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Canopy adaptation to shade can make forage nutritive value in a silvopastoral system similar or even greater than of open pasture. Our objective was to evaluate the shading effect on nutritive value of Marandu palisade grass [Urochloa brizantha (Hochst A. Rich) Stapf] under clipping in a silvopastoral system (SPS) with Eucalyptus urograndis (hybrid of Eucalyptus grandis W. Hill ex Maiden × Eucalyptus urophylla S.T. Blake) compared with an open pasture system, in the Amazon biome. The SPS plots were evaluated for 2 growing seasons at four distances from the Eucalyptus grove (3, 6, 10, and 15 m), on the north and south of the grove. Each grove consisted of 3 rows of trees planted in an east–west direction. Total herbage (3450 kg DM/ha) and leaf accumulation (2760 kg DM/ha) did not differ between systems. Forages growing north of tree rows (i.e., under greater shade) had lesser leaf proportions (81 vs. 78%) and greater accumulated stems, however, was offset by the greater SLA, not affecting the leaf accumulation. Crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) concentrations were 14.8, 4.9, and 10.9% greater in the SPS. The CP concentration was greater at 3 m (16%) than 10 and 15 m (14.6%), regardless of the face. The Marandu palisade grass grown in SPS had similar total herbage accumulation and greater nutritive value compared with an open pasture, which associated with a shaded environment may potentialize animal performance, making this system an interesting option for sustainable forage-livestock systems.

Leaching and nitrous oxide (N2O) emissions can represent substantial nitrogen (N) losses from chemical fertilizers, and slow-release fertilizers (SRFs) can mitigate these effects. Thus, biochar can be an alternative from an agronomic and environmental point of view to synthesize SRFs due to its physicochemical characteristics. We investigated the effect of nitrogenous organomineral fertilizers (OMF-N) formulated based on activated biochar on N losses by leaching and N2O emissions. The OMF-N were developed from a dry mechanical pelleting process with different biochar and urea proportions (2:1; 1:2, and 1:4). Three experiments were conducted using four fertilizer sources (urea, OMF-N 2:1, OMF-N 1:2, and OMF-N 1:4): i. to analyze the kinetics of N release from OMF-N at times: 5, 15, 30, 60, 90, and 120 min; ii. for N2O emission analysis determined at 3, 6, 10, 14, 24, 44, 54, 64, 74, 84, 104, and 118 days after application to the soil; and iii. for a double factorial design that was adopted to analyze N leaching, consisting of the combination of applying 160 kg N ha−1 of fertilizers in PVC columns at different depths (20, 40, 60, and 80 cm) and analyzed at five times (1, 7, 14, 21, and 28 days). FTIR spectroscopic analysis, specific surface area, porosity, and surface morphology showed physicochemical interactions of N of the OMF with biochar; the N from the OMF interacts physically and chemically binds to the functional surfaces of biochar, delaying the dissolution flow. The OMF-N proved capable of retaining 48% to 60% more NH4+ and reduced the release of Ntotal from urea from 27% to 60%, as well as reduced N2O emissions from 47% to 66%. Although absolute CO2 emissions intensified with the application of OMF-N, its use provides C sequestration in the soil to due to the recalcitrant C of the biochar, which results in a positive input-output balance in the system. The NO3− concentration profiles revealed that the OMF-N application was able to reduce leaching in the soil to a depth of 80 cm. These studies enabled better understanding of the processes involved in the biochar:urea interaction and revealed that biochar can be used as an organic matrix in the synthesis of SRF.

In the Brazilian Amazon, nitrogen input strategies are required to maintain forage-livestock systems productivity. However, greenhouse gases (GHG) emissions mitigation from tropical soils is also a global demand. This research aims to assess productivity and nitrous oxide (N2O) emissions from Oxisol cultivated with Marandu palisade grass (Brachiaria brizantha [Hochst. Ex A.Rich.] Stapf) submitted to nitrogen (N) input strategies (N fertilization and biological N fixation) in the Brazilian Amazon. The treatments were the following: control (unfertilized); U40 (fertilized with 40 kg N/ha as urea); U80 (fertilized with 80 kg N/ha as urea); AS40 (fertilized with 40 kg N/ha as ammonium sulfate); AS80 (fertilized with 80 kg N/ha as ammonium sulfate); and IAB (inoculated with Azospirillum brasilense ). From January to March 2016, soil N2O emission, forage accumulation (FA) and relative emission (RE) were assessed during two 28-day cycles. The FA was greater in the U80 and AS80 than in control and IAB. The highest peaks of soil N2O flux occurred from 4 to 7 days after N fertilization, primarily in the highest N rates treatments. Overall, 40 kg N/ha resulted in higher N2O flux than control and IAB, which were lower than 80 kg N/ha regardless of the N source. The lowest fluxes occurred in the control and IAB (below 20 ug N-N2O m-2 hr-1). All of the emission factors (EF) calculated for both fertilizers and rates were lower than 0.35%, which is below the 1% established by the IPCC. Our results indicate the need for discussion of the EF in the pasture intensification to contribute to avoid deforestation and mitigating emissions. The inputs of 40 kg N/ha per application with urea or ammonium sulfate, due to the low EF and RE, are recommended as a pasture N input strategy in the Brazilian Amazon. Made available in DSpace on 2022-01-29T02:06:21Z (GMT). No. of bitstreams: 1 2021-cpamt-bcp-nitroux-oxide-emissions-forage-accumulation-brazilian-amazon-forage-livestock-systems-input-strategies.pdf: 918233 bytes, checksum: cdb36c91edc2d8b49149523b66a85855 (MD5) Previous issue date: 2021

