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Context Energy supplementation with highly fermentable carbohydrates can be a strategy to maximise the efficiency of nitrogen use (ENU) from high-nutritional value forages. Aims The study aimed to investigate the independent or associated effects of two diurnal feeding times (0900 or 1700 hours) with two sources of energy supplementation (corn or citrus pulp) in the growing of F1 Angus × Nellore young bulls on palisade grass pastures, and their implications on the forage chemical composition, nutrient intake and digestibility, ENU, microbial protein synthesis, animal performance, and gain per area. Methods There were 36 bulls used as experimental animals, with initial bodyweight (BW) of 290 ± 5 kg, and 32 similar bulls were used in a put-and-take system to maintain sward characteristics. The experiment was conducted in a complete randomised design with four treatments and three replications (paddocks). The treatments consisted of energy supplementation at 0.3% BW with corn or citrus pulp fed at 0900 or 1700 hours for four periods of 28 days. For evaluation of ruminal and blood parameters, ENU, intake, and nutrient digestibility, eight ruminal cannulated 1/2 Aberdeen Angus × 1/2 Nellore young bulls were used, with 280 ± 7 kg of initial BW, distributed in a 4 × 4 double Latin square design, consisting of four periods and four treatments. Key results Supplementation at 0.3% of BW with corn or citrus pulp at 0900 or 1700 hours can reach up to 1.06 kg/day of young bulls reared on palisade grass pastures fertilised with 180 kg nitrogen/ha/year and managed at 25 cm of height compared with corn-based supplements. There were no effects on microbial protein synthesis or its efficiency. Conclusions Citrus pulp can be used as an alternative energy source to corn, because it has the same potential for animal performance, ENU and microbial protein synthesis in tropical pastures with a high proportion of soluble protein, and structural and non-fibrous carbohydrates with high dry matter digestibility. Implications Supplementing grazing beef cattle at 0.3% BW with corn or citrus pulp in the morning or afternoon is an efficient nutritional strategy to improve animal performance.

Animal supplementation during the background phase may increase greenhouse gas emissions (GHG). The inclusion of tannins in the diet of Nellore bulls can mitigate nitrous oxide (N2O), methane (CH4), and ammonia (NH3) production. The objective of this study was to quantify the effect of energy supplementation associated with sources of tannins in the diet of young Nellore bulls backgrounded in pastures with N2O, CH4, and NH3 emissions. Two experiments were conducted in a completely randomized design. The treatments were three supplementation strategies: (1) soybean hulls 0.3% of body weight (BW), (2) sorghum grain 0.3% of the BW, and (3) peanut peel 0.3% of BW, the last two being sources of tannin. The static closed chambers method was used to quantify N2O and CH4 emissions and the semi-open chamber technique to estimate NH3 volatilization. Supplementation strategies did not affect the N2O emissions (p = 0.9116). The soil water-filled pore space explained the variation in the N2O fluxes (p = 0.0071). The treatments did not change the total CH4 emissions (p = 0.3599), and no explanatory variable was correlated with the CH4 fluxes. The NH3 volatilization did not vary according to the supplements or tannin inclusion (p = 0.5170). However, the type of excreta affected the NH3 volatilization (p < 0.0001). Ammonia volatilization averaged 14.05, 4.16, and 2.25% of the applied N for urine, urine + dung, and dung, respectively. The energetic supplementation of Nellore bulls containing sources of tannins in the evaluated dosages was not a mitigation strategy for the emissions of N2O, CH4, and NH3.

This study aimed to evaluate the forage mass and nutritional value (NV) of Guinea Massai grass (Megathyrsus maximus × Megathyrsus infestum) in an open pasture (OP) or the silvopastoral system (SPS) at different stages of development (SDs). The experimental design was completely randomized, with five replications. The treatments were distributed in a factorial scheme 2 × 4, corresponding to types of systems (OP and SPS) and four SD (vegetative stage—S1, pre-flowering—S2, full flowering—S3 and maturity after flowering—S4). There was no interaction of the system × stage of plant development in any of the variables evaluated. The production of forage mass and Guinea Massai grass morphological components did not differ (p > 0.05) between SPS and OP. However, they differed between the SDs (p ≤ 0.05), with an increasing linear effect for forage mass, percentage of the stem, and dead material, and decreasing for leaf percentage and leaf: stem ratio. Only protein content differed (p < 0.05) among the chemical composition variables between culture systems. The shading caused by the SPS did not decrease the forage mass, NV, and in vitro dry matter digestibility of Guinea Massai grass compared to the system in OP. The advance of the SD of Guinea Massai grass increases the forage mass, with higher proportions of morphological components of low NV, such as stem and dead material. Silvopastoral system of Guinea Massai grass and eucalyptus is effective to prolongate the grazing season, with a greater amount of green leaves in the sward and better NV, without compromising herbage mass production in the forage growing season.

Condensed tannins are a potentially important treatment option to mitigate N

The objective of this study was to evaluate the effect of the addition of a phytogenic compound blend (PHA) containing hydrolyzable tannins, carvacrol, and cinnamaldehyde oil to mineral salt or energy supplementation on the rumen microbiota and nitrogen metabolism of grazing Nellore cattle. Eight castrated Nellore steers were distributed in a double-Latin-square 4 × 4 design, with a 2 × 2 factorial arrangement (two types of supplements with or without the addition of the PHA), as follows: energy supplement without the PHA addition (EW); energy supplement with the PHA addition (EPHA); mineral supplement without the addition of the PHA (MW); mineral supplement with the PHA addition (MPHA). Steers that received supplements with the PHA have a lower ruminal proportion of valerate (with the PHA, 1.06%; without the PHA, 1.15%), a lower ruminal abundance of Verrucomicrobia, and a tendency for lower DM digestibility (with the PHA, 62.8%; without the PHA, 64.8%). Energy supplements allowed for higher ammonia concentrations (+2.28 mg of NH3-N/dL), increased the propionate proportion (+0.29% of total VFA), and had a higher ruminal abundance of Proteobacteria and Spirochaetae phyla in the rumen. The PHA addition in the supplement did not improve nitrogen retention, reduced the ruminal proportion of valerate, and had a negative impact on both the total dry-matter digestibility and the abundance of several ruminal bacterial groups belonging to the Firmicutes and Verrucomicrobia phyla.

This study aimed to evaluate the emission factor of N2O, CH4, and the volatilization of NH3 for the combination of feces or urine with increasing doses of ammonium nitrate in tropical palisade grass pastures. The emission of greenhouse gases was assessed in eight treatments combining feces and urine with doses (75 and 150 kg of N ha−1) of ammonium nitrate, (32% N). The emission factor of N2O was 0.11, 0.19, and 0.17% for feces, urine, and 75 kg N ha−1 year−1 (as ammonium nitrate) and showed an additive linear effect when feces or urine were combined with increasing doses of N fertilizer. The emission factor of CH4 of feces (0.18 kg CH4 animal−1 year−1) was similar irrespective of combination with ammonium nitrate. The N loss by volatilized NH3 has a decreasing linear effect (p < 0.05) for the combination of feces or urine with ammonium nitrate. We concluded that N2O and CH4 emission factors of feces and urine in tropical climate conditions are lower than those reported by the IPCC. However, their N2O emission factors are sharply enhanced when combined with ammonium nitrate. These results may contribute to improvements in national and regional greenhouse gas inventories of livestock production.

