamento experimental foi em blocos casualizados, com quatro repetições sendo duas modalidades de cultivo do milho, consorciado com duas braquiárias (capim marandu e capim convert) e, com e sem consórcio com feijão guandu (Cajanus cajan) cv. BRS Mandarim. Foi avaliada a produtividade de massa seca, a composição morfológica do milho, a composição botânica das braquiárias e do feijão guandu, bem como a composição bromatológica das silagens e das braquiárias e, as perdas por efluentes. Os consórcios não interferiram na produtividade do milho para silagem, sendo que a silagem proveniente do consorcio com o feijão guandu apresentou maior concentração de proteína bruta, evidenciando que a modalidade do sistema integrado de produção agropecuária da cultura do milho com braquiárias e feijão guandu constitui alternativa para aumentar o teor de proteína do material ensilado e proporcionar maior diversidade da forragem remanescente.

Intercropping grain with forage crops bridges the gap between agriculture and sustainability. In tropical regions, forage grasses are increasingly being adopted as winter pasture intercropped and in rotation with maize to maximize food production. However, current recommendations for nitrogen (N) fertilizer application are based on monocropped maize (Zea mays), and the best N management approach for intercropping systems remains unclear. A field experiment was carried out in three growing seasons with three intercropping systems [monoculture maize, intercropped with palisadegrass (Urochloa brizantha), and intercropped with guineagrass (Megathyrus maximus)] combined with six different split applications of N to maize (0–0, 100–0, 70–30, 50–50, 30–70, and 0–100 kg N ha−1 at seeding-sidedressing) with four replicates. We measured dry matter (DM) and accumulated N in maize and forage grasses, as well as maize production components and yields. Additionally, land equivalent ratio, relative crowding coefficient, aggressivity of maize with forage grasses, forage crude protein (CP) concentration, estimated animal stocking rate, and estimated meat production and economic outcomes. Greatest maize yield was 8.7 Mg ha−1 for monocropped maize. However, favorable maize yield was also obtained in intercropping systems. Although no difference was observed between intercropping systems, applying all N at sidedressing of maize negatively affected maize and forage yields and, consequently, land use and economic evaluation. For both intercropping systems, estimated meat and land use were 114 and 10% higher when N fertilizer was applied than the control (0–0 kg N ha−1), on average. Maize-forage grass intercropping is a viable alternative production system for improving yields and land use. In addition, estimated meat production and revenue can be enhanced with palisadegrass or guineagrass. At least half of the N fertilizer must be applied early in the growing season of maize to maximize production of the entire system.

In the context of sustainable tropical agriculture, an innovative corn (Zea mays L.) to silage-grass-legume intercropping system can promotes plant diversity, improves agronomic performance and land-use efficiency, and increases the yield of oversown black oat (Avena strigosa Schreb) and soybean [Glycine max (L.) Merr.] to silage in succession. Thus, during three growing seasons on a Typic Haplorthox in Botucatu, São Paulo State, Brazil, four treatments of a corn to silage production system were implemented in summer/autumn with black oat oversown in winter/spring: (1) corn intercropped with palisade grass (Urochloa brizantha “Marandu”) and black oat overseeded in lines; (2) corn intercropped with palisade grass and black oat overseeded in a broadcast system with superficial incorporation; (3) corn intercropped with palisade grass + pigeon pea [Cajanus cajan (L.) Millsp.] and black oat overseeded in lines; and (4) corn intercropped with palisade grass + pigeon pea and black oat overseeded in a broadcast system with superficial incorporation. During winter/spring, the black oat pastures were grazed by lambs, but results on forage allowance and nutritive value for animal grazing and on animal performance are not reported in the present manuscript. In the fourth growing season, the effect of soybean to silage intercropped with guinea grass (Panicum maximum “Aruana”), with only a residual effect of the four production systems from the previous three growing seasons, was evaluated. Despite greater interspecific competition of palisade grass and pigeon pea intercropped with corn, this more complex system produced better results. Thus, when analyzing this system as a whole, the triple intercrop (corn + pigeon pea + palisade grass) combined with oversown black oat in lines was the most effective option for silage production and for the improvement of other elements of system productivity, such higher surface mulch quantity, leaf nutrient concentrations, and yield of soybean to silage intercropped with guinea grass. This intercrop also generated better nutrient cycling because an increased quantity of nutrients was retained in standing plant residue and surface mulch, which resulted in better land- and nutrient-use efficiency, with an emphasis on nitrogen and potassium.

Intercropping forage grasses with upland rice is an alternative cropping system to improve agroecosystem diversification and could potentially enhance sustainability in tropical regions. However, nitrogen (N) immobilization and nutrient competition between rice and forage grasses could reduce rice grain yield and decrease overall productivity. Therefore, fertilizer N requirements of upland rice intercropped with forage grasses needs to be better defined. Field experiments were carried out during three growing seasons on a Typic Haplorthox soil in São Paulo state of Brazil. The experimental design was a randomized block design with a 3 × 4 factorial scheme with four replications. Treatments were cropping system [monocropped rice (Oryza sativa L.), rice intercropped with palisadegrass (Urochloa brizantha), and rice intercropped with guineagrass (Megathyrsus maximus) and sidedress N application rate (0, 40, 80, and 120 kg N ha−1). Intercropped grasses were sown between upland rice rows 30 days after rice emergence. On average, intercropping of rice with palisadegrass or guineagrass decreased rice shoot dry matter and grain yield by 11% and milled rice productivity by 10% compared with monocropped rice. Grain yield, grain protein, and milled productivity of rice increased as N application rate increased. Forage dry matter production (first and second cut) and crude protein (second cut) were greatest in the rice + palisadegrass intercropping system. Production of both forage grasses increased with up to 80 kg N ha−1 in the first cut and increased linearly with N in the second cut. Intercropping of rice with palisadegrass or guineagrass with 80 kg N ha−1 application resulted in the greatest land equivalent ratio (1.96 and 1.55, respectively). Relative N yield was greatest at 120 kg N ha−1 (220 and 173%, respectively). Although rice monocropping had greatest grain yield, intercropping systems with forage grasses were more favorable from both economic and environmental perspectives by enhancing plant diversification, nutrient cycling with forage grasses, land use production per unit area, and profitability throughout the year.