This study evaluated sorghum cultivars? agronomic performance and ensilability with different purpose. The experiment was conducted in Sinop/MT in the 2020 growing season. Eight experimental hybrids from Embrapa (forages 15F30005 and 15F30006, sweet CMSXS 5027, 5030, 5043, and 5045, and biomass 2019B008 and CMSXS 7501), and seven commercial hybrids (forages BRS 658, BRS 659, Volumax, BRS Ponta Negra, the sweet BRS 511, and biomass BRS 716 and AGRI-002E) were planted in a randomized block design, with 15 treatments and three replicates. The highest yields in green matter belonged to the group formed by BRS 716 and CMSXS 5043, with an average of 101.9 Mg ha-1. The group with the highest dry matter productivity was formed by the cultivars AGRI-002E and BRS 716, with a 28.77 Mg ha-1 average. BRS 716, AGRI-002E, BRS 658, and 659 showed higher dry matter contents (DM), with 297.7 g kg-1 of DM. For buffering capacity, BRS 511 had the lowest value, with 16.2 g kg-1 DM. BRS 511 and CMSXS 5030 presented the highest average, 391.7 g kg-1 DM for water soluble carbohydrates. All genotypes showed potential to be ensiled and produce silages with a good fermentation pattern. RESUMO - Objetivou-se avaliar o desempenho agronômico e a ensilabilidade de cultivares de sorgo com diferentes aptidões. O experimento foi conduzido em Sinop/MT, com plantio na Safra 2020. Oito híbridos experimentais da Embrapa (os forrageiros 15F30005 e 15F30006, os sacarinos CMSXS 5027, 5030, 5043 e 5045 e os biomassa 2019B008 e CMSXS 7501) e sete comerciais (os forrageiros BRS 658, BRS 659, Volumax, BRS Ponta Negra, o sacarino BRS 511, e os biomassas BRS 716 e AGRI-002E) foram plantados em delineamento de blocos casualizados, com 15 tratamentos e três repetições. As maiores produtividades em matéria verde foram observadas no grupo formado por BRS 716 e CMSXS 5043, com média de 101,9 Mg ha-1. Para produção em matéria seca (MS), os cultivares AGRI-002E e BRS 716 compuseram o grupo de maior média, com 28,77 Mg ha-1. BRS 716, AGRI-002E, BRS 658 e 659 obtiveram maiores teores de matéria seca, com 297,7 g kg-1 de MS. Para capacidade tampão, BRS 511 obteve menor teor, 16,2 g kg-1 MS. Para carboidratos solúveis, BRS 511 e CMSXS 5030 apresentaram a maior média, de 391,7 g kg-1 MS. Todos os genótipos se mostraram passíveis de serem ensilados e produzirem silagens de adequado padrão fermentativo. Made available in DSpace on 2022-07-11T13:19:52Z (GMT). No. of bitstreams: 1 Characterization-of-forage-sweet-and-biomass-sorghum.pdf: 757937 bytes, checksum: 82c98d88e26f9532415126d008cdd29f (MD5) Previous issue date: 2022

Maize is an important crop around the world supporting food security, especially in developing countries. The increasing demand for food and renewable energy resources has been supported studies of competitiveness and complementarity interactions between trees, crops, and animals. Thus, the integrated systems should promote a synergic relationship between the components, resulting in greater production of crops, animals, and forestry. Our objective was to describe recent advances on maize production in integrated systems and how recent research can contribute to intensify and/or diversify the production system. The current literature supports the following appointments. The increase in the soil organic carbon in integrated systems improves the physical (density and aggregate stability), chemical (nutrient retention), and biological (greater diversity and microbial mass) properties. Great grain yield and input reduction are possible with the microbial inoculants' use. The inoculants' action is maximized when associated with fertilizers and/or biochar. The biochar acts as a soil conditioner, increasing the water and nutrients retention in the soil, favoring the maize growth. Maize can be grown in the understory (moderate shade), but productivity will be reduced. Thus, we identified the need for research on shading-tolerant genotypes, intercropped management to minimizes competition, quantification of the stratified light profile by a system component (tree, maize, and grass), and more complex and accurate mathematical models to support decisions in the integrated systems arrangements. Understanding these practices would encourage producers to enhance the use of integrated systems.

Silvopasture is an alternative to open pasture (OP), but the effect of trees on understory grass canopy structure and tiller morphology is not well defined. Our objective was to compare herbage accumulation, canopy structure, and tiller morphology of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. cv. Marandu (palisadegrass) growing in OP or in silvopasture with Eucalyptus urograndis (hybrid of E. grandis W. Hill ex Maiden and E. urophylla S. T. Blake), in the Amazon biome. From October 2015 to September 2016, all experimental units were stocked continuously with beef cattle using a variable stocking rate to maintain a palisadegrass canopy height of 30 cm. The trees were planted in triple-row groves (3.0 m between trees, 3.5 m between rows), with 30 m between groves, totaling 270 trees ha−1. The herbage accumulation (HA) was similar among systems (averaging 12.1 Mg ha−1 year−1). The silvopasture decreased herbage mass (HM) 24% and herbage bulk density (HBD) by 20% compared with OP. Tiller leaf area was 18% greater in the silvopasture. Total number of leaves (4.95 ± 0.26), and live leaves tiller−1 (3.25 ± 0.14) were not affected by system or system × season interaction. In a silvopasture, palisadegrass maintained leaf area index, number of total, live and dead leaves, tiller weight, internode length and stem length similar to the OP. Under moderate shade, especially at 4-m distance from the edge row of trees, palisadegrass enhanced the area of each leaf while the number of live leaves tiller−1 and tiller density decreased in order to maintain productivity. Silvopasture has potential as an alternative system for livestock production in the Brazilian Amazon Biome.

Diversification of monoculture grass pastures may provide opportunity for increased productivity, efficiency, and sustainability of forage-livestock systems. Our objective was to compare herbage accumulation (HA), nutritive value, and animal performance on a grass monoculture control and two alternative systems, all based on ‘Marandu’ palisadegrass [Brachiaria (syn. Urochloa) brizantha (A. Rich.) Stapf] in the Amazon Biome. Alternatives were a crop-livestock system based on soybean [Glycine max (L.) Merr.] and palisadegrass, and a eucalyptus [Eucalyptus urograndis (hybrid of E. grandis W. Hill ex Maiden and E. urophylla S. T. Blake) clone H13]-palisadegrass silvopasture. From July 2017 to May 2018 all experimental units were stocked continuously with beef cattle using a variable stocking rate to maintain a palisadegrass canopy height of 30 cm. The grass monoculture and silvopasture systems had similar HA (13,200 kg dry matter [DM] ha−1) and herbage accumulation rate (HAR; 40 kg DM ha−1 day−1), whereas crop-livestock resulted in greater HA (127%) and HAR (158%) than the other systems. Animal weight gain ha−1 for crop-livestock was 860 kg, 15% greater than for grass monoculture and silvopasture systems (average of 750 kg). Greatest palisadegrass HA and animal performance following 2 years of soybean production support the crop-livestock as an alternative for sustainable intensification. The similar HA and gain ha−1 in the seventh year of the silvopasture and grass monoculture indicates tree-pastures systems need wider arrangements to warrant long-term productivity. The maintenance of soil fertility, appropriate grazing management, and animal nutritional supplementation can greatly improve forage-based systems in the Amazon Biome.