The objective of this study was to evaluate the effect of the addition of a phytogenic compounds blend (PHA) containing hydrolyzable tannins, carvacrol and cinnamaldehyde oil in the mineral salt or energy supplement on the rumen microbiota and nitrogen metabolism of grazing Nellore cattle. Eight castrated Nellore steers were distributed in a double Latin square 4 × 4 design, with a 2 × 2 factorial arrangement (two type supplements and the addition or not of PHA) as follows: energy supplement without PHA addition (EW); energy supplement with PHA addition (EPHA); mineral supplement without the addition of PHA (MW); and mineral supplement with PHA addition (MPHA). Steers that received supplements with PHA have a lower ruminal proportion of Valerate (with PHA 1.06%; without PHA 1.15%), a lower ruminal abundance of Verrucomicrobia and a tendency for lower DM digestibility (with PHA 62.8%; without PHA 64.8%). Energy supplements allowed higher ammonia concentrations (+2.28 mg of NH3-N/dL), increased the propionate proportion (+0.29% of total VFA), and showed a tendency to have a higher abundance of Bacteroidetes and a lower abundance of Firmicutes in the rumen. The PHA addition in the supplement did not improve the use of nitrogen in grazing cattle, but negatively affected the diet digestibility.

Here, the effects of sources of rumen undegradable protein (RUP) in diets on methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions from the manure of feedlot-finished cattle were evaluated. We hypothesized that the use of different RUP sources in diets would reduce N loss via urine and contribute to reduced N2O, CH4 and NH3 emissions to the environment. Nellore cattle received different diets (18 animals/treatment), including soybean meal (SM, RDP source), by-pass soybean meal (BSM, RUP source) and corn gluten meal (CGM, RUP source). The protein source did not affect the N and C concentration in urine, C concentration in feces, and N balance (P > 0.05). The RUP sources resulted in a higher N2O emission than the RDP source (P = 0.030), while BSM resulted in a higher N2O emission than CGM (P = 0.038) (SM = 633, BSM = 2521, and CGM = 1153 g ha− 2 N-N2O); however, there were no differences in CH4 and NH3 emission (P > 0.05). In conclusion, the use of RUP in diets did not affect N excretion of beef cattle or CH4 and NH3 emission from manure, but increased N2O emission from the manure.

Made available in DSpace on 2021-06-25T11:49:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-26 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) In warm-climate grasslands, litter deposition and decomposition are one of the main pathway of nutrient cycling. The application of nitrogen (N) fertilizer or the inclusion of a legume in such grasslands modifies litter characteristics and chemical composition. This study evaluated how the N supply of palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster] pastures affect litter characteristics two years after seeding. Treatments were palisadegrass fertilized or not with N (150 or 0 kg N ha(-1) year(-1)) or mixed with the legume forage peanut (Arachis pintoi cv. Amarillo). The experimental period covered two consecutive rainy seasons. Nitrogen fertilization increased by 43 and 62% the existing litter mass (organic matter, OM), and by 32 and 23% the litter deposition rate compared to unfertilized palisadegrass or legume-grass mixtures, respectively. Both variables were affected by grazing cycle (GC), with low litter deposition rate (14 kg ha(-1) d(-1) OM) and existing litter mass (1390 kg ha(-1) OM) in the GC4 due to low rainfall. Nitrogen fertilized palisadegrass had greater litter N concentration (7.9 +/- 0.4 g kg(-1) OM-C:N ratio 34 +/- 2) than in monoculture or legume-grass mixtures (C:N ratios 45 and 58 +/- 2, respectively). Our results indicated that N fertilization of palisadegrass increased litter accumulation, however, N fertilization was not a key driver of the litter decomposition rate, even though it increased litter N concentration. After 2 years of establishment, the proportion of forage peanut in the litter was still low, reducing the benefits of legume inclusion to enhance litter nutrient cycling in these pastures. Sao Paulo State Univ, Dept Anim Sci, Via Acesso Prof Paulo Donato Castellane, BR-14884900 Jaboticabal, SP, Brazil Embrapa Agrobiol, Rodovia BR 465,Km 7, BR-23891000 Seropedica, RJ, Brazil Univ Florida, North Florida Res & Educ Ctr, Marianna, FL 32446 USA Sao Paulo State Univ, Dept Anim Sci, Via Acesso Prof Paulo Donato Castellane, BR-14884900 Jaboticabal, SP, Brazil FAPESP: 2016/11086-1 FAPESP: 2017/11274-5 FAPESP: 2015/16631-5 CNPq: 404169/2013-9

The increasing demand of meat requires the adoption of sustainable intensification livestock systems, applying nutritional strategies to reduce any negative contribution from beef cattle to global warming and, at the same time, to increase animal performance and productive efficiency. The pasture management practices and feed supplementation, mainly using non-edible feed with less costs, could minimize environmental and social impacts, resulting in higher productivity with less inputs utilization. Tropical grass submitted to grazing management according to plant height present high soluble protein and low levels of indigestible neutral detergent fiber contents. Energy or rumen undegradable protein supplementation, associated to alternative additives to antibiotics effects, such as probiotics, tannin, essential oils and saponin, can help to fully exploit the animal genetic potential and nutrient utilization efficiency, which decreases greenhouse gases emissions and improves animal performance. Hence, more information about these tools can make the livestock systems in tropical pasture more efficient and eco-friendlier.

Made available in DSpace on 2021-06-25T10:36:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Greenhouse gases (GHGs) emissions from livestock systems are important because of their significant contribution to global warming. Nitrogen fertilization can improve system production; however, it alters soil gas emissions. We evaluated soil nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions to investigate how they are affected by increasing levels of N fertilizer (urea) in a productive Marandu grass [Urochloa brizantha (Hochst ex A. Rich) Stapf] pasture subjected to continuous grazing by young Nellore beef cattle (Bos indicus). The N2O, CH4, and CO2 emissions were significantly affected by increasing N fertilizer levels. The seasons also affected GHGs emissions. Nitrogen fertilizer favored CH4 consumption relative to the control plot without N, with mean emission of 23.7 μg CH4−C m−2 h−1 in the fertilized plots compared to 61.6 μg CH4−C m−2 h−1 in the control. The N-fertilized areas presented higher CO2 emissions compared to the control plot without N. The areas that received N fertilization showed a positive linear association between the water-filled pore space and N2O emission. Soil temperature drove CO2 emissions. Increasing N fertilization in grazed marandu grass increases N2O and CO2 emissions during the growing season, while reducing CH4. The effect of fertilization during the transition season was not apparent, and perhaps other factors could provide a better explanation for the GHG emissions during this period. Department of Animal Science Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), Via de acesso Professor Paulo Donato Castellane Department of Exact Science Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), Via de acesso Professor Paulo Donato Castellane Department of Animal Science Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), Via de acesso Professor Paulo Donato Castellane Department of Exact Science Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), Via de acesso Professor Paulo Donato Castellane CNPq: 118700/2017-0 FAPESP: 2015/15631-3 FAPESP: 2015/16631-5 FAPESP: 2017/11274-5

Pastures are important environments worldwide because they offer many ecosystem services and sustain meat and milk production. However, pastures ecosystems are responsible for greenhouse gas (GHG) emission. The major GHGs include CO2, CH4, and N2O. The present review summarizes GHG emission from pasture ecosystems and discusses strategies to mitigate this problem. In pastures, emissions originate from animal excretion, fertilization, and organic matter decomposition. Emissions of specific gases can be measured based on certain factors that were recently updated by the United Nation’s Intergovernmental Panel on Climate Change in 2019. Urine is the main source of N2O emission. Forage structure is an important factor driving GHG transport. Forage fiber content and animal intake are the key drivers of enteric CH4 emission, and the introduction of forage legumes in pasture systems is one of the most promising strategy to mitigate GHG emission.

Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security, producing 23 and 11% of the global beef and milk production, respectively. The region's ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and influence on global climate change. Thus, the identification of effective CH4 mitigation strategies which do not compromise animal performance is urgently needed, especially in context of the Sustainable Development Goals (SDG) defined in the Paris Agreement of the United Nations. Therefore, the objectives of the current study were to: 1) collate a database of individual sheep, beef and dairy cattle records from enteric CH4 emission studies conducted in the LAC region, and 2) perform a meta-analysis to identify feasible enteric CH4 mitigation strategies, which do not compromise animal performance. After outlier's removal, 2745 animal records (65% of the original data) from 103 studies were retained (from 2011 to 2021) in the LAC database. Potential mitigation strategies were classified into three main categories (i.e., animal breeding, dietary, and rumen manipulation) and up to three subcategories, totaling 34 evaluated strategies. A random effects model weighted by inverse variance was used (Comprehensive Meta-Analysis V3.3.070). Six strategies decreased at least one enteric CH4 metric and simultaneously increased milk yield (MY; dairy cattle) or average daily gain (ADG; beef cattle and sheep). The breed composition F1 Holstein × Gyr decreased CH4 emission per MY (CH4IMilk) while increasing MY by 99%. Adequate strategies of grazing management under continuous and rotational stocking decreased CH4 emission per ADG (CH4IGain) by 22 and 35%, while increasing ADG by 22 and 71%, respectively. Increased dietary protein concentration, and increased concentrate level through cottonseed meal inclusion, decreased CH4IMilk and CH4IGain by 10 and 20% and increased MY and ADG by 12 and 31%, respectively. Lastly, increased feeding level decreased CH4IGain by 37%, while increasing ADG by 171%. The identified effective mitigation strategies can be adopted by livestock producers according to their specific needs and aid LAC countries in achieving SDG as defined in the Paris Agreement. Fil: Congio, Guilhermo Francklin de Souza. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil. Corporación Colombiana de Investigación Agropecuaria; Colombia Fil: Bannink, André. University of Agriculture Wageningen; Países Bajos Fil: Mayorga Mogollón, Olga Lucía. Corporación Colombiana de Investigación Agropecuaria; Colombia Fil: Jaurena, Gustavo. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Animal. Cátedra de Nutrición Animal; Argentina Fil: Gonda, Horacio Leandro. Uppsala Universitet; Suecia Fil: Gere, José Ignacio. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología Veterinaria - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Patobiología Veterinaria; Argentina Fil: Cerón Cucchi, María Esperanza. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina Fil: Ortiz Chura, Abimael. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Tieri, María Paz. Universidad Tecnológica Nacional. Facultad Regional Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación de la Cadena Láctea. - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea; Argentina Fil: Hernandez, Olegario. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Tucuman-Santiago del Estero; Argentina Fil: Ricci, Patricia. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Sur. Estacion Experimental Agropecuaria Balcarce. Instituto de Innovación Para la Producción Agropecuaria y El Desarrollo Sostenible. Grupo Vinculado Estacion Experimental Agropecuaria Cuenca del Salado Al Ipads | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Innovación Para la Producción Agropecuaria y El Desarrollo Sostenible. Grupo Vinculado Estacion Experimental Agropecuaria Cuenca del Salado Al Ipads.; Argentina Fil: Juliarena, María Paula. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; Argentina Fil: Lombardi, Banira. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; Argentina Fil: Abdalla, Adibe Luiz. Universidade de Sao Paulo; Brasil Fil: Abdalla Filho, Adibe Luiz. Universidade de Sao Paulo; Brasil Fil: Berndt, Alexandre. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil Fil: Oliveira, Patrícia Perondi Anchão. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil Fil: Henrique, Fábio Luis. Colegios Asociados de Uberaba; Brasil Fil: Monteiro, Alda Lúcia Gomes. Universidade Federal do Paraná; Brasil Fil: Borges, Luiza Ilha. Universidade Federal do Paraná; Brasil Fil: Ribeiro Filho, Henrique Mendonça Nunes. Universidade Federal de Santa Catarina; Brasil Fil: Ribeiro Pereira, Luiz Gustavo. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil Fil: Tomich, Thierry Ribeiro. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil Fil: Campos, Mariana Magalhães. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil Fil: Machado, Fernanda Samarini. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; Brasil Fil: Marcondes, Marcos Inácio. Universidade Federal de Viçosa.; Brasil Fil: Mercadante, Maria Eugênia Zerlotti. Agencia de Tecnología Agroindustrial de Sao Paulo; Argentina Fil: Sakamoto, Leandro Sannomiya. Agencia de Tecnología Agroindustrial de Sao Paulo; Argentina Fil: Albuquerque, Lucia Galvão. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Carvalho, Paulo César de Faccio. Universidade Federal do Rio Grande do Sul; Brasil Fil: Hristov, Alexander Nikolov. State University of Pennsylvania; Estados Unidos. University of Agriculture Wageningen; Países Bajos. Universidade de Sao Paulo; Brasil. Corporación Colombiana de Investigación Agropecuaria; Colombia

Made available in DSpace on 2022-04-29T08:34:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Supplementation of grazing cattle may improve forage utilization, methane emission and efficiency of nutrients use. This study aimed to evaluate the effect of different supllementation strategies on performance, metabolic parameters and methane emission in Nellore cattle reared on well-managed marandu palisadegrass (Urochloa brizantha cv Marandu) pastures. Three supplementation strategies consisted of protein and energy sources from traditional ingredients compared to a novel feedstuff: TS) Traditional supplement (protein-energy) composed of ground corn and soybean meal; ES) energy supplement composed of ground corn; and DS) Distiller's coproduct supplement (protein-energy) composed of ground corn and dried distiller grain (DDG). All supplements were offered at 0.3% of body weight (BW). Sixty-nine growing Nellore bulls [251 kg of body weight (BW) ± 13.0 kg] were randomly distributed according to initial BW in nine paddocks (twenty-three animals per treatment, three paddocks per treatment) to evaluate liveweight gain. From these, eighteen bulls (381.83 kg BW ± 16.15 kg) were selected for methane emission measurements (six animals per treatment) using sulfur hexafluoride tracer gas technique. Six rumen cannulated steers (289.5 kg BW ± 19.6 kg) across six paddocks (two per treatment) were used in an incomplete double Latin square design (3 treatments x 4 periods) to evaluate metabolic parameters. Statistical analyses were done using the Mixed Procedure in SAS and adopting significance level at 5%. It was hypothesized that the use of DS or ES, could increase the N use efficiency because of a higher rumen undegradable protein content, and more energy available for microbial synthesis in the rumen, respectively. Overall, there were no differences on animal performance, intake, nutrients digestibility, ruminal parameters, and microbial protein synthesis among treatments indicating that any of the supplemental sources could be utilized. Although, animals in DS had lower urine N excretion. The ES supplement increased methane yield (g/DMI) and the methane conversion factor Ym (% of gross energy intake) when compared to other treatments, but not methane production, which was similar among all treatments. São Paulo State University Animal Science Department, Zip Code: 14884-900 Jaboticabal Federal Rural University of Rio de Janeiro, Zip Code: 23897-000 Seropédica Central Queensland University Institute for Future Farming Systems, Zip Code: 4701 Rockhampton São Paulo State University Animal Science Department, Zip Code: 14884-900 Jaboticabal CNPq: #141611/2017-0 FAPESP: #2015/16631-5