This work aimed to evaluate the thiol-disulphide homeostasis in serum of lambs naturally infected by gastrointestinal nematodes presenting different levels of parasite load indirectly indicated by faecal worm egg counts (EPG). Furthermore, the possible changes in the thiol-disulphide dynamic after different procedures to reduce the parasitic charge, such as the integrated crop-livestock system or anthelmintic treatment, were assessed. The results were compared with a panel of various oxidative stress and inflammatory biomarkers. The lambs were divided into three groups: animals highly infected (EPG higher than 5000) and packed cell volume (PCV) lower than 24% (G1); animals highly infected (EPG higher than 5000) and normal PCV (>24%) (G2); and animals presenting EPG lower than 5000 and normal PCV (>24%) (G3). The highly infected lambs (G1 and G2) showed lower total thiol (TT) and native thiol (SH) (p ≤ 0.01) than those from G3. After treatment, TT and SH increased significantly in all groups (p ≤ 0.01), and the disulphide (SS)/TT and SS/SH ratios decreased significantly (p < 0.01) in G1 and G2. These results show that the thiol-disulphide balance was impaired in lambs infected by gastrointestinal nematodes and that it could be potentially used as a biomarker to monitor this disease.

Abstract: The objective of this work was to evaluate the effect of intercropping systems between corn and tropical forages, at different cutting heights, on silage production, light interception, land use efficiency, intercropping competition factors, and pasture production. In the 2010/2011 and 2011/2012 crop seasons, two cultivation modalities were evaluated in the summer/autumn - monocropped corn with residual regrowth of signal grass (Urochloa decumbens) from the soil seed bank and corn intercropped with palisade grass (U. brizantha 'Marandu') -, in a factorial arrangement with two cutting heights for silage production - 0.20 and 0.45 m. After corn silage harvest, the forages were grazed by lambs in a semi-feedlot system, in the winter/spring. Monocropped corn and 0.45-m cutting height both reduced dry matter yield for silage. Corn intercropped with palisade grass improved land use efficiency from 13 to 31% compared with monocropped crop, with land equivalent ratio greater than 1. Palisade grass showed higher light interception than signal grass over the intercrop period with corn and provided greater forage yield for lambs to graze during winter/spring. Corn intercropped with palisade grass, compared with monocropped corn, especially at the cutting height of 0.45 m, is a viable option for improving silage and pasture production, as well as land use efficiency in the integrated crop-livestock system.

A adaptação da Urochloa brizantha aos ecossistemas brasileiros e a utilização de sombreamento artificial em estudos de produção sob baixas luminosidades são ferramentas importantes para se obter respostas produtivas e conhecer o comportamento das plantas quando utilizadas em integrações com componentes arbóreos. O experimento foi conduzido na FMVZ – UNESP Botucatu, com objetivo de avaliar a produtividade da cultivar de Urochloa brizantha (syn Brachiaria brizantha) cv. Xaraés submetida a três intensidades luminosas e quatro cortes. O delineamento experimental foi em blocos ao acaso, sendo os tratamentos: luminosidade natural, redução de 30% e 60% de luz, com três repetições e quatro cortes. Foi realizada a separação morfológica, índice de área foliar e a taxa de acúmulo, também foi calculada a produção de massa seca total, colmo e folhas, além da produção de material morto. A produtividade foi influenciada pelos níveis de intensidade de luz, sendo o melhor desempenho obtido no tratamento com 60% de sombreamento, que apresentou maior produção de massa seca total, de folha e colmo, índice de área foliar e maior taxa de acúmulo em comparação ao pleno sol. O tratamento com 60% de redução de luminosidade foi o mais produtivo, sendo o melhor tratamento nestas condições.

O objetivo deste estudo foi avaliar o efeito das associações de grãos secos e úmidos de milho e sorgo nas características de carcaça de cordeiros mestiços Suffolk x Santa Inês terminados em confinamento. O delineamento experimental foi em blocos casualizado com quatro tratamentos e três repetições. Foram utilizados 60 cordeiros machos não castrados, com média de 15,5 kg de peso corporal. Quatro associações de grãos na dieta foram avaliadas: sorgo seco triturado + silagem de grãos úmidos de sorgo (SS:SU); milho seco triturado + silagem de grãos úmidos de sorgo (MS:SU); milho seco triturado + silagem de grãos úmidos de milho (MS:MU); sorgo seco triturado + silagem de grãos úmidos de milho (SS:MU). Não houve diferença entre os tratamentos para rendimento, peso de carcaça quente e fria e para perda por resfriamento. Os pesos de abate dos cordeiros alimentados com associações MS:SU foram superiores (29,46 kg) aos dos cordeiros alimentados com MS:MU (24,17 kg) porém, ambos não diferiram SS:SU (26,18 kg) e SS:MU (25,21 kg). Houve influência das associações de grãos sobre rendimento dos cortes comerciais paleta e pernil. As associações de grãos de milho e sorgo, secos e ensilados, podem ser utilizadas na alimentação de cordeiros em confinamento para produção de carne.

Indigestible fractions of dry matter (iDM) and neutral detergent fiber (iNDF) in the feed of ruminants are mainly estimated by in situ incubation time with regard to particle size and textile types. Samples of alfafa, ground into three particle sizes, were analyzed. Samples, processed in a Willey mill with 1.0; 2.0 and 3.0 mm sieve pores, were conditioned in F57 (Ankon®), nonwoven (100 g m-2) and polyester textile bags measuring 4 x 5 cm. Material was divided into 13 incubation periods and 8 replications, and incubated in the rumen of two multiparous cows adapted to a 70:30 diet, roughage:concentrate, respectively, for 288h. iDM and iNDF rates were evaluated sequentially for non-digested percentage and data underwent analysis of variance (ANOVA p < 0.05); means were compared by tukey’s test (p < 0.05). Particle size and material employed for incubation affected iDM and iFDN at the initial periods of incubation (p < 0.05).

Este trabalho teve por objetivo utilizar o hidrogenoftalato de potássio como molécula modelo para estudos de adsorção em TiO2. Os resultados de adsorção do hidrogeneoftalato sobre TiO2 se ajustaram aos modelos de adsorção propostos por Langmuir e Freundlich, sendo que o modelo de Freundlich descreveu melhor o fenômeno. A adsorção foi função da temperatura e a capacidade de adsorção aumentou de 2,4 para 4,5 mg.g-1 quando se elevou a temperatura de 20 para 30ºC.

Current paper assesses the relationship between in situ incubation time, particle size and types of materials on estimates of indigestible fractions of dry matter (iDM) and neutral detergent fiber (iNDF) in cattle feed and feces. Samples of soybean meal, alfalfa and feces of cattle fed on high concentrated diets were analyzed. The samples were processed in a Wiley mill, with 0.5 and 1.5 mm porosity for food and 1.5 mm for feces, which were packed in 4 × 5 cm F57 bags (Ankon®) and nonwoven fabric (100 g m-2) of two brands. The material was divided into two groups, with and without treatment with acetone, and five replications. Samples of each group were incubated in the rumen of a multiparous cow adapted to a 70:30 diet, forage:concentrate diet, for 240 hours. The iDM and iNDF levels were evaluated sequentially to interpret the percentages of undigested material. Data underwent analysis of variance (ANOVA, p < 0.05) and means were compared by Tukey’s test (p < 0.05). Material, size of particles and incubated material affected iDM and iNDF estimates.