Brazil is one of the few countries in the world that can produce animal products, grains, fibers, and bioenergy in the same area, either in a consortium, rotation, or succession. Our objective was to compare pasture productivity and animal performance in agroforestry systems with grass monoculture in the Brazilian Amazon Biome. The experiment was carried out in Sinop, MT, Brazil, with Nellore steers in a continuous stocking with variable stocking rate. The experimental design was a randomized complete block, with four systems and four replicates. The palisadegrass [Brachiaria brizantha (Hochst. ex A. Rich.) R. D. Webster cv. Marandu] was planted in the four systems: livestock (grass monoculture); livestock–forestry [eucalyptus trees (Eucalyptus urograndis; hybrid of Eucalyptus grandis W. Hill ex Maiden and Eucalyptus urophylla S. T. Blake) arranged in three-row groves spaced 30 m apart]; crop–livestock (palisadegrass after two years of crops); and crop–livestock–forestry (palisadegrass after two years of crops with single rows of eucalyptus trees spaced 37 m apart). The herbage accumulation was greater in the systems with the two previous cropping years (crop–livestock and crop–livestock–forestry) than in the livestock and livestock–forestry, in both seasons. In the crop–livestock–forestry, the greatest herbage accumulation associated with the modified microclimate supported the greatest average daily gain (0.750 kg BW day− 1), stocking rate in both seasons, resulting in the greatest gain per area (940 kg BW ha− 1). We conclude that agroforestry systems assure pasture productivity and animal performance similar or greater than livestock (grass monoculture). Furthermore, the combination of two previous crop years and the least tree density optimized the synergy between crop, livestock, and forestry components, improving beef cattle productivity in crop–livestock–forestry systems.

The main system for feeding cattle in Brazil is the forage-based. It happens due to low cost and high potential of forage production, which can be widely explored in a tropical climate country. Although, the nutritive value of the forage oscillates according to the grazing management. The success in production is related to the three main stages: herbage growth, consumption by grazing animals and conversion into animal product, maximizing profitability while providing sustainability. Thus, the objective with this literature review is to address detailed information on how grazing management can affect qualitative indicators of forage plants. Made available in DSpace on 2018-11-06T23:39:10Z (GMT). No. of bitstreams: 1 2018cpamtbrunopedreiragrazingmanagementforagequalitative.pdf: 368238 bytes, checksum: 59e4ae0a3b7510023ceae3591a783e5d (MD5) Previous issue date: 2018-11-06

The effect of the association of non-protein nitrogen, yeast, and bacterial probiotics on the ruminal microbiome of beef cattle intensively finished on pasture was evaluated. The experiment was carried out in a completely randomized design with five treatments and four replications. The treatments consisted of a group of animals kept on pasture that received low consumption supplementation (LS) and four groups that received for 98 days, 17.5 g concentrate kg-1 body weight. The supplements were composed of the association of additives: urea (U), slow-release non-protein nitrogen (U+SRN), yeast (Saccharomyces cerevisiae; U+SRN+Y), and bacterial probiotics (live strains of bacteria; U+SRN+Y+BP). All supplements also contained salinomycin and virginiamycin. After slaughtering the animals, samples of ruminal content were collected to quantify groups of fibrolytic bacteria (Ruminococcus albus and Fibrobacter succinogenes), non-fibrolytic (Prevotella ruminicola, Selenomonas ruminantium, and Streptococcus bovis), Archaea, and ciliate protozoa, using the qPCR technique. The abundance of F. succinogenes was the same for the LS animals and those that received the supplement U+SRN+Y (1.42×108 copies mL-1) but higher than the other treatments. Supplementation reduced by 90% the abundance of S. bovis compared to the LS. The inclusion of yeast increased the abundance of fibrolytic bacteria by 2.2-fold. For animals that received the supplement U+SRN+Y+BP and the LS, there was no difference for non-fibrolytic bacteria (3.07×109 copies mL-1). The use of yeasts and sources of non-protein nitrogen in high-concentrate diets for beef cattle stimulates the growth of fibrolytic bacteria, which can contribute to the reduction of digestive disorders and metabolic diseases in animals that receive diets with high concentrate in pasture intensive termination systems.

EN-US: The objective with this study was to evaluate the effect of different levels of water inclusion on the chemical composition and fermentation profiles of reconstituted corn grain silage. The experiment was carried out in a factorial arrangement in a completely randomized design, with three replicates per treatment. Five treatments were evaluated with different levels of water inclusion (% of the natural matter): dry corn grain (control); 90% dry corn grain (DCG) and 10% water; 80% DCG and 20% water; 70% DGC and 30% water; and 60% DCG and 40% water, totaling 45 experimental silos. Inclusion of water in the silage of reconstituted corn grain promoted a reduction in the CP (%) and NDF (%) contents. However, the water increase elevated the NPN/TN contents and the amount of effluent, gas and dry matter (%) losses. The treatment with inclusion of 30% water in the natural matter leads to a better fermentation profile and fewer losses of effluent and dry matter, so it is recommended for ensiling dry ground corn grain. | PT-BR: Objetivou-se avaliar o efeito de diferentes níveis de inclusão de água na composição química e no perfil fermentativo de silagem de grão de milho reidratado. O experimento foi conduzido em esquema fatorial, em um delineamento inteiramente ao acaso. Cinco tratamentos com diferentes níveis de inclusão de água (% da matéria natural) foram avaliados: milho grão seco (controle); 90% de milho grão seco (MGS) e 10% de água; 80% de MGS e 20% de água; 70% de MGS e 30% de água e 60% de MGS e 40% de água, totalizando 45 silos experimentais. A inclusão de água na silagem do grão de milho reconstituído promoveu redução nos conteúdos de PB (% MS) e FDN (% MS). Contudo, o incremento de água aumentou os teores de NNP/NT e as perdas por efluente, gás e matéria seca. O tratamento com a inclusão de 30% de água na matéria natural propicia um melhor perfil fermentativo e menores perdas por efluente e matéria seca, sendo recomendado para a ensilagem de grão de milho seco moído. Made available in DSpace on 2019-07-10T00:49:21Z (GMT). No. of bitstreams: 1 2019cpamtbrunopedreirasilagerehydratedgrain.pdf: 604930 bytes, checksum: 2ad0f4b30b836d33af5e6f44a689a632 (MD5) Previous issue date: 2019