Two experiments were conducted to evaluate the effect of replacing cottonseed meal with DDG on ruminal parameters, methane (CH4) emissions (Experiment 1), and animal performance (Experiment 2) of young Nellore bulls grazing Marandu grass during the rainy season. Four supplementation strategies were used in both experiments: (1) Mineral supplementation (MS), (2) conventional multiple supplement (energy/protein) with cottonseed meal and citrus pulp (CMS), (3) CMS with 50% cottonseed meal replaced by DDG (50DDG), and (4) CMS with 100% cottonseed meal replaced by DDG (100DDG). The 50DDG condition resulted in greater intake of dry matter (p = 0.033), organic matter (OM) (p = 0.050), forage (p = 0.035), and digestible OM (p = 0.031) than 100DDG. The supplemented animals presented greater final body weight (BW) and average daily gain than the animals consuming MS (p = 0.011), and lower pH, acetate, and acetate:propionate (p &lt, 0.05). However, the treatments had no influence on stocking rate, gain per area, and enteric CH4 emissions (p &gt, 0.05). Replacing cottonseed meal with DDG does not result in great variations in ruminal parameters, animal performance, and enteric CH4 emissions of grazing Nellore cattle during the rearing phase in the wet season. Both protein sources in 0.3% BW supplementation can be used to intensify beef cattle production in pastures.

Pasture intensification through higher stocking rates, nitrogen fertilization and intensified grazing management in beef cattle production optimizes pasture use by increasing the forage harvested. We aimed to assess its effects on the morphogenesis and canopy structure of Urochloa brizantha ‘Marandu’ (marandu palisadegrass) pastures. The treatments consisted of marandu palisadegrass pastures managed under continuous stocking and a canopy height of 25 cm, with different levels of intensification: extensive, semi-intensive, and intensive systems N-fertilized with 0 kg, 75 kg, and 150 kg N ha−1 year−1, respectively, as ammonium nitrate (32% of N), with four replicates (paddocks) in a completely randomized design. Phyllochron (9.8 days) and leaf lifespan (34.7 days) were shorter in intensified pastures, whereas herbage mass was similar among treatments. Extensive pastures had a higher proportion of senescent material, thus, more intensive systems showed higher proportions of leaves and stems, although the leaves-to-stem ratio remained similar across production systems. The defoliation interval was lower in intensive (14.4 days) and higher in extensive (18.7 days) treatments. Thus, pasture intensification accelerates leaf appearance, decreases leaf lifespan, shortens the tiller defoliation interval and increased herbage accumulation rate but does not change herbage mass. The extensive system produces excessive forage losses due to dead material.

The reduction in ammonia (NH3) losses from volatilization has significant implications in forage production. The objective of this study was to evaluate the impact of N fertilizers (urea, ammonium nitrate, and ammonium sulfate) and four doses (0, 90, 180 and 270 kg N ha−1) on N losses by NH3 volatilization, accumulation, and forage chemical composition of Urochloa brizantha cv Marandu. Two field experiments were conducted to measure NH3 losses using semi-open chambers. The forage accumulation and chemical composition were evaluated in the third experiment, the response variables included forage accumulation, crude protein (CP), and neutral detergent fiber (NDF). Compared to urea, ammonium nitrate and ammonium sulfate reduced NH3 losses by 84% and 87% and increased total forage accumulation by 14% and 23%, respectively. Forage accumulation rate and CP increased linearly with the N levels, while NDF contents decreased linearly with the N levels. In both experiments, NH3 losses and forage characteristics were different according to the rainfall pattern and temperature variations. Our results indicate that the use of nitric and ammoniacal fertilizers and the application of fertilizer in the rainy season constitute an efficient fertilizer management strategy to increase forage yield and decrease losses from volatilization of NH3.

Made available in DSpace on 2022-05-01T07:58:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) This study investigated the performance, carcass traits, and greenhouse gas emission of Nellore and F1 Angus × Nellore yearling bulls raised under two [lenient (S1) and intensified (S2)] production systems during the backgrounding and finishing phases. S1 was practiced on a 18.6 ha palisade grass pasture, divided into eight paddocks, which was not fertilized and managed using continuous stocking at a constant rate of two animals per hectare during backgrounding. Then, 20 Nellore [initial body weight (BWi), 277±13 kg; initial age, 15.2±1.1 months] and 20 F1 Angus × Nellore (BWi, 304±21 kg; initial age, 15.8±0.44 months) yearling bulls were randomly allocated to four paddocks for each breed. During finishing, animals remained on the pasture and received high supplementation (at rate of 2.0 kg•100 kg−1 BW). S2 was practiced on a 11.4 ha palisade grass pasture, divided into six paddocks, which was fertilized (150 kg N•ha−1•year−1) and managed using continuous stocking at variables rates during backgrounding. Then, 24 Nellore (BWi, 288±16 kg; initial age, 15.6±0.65 months) and 24 F1 Angus × Nellore (BWi, 325±18 kg; initial age, 15.8±0.42 months) yearling bulls were randomly allocated to three paddocks for each breed. During finishing, the bulls were moved to feedlots. During backgrounding, F1 Angus × Nellore bulls in S2 achieved the highest average daily gain (ADG) and final shrunk body weight (SBWf), whereas Nellore bulls in S1 achieved the lowest ADG and SBWf. During finishing, ADG and SBWf were greater in S2 than in S1 as well as for F1 Angus × Nellore bulls than for Nellore bulls. From the beginning of backgrounding until the end of finishing, the ribeye area of F1 Angus × Nellore bulls in S2 was larger than that of other bulls. The greatest backfat deposition occurred during finishing, resulting in greater backfat thickness of bulls in S2 than that of bulls in S1. The carbon footprint of F1 Angus × Nellore bulls in S2 (10.8 kg•CO2e•kg−1 carcass) was similar to that of Nellore bulls in S1, but it was approximately 13% and 11.5% lower than that of Nellore bulls in S2 and F1 Angus × Nellore bulls in S1, respectively. This study demonstrated that the enhancement of productivity through improving genetic merit and pasture management is a suitable strategy to reduce environmental impact and achieve environmental sustainability. Department of Animal Science São Paulo State University – Unesp Trouw Nutrition Campinas Department of Animal Science São Paulo State University – Unesp FAPESP: 15/16631-5; #17/18750-7; #17/11274-5

The effects of nitrogen (N) fertilization levels on protein and carbohydrate fractions in Marandu palisadegrass pasture [Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster] were investigated in a pasture over five years. The experimental design was completely randomized with four levels of N (0, 90, 180, and 270 kg N ha-1, as urea) for five years, and with three replicates. The study was conducted in a continuously stocked pasture during the forage growing season (December to April) in a tropical region. The effects of N fertilization were similar across the five years. With increasing N fertilization, the concentrations of crude protein (CP) increased from 103 to 173 g kg−1 (P −1 of total CP (P = 0.006); neutral detergent fiber (NDF) decreased from 609 to 556 g kg−1 (P = 0.037); indigestible NDF (P = 0.046), potentially degradable neutral detergent fiber (P = 0.037), and acid detergent fiber decreased (P = 0.05), and total digestible nutrient (TDN) increased (P P = 0.014) and total carbohydrates (P P P P = 0.11), CP (P P P P P