Nitrogen is required in large amounts by plants and their dinamics in corn and perennial forages intercropped is little known. This study analyzed the efficiency of nitrogen fertilization (15NH4NO3) applied after corn grain harvest to palisadegrass (Brachiaria brizantha cv. Marandu) in intercrops sown at two times, as well as the N residual effect on the subsequent corn crop. The field experiment was performed in Botucatu, São Paulo State, in southeastern Brazil, on a structured Alfisol under no-tillage. The experiment was arranged in a randomized block design in a split plot scheme with four replications. The main plots consisted of two intercropping systems (corn and palisadegrass sown together and palisadegrass sown later, at corn top-dressing fertilization). The subplots consisted of four N rates (0, 30, 60, and 120 kg ha-1 N). The subplots contained microplots, in which enriched ammonium nitrate (15NH4NO3) was applied at the same rates. The time of intercrop sowing affected forage dry matter production, the amount of fertilizer-derived N in and the N use efficiency by the forage plants. Nitrogen applied in autumn to palisadegrass intercropped with corn, planted either at corn sowing or at N top-dressing fertilization, increased the forage yield up to a rate of 60 kg ha-1. The amount of fertilizer-derived N by the forage plants and the fertilizer use efficiency by palisadegrass were highest 160 days after fertilization for both intercrop sowing times, regardless of N rates. Residual N did not affect the N nutrition of corn plants grown in succession to palisadegrass, but increased grain yield at rates of 60 and 120 kg ha-1 N, when corn was grown on palisadegrass straw from the intercrop installed at corn fertilization (top-dressing). Our results indicated that the earlier intercropping allowed higher forage dry matter production. On the other hand, the later intercrop allowed a higher corn grain yield in succession to N-fertilized palisadegrass.

O objetivo do estudo foi comparar a silagem de milho processada por esmagamento frente à convencional em duas relações concentrado:volumoso (60:40 e 80:20) sobre o desempenho animal. Foram utilizados 72 animais machos da raça Nelore, inteiros, com dezoito meses de idade e peso vivo inicial de 392,80 ± 24,42 kg. O delineamento experimental foi com arranjo fatorial 2 x 2 (processamentos e relação concentrado:volumoso). Não houve interação para as variáveis consumo de matéria seca e conversão alimentar. Houve efeito significativo para processamento da silagem e relação concentrado:volumoso no consumo de matéria seca em função do peso metabólico. O maior consumo foi observado com a silagem processada e para a relação concentrado:volumoso de 60:40. A relação concentrado:volumoso teve efeito sobre consumo de matéria seca/dia, com maior consumo na relação 60:40. Para ganho de peso houve interação silagem e relação concentrado:volumoso. Verificou-se menor consumo para a silagem processada na relação 80:20. O processamento da silagem de milho é uma alternativa para a pecuária brasileira, por maximizar o ganho de peso animal com adição de 60% de concentrado na dieta.

The objective of this work was to evaluate the effect of processing two corn hybrids conserved, dry and humid grains, the dry matter (DM) and crude protein (CP) degradability in situ. The particle size was determined and difference was verified in MGD (Medium Geometric Diameter) of processed ingredients. Three sheep were used with rumen canulated, in a completely randomized design, using a factorial outline 2 x 2 x 3, being two corn hybrid, two conservation methods and three processing forms (whole, coarsely and finely ground), with five times of incubation (3, 6, 12, 24 and 48 hours). The fraction A in SDC (silage of dent corn) of DM was superior to GDC (grain of dent corn) in all of the particles size. The ensiling process increased the DM solubility, reducing the fraction B in comparison to dry grain. The values regarding the fractions DP and DE the 5% per hour of the protein, were larger for SDC and GDC, it presents a decreasing when the incubation time advances. The fermentation rate was superior for SDC and GDC. The ensiling process has positive effect in the decreasing of DM and CP in comparison to GDC.

Water deficiency during the dry seasons influences the relationship between water and gas exchange in tropical grasses, reducing their productive potential. In addition, the phosphorus (P) deficiency Brazilian soils adds to the set of factors limiting crop production. In this context, the objective of this study was to evaluate the responses of different tropical forage species to phosphorus supplementation as mitigating the damage caused by water stress. Seeds of Urochloa brizantha cv. MG-4, Urochloa decumbens cv. Basilisk, Panicum maximum cv. Áries, Panicum maximum cv. Tanzânia and Paspalum atratum cv. Pojuca were germinated in pots containing 10 liters of red-yellow podzolic type soil. Experiments were conducted by combining levels of phosphorus, 8,0 and 100,0 mg of P dm-3, with two irrigation regimes, 100% and 40% replacement of transpired water. The biometric parameters, photosynthetic capacity, leaf water potential and soil chemical characteristics were evaluated, and the data was submitted to analysis of variance (ANOVA, p < 0.05), and subsequently the means were compared using a Tukey test (p < 0.05). The results showed for tropical grasses grown under water stress, there is a clear mitigating effect of phosphorus supplementation, especially on the maintenance of biomass growth.

A matéria orgânica do solo (MOS) é responsável pela fertilidade, ciclagem de nutrientes e estabilidade da estrutura, possuindo estreita relação com a agregação do solo. No entanto, ainda não é clara a relação entre as classes de agregados na dinâmica de acúmulo ou perda de MOS em função do uso e manejo do solo. Este trabalho teve como objetivo avaliar os teores de carbono (C) em agregados do solo sob quatro usos e manejos: Cerrado nativo (CE), sistema plantio direto (SPD), sistema plantio convencional (SPC) e pastagem (PA). As áreas de estudo estão localizadas no município de Rio Verde (GO), em solo classificado como Latossolo Vermelho distrófico de textura argilosa. Em amostras de solo coletadas em fevereiro de 2007 nas camadas de 0-5, 5-10 e 10-20 cm de profundidade, foram determinados: a quantidade de macroagregados (maiores que 2,0 mm), mesoagregados (maiores que 0,25 e menores que 2,00 mm) e microagregados (maiores que 0,05 e menores que 0,25 mm) estáveis em água, os índices de agregação diâmetro médio ponderado (DMP) e geométrico (DMG) e os teores de C nas classes de agregados estabelecidas. No solo avaliado observou-se predominância de macroagregados, com maior quantidade sob CE e PA, em comparação ao solo sob SPD e SPC, indicando efeito negativo do cultivo do solo na conservação de macroagregados. Contudo, os teores de C nos agregados do solo na camada de 0-20 cm foram maiores no CE e SPD em relação a PA e SPC, sugerindo que o não revolvimento e a manutenção dos resíduos culturais na superfície do solo favorecem o acúmulo de C. Com isso, foi verificado que os macro e mesoagregados podem ser mais sensíveis ao tipo de uso e manejo do solo, quando comparados aos microagregados. A agregação do solo sob PA é semelhante à do CE, embora com menores teores de C, sugerindo dinâmica de agregação diferenciada, o que merece a atenção de novas pesquisas.