The effect of the association of non-protein nitrogen, yeast, and bacterial probiotics on the ruminal microbiome of beef cattle intensively finished on pasture was evaluated. The experiment was carried out in a completely randomized design with five treatments and four replications. The treatments consisted of a group of animals kept on pasture that received low consumption supplementation (LS) and four groups that received for 98 days, 17.5 g concentrate kg

We investigated whether the feed intake efficiency, digestibility, microbial efficiency, and nitrogen balance would be affected by inclusion of rehydrated corn grain silage with crude glycerin or water to substitute the dry corn in diets for feedlot lambs. Ten crossbred (Santa Ines × Dorper) uncastrated male lambs (25.6 ± 4.0 kg body weight) were assigned in a replicated 5 × 5 Latin square design and subjected to five experimental diets, one containing dry corn and four diets containing corn grain silage rehydrated with crude glycerin in levels of 0, 75, 150, and 225 in g/kg of natural matter. The moisture of 32.5% was maintained in all silages. The inclusion of crude glycerin represented 0, 40, 80, and 120 g/kg of total diet. The inclusion of rehydrated corn silage did not affect the DM, CP, EE, and ED intake. The diets with rehydrated corn silage improved the digestibility of DM, without affecting the fiber digestibility. The nitrogen losses were insignificant, resulting in the efficient use of dietary nutrients. In conclusion, corn silage rehydrated with 150 g/kg NM of crude glycerin is recommended as a feed to substitute dry corn diet, as it did not influence the nutrients intake, increased the dry matter digestibility with efficient use of the dietary nutrients, improving the animal performance in the feedlot.

This study aimed to evaluate the frequency and intensity of GreenFeed (GF) use by Nellore steers using different attractants in pastures of integrated systems. The attractant protein supplement and Tifton bermudagrass pelleted hay flavored with vanilla were evaluated over a period of 15 days. The pelleted hay stimulated the animals to stay longer in the equipment (24.23 s), with 8% more visits in intervals longer than 30 s in contrast to protein supplement. This indicates that pelleted hay flavored with vanilla is a potential attractant to encourage Nellore steers to visit GF in grazing systems. Made available in DSpace on 2018-11-06T23:36:52Z (GMT). No. of bitstreams: 1 2018cpamtbrunopedreiraautomatedemissionmeasurementgreenfeedpastagem.pdf: 322080 bytes, checksum: f9ab52cd422dcb26edacc39531323459 (MD5) Previous issue date: 2018-11-06

This study assessed the fermentation profile, losses and the chemical composition of Piata palisadegrass (Brachiaria brizantha cv. Piata) ensiled with different additives. The experimental design was completely randomized, with four replicates per treatment, and five treatments with different additives, as follows: T1 control without additives; T2 - microbial inoculant SiloMax Centurium (Matsuda); T3 - enzyme-bacterial inoculant Sil All C4 (Alltech do Brasil); T4 - corn meal (100 g kg-1 in the fresh matter); and T5 - crude glycerin (100 g kg-1 in the fresh matter), totaling 20 experimental silos. Addition of cornmeal caused an increase in the dry matter (DM) and non-fiber carbohydrates (NFC) contents and a decrease in the neutral detergent neutral (NDF) content of the silage. The highest loss of total DM (124.7 g kg-1) was observed for the silage without additives, whereas addition of cornmeal provided the lowest loss of total DM (32.2 g kg-1). Lower pH values and higher titratable acidity values were observed in the silages containing cornmeal and crude glycerin, respectively, as well as greater production of lactic acid. It is recommended to include corn meal at 100 g kg-1 in the fresh matter, as it provides a better fermentative profile and nutritive value, in addition to lower losses of DM. In addition, the inclusion of glycerin at 100 g kg-1 of the fresh matter suggested it as a potential additive.

Embora a produção de bovinos alimentados com suplementos concentrados seja crescente, sua aplicação em associação à sistemas de integração lavoura e pecuária ainda carece de mais estudos. Este trabalho teve o objetivo avaliar o desempenho produtivo de bovinos em pastagem de Brachiaria brizantha cv. Marandu, consumindo quatro diferentes suplementos, SM - mistura mineral, SE - suplemento energético, SEP - suplemento energético-protéico e SPE - suplemento protéico-energético. Foram utilizados 100 novilhos não castrados, sendo 57 mestiços (Holandês x Nelore) e 43 da raça Nelore, com idade média de 15 meses e peso corporal médio de 281 ± 31kg. A área experimental constituiu-se de quatro piquetes formados com B. brizantha cv. Marandu. O experimento foi estruturado segundo o esquema fatorial (2x4) distribuído em um delineamento inteiramente casualizado, onde foram avaliados dois grupos genéticos e quatro diferentes formulações de suplementos. A quantidade ofertada foi de 0,5 kg/animal/dia para SE, SEP e SPE, salvo o SM ofertado ad libitum. Houve diferença de grupo genético sobre a produção dos animais, sendo que os novilhos mestiços apresentaram melhor desempenho. A média de ganho de peso diário, ganho de peso total e peso corporal final, foram maiores nos animais que consumiram SE em relação ao SM e SPE. O SE, possibilita desempenho animal superior à SM e a SPE para bovinos em pastejo em sistema de integração lavoura e pecuária no período das águas. A recria de novilhos mestiços (Holandês x Nelore) no sistema integração lavoura e pecuária durante período das águas apresenta melhor desempenho comparado a recria novilhos Nelore. Although the production of cattle fed concentrate supplement is growing, its application in association with integrated crop and livestock still needs further studies. This work was objective to evaluate the performance development of cattle grazing Brachiaria brizantha cv. Marandu, consuming four different supplements, MM - mix mineral, SE - energy supplement, SEP - protein and energy supplement and SPE - energy protein and supplement. A total of 100 steers uncastrated, 57 crossbred (Holstein x Nelore) and 43 Nelore, with 15 months of average age and 280 ± 31 kg of body weight. The experiment consisted of four paddocks formed by B. brizantha cv. Marandu. The work was designed as factorial arrangement (2x4) in a completely randomized design, were evaluated two genetic groups and four different formulations of supplements. The quantity of supplements offer of 0.5 kg/animal/day for the SE, SEP and SPE, except the MM offered ad libitum. There was significant effect of genetic group on productive performance of animals, crossbred steers and that had better performance. The average daily and total gain weight, were higher in animals that consumed SE in relation to SM and SPE. The SE, allows animal performance superior to MS and SPE for grazing cattle in integrated crop and livestock during the rainy season. The rearing of crossbred steers (Holstein x Nelore) in integrated crop and livestock during the rainy presents better performance compared to recreate Nelore.