Made available in DSpace on 2021-06-25T10:48:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The effect of pasture management on CH4 emissions was investigated from goats in a tropical climate. Two experiments were conducted in a “Tanzania Guinea grass” (Panicum maximum Jacq.) pasture to assess enteric CH4 production in a completely randomized design. Emissions from light, moderate, and heavy grazing intensities were analyzed in the first experiment, and variations between grazing days were explored in the second experiment. Grazing intensity was defined as 2.4, 1.6, and 0.8 post-grazing leaf area index. Pasture management employed intermittent grazing with variable stocking rate using Anglo Nubian female adult goats. SF6 tracer gas technique was used to measure CH4 production. Grazing intensity was not found to affect CH4 emissions per animal, dry matter forage intake (DMI), and gross energy (GE) intake. However, the second experiment showed that CH4 production was influenced by the grazing day. CH4 emissions were 18.1 g day−1, and the variables were 0.88 g kg−1 of metabolic weight, 17.45 g kg−1 of DMI, and 5.5% of GE. CH4 production increased linearly with the grazing day, possibly reflecting a reduction in forage quality. These findings suggest that the day of occupation in intermittent grazing has a greater effect on CH4 emissions than that by grazing intensity and that a single day grazing of Tanzania Guinea grass could mitigate CH4 emissions. Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias UNESP - Universidade Estadual Paulista Centro Universitário de Araras Dr. Edmundo Ulson Universidade Federal do Sergipe Embrapa Meio Ambiente, Empresa Brasileira de Pesquisa Agropecuária Departamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias UNESP - Universidade Estadual Paulista Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias UNESP - Universidade Estadual Paulista Departamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias UNESP - Universidade Estadual Paulista FAPESP: 2009/13961-3 FAPESP: 2017/11274-5

The objective of this study was to evaluate the intake and digestibility of nutrients, emission of enteric CH4, and productive performance of Nellore bulls grazing Urochloa brizantha cv. Marandu palisade grass pastures during the rainy season, receiving an energy supplement or mineral supplement, with or without the inclusion of phytogenic additives. Forty-eight Nellore bulls were treated with: (1) energy supplement without the inclusion of phytogenic additives; (2) energy supplement with the inclusion of phytogenic additives; (3) mineral supplement without the inclusion of phytogenic additives; and (4) mineral supplement with the inclusion of phytogenic additives. Consumption of total dry matter (DM), crude protein (CP), apNDF, and energy; digestibility of DM, CP, and energy; average daily gain; stocking rate; and gain per area were higher in animals consuming energy supplements than those consuming mineral supplements. Digestibility of DM, NDF, and energy levels were lower in animals that consumed phytogenic additives. Compared with mineral supplements, the supply of energy supplements provides higher nutrient intake, increases enteric CH4 emission, and improves nutrient digestibility, providing a greater productive performance. The inclusion of phytogenic additives negatively affected nutrient intake and digestibility, did not reduce enteric CH4 emission, and influenced productive performance.

Nitrogen (N) management affects herbage production and chemical composition, however, information on the impact of tropical herbage on N and carbohydrate fractions is scarce. A two-year study was conducted to investigate the potential use of pintoi peanut (Arachis pintoi) compared with N fertilization of palisade grass (Brachiaria brizantha cv. Marandu) by evaluating the herbage chemical composition (fractionation of protein and carbohydrate), herbage mass and accumulation rate, herbage disappearance rate, and stocking rate of pastures. The experiment was conducted in a completely randomized design with three treatments, and four replications (paddocks) were used with twenty-one non-lactating crossbred dairy heifers. Treatments consisted of pastures of palisade grass without a N source (control), fertilized with urea (150 kg/ha/year, fertilized), or mixed with pintoi peanut (mixed). Inclusion of the legume increased concentrations of fractions A (p = 0.009), which is the soluble N compound, and B3 (p &lt, 0.001), which is slowly degraded true protein, compared with pastures fertilized with N and non-fertilized pastures. Nitrogen fertilization increased fraction B1 + B2 (p = 0.046), mainly true proteins, and decreased fraction C (p = 0.0007), indigestible protein, and neutral detergent fiber concentrations (p = 0.0003), contributing to increasing the nutritive value of the herbage. Additionally, N fertilization increased herbage mass (p = 0.004) and herbage allowance (p = 0.0001). Both N fertilization and biologically fixed N increased herbage allowance (p = 0.02) and accumulation rate (p = 0.02), as well as the crude protein content of herbage (p &lt, 0.0001) compared with non-fertilized pastures. Nitrogen fertilization increased true protein and decreased indigestible protein of herbage and promoted a greater herbage mass production, while the inclusion of legumes increased soluble protein and decreased the slowly degraded true protein of herbage. Both N management strategies increased herbage allowance and accumulation rate.

The study aimed to evaluate the effect of replacing cottonseed meal by dried distiller&rsquo, s grains (DDG) in terms of efficiency in the productive aspects of beef cattle finishing in pasture versus feedlot. The experiment was conducted in a completely randomized design in a 2 &times, 3 factorial arrangement, with two production systems (pasture versus feedlot) and three supplements: CM, conventional supplement with cottonseed meal (CM) as a protein source, 50DDG: supplement with 50% replacement of CM by DDG, and 100DDG: 100% replacement. The effect of replacing CM by DDG on dry matter and nutrients intake and nutrients digestibility depends on the finishing system (p &lt, 0.05). While in the pasture system animal consumed more nutrients in the CM, a greater intake was observed in the 100DDG in feedlot. The nutrients digestibility was lower in the pasture (p &lt, 0.05). Animal performance and final body weight were higher in the feedlot (p &lt, 0.0001), with averages of 1.57 kg/d and 566 kg of final body weight (FBW) for feedlot, and 0.99 kg/d and 504 kg FBW for pasture. The use of DDG does not change the animal performance finished in pasture or feedlot, and it is a viable alternative to replace conventional supplements in finishing phase in both systems in tropical environment.

Made available in DSpace on 2021-06-25T10:52:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The inclusion of corn-dried distillers’ grains (DDG) could be an alternative supplement to increase animal performance, nitrogen efficiency usage (NEU), and decrease enteric methane (CH4) emissions. Our goal was to determine whether DDG could replace a traditional supplement (cottonseed meal) without affecting animal performance, N balance, and CH4 emissions. The experiment was conducted during the forage growing season (December to April), with 15 d adaptation, and a 112 d experimental period. The experimental design was completely randomized with four treatments: a mineral supplement (MS), cottonseed meal supplement (CS), 50% replacement of CS by DDG (50DDG), and 100% replacement of CS by DDG (100DDG). Cottonseed meal and DDG were used as protein supplement. A total of 12 paddocks, 3 per treatment, were used to measure forage mass: morphological and chemical composition of forage, forage allowance, and animal performance. Six animals per treatment were used to evaluate DM intake, digestibility, CH4 emissions, microbial protein production (MCP), and NEU of each treatment. Eighty-one Young Nellore bulls (48 testers, 12 per treatments and 33 adjusters) with initial BW of 255 ± 5 kg (10–12 months old) were supplemented with each supplement type at a level of 0.3% of BW. Pasture management was continuous stocking with a variable stocking rate (put-and-take). Enteric CH4 was measured using the gas tracer technique. The MCP was quantified using purine derivatives and the NEU mass balance. No differences were found in nutrient intake (P > 0.228). Individual animal performance and gain per area were higher in the treatments with concentrates compared with that of MS; however, there was no difference among treatments CS, 50DDG, and 100DDG. The ADG was 0.83 for MS and 1.08 kg/animal/d when supplemented (P < 0.05). Gain per hectare was 709 kg/ha for MS and 915 kg/ha when supplemented with concentrates (P < 0.05). There was no difference in CH4 production among treatments that average 180 g/animal/d; however, CH4 per kg of gain was reduced with CS. The CH4 conversion factor averaged 5.91%. There was no difference in the synthesis of MCP and NEU. Corn DDG can replace 100% of cottonseed meal as a protein source for supplementation of young Nellore bulls grazing in tropical pastures without affecting animal performance, NEU, MCP, and CH4 emissions. Department of Animal Science São Paulo State University – Unesp, Jaboticabal Trouw Nutrition Embrapa Pecuária Sudeste, São Carlos Department of Animal Science São Paulo State University – Unesp, Jaboticabal FAPESP: 2015/16631-5 FAPESP: 2017/11274-5