O trabalho foi desenvolvido com o objetivo de avaliar a resposta das características objetivas e subjetivas das carcaças e dos não componentes da carcaça de cordeiros desmamados precocemente e terminados em pasto de azevém anual ao fornecimento crescente de suplemento concentrado (sem suplementação; 0,9%; 1,8% do peso corporal e ad libitum) na dieta. Os cordeiros foram abatidos ao atingirem 32kg de peso corporal e medidas corporais foram tomadas antes do abate. Após o abate, registraram-se os pesos da carcaça quente, do conteúdo digestivo e dos não-componentes da carcaça. As carcaças permaneceram por 24 horas em câmara fria a 5°C, obtendo-se o peso da carcaça fria. Obtiveram-se os rendimentos e as medidas objetivas e subjetivas das carcaças e, por cálculos, as compacidades de perna e carcaça. Os dados foram submetidos às análises de regressão e de correlação simples. A suplementação concentrada apresentou efeito linear positivo (PThe study was performed to evaluate the subjective and objective measurements of the carcasses and non-carcasses components of weaned lambs grazing on Italian ryegrass pasture fed with different levels of concentrate supplementation (without supplementation, 0,9%, 1,8% of body weight and ad libitum). Lambs were slaughtered at 32kg of live weight. After slaughtering, hot carcass, digestive content and weight of non-carcass components were recorded. Weight of cold carcasses was assessed after the refrigeration for 24h at 5°C. Weight, yield and carcasses measurements were taken and then the leg and carcass compactness were calculated. Data were subjected to regression and simple correlation analysis. The concentrate supplementation levels had a positive linear effect on the weights and yields of hot and cold carcass and leg and carcasses compactness. Supplementation of weaned lambs grazing on annual ryegrass enabled to get carcasses of better conformation and fat covering. These effects may result in better price opportunities and marketing for farmers.

The feeding diets were evaluated containing low and high levels of soybean oil for horses athletes subjected to two protocols of aerobic training on the response of basal blood biochemical parameters. Four horses were used in latin square design with treatments in a 2 x 2 factorial arrangement. Treatments consisted levels of 5 and 15% oil concentrates and two aerobic training, 40' and 60' minutes. Plasmatic parameters were monitored, triglyceride (TG), total cholesterol (TC), glucose (GLU) and lactate (LAC), during basal metabolism. The TG, TC, GLU and LAC from horses at rest were not affected (P> 0.05) neither of diet and physical activity, 0.21, 3.79, 4.18, 0.93 mmol L-1, respectively. It can be concluded that offer concentrate with high content of soybean oil to athletic horses in aerobic activities can be performed without altering the blood biochemical profile of basal metabolism.

There were used four castrated male horses, crossbred. It was used randomized block by design for four replications. The objective was to evaluate the effect of using samples, ground or in natura, in the precision of the mobile nylon bag technique (MNBT) in comparison to the total collection (CT) method in oder to estimate the apparent digestibility coefficient (DC) of nutrients of high-moisture grains silage of sorghum with low (SSLT) and high (SSHT) tannin in the feeding equine. No effect was observed for MNBT and CT methods with in natura sample for DC of DM, OM, CE, CP to SSLT (P>0.05), whose average values were 81.71, 84.23, 82.27 e 81.43%, respectively. The MNBT did not show acuracy to evaluate of DC of the SSHT, with ground and in natura samples. It was concluded that MNBT containing in natura sample should be used to determinating the DC of SSLT to DM, OM, CE and CP for equines.

Four castrated crossbred horses were used in a randomized block design to study the use of indigestible internal markers iNDF and iADF obtained in situ (from bovines) or in vivo (from equines). Treatments consisted of determining digestibility by the direct method comprising total feces collection (TC) and by the indirect method comprising internal markers iNDF and iADF obtained by in situ incubation in bovine rumen or in vivo by the mobile nylon bag (MNB) technique with horses. iNDF-IV and iADF-IV resulted in better marker recovery rate (RR) (91.50%), similar to TC. The in situ technique resulted in lower RR values for the two indigestible markers, averaging 86.50% (p < 0.05). Estimates of the nutrient coefficient of digestibility (CD) were adequately predicted by iADF-IV, for horses fed on hay exclusively, with rates 46.41, 48.16, 47.92 and 45.51% for dry matter (DM), organic matter (OM), FDN and gross energy, respectively. Results show that MNB may be used to obtain iADF in horses fed on coast-cross hay exclusively, whereas NDFi and ADFi were selected for horses fed on mixed diets to predict the coefficient of nutrient digestibility.Foram utilizados quatro cavalos castrados sem raça definida pelo delineamento em blocos casualizados. Objetivou-se viabilizar os indicadores internos indigestíveis, FDNi e FDAi, obtidas pelas técnicas in situ nos bovinos e in vivo nos equinos por meio do saco de náilon móvel (SNM). Os tratamentos consistiram de digestibilidade determinada por método direto com a coleta total de fezes (CT) e indireto pelo uso de FDNi e FDAi obtidos pelas técnicas in situ (IS) na cavidade ruminal de bovinos e in vivo (IV) nos equinos por meio do SNM. As FDNi-IV e FDAi-IV promoveram a melhor taxa de recuperação (TR) do indicador, igualando-se ao grupo CT, em 91,50%, enquanto a técnica in situ resultou nas piores taxas, na média 86,50%, para ambos os indicadores indigestíveis (p < 0,05). As estimativas dos CD dos nutrientes foram adequadamente preditos pela FDAi-IV, para equinos alimentados com feno, no qual os valores observados foram de 46,41; 48,16; 47,92 e 45,51% para MS, MO, FDN e EB, respectivamente. Concluiu-se que o SNM em equinos pode ser usado para obter a FDAi em equinos alimentados exclusivamente com feno de coast-cross e para cavalos consumindo dieta mista, as FDNi e FDAi foram eleitas para predizer CD de nutrientes.

Weight-age and hip height-age relations of Nellore calves, from birth to 10 months old were fitted using a logistic model including sex and year of birth as fixed effects. Calves and their dams were reared on natural pasture using continuous grazing system. The crude protein content and total digestible nutrients were analyzed for pasture selected by the animals. The weights of the calves were adjusted to 205 days and 365 days. There were no significant effects of sex and birth year on the growth curve parameters, but there were significant effects of sex on hip height. The average weight (a parameter) at 10 months of age was 170 kg and the inflection point was observed at 93.5 days old. When weight-age and hip height-age curves were combined in the same graph, the intersection occurred at 142 days. The number of days to gain 160 kg from birth to 205 days of age (adjusted) and number of days to gain 240 kg from 205 days to slaughter was different between the birth years, which were probably due to the quality of the natural pastures. It is necessary to implement nutritional management strategies such as high quality pasture and/or feeding supplementation for calves once they reach three months of age.