Brazil is a prominent country in the production of beef cattle, where pastures are the basis for ruminant feed, because it is the most economical and practical form of food supply. Nitrogen is the main nutrient for maintaining and increasing the productivity of forage grasses, but its application is one of the most costly and greenhouse gas emitting practices for the system. The introduction of this element into the soil-plant-animal complex can be directly, with mineral fertilizers and with other alternatives, for example, through symbiosis of plants with atmospheric nitrogen fixing bacteria and plant growth promoting bacteria. Owing to future climate changes and increasing food demand, plant and animal production systems need to be increasingly competitive, responsible and efficient. Therefore, the objective of this study was to discuss nitrogen supply strategies in pastures: nitrogen fertilization, inoculation with Azospirillum brasilense and consortium with forage peanuts.

Adoption of silvopasture is increasing, but proper design and management of pasture–tree associations is required to sustain pasture productivity. Our objective was to compare agronomic and physiological characteristics of Brachiaria brizantha (Hochst. Ex A.Rich.) Stapf. (palisade grass) cv. Marandu growing in monoculture, or in silvopasture with Eucalyptus urograndis, in the Brazilian Amazon biome. Trees were planted in triple rows (intra-row spacing 3 m, inter-row spacing 3.5 m), referred to as a grove, with three groves per 2-ha silvopasture experimental unit. Space between groves was 30 m, and tree density was 270 ha–1. From October 2015 to September 2016, all experimental units were stocked continuously with cattle by using a variable stocking rate to maintain a Marandu canopy height of 30 cm. In the silvopasture, sampling occurred at 4, 7.5 and 15 m into the non-treed area from the outer tree row in a grove. Photosynthetically active radiation (PAR) reaching the Marandu canopy averaged 21% less for silvopasture than for grass monoculture; however, forage accumulation was not different between systems, nor were Marandu stomatal conductance, water-use efficiency (WUE), transpiration rate, transpiration ratio and leaf temperature. In silvopasture, PAR and forage accumulation were 33% and 29% less, respectively, at the 4-m distance than the 15-m distance from the edge row of trees, associated with lower transpiration rate and transpiration rate and greater WUE. We conclude that Marandu palisade grass can tolerate PAR reduction in silvopasture up to ~20% without reduction in forage accumulation, supporting its potential use in agroforestry systems for cattle production in the Brazilian Amazon Biome.

This study aimed to evaluate performance and behaviour of Nellore steers (Bos taurus indicus) in integrated systems. Treatments consisted of three different systems: livestock; crop-livestock; and livestock-forestry, with triple rows of eucalyptus trees. The experiment was carried out in Sinop, MT, Brazil, in a randomised complete block design with four replicates, during two seasons (dry-rainy transition and rainy). The experimental period was from 19 September 2015 to 10 January 2016. Nellore steers used in the experiment had an average initial weight of 344 kg ± 11 kg, in continuous stocking and variable stocking rate. Forage mass accumulation rate was evaluated and, independently of the system, had the highest values recorded during the rainy season. Microclimate was evaluated through temperature and humidity index, black globe temperature and humidity index and radiant heat load. Highest values were obtained from 11:00 a.m. to 3:00 p.m. at the dry-rainy transition period for all systems. Animal behaviour was assessed every 10 min from 7:00 a.m. to 5:00 p.m., and averages were calculated for every 2 h. The longest grazing period was recorded from 9:00 a.m. to 1:00 p.m., and then after 3:00 p.m., regardless of the system. Rumination occurred more frequently from 1:00 p.m. to 3:00 p.m. during the rainy season, and also in the shade for the livestock-forestry system. Highest weight gains per area were recorded during the rainy season and for the crop-livestock system. It is concluded that the highest yields can be achieved with the inclusion of the crop component in livestock production systems, and that Nellore steers in silvopastoral systems prefer to ruminate and stay idle in the shade.

The intake and total apparent and partial digestibility of nutrients, ruminal pH and ammonia concentrations and efficiency of microbial synthesis were evaluated in beef cattle fed diets containing sorghum silage and concentrate in the following ratios: 800:200, 650:350, 500:500 and 350:650 g/kg, in a total dry matter basis. Four crossbred Holstein x Zebu rumen and abomasum fistulated steers, 224 ± 23 kg-average initial live weight, were assigned to a 4 × 4 Latin square design. Chromic oxide was used as marker to estimate fecal and abomasal dry matter flows, and microbial efficiency was determined from purine basis. The intakes and total apparent digestibilities of DM, OM, CP and NFC and TDN intakes increased linearly (P < 0.01) with the increase of concentrate in the diet. NDF intake and total apparent digestibility decreased linearly (P < 0.05). The apparent ruminal and intestinal digestibilities of DM, OM, CP, NDF and NFC were not influenced (P > 0.05) by increasing the concentrate in the diet, and the mean values were 619 and 381 (g/kg); 656 and 349; 391 and 498; 902 and 79 and 600 and 399 (g/kg DM), respectively. There was a quadratic effect of collection time (P < 0.01) on the concentration of ruminal NH3–N and pH, considering maximum and minimum values of 14.89 mg/dL and 6.16 at 2.39 and 4.28 h after feeding, respectively. The efficiency of microbial synthesis, expressed in different ways was not influenced (P > 0.05) by treatments, with 11.39 g CPmic/100 gTDN on average. Although increasing concentrate levels in the diets resulted in higher intakes of almost all nutrients, this did not result in alterations in the ruminal variables evaluated.