The aim of this study was to characterize four corn and sorghum co-products (DDG) in terms of their protein and carbohydrate fractions; we also evaluated the effects of substituting the protein source of the conventional supplement by DDG on consumption and nutrient digestibility in confined finishing cattle. Thirty-six male Nellore cattle with a mean age of 24 months were used. The treatments were: FA: concentrate with corn as an energy source and cottonseed meal as a protein source; DDG50: concentrate with a 50% substitution of the FA protein source by DDG; DDG100: concentrate with 100% substitution of the FA protein source by DDG. The experimental design was completely randomized with three treatments and three replicates (pens) containing four animals per pen. We found that the use of DDG in the finishing phase did not interfere with the animals’ food intake or the digestibility of the nutrients (p > 0.05). Nutrients were used by the animals; therefore, DDGs may be viable substitutes of cottonseed meal. We conclude that the bromatological composition of this co-product is influenced a lot during processing; therefore, the nutritional values of this co-product present in the composition tables may not be true. The aim of this study was to characterize four corn and sorghum co-products (DDG) in terms of their protein and carbohydrate fractions; we also evaluated the effects of substituting the protein source of the conventional supplement by DDG on consumption and nutrient digestibility in confined finishing cattle. Thirty-six male Nellore cattle with a mean age of 24 months were used. The treatments were: FA: concentrate with corn as an energy source and cottonseed meal as a protein source; DDG50: concentrate with a 50% substitution of the FA protein source by DDG; DDG100: concentrate with 100% substitution of the FA protein source by DDG. The experimental design was completely randomized with three treatments and three replicates (pens) containing four animals per pen. We found that the use of DDG in the finishing phase did not interfere with the animals’ food intake or the digestibility of the nutrients (p > 0.05). Nutrients were used by the animals; therefore, DDGs may be viable substitutes of cottonseed meal. We conclude that the bromatological composition of this co-product is influenced a lot during processing; therefore, the nutritional values of this co-product present in the composition tables may not be true.

A 7 year experiment (2008&ndash, 2014) evaluated cattle grazing intensity (sward height) effects on herbage mass, forage quality, and greenhouse gas emissions in continuously stocked pastures containing the tropical &lsquo, Marandu&rsquo, palisade grass (Brachiaria brizantha (Hochst. ex A. Rich) Stapf cv. Marandu). The experiment consisted of three sward height treatments (15, 25, and 35 cm) and six replicates. There were four periods each year during the rearing phase. Significant effects were found for herbage mass, proportions of leaf and stem, crude protein, neutral detergent fiber, acid detergent fiber, lignin, animal performance, enteric methane (CH4), and greenhouse gas (GHG) emissions from soils. When the canopy height increased from 15 to 35 cm, the herbage mass rose from 5.23 to 9.86 kg t ha&minus, 1, leaf percentage decreased, and stem percentage increased. Crude protein content averaged 14.2%, and neutral detergent fiber averaged 58%. Average daily gain averaged 0.67, 0.81, and 0.90 kg &minus, 1 head&minus, 1, while live weight gain ha&ndash, 1 was 649, 530, and 439 kg for the 15, 25, and 35 cm treatments, respectively. The weather variables explained the GHG emissions, interannual herbage mass, and structure variations.

Made available in DSpace on 2021-06-26T02:53:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundacao de Amparo a Pesquisa doEstado de Sao Paulo Cattle excreta and nitrogen (N) fertilizer deposited on tropical grasslands are important sources of ammonia (NH3) emission. We conducted three field trials (wet, intermediate, and dry conditions) to quantify NH3 emissions from urea fertilizer and simulated excretions of heifer urine and dung on warm-climate grasslands in Brazil. Heifer excreta were derived from pastures of palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R. D. Webster 'Marandu'] under three forms of N supply (without or with N fertilization [0 or 150 kg N ha(-1) yr(-1)] or mixed with forage peanut [Arachis pintoi 'Amarillo']). Cumulative NH3-N emissions across rainfall conditions were 7.6-16.6% (mean, 11.7%) for urine, 1.4-2.9% (mean, 2.0%) for dung, and 11.2-20.5% (mean, 14.8%) for urea. Ammonia loss from urine was significantly greater than from dung under all rainfall conditions. Emission from urine and dung differed from those when urea was applied on palisadegrass. There were greater NH3 emissions from urine in the wetter times of the year. Heifer excreta from N-fertilized pasture had greater NH3 emission than excreta from the grass-legume mixture and unfertilized palisadegrass. Urea applied on palisadegrass presented greater NH3 emissions in wet rainfall conditions compared with dry conditions but did not differ from intermediate conditions. Our study showed that N-fertilized systems increase N losses as NH3 emission from excreta, and emissions from urea fertilizer must be included in this system. Heifer excreta and urea fertilizer deposited on warm-climate grasslands increased the NH3 emissions mainly under wet conditions. Sao Paulo State Univ, Dep Anim Sci, Via Acesso Prof Paulo Donato Castellane, BR-14884900 Jaboticabal, SP, Brazil Embrapa Agrobiol, Rodovia BR 465,Km 7, BR-23891000 Seropedica, RJ, Brazil Univ Florida, North Florida Res & Educ Ctr, Marianna, FL 32446 USA Sao Paulo State Univ, Dep Anim Sci, Via Acesso Prof Paulo Donato Castellane, BR-14884900 Jaboticabal, SP, Brazil CNPq: 404169/2013-9 Fundacao de Amparo a Pesquisa doEstado de Sao Paulo: 2015/16631-5

Made available in DSpace on 2020-12-11T23:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Greenhouse gases are known to play an important role in global warming. In this study, we determined the effects of selected soil and climate variables on nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions from a tropical grassland fertilized with chicken slurry, swine slurry, cattle slurry, and cattle compost. Cumulative N2O emissions did not differ between treatments and varied from 29.26 to 32.85 mg N m(-2). Similarly, cumulative CH4 emissions were not significantly different among the treatments and ranged from 6.34 to 57.73 mg CH4 m(-2). Slurry and compost application induced CO2 emissions that were significantly different from those in the control treatment. The CH4 conversion factors measured were 0.21%, 1.39%, 4.39%, and 5.07% for cattle compost, chicken slurry, swine slurry, and cattle slurry, respectively, differing from the recommendations of the Intergovernmental Panel on Climate Change (IPCC). The fraction of added N emitted as N2O was 0.39%, which was lower than the IPCC default value of 2%. Our findings suggest that N2O emissions could be mitigated by replacing synthetic fertilizer sources with either biofertilizer or compost. Our results indicate the following: N2O emission was mainly controlled by soil temperature, followed by soil moisture and then soil NH4 content; CH4 fluxes were mainly controlled by soil moisture and chamber headspace temperature; and CO2 fluxes were mainly controlled by chamber headspace temperature and soil moisture. Sao Paulo State Univ, Dept Anim Sci, Coll Agr & Vet Sci, BR-14884900 Jaboticabal, Brazil Kenji Agr & Environm Consultancy, BR-14010079 Ribeirao Preto, Brazil Sao Paulo State Univ, Dept Anim Sci, Coll Agr & Vet Sci, BR-14884900 Jaboticabal, Brazil FAPESP: 2012/06718-8 FAPESP: 2017/112745