Four castrated crossbred horses were used in a randomized block design to study the use of indigestible internal markers iNDF and iADF obtained in situ(from bovines) or in vivo (from equines). Treatments consisted of determining digestibility by the direct method comprising total feces collection (TC) and by the indirect method comprising internal markers iNDF and iADF obtained by in situincubation in bovine rumen or in vivo by the mobile nylon bag (MNB) technique with horses. iNDF-IV and iADF-IV resulted in better marker recovery rate (RR) (91.50%), similar to TC. The in situ technique resulted in lower RR values for the two indigestible markers, averaging 86.50% (p < 0.05). Estimates of the nutrient coefficient of digestibility (CD) were adequately predicted by iADF-IV, for horses fed on hay exclusively, with rates 46.41, 48.16, 47.92 and 45.51% for dry matter (DM), organic matter (OM), FDN and gross energy, respectively. Results show that MNB may be used to obtain iADF in horses fed on coast-cross hay exclusively, whereas NDFi and ADFi were selected for horses fed on mixed diets to predict the coefficient of nutrient digestibility

The aim of this study was verify alterations in soil biologic attributes under different management systems at Cerrado. Soil samples were taken at dry (july 2006) and wet (february 2007) season at Red distrofic Oxisol (50 – 70 % clay) in Rio Verde, Brazil (17o39’07’’S - 51o06’49’’O) under: native Cerrado (CE), 20 years old pasture (PA), 29 years old conventional tillage (CT), and 10 and 15 years old no-tillage (NT - 10 and NT - 15). Were analysed: soil and microbial carbon and nitrogen levels (C, N, Cmic and Nmic), Cmic:C and Nmic:N ratios, basal respiration (BR) and metabolic quotient (qCO2). Higher soil moisture at wet season led 100 % higher Cmic and Nmic and lower qCO2 level than dry season. Among the management systems, the grass cultivation, animal wastes and area reform were possibly majors factors with which led to higher Cmic e Nmic values in PA, indeed under degradation, than any other one. NT adoption was important to increase Cmic and Nmic, and at least after 10 years pointed out higher values than CT.C and N microbial were more sensitive than total C and N, while other biological parameters also did not show differences.

O objetivo deste trabalho foi avaliar o efeito do manejo da adubação nitrogenada sobre a cultura do sorgo granífero, cultivado solteiro e em consócio com capim-marandu e capim-mombaça, e determinar a produtividade de matéria seca das forrageiras, nos anos agrícolas 2003/2004 e 2004/2005, em plantio direto. Foi utilizado o delineamento experimental em blocos ao acaso, em arranjo fatorial 3x5, com quatro repetições. Os tratamentos consistiram de três sistemas de cultivo de sorgo granífero (solteiro e consorciado com capim-marandu ou capim-mombaça, na linha de semeadura) e cinco manejos de adubação nitrogenada: 30-70; 70-30; 50-50; 100-0; e 0-100 kg ha-1 de N, quantidades aplicadas na semeadura e na cobertura, respectivamente. O cultivo consorciado não afetou a nutrição nem a produtividade de grãos de sorgo. Apenas no primeiro ano de cultivo, o parcelamento 50-50 kg ha-1 de N proporcionou maior produtividade de grãos. O manejo da palhada interferiu no estabelecimento do sorgo no segundo ano de cultivo, e diminuiu a produtividade de grãos. As maiores doses de N aplicadas em cobertura elevaram a produtividade de matéria seca do capim-marandu e, as aplicadas em semeadura, a elevaram no capim-mombaça.

O objetivo deste trabalho foi avaliar o efeito do consórcio com capim-marandu (Urochloa brizantha) na nutrição e produtividade de híbridos de sorgo granífero de ciclos contrastantes, em sistema plantio direto. Utilizou-se o delineamento experimental de blocos ao acaso, em arranjo fatorial 2x2, com seis repetições. Os tratamentos consistiram de dois híbridos de sorgo granífero de ciclos contrastantes (P8118, ciclo médio; e P8419, ciclo precoce) e dois sistemas de cultivo (monocultivo e consórcio com capim-marandu na linha de semeadura), com semeadura no início de dezembro. Avaliou-se a nutrição, as características agronômicas, os componentes da produção e a produtividade de matéria seca e grãos da cultura do sorgo. Com exceção do potássio e do enxofre, os teores foliares dos demais nutrientes foram adequados à cultura do sorgo granífero, em todos os tratamentos. O híbrido P8118 apresentou a maior produtividade de grãos e, após o consórcio, contribuiu para a maior produtividade de matéria seca da forragem de capim-marandu, no corte realizado em outubro. O cultivo consorciado com capim-marandu não afeta a nutrição e a produtividade de matéria seca e de grãos de sorgo, em comparação ao monocultivo, independentemente do ciclo do híbrido utilizado.

Diferentes sistemas de uso e manejo alteram o teor de carbono no solo (C), porém diminuições no C do solo têm sido reportadas quando áreas de Cerrado nativo são convertidas em pastagem. Disso resulta a necessidade da realização de pesquisas em diferentes sistemas e condições edafoclimáticas, a fim de elucidar as tendências encontradas. O objetivo deste trabalho foi avaliar a agregação, os teores de C e a abundância natural de δ13C do solo em uma área cultivada há nove anos sob lavoura seguida de 20 anos sob pastagem, a qual atualmente apresenta sinais de degradação (PA), comparando-a a uma vegetação nativa no bioma Cerrado (CE) que ocorre em área adjacente. As áreas de estudo estão localizadas no município de Rio Verde (GO), em solo classificado como Latossolo Vermelho distrófico, de textura argilosa. Em amostras de solo coletadas nas camadas de 0-5, 5-10 e 10-20 cm de profundidade, foram determinados a distribuição de agregados estáveis em água (micro, meso e macroagregados), o diâmetro médio aritmético (DMA) e geométrico (DMG), os teores de C total e de δ13C, o tempo de residência média do C (TRM) e a fração da matéria orgânica leve livre (FLL). Os resultados indicaram que o uso sob lavoura seguido de pastagem reduziu em 21 % o estoque de C original, possivelmente devido ao menor aporte de material na FLL. O solo apresentou elevada agregação e não houve diferenças significativas entre as áreas avaliadas. No entanto, os teores de C nos macroagregados foram menores na PA em relação ao CE, enquanto nos microagregados não houve diferença entre os sistemas de uso, sugerindo, respectivamente, maior e menor sensibilidade ao manejo e menor e maior proteção do C por essas classes de agregados. Os valores de TRM e as análises isotópicas reforçaram esses resultados, mostrando, ainda, substituição de 83 % do C original durante os 29 anos de cultivo. O constante aporte de resíduos vegetais, assim como a manutenção do C no interior dos macro e mesoagregados, são importantes fatores para que ocorra o acúmulo de C nesse tipo de solo.