Avaliaram-se o consumo e a digestibilidade total dos nutrientes e o desempenho de novilhos Nelore recebendo dietas contendo silagens de capim-braquiarão e de sorgo como fonte de volumoso nas proporções de 100:0, 67:33, 33:67 e 0:100, com base na matéria seca. Foram utilizados 24 novilhos Nelore, castrados, com peso médio inicial de 380 kg, distribuídos em um delineamento em blocos casualizados, com seis repetições, recebendo 60% de volumoso e 40% de concentrado, com base na matéria seca. O ensaio teve duração de 78 dias - 15 dias de adaptação seguidos de três períodos de 21 dias. Os consumos médios de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), carboidratos não-fibrosos (CNF) e nutrientes digestíveis totais (NDT), assim como a taxa de passagem, aumentaram linearmente com o incremento da silagem de sorgo nas dietas. Tendência semelhante foi observada para o ganho de peso médio diário, estimando-se acréscimos de 0,00313 kg/unidade de silagem de sorgo adicionada. As digestibilidades totais de MS, MO, PB e fibra em detergente neutro (FDN) também apresentaram comportamento linear crescente com o incremento dos níveis de silagem de sorgo. Contudo, as digestibilidades aparentes do EE e dos CNF não foram influenciadas pelas dietas, registrando-se, respectivamente, valores médios de 80,1 e 89,5%. A associação de 67% de silagem de sorgo e 33% de silagem de capim-braquiarão consistiu em como boa alternativa de volumoso para a alimentação de novilhos Nelore, uma vez que promoveu consumo e ganho de peso próximos aos observados para a dieta contendo apenas silagem de sorgo. The objective of this trial was to study intake, apparent total tract digestibility, and production of Nellore steers fed diets containing the following ratios of Brachiaria brizantha and sorghum silages: 100:0, 67:33, 33:67, and 0:100 on dry matter (DM) basis. Twenty-four castrated steers averaging 380 kg at the beginning of the trial and receiving a forage:concentrate ratio of 60:40 (DM basis) were used in a randomized complete block design (six replicates per treatment). The experiment lasted 78 days with three 21-days periods and 15 days for diet adaptation. The average intakes of DM, organic matter (OM), crude protein (CP), ether extract (EE), non-fiber carbohydrates (NFC), and total digestible nutrients (TDN) as well as passage rate all increased linearly with the increment of sorghum silage in the diet. Similarly, average body weight gain increased 0.00313 kg per unit of sorghum silage included in the diet. Apparent total tract digestibilities of DM, OM, CP, and neutral detergent fiber (NDF) also increased linearly when sorghum silage replaced Brachiaria brizantha silage in the diet whereas those of EE and NFC did not change significantly averaging 80.1 and 89.5%, respectively. It can be concluded that a Brachiaria brizantha:sorghum silages ratio of 67:33 can be fed to Nellore steers because it resulted in similar intake and body weight gain compared to the diet containing only sorghum silage.

Avaliaram-se os consumos e as digestibilidades total e parcial dos nutrientes em novilhos Holandês x Zebu recebendo dietas contendo quatro níveis de proteína bruta (10,5; 12; 13,5 e 15% de PB na matéria seca), constituídas de 65% de feno de capim-tifton 85 e 35% de concentrado. Foram utilizados quatro animais castrados, fistulados no rúmen e abomaso, com peso vivo médio inicial de 487,3 kg, distribuídos em um quadrado latino 4 x 4. Cada período experimental teve duração de 20 dias - 10 para adaptação às dietas, seis para coletas de amostras de fezes e digestas de abomaso, um para a coleta de líquido ruminal, um para a coleta total de urina, em 24 horas, e dois para a coleta de conteúdo ruminal. Para determinação da excreção fecal, utilizou-se o óxido crômico como indicador. Os consumos de matéria seca (MS), matéria orgânica (MO), fibra em detergente neutro (FDN) e nutrientes digestíveis totais (NDT) não foram influenciados pelos níveis de proteína bruta (PB) das dietas, mas os consumos de PB aumentaram e os de extrato etéreo (EE) e carboidratos não-fibrosos (CNF) reduziram com o incremento de PB das dietas. As digestibilidades aparentes totais da MS, MO e PB aumentaram linearmente com a concentração protéica das dietas. As digestibilidades aparentes ruminal e intestinal dos nutrientes não foram afetadas pelos níveis de PB das dietas, com exceção à digestibilidade intestinal da PB, que aumentou 2,77 unidades para cada percentual de PB acrescentado à dieta. The objective of this trial was to study the effects of different dietary levels of crude protein (CP) on intake and apparent total tract, intestinal, and ruminal digestibilities of nutrients in Holstein x Zebu steers. The diets contained [dry matter (DM) basis]: 10.5, 12, 13.5, or 15% of CP and a forage (Tifton 85):concentrate ratio of 65:35. Four castrated animals averaging 487.3 kg of body weight at the beginning of the trial and fitted with both abomasum and rumen cannulas were randomly assigned to a 4 x 4 Latin square. Each experimental period lasted 20 days with 10 days for diet adaptation and 10 days for sample collection (feces, abomasum digesta, ruminal content, and urine). Chromium oxide was used as the external marker for determination of fecal excretion. Increasing dietary levels of CP did not change significantly the intakes of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), and total digestible nutrients (TDN). However, intake of CP increased while that of ether extract (EE) and non-fiber carbohydrate (NFC) decreased with the increment of dietary CP. Apparent total tract digestibilities of DM, OM, and CP all increased linearly by increasing the dietary CP from 10.5 to 15%. Except for intestinal digestibility of CP that increased 2.77 percentage units for each 1% increment in the diet CP, the different dietary CP levels did not affect intestinal and ruminal digestibilities of all remaining nutrients in the current trial.