Made available in DSpace on 2020-12-12T01:59:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) We quantified nitrous oxide (N2O), methane (CH4), and ammonia (NH3) emissions from cattle urine and dung patches on Brachiaria decumbens growing in a long-term silvopasture (SPS) or in monoculture (MONO) during the annual rainy and dry periods in southwest Brazil. We hypothesized that microenvironmental changes triggered by dense shade and litter, provided by trees, and pasture quality in SPS would affect greenhouse gas emissions from cattle excreta. Two field trials (rainy and dry season) were carried out using manual closed static chambers in a 3 × 2 factorial scheme, corresponding to three excreta types (urine, dung, and control without excreta) and two pasture systems (SPS and MONO), in a block design with three blocks and two replicates per block (n = 6 per treatment). Generally, N2O and CH4 fluxes were higher in SPS than in MONO. Notably, N losses in the form of N2O did not exceed 0.10 %, except for N2O emissions from urine deposited during the rainy season in SPS (0.39 % of applied N). Cattle dung was also a source of CH4. The highest fluxes were observed under SPS during the rainy season, but emissions were generally low, with emission rates < 0.1 kg CH4 head−1 yr−1. The highest N losses by NH3 volatilization were observed for urine under MONO, amounting to 8.3 % of total N applied during the rainy season and 17.1 % during the dry season. Our results demonstrate that N2O, CH4, and NH3 emissions from cattle are influenced by pasture system, excreta type, and season. N2O and CH4 emissions increase in long-term SPS, while NH3 losses reduce. Department of Animal Sciences Universidade Federal de Viçosa, Av. PH Rolfs, s/nº, Campus Universitário Embrapa Gado de Leite, Av. Eugênio do Nascimento, 610 Embrapa Agrobiologia, Rodovia BR 465, KM 07 Departament of Animal Sciences Faculdade de Ciências Agrárias e Veterinárias UNESP – Univ. Estadual Paulista, Via de acesso Prof. Paulo Donato Castellane Embrapa Solos, R. Jardim Botânico, 1024, Jardim Botânico Departament of Animal Sciences Faculdade de Ciências Agrárias e Veterinárias UNESP – Univ. Estadual Paulista, Via de acesso Prof. Paulo Donato Castellane FAPEMIG: APQ-02158-15

We quantified nitrous oxide (N2O) fluxes and total denitrification (N2O + N2) in an acidic (Ferralsol) and a near-neutral pH soil (Cambisol) to determine whether biochar’s alkalinization effect could be the mechanism inducing potential reductions in N2O fluxes. In Ferralsol, decreases in N2O emissions and in the N2O to N2O + N2 ratio were observed in both biochar and lime treatments. In Cambisol, neither biochar nor lime decreased N2O emissions, despite significantly increasing soil pH. The abundance and community structure of nosZ gene-bearing microorganisms indicated that gene abundances did not explain biochar effects, but a higher diversity of nosZ gene-bearing microorganisms correlated to lower total denitrification. Overall, our results suggest that biochar’s potential to decrease N2O emissions, through soil alkalinization, may be more effective in acidic soils, Soil Systems, 3 (4)

This study evaluated soil parameters involved in ammonia (NH3) fluxes from livestock excreta and urea fertilizer. Treatments were distributed in a randomized block design, with five replicates. Treatments included application of 1) urine; 2) dung; or 3) urea fertilizer (50 kg N ha-1) on palisadegrass pasture (Brachiaria brizantha cv. Marandu). Excreta was collected from crossbred heifers grazing palisadegrass pastures. One soil background treatment without excreta or urea was included for the measurement of NH3 fluxes. Treatments were applied in May/2017, April/2018, and Jul/2018. One liter of urine, 1.6 kg of dung, and 2.67 g of urea fertilizer were added inside the chamber according to treatment. Ammonia flux was evaluated using a semi-opened free static chamber and N determination by steam distillation. The extracted solution of fresh soil was analyzed in spectrophotometer. Pearson’s correlation and linear regression analyses were run to identify which soil parameters explained NH3 fluxes. Soil parameters were ammonium (NH4+), nitrate (NO3-), pH, and water filled pore space (%WFPS). For urine, a negative correlation (r = -0.68; P = 0.005) was found between NH3 flux and NO3-. Soil NO3- and pH affected NH3 fluxes as determined by multivariate regressions analysis. For urea fertilizer, a positive correlation was found between NH3 flux and NH4+ (r=0.62; P = 0.03), NH3 flux and NO3- (r = 0.57; P = 0.03), and NH3 flux and %WFPS (r = 0.59; P = 0.02). The %WFPS affected NH3 fluxes as determined by single regressions analysis. There was no significant correlation between NH3 fluxes and the soil parameters (P > 0.05) when dung was applied. Greatest N loss by NH3 emission when urine was applied decreased soil NO3-. Dung formed a superficial crust that might have acted as a physical barrier, reducing losses. Greater soil moisture increased urea hydrolysis resulting in soil ammonification and nitrification. Nitrates for urine and %WFPS for urea were the major drivers affecting NH3 fluxes.

Made available in DSpace on 2018-12-11T17:21:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 The effect of mineral salts on water ingestion and urine volume in cattle has been extensively studied. However, recently, this effect has been investigated as a potential mitigator of environmental aspects related to the nitrogen (N) cycle, such as nitrate (NO3 −) lixiviation, ammonia (NH3) volatilisation, and nitrous oxide (N2O) emissions. The effect of mineral salts, particularly sodium chloride (NaCl), on urine-N concentration, urine volume, the proportion of N compounds in the urine, and faecal-N concentration has not yet been explored in field conditions with respect to environmental aspects of beef cattle production. The present study investigated the effect of dietary mineral salt rates on these parameters. A Latin square (5 × 5) experimental design was utilised with five concentrations of mineral salts in the diet: 0.0, 2.0, 4.0, 6.0, and 8.0 g based on dry matter (DM) ingestion (g/kg DM). The nitrogen concentration in the urine and urine volume increased linearly. The total N excreted (g/day) via urine did not vary with increasing mineral salt concentrations. When evaluated, the N compounds of urine (urea-N, allantoin-N, and hippuric acid-N) also reacted to the increased mineral salt concentrations, while creatinine-N did not. Urea-N, allantoin-N, and hippuric acid-N linearly increased their proportions in total N-urine. The N concentration in faeces was not affected by mineral salt concentrations. The urine volume, concentration of N, and proportion of N compounds in the urine affected N2O emissions and NH3 volatilisation. Therefore, mineral salt utilisation may be an option for mitigating N pollution from beef cattle, especially for grasslands in tropical countries. Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), via de acesso Prof. Paulo Donato Castellane, km 5 Nutripura Embrapa Southeast Livestock Faculdade de Medicina Veterinária Universidade Federal de Uberlândia Queensland University Universidade Estadual do Mato Grosso do Sul Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), via de acesso Prof. Paulo Donato Castellane, km 5