Com o objetivo de avaliar o efeito dos níveis de suplementação com concentrado contendo 25 % de PB e 3,18 Mcal EM kg-1 MS-1 para cordeiras em pastagem com comedouro privativo sobre o peso e desempenho em distintas idades, início da puberdade e desempenho reprodutivo, foram utilizadas 21 cordeiras Suffolk, divididas em três lotes, sem e com suplementação, alimentadas do nascimento ao desmame com dois níveis de ingestão de concentrado (300 e 600g dia-1) fornecido uma vez ao dia com o registro das sobras diárias. As cordeiras foram identificadas, pesadas ao nascimento e a cada 30 dias, sendo desmamadas aos 60 dias. Não houve diferença significativa para peso e ganho médio de peso diário aos 30 dias de idade. O peso e ganho médio de peso diário foram influenciados pelo nível de suplementação alimentar. O lote com consumo de 600 g mostrou desempenho superior aos demais lotes aos 60 e 120 dias de idade. Para os lotes de 300 gramas e sem suplementação não houve diferença para os parâmetros analisados. A disponibilidade de 600 g diários de concentrado para as cordeiras até o desmame promoveu maior ganho médio de peso diário aos 60 e 120 dias de vida e melhor desempenho reprodutivo no segundo ano de cobertura.

A conversão de áreas nativas com o corte e queima de vegetação seguida do cultivo do solo resultam em mudanças na dinâmica da matéria orgânica do solo, com alterações nas emissões dos gases causadores de efeito estufa (GEE: CO2, CH4 e N2O) da biosfera para a atmosfera, que causam a elevação da temperatura média e, consequentemente, as mudanças climáticas globais. O objetivo deste estudo foi verificar as relações entre os fluxos de CO2, CH4 e N2O com a umidade, biomassa microbiana e as formas inorgânicas de N no solo com diferentes usos das terras no bioma Cerrado (Rio Verde, Goiás). O clima da região é do tipo Aw (Köppen-Geiger), e o solo foi classificado como Latossolo Vermelho distrófico caulinítico textura argilosa com vegetação original de Cerradão. O delineamento experimental foi inteiramente casualizado (DIC), com quatro tratamentos (áreas): vegetação nativa - Cerradão (CE); pastagem (PA) de braquiária, semeadura convencional (SC) de soja; e semeadura direta (SD) de milho sucedido por milheto. As emissões anuais de CO2 e N2O não mostraram diferenças significativas entre os tratamentos; isso ocorreu devido à elevada variação nos fluxos dos gases em decorrência da sazonalidade no clima, com as menores emissões observadas durante o inverno, devido à ausência da umidade do solo. A média na emissão de CO2 foi de 108,9 ± 85,6 mg m-2 h-1 , e para o N2O, de 13,5 ± 7,6 µg m-2 h-1. Os fluxos de CH4 apresentaram diferenças significativas somente para a pastagem, com emissão de 32 µg m-2 h-1 , enquanto nas demais áreas foram observados influxos entre 46 e 15 µg m-2 h-1 . Com os resultados das correlações, pode-se verificar que a umidade foi a variável do solo que apresentou maior correlação com o fluxo dos três gases de efeito estufa. O teor de N-NO3- e as emissões de CO2 mostraram correlações para todas as áreas. Quando consideradas as correlações para todos os tratamentos conjuntamente, verificou-se que os fluxos dos três gases apresentaram correlações significativas com os teores de C e N-microbiano. Contudo, a relação Cmicro:Nmicro não mostrou correlação significativa com o fluxo dos gases de efeito estufa. A pastagem foi a única situação em que os fluxos de CO2 e N2O apresentaram correlação com as quantidades de N-inorgânico. Os resultados sugerem que os fluxos dos GEE são dependentes do regime pluvial no bioma Cerrado, principalmente nas áreas cultivadas que recebem altas doses de fertilizantes para o aumento da produtividade.

This research evaluated corn grains with flint and dent texture (ensiled high-moisture or dried), submitted to grinding degrees, using the in situ ruminal degradation technique. Three rumen canulated adult sheeps were used in a complete randomized design, using a factorial outline 2 x 2 x 3, with two corn hybrids (flint and dent texture), two conservation methods (ensiled high-moisture and dry) and three grinding degress (whole, coarsely and finely ground, corresponding to the sieve of 12; 10 and 8 mm). Starch soluble fraction (A) of the dent hybrid ensiled corn grains was greater comparing to the dry materials and in both conservation forms this fraction was reduced in the flint texture hybrid, while the insoluble fraction potentially degradable (B) the opposite occurred. The degradation potential was higher in grains ensiled in two textures. The ensiled allowed more starch effective degradation in relation to dry grain in two textures and the grains dent texture hybrid also increased such degradation in both conservation methods. The dent texture and the ensiled high-moisture grains proved the best option considering the starch degradability. Regardless of the conservation forms, the grains of corn hybrid flint texture should be finely ground, for providing higher ruminal degradation, while for the dent texture hybrid, the coarsely and whole grinding are the most suitable for ensiled and dry grain, respectively.

This study was carried out at Campo Experimental do Cerrado in Embrapa Amapá, Brazil, aiming to select, based on the agronomic characteristics of productivity, dry matter and nutritional quality of the forage, the accesses of species from the genus Paspalum that possess potentiality of use as forage plants. During the years 2000, 2001 and 2002, 21 accesses of grasses were evaluated, including 18 of Paspalum and three control species: Brachiaria decumbens, Andropogon gayanus cv. Baetí and Brachiaria brizantha cv. Marandú. The experimental design was complete randomized block with three replications. The variables studied were: production of dry matter, neutral detergent fiber on the dry matter, in vitro digestibility of dry matter and crude protein content in the dry matter. All the accesses showed marked reduction in productivity and quality of produced forage, when the climatic conditions became unfavorable, showing that Paspalum as the other tropical grasses have high seasonal production. Based on the variables studied, the selected accesses were P. guenoarum (BRA-014851), P. atratum (BRA-9661) and Paspalum sp. (BRA- 009407).