Objetivou-se avaliar os parâmetros nutricionais (consumo e digestibilidade) de bovinos de corte de dois grupos geneticos, alimentados com suplementos proteico-energeticos formulados a partir de diferentes niveis de substituicao do milho pelo grao de milheto no periodo da seca. Foram utilizados 64 novilhos, nao castrados, com media de idade de 20 meses e o peso corporal medio inicial de 388 ± 26 kg. A area experimental constituiu-se de quatro piquetes de aproximadamente 4,7 ha, formados com Brachiaria brizantha cv. Marandu em sistema de integracao lavoura e pecuaria. O experimento foi estruturado em esquema fatorial (2x4) distribuido em um delineamento experimental inteiramente casualizado, onde foram avaliados dois grupos geneticos (Mesticos e Nelore) e quatro diferentes niveis de grao de milheto (0%, 33%, 66% e 100%) em substituicao ao grao de milho na formulacao dos suplementos. Nao houve efeito tanto para o fator grupo genetico, quanto para os niveis de substituicao do milho pelo grao de milheto e ao consumo de materia seca (MS) total de pasto e dos nutrientes da dieta e para os coeficientes de digestibilidade total dos nutrientes. A concentracao dietetica de materia orgânica digerida nao foi influenciada pelos niveis de grao de milheto com valores de 514,88; 515,76; 516,01 e 515,98 g kg-1 de MS, respectivamente para os niveis 0%, 335, 66% e 100%. O grao de milheto como ingrediente energetico de suplementos concentrados pode ser utilizado como substituto ao grao de milho de forma parcial ou total na dieta de bovinos de corte Nelores ou Mesticos em pastos formados no sistema de integracao lavoura e pecuaria.

Objetivou-se avaliar o desempenho produtivo e econômico de animais consumindo quatro suplementos diferenciados pelos níveis crescentes de grão de milheto em substituição ao grão de milho, assim como analisar as características nutricionais do pasto de Brachiaria brizantha cv. Marandu em sistema de integração lavoura e pecuária. Foram utilizados 64 novilhos, não castrados, sendo 32 mestiços (Holandês x Nelore) e 32 da raça Nelore, com média de idade de 20 meses e o peso corporal médio inicial de 388 ± 26kg. A área experimental constituiu-se de quatro piquetes de 4,68ha, formados com B. brizantha cv. Marandu. A massa de forragem total e a massa de forragem potencialmente digestível foram de 5,24t/ha e 3,39t/ha, respectivamente. O experimento foi estruturado segundo um esquema fatorial (2x4) distribuído em delineamento inteiramente casualizado, onde foram avaliados dois grupos genéticos e quatro diferentes níveis de grão de milheto em substituição ao grão de milho na formulação dos suplementos (0%; 33%; 66% e 100%). A quantidade ofertada de suplemento foi de 4,0kg/animal/dia. Houve efeito de grupo genético sobre o ganho produtivo dos animais, sendo que novilhos Nelore apresentaram melhor desempenho. O ganho de peso médio diário, ganho de peso total e peso corporal final, reduziram linearmente com a substituição do alimento energético grão de milho por grão de milheto nos suplementos. A inclusão de 33% de grão de milheto em suplementos concentrados promove redução nos dias necessários para a obtenção de animais de peso corporal de 450kg. The objective was to evaluate the performance and economic development of animals receiving four supplements differentiated by the levels of grain of millet as replacement for corn grain, as well as assess nutritional characteristics of pasture of Brachiaria brizantha cv. Marandu in integrated crop and livestock. Used 64 steers, uncastrated, 32 crossbred (Holstein x Nelore) and 32 Nelore, with 20 months average age and 388 ± 26kg initial body weight. The experiment consisted of four paddocks of 4.68 ha, formed by B. brizantha cv. Marandu. The availability of dry matter and potentially digestible dry matter was 5.24t/ha and 3.39t/ha, respectively. The work was designed as a factorial arrangement (2x4) in a completely randomized design to evaluate two genetic groups and four different levels of grain instead of millet to maize grain in the formulation of supplements (0%; 33%; 66% e 100%). The quantity supplied of 4.0kg/animal/day. A significant effect of genetic group on productive performance of animals, and that Nelore steers have better performance. The average daily weight gain, total weight gain and final body weight decreased linearly with the inclusion of millet in supplements. The replacement of 33% of the corn grain millet concentrated supplements promotes reduction in the days required to obtain animal body weight of 450kg.

Avaliaram-se, em esquema factorial 2x2, o efeito das silagens de dois híbridos de milho (A: Agromen - AGN35-A42; B:Bayer - A3663) e dois níveis de concentrado (25 e 50%) sobre o desempenho animal. Para avaliar o consumo, a digestibilidade e o desempenho animal, utilizaram-se 24 novilhos cruzados, Holandês x Zebu, com média de peso de 335±30kg, distribuídos em seis blocos ao acaso. Os tratamentos consistiram em 75% de silagem de milho A + 25% de concentrado; 50% de silagem de milho A + 50% de concentrado; 75% de silagem de milho B + 25% de concentrado; e 50% de silagem de milho B + 50% de concentrado (na base de matéria seca) e foram formulados para serem isonitrogenados (13% proteína bruta). Não houve diferenças entre os consumos diários de matéria seca, matéria orgânica e proteína bruta. Houve efeito de concentrado sobre os consumos de carboidratos não-fibrosos e nutrientes digestíveis totais, e sobre as digestibilidades da matéria seca e da matéria orgânica. O maior consumo foi observado em animais alimentados com dietas que continham 50% de concentrado. Entretanto, o ganho de peso diário não foi influenciado pelos tratamentos. A utilização de silagem dos dois híbridos de milho associada a 25% de concentrado é uma alternativa para reduzir o custo de dietas para novilhos em confinamento, com ganho de peso diário próximo a 1kg. A trial involving a 2x2 factorial arrangement of treatments was conducted to evaluate two corn silage hybrids (Agromen, AGN35-A42) and (Bayer, A3663) and concentrate levels (25 and 50%) on animal performance. Twenty-four Holstein x Zebu crossbred steers, averaging 335±30kg of BW, were distributed in six randomized blocks to evaluate intake, digestibility, and performance. Treatments consisted of 75% corn silage A + 25% concentrate, 50% corn silage A + 50% concentrate, 75% corn silage B + 25% concentrate, and 50% corn silage B + 50% concentrate (dry matter basis); formulated to be isonitrogenous (13% crude protein, dry matter basis). There were no differences in the daily intakes of dry matter (DM), organic matter (OM), and crude protein. Additionally, there was a concentrate effect on non-fiber carbohydrates and total digestible nutrients intakes, and on total apparent digestibility of DM and OM, with higher intakes for steers fed diets with 50% of concentrate. However, average daily gain (ADG) was not influenced by treatments. The utilization of both corn silage hybrids in association with 25% of concentrate is a good option to feed crossbred steers with ADG close to 1.0kg in order to reduce diet cost.