This study was conducted at University of Marília, SãoPaulo State, Brazil, aiming to determine the phase of intake transitionbetween exclusively liquid diet (milk) and diet based onmilk, grass and/or ration by lambs by δ13C technique. Six Suffolkcrossbreeding lambs were distributed in a totally random design(3x2), with two experimental groups and three replications. At thefirst one, lambs were penned and sucked milk from dams fed withC4 diet. besides, they had access to C3 ration in creep feeding, sincetheir birth. At the second group, lambs were kept on a paddock withTifton – 85 grass (C4 photosynthetic way) as well as their dams andhad access to C3 ration in creep feeding, since their birth. The C3ration contained soybean meal, ground oat grains, lucerne hay andalso mineral salt. The penned lambs’ ration consumption overcamethe milk intake at 30-35 days after birth; however, grazing lambsingested more milk and pasture than ration until 40 days afterbirth. The δ 13C technique was considered effective on studies oflambs feeding behavior.

Mulberry leaves (IZ 56/4 cultivar) in the pos-harvest, had been taken to the laboratory and submitted to six storage environments (8 hours in open ambient-O, 8 hours in cover ambient- C, 1hO/7hC, 2hO/6hC, 3hO/5hC and 4hO/4hC), aiming to evaluate moisture exchange capacity . It was utilized the experimental design split plot with five replications (blocks), six principal treatments (parcels) and nine secondary treatments (sub parcels, weighing of hour in hour, of 08h00min. until 16h00min.). In the period of eight hours of experimentation mulberry leaves moisturedevreased in all the ambients evaluated. However, for cover leaves with wet cloth, for all periods, the water purport (74,63%) was maintained close to the original value (08h00min.- 76,07%), demonstrating the efficiency technique in the conservation of the humidity of leaves for feeding silkworm.

National inventories of anthropogenic greenhouse gas (GHG) emissions (implementation of the National Communications) are organized according to five main sectors, namely: Energy, Industrial Processes, Agriculture, Land-Use Change and Forestry (LUCF) and Waste. The objective of this study was to review and calculate the potential of greenhouse gas mitigation strategies in Brazil for the Agricultural and LUCF. The first step consisted in an analysis of Brazilian official and unofficial documents related to climate change and mitigation policies. Secondly, business as usual (BAU) and mitigation scenarios were elaborated for the 2010-2020 timeframe, and calculations of the corresponding associated GHG emissions and removals were performed. Additionally, two complementary approaches were used to point out and quantify the main mitigation options: a) following the IPCC 1996 guidelines and b) based on EX-ACT. Brazilian authorities announced that the country will target a reduction in its GHG between 36.1 and 38.9% from projected 2020 levels. This is a positive stand that should also be adopted by other developing countries. To reach this government goal, agriculture and livestock sectors must contribute with an emission reduction of 133 to 166 Mt CO2-eq. This seems to be reachable when confronted to our mitigation option values, which are in between the range of 178.3 to 445 Mt CO2-eq. Government investments on agriculture are necessary to minimize the efforts from the sectors to reach their targets.Inventários nacionais acerca de emissões de gases do efeito estufa (GEE) (refinamentos das Comunicações Nacionais) são organizadas de acordo com cinco principais setores, a saber: Energia, Processos Industriais, Agropecuária, Mudanças do Uso da Terra e Florestas e Tratamento de Resíduos. O objetivo dessa revisão foi calcular o potencial das estratégias de mitigação de GEE no Brasil para agropecuária e mudança de uso da terra e florestas. A primeira etapa consistiu na análise de documentos oficiais e não-oficiais do Brasil relacionados a mudanças climáticas e políticas de mitigação. O cenário atual, sem adoção de ações mitigadoras (BAU), e os cenários de mitigação foram elaborados para o período 2010-2020. Efetuaram-se os cálculos associados às emissões e remoções de GEE. Adicionalmente, duas estratégias foram utilizadas para destacar e quantificar as principais opções de mitigação: a) seguindo metodologia do IPCC 1996 e b) baseando-se no EX-ACT. Autoridades brasileiras anunciaram que o país buscará reduzir sua taxa de emissão de GEE em 36.1 a 38.9% em relação a 2020. Este é um posicionamento positivo que deve ser adotado por outros países em desenvolvimento. Para alcançar essa meta governamental, os setores agricultura e pecuária devem contribuir reduzindo a emissão em 133 a 166 Mt CO2-eq. Tal redução parece ser atingível quando confrontada com os valores do presente trabalho sobre opções de mitigação os quais estão entre 178,3 e 445 Mt CO2-eq. Investimentos governamentais nos setores agrícola, pecuária e silvicultura são necessários para minimizar os esforços para atingir as metas de redução de emissão pelos outros setores do país.

Due to its nutritional characteristics sorghum has been indicated as substitute cereal to corn and wheat. Besides, in Brazil sorghum is not used for human feeding unlike corn, witch reduces its costs in almost 20% in comparison to corn costs. This research was conducted at UNESP, in Botucatu and Jaboticabal Campus, São Paulo, Brazil, with the purpose to evaluate the grinding effect on two sorghum genotypes grain (with and without tannin) preserved dry or ensiled humid above the degradability in situ of the dry matter, crude protein and starch. Three rumen fistulated sheep were used, distributed in an experimental block design, at 2 x 2 x 3 factorial outline, with two sorghum genotypes (with and without tannin), two forms of conservation (dry grain and high moisture grains silage) and three grinding ways (undivided, thick grinding and fine grinding) and the time as sub-portion. According to the results the grinding is recommended to sorghum grains because it increases the ruminal and effective degradability of the dry matter, crude protein and starch. The presence of tannin in sorghum grain changed the degrability potential of crude protein and starch. The thick grinding in dry grain without tannin was the better treatment.

This article analyses the greenhouse gas (GHG) impact potential of improved management practices and technologies for smallholder agriculture promoted under a global food security development program. Under ‘business-as-usual’ development, global studies on the future of agriculture to 2050 project considerable increases in total food production and cultivated area. Conventional cropland intensification and conversion of natural vegetation typically result in increased GHG emissions and loss of carbon stocks. There is a strong need to understand the potential greenhouse gas impacts of agricultural development programs intended to achieve large-scale change, and to identify pathways of smallholder agricultural development that can achieve food security and agricultural production growth without drastic increases in GHG emissions. In an analysis of 134 crop and livestock production systems in 15 countries with reported impacts on 4.8 million ha, improved management practices and technologies by smallholder farmers significantly reduce GHG emission intensity of agricultural production, increase yields and reduce post-harvest losses, while either decreasing or only moderately increasing net GHG emissions per area. Investments in both production and post-harvest stages meaningfully reduced GHG emission intensity, contributing to low emission development. We present average impacts on net GHG emissions per hectare and GHG emission intensity, while not providing detailed statistics of GHG impacts at scale that are associated to additional uncertainties. While reported improvements in smallholder systems effectively reduce future GHG emissions compared to business-as-usual development, these contributions are insufficient to significantly reduce net GHG emission in agriculture beyond current levels, particularly if future agricultural production grows at projected rates.