Realizou-se um estudo com quatro novilhos cruzados Holandês x Nelore (225±22kg de peso vivo), canulados no rúmen e abomaso, distribuídos em quadrado latino 4 x 4 para avaliar o efeito de diferentes proporções de silagem de Braquiária brizantha e silagem de sorgo sobre o consumo e a digestibilidade dos nutrientes no trato digestório total e parcial, sobre os parâmetros ruminais e sobre a eficiência microbiana. As dietas continham 60% de volumoso e 40% de concentrado e foram formuladas para serem isonitrogenadas (12,5% de proteína bruta na matéria seca). Os tratamentos consistiram em diferentes proporções de silagens de Brachiaria brizantha e de sorgo: 100:0; 67:33; 33:67 e 0:100%, respectivamente (% da matéria seca). O consumo de matéria seca, matéria orgânica, proteína bruta, extrato etéreo, carboidratos não-fibrosos e nutrientes digestíveis totais aumentou linearmente (P0,05). O uso de 67% de silagem de sorgo com 33% de silagem de braquiária aumentou o consumo e a digestibilidade dos nutrientes sem afetar o pH e N-amoniacal ruminais, bem como a eficiência microbiana. A trial was carried out with four Holstein x Nellore crossbred steers (225±22kg of BW) fitted with ruminal and abomasal cannulaes in a 4 x 4 Latin Square design to evaluate the intake and the total and partial apparent digestibilities of nutrients, ruminal parameters, and microbial synthesis. Diets consisted of 60% silage and 40% concentrate formulated to be isonitrogenous (12.5% of crude protein, dry matter basis). Treatments consisted of different proportions of Brachiaria brizantha grass silage and sorghum silage: 100:0; 67:33; 33:67, and 0:100%, respectively, on dry matter basis. The intake of dry matter, organic matter, crude protein, ether extract, non-fiber carbohydrates, and total digestible nutrients linearly increased (P0.05) by the treatments. The use of 67% of sorghum silage and 33% of grass silage increased intake and digestibility of nutrients without affecting ruminal pH, ruminal NH3-N, and microbial efficiency.

Two trials were conducted to evaluate the effects of dietary NPN levels on animal performance, diet digestibility, ruminal characteristics, and microbial efficiency. Experiment 1 was conducted with 24 Holstein x Nellore crossbred steers (350 +/- 20 kg of BW) distributed in 6 blocks to evaluate intake and digestibility of nutrients and performance. The diets consisted of 70% corn silage and 30% concentrate (DM basis) and were formulated to contain 12.5% CP (DM basis). Treatments consisted of 0, 15.5, 31, and 46.5% of dietary N as NPN. There were no treatment differences in the daily intakes of DM (P = 0.47), OM (P = 0.60), CP (P = 0.24), nonfiber carbohydrates (NFC; P = 0.74), or TDN (P = 0.63); however, NDF intake decreased linearly as NPN increased (P = 0.02). Additionally, no effects of NPN were observed on apparent total tract digestibility of DM (P = 0.50), OM (P = 0.53), NDF (P = 0.63), or NFC (P = 0.44). The apparent total tract digestibility of CP increased linearly (P = 0.01), but ADG (1.14 kg/d) was not influenced (P = 0.96) as NPN increased. In Exp. 2, 4 ruminally and abomasally cannulated steers (300 +/- 55 kg of BW) were fed the same diet used in Exp. 1 to evaluate the effects of NPN levels on intake and digestibility of nutrients, ruminal characteristics, and microbial efficiency. There were no differences in the daily intakes of DM (P = 0.22), OM (P = 0.17), CP (P = 0.31), NDF (P = 0.29), or TDN (P = 0.49). However, NFC intake increased linearly (P = 0.02), and there was a quadratic effect (P = 0.01) on intake of ether extract as NPN increased. Ruminal digestibility of CP increased linearly (P = 0.01) with the increase of dietary NPN. There were no differences (P >or= 0.28) in microbial protein synthesis and microbial efficiency among the treatments. The results of these trials suggest that dietary NPN levels (up to 46.5% of total N) can be fed to crossbred steers receiving corn silage-based diets without affecting their growth performance or ruminal protein synthesis.

Nutrient intake, total apparent and partial digestibility, ruminal pH and ammonia (NH3-N) concentrations were evaluated in beef cattle fed diets containing Brachiaria brizantha cv. Marandu silage and concentrate levels of 200, 350, 500 and 650 g/kg dry matter base. Four crossbred Holstein × Zebu rumen and abomasum fistulated steers, 224 ± 23 kg-average initial live weight, were assigned to a 4 × 4 Latin square design. Chromic oxide was used as marker for estimates of faecal and abomasal dry matter flow. dry matter (DM), crude protein (CP), ether extract (EE), total carbohydrates (TCHO) and non-fibrous carbohydrates (NFC) (kg/d) intakes increased linearly (P0.05) by the diets. Concentrate level only affected apparent ruminal and intestinal digestibility for DM, CP and EE, using an adjusted quadratic equation (P