No presente trabalho que foi realizado na Fazenda Experimental Lageado, da Universidade Estadual Paulista em Botucatu, SP, objetivou-se avaliar os custos envolvidos na produção de silagem de grãos úmidos de milho, tendo como referência o processamento seco deste cereal, ambos cultivados em sistema de plantio direto. Para a avaliação foram determinados os custos envolvidos nas operações de máquinas agrícolas, insumos e na etapa de pós-colheita. Os resultados observados permitiram concluir que o custo por hectare para produção de silagem de grãos úmidos foi de R$1.398,06, sendo 8,8% menor do que os custos para produção de milho seco (R$ 1.533,78).This work was carried out at FCA-Botucatu/UNESP - São Paulo State University, with the aim to evaluate the costs involved in high moisture corn silage production, using the corn drying process as witness, both cultivated in no-tillage system. The costs involved in the operations of agricultural machines, inputs and post harvest phase were obtained for evaluation. The results allowed concluding that the cost per hectare for high moisture corn silage (US$ 607.85) was 8.8% smaller than the costs for dried corn (US$ 666.86).

Objetivou-se avaliar os efeitos dos aditivos própolis verde, própolis marrom e monensina sódica sobre as características de carcaça, avaliadas por ultra-som e pós-abate, os componentes corporais e o rendimento de cortes de cordeiros terminados em confinamento. Foram utilizados 32 cordeiros machos, com oito animais por tratamento, mantidos em confinamento por 64 dias. Os animais receberam dieta com relação volumoso:concentrado de 50:50, à base de feno de capim-tifton 85 (Cynodon spp.) e concentrado comercial. O delineamento experimental foi o de blocos ao acaso, com oito animais por dieta, distribuídos aleatoriamente de acordo com o peso: controle, dieta sem aditivo, própolis verde, própolis marrom e monensina sódica. Os rendimentos de carcaça (verdadeiro, quente e comercial) não diferiram entre os aditivos, com médias de 54,97; 44,89 e 41,81%, respectivamente. Os componentes corporais e rendimento de cortes comerciais não foram influenciados pelos aditivos utilizados nas dietas. A metodologia utilizada na determinação teve efeito nas medidas de área de olho-de-lombo (AOL) e espessura de gordura subcutânea (EGS), de modo que, pelo método tradicional, com medidas na carcaça, foram obtidas as maiores médias para AOL (12,14 vs. 9,08 cm²) e as menores para EGS (2,42 vs. 2,69 mm). A correlação entre as medidas de área de olho-de-lombo (AOL) da carcaça e aquelas obtidas por ultra-sonografia foi de 0,8597. Os aditivos não influenciaram as características de carcaça, os componentes corporais e o rendimento de cortes de ovinos terminados em confinamento. A realização de medidas ultra-sonográficas de AOL e marmoreio pode ser utilizada na avaliação de carcaça in vivo em ovinos.This work was aimed at evaluating the effects of green propolis, brown propolis and sodic monensin aditives on the carcass characteristics by means of ultrasound and after-slaughter measures such as carcass non-components and yield of retail products from lambs finished in feedlot system. Thirty-two male lambs, with eight animal per treatment, were feedlot during 64 days. The animals were fed a diet with roughage:concentrate ratio of 50:50, composed of Tifton 85 hay grass (Cynodon spp.) and commercial concentrate. The experimental design was a randomized block design, with eight animals randomly assigned according to weight and the following treatments: control, diet without additive, green propolis, brown propolis and sodic monensin. The true, hot and commercial carcass percentage did not differ between treatments, with means of 54.97; 44.89 and 41.81%, respectively. Carcass non-components and yield of retail products were not influenced by treatments. The methodology used in the determinations affected the LEA and FT measures, so that the traditional method, obtained through measures in the carcass presented the highest averages for LEA (12.14 vs. 9.08 cm²) and lowest for FT (2.42 vs. 2.69 mm). The correlation between the of loin eye area (LEA) measures of the carcass with those obtained by ultrasound scan was 0.8597. The additives did not influence the carcass characteristics, non- components and yield of retail products from lambs finished in feedlot system. The performance of LEA and marbling ultrasound measures can be used in the in vivo carcass evaluation in sheep.

The objective of this experiment was to verify the outcome of the grazing above the productivity and the persistence of three accesses of Paspalum. The experiment was developed on Southeastern Cattle Embrapa, in São Carlos, SP, in the period of January to December 2005. Three genotypes of Paspalum (Paspalum. Guenoarum – BRA-006572, Paspalum malacophyllum - BRA-003077 and Paspalum atratum – BRA-011681) and two controls (Brachiaria decumbens and Paspalum atratum cv. Pojuca) were compared under two grazing intensities (1500 and 3000 kg MS/ha of post-graze residue). Plots were mob grazed (1-day grazing followed by 27-day rest (water period) and 1-day grazing followed by 55-day rest (dry period) and stocking rate was adjusted according to the herbage mass available and the treatment grazing intensity. The following variables have been evaluated: total herbage mass before and after grazing; proportion of leaf, stem and dead material; occurrence of weeds and tiller density and occurrence of diseases and symptoms of mineral toxicity or deficiency. For both grazing intensities the Paspalum atratum demonstrated positive characteristics of production and persistence indicating that these are promising genotypes for use in intensive systems of pasture. KEY WORDS: Intensity of grazing, pasture, production of forage, tillers. Desenvolveu-se o experimento na Embrapa Pecuária Sudeste, localizada em São Carlos, SP, no período de janeiro a dezembro de 2005, objetivando verificar o efeito do pastejo sobre a produtividade e a persistência de três acessos de Paspalum (Paspalum guenoarum – BRA-006572, Paspalum malacophyllum – BRA-003077 e Paspalum atratum – BRA-011681) comparados com duas testemunhas (Brachiaria decumbens e Paspalum atratum cv. Pojuca), em dois níveis de desfolha (1.500 e 3.000 kg MS/ha de resíduo pós-pastejo). O ensaio foi do tipo mob grazing, em que se utilizou o método de pastejo rotacionado com 27 dias de descanso e um dia de ocupação (período das águas) e 55 dias de descanso e um dia de ocupação (período das secas). Ajustou-se a taxa de lotação animal das parcelas de acordo com a massa de forragem disponível antes do pastejo e com o nível de desfolha previsto pelos tratamentos. As variáveis foram: massa de forragem antes e após o pastejo; proporções de folhas, hastes e material morto; densidade de perfilhos; incidência de plantas invasoras; observações relativas à susceptibilidade a pragas e doenças, sintomas de toxidez e deficiência mineral. O Paspalum atratum BRA-011681 apresentou características positivas de produção e persistência, tanto na altura de pastejo de 0,15 m como na de 0,30 m, evidenciando que essa espécie é promissora para uso em sistemas intensivos de pastejo. PALAVRAS-CHAVES: Intensidade de pastejo, pastagem, perfilhos, produção de forragem.