In Brazil beef cattle production is one of the most important activities in the agricultural sector and has an important impact on environmental and resources consumption. In this study assessed greenhouses gases (GHG) impacts from on farms representative productive system and the possible improvements of the production chain. Primary data from animal production index and feeding were collected from 17 farms, which covers 300.000 animals and 220.000 hectares. Emissions of methane, nitrous oxide and carbon dioxide were made using intergovernmental panel on climate change (IPCC) guidelines for national inventories. The GHG inventory included emissions from animals, feeds and operations for animal operation from “cradle to farm gate”. Emissions of each farm were converted to carbon dioxide equivalent (CO2eq) and divided by carcass production. Regression analysis between carbon dioxide equivalent and productive index was run to identify possible hotspot of GHG emissions. A large variation between farms were observed. The GHG yield ranged from 8.63 kg to 50.88 CO2eq kg carcass-1. The productive index age of slaughtering (P < 0.0001), average daily gain (P < 0.0001) and productivity (P = 0.058) per area were positive correlated to GHG yield. While no correlation was found with stocking rate (P = 0.21). Improvements of the production chain could be realized by accurate animal management strategies that reduce the age of slaughtering (feeding and genetic improvements) and gain individual or per area using strategic animal supplementation and pasture management, in order to obtains reduction of GHG emissions of beef cattle.

Beef cattle production is an important agricultural activity in Brazil, which influences environmental and resource consumption. This study analyzed greenhouse gas (GHG) emission impacts from 17 farms, representing the Brazil’s productive system and determined possible improvements in the production chain. Methane, nitrous oxide, and carbon dioxide emissions were evaluated using the updated Intergovernmental Panel on Climate Change (IPCC) guidelines for national inventories. The GHG inventory included emissions from animals, feeds, and “cradle-to-farm-gate” operations for animal management. Regression analyses of carbon dioxide equivalent (CO2eq) emissions and productive indices were performed to identify possible GHG emission hotspots. The results varied considerably among the farms. The GHG yield ranged from 8.63 to 50.88 CO2eq kg carcass−1. The productive indices of average daily gain (p &lt, 0.0001), area productivity (p = 0.058), and slaughtering age (p &lt, 0.0001) were positively correlated with GHG yield. However, no correlation was found with the stocking rate (p = 0.21). The production chain could be improved through accurate animal management strategies that reduce the slaughtering age and daily weight gain individually or per area using pasture management and strategic animal supplementation, which could subsequently reduce GHG emissions in beef cattle production.

Made available in DSpace on 2018-12-11T17:12:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Increasing attention is being paid to the importance of N2O emissions due to livestock activities in tropical countries. Understanding the key variables driving N2O emission could help minimize impacts of N2O release and improve the accuracy of N2O inventories. We aimed to investigate the effects of soil moisture, soil compaction, urine composition, urine volume, and dung addition on N2O emissions from a urine-treated tropical Ferralsol under controlled conditions. Manipulated soil conditions (e.g., moisture content, compaction, and dung addition) affected N2O emissions when varying quantities of urine-N (p = 0.02) were applied (urine volumes remained equal) and when varying urine volumes (p = 0.04) were applied (quantities of urine-N remained equal). When the amount of urine-N applied was varied, the estimated N2O emission factor (EF) was 3.14 ± 0.70%, 2.29 ± 1.25%, 3.90 ± 0.64%, 4.73 ± 0.88%, and 6.62 ± 1.10% for moist soil, dry soil, compacted soil, plus dung, and plus dung and compacted soil treatments, respectively. While varying the volume of urine, the estimated N2O EF was 4.96 ± 1.66%, 4.27 ± 1.42%, 3.99 ± 1.19%, 6.50 ± 0.35%, and 7.37 ± 0.76% for moist, dry soil, compacted soil, plus dung, and plus dung and compacted soils treatments, respectively. The urine-N concentration influenced N2O emissions (p = 0.02) [which decreased linearly (p = 0.062)] as well the volume of urine (p < 0.01) [which increased linearly (p < 0.01)]. The chemical form of the applied urine-N (urea, nitrate, or ammonium) did not affect N2O emissions and the emissions factor averaged 1.40 ± 0.38%. N2O production was affected by the KCl concentration in the urine (p < 0.01), and the effect was curvilinear. The key driving factor affecting N2O emissions was soil moisture content. The N2O response varied when the urine volume differed (in both moist and dry soil conditions), and with the addition of dung. Department of Animal Science Faculdade de Ciências Agrárias e Veterinárias UNESP – Univ Estadual Paulista Federal University of Uberlândia (UFU), Rua João Naves de Ávila 2121, Santa Mônica Department of Animal Science Faculdade de Ciências Agrárias e Veterinárias UNESP – Univ Estadual Paulista FAPESP: 2011/00060-8 FAPESP: 2012/04605-1 FAPESP: 2012/06718-8 FAPESP: 2013/00204-5 FAPESP: 2013/24782-8

Made available in DSpace on 2020-12-11T03:11:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Livestock production systems are an essential agribusiness activity in Brazil, but a critical challenge of Brazilian farmers is to maintain the equilibrium of the ecosystem, using herbage resources efficiently with a minimum impact on the environment. Nitrogen (N) fertilization and the inclusion of forage legumes into tropical grass pastures are management strategies which increase the productivity and nutritive value of pastures and may also affect methane (CH 4) production by ruminants. The objective of this study was to examine the effects of either fertilizing palisade grass pastures with N or including the forage peanut (Arachis pintoi) into grass pastures on enteric CH4 emission, microbial protein production in the rumen via purine derivatives in the urine, and N balance. Twenty-one nonlactating crossbred dairy heifers were used in a completely randomized design with 3 treatments. The treatments consisted of pastures of palisade grass without N fertilization (control), fertilized with urea (fertilized), and palisade grass mixed with forage peanut (mixed). Seven animals (replications) were used to evaluate dry matter intake, digestibility, CH4 emission, urea, purine derivatives, and volume of urine, and N ingestion and excretion. Four paddocks (replications) were used to measure herbage mass; morphological, botanical, and chemical composition of herbage; and herbage allowance. The CH4 emissions were determined using the sulfur hexafluoride (SF6) tracer gas technique. The efficiency of N utilization (ENU) was calculated using the N balance data. Crude protein (CP) concentration of herbage increased with fertilization or legumes inclusion (P < 0.0001) while neutral detergent fiber (NDF) concentration decreased (P = 0.0355). The leaf allowance was higher in the fertilized treatment (P = 0.0294). Only uric acid excretion increased with N fertilization (P = 0.0204). The ENU was not affected by fertilized or mixed compared to control and averaged 55% (P = 0.8945). The enteric CH4 production was similar between treatments and averaged 129 g/d (P = 0.3989). We concluded that the changes in chemical composition of herbage provided by N fertilization or the inclusion of the legume showed no reduction in enteric CH4 emissions, but the ENU was more significant than previous studies with palisade grass, suggesting that different management strategies might alter the ENU under grazing conditions. Sao Paulo State Univ, Dept Anim Sci, BR-14884900 Jaboticabal, SP, Brazil Texas A&M Univ, Dept Anim Sci, College Stn, TX 77843 USA Embrapa Agrobiol, BR-23891000 Seropedica, RJ, Brazil Embrapa Pecuaria Sudeste, BR-13560970 Sao Carlos, SP, Brazil Sao Paulo State Univ, Dept Anim Sci, BR-14884900 Jaboticabal, SP, Brazil FAPESP: 2015/16631-5 FAPESP: 2016/110861 FAPESP: 2017/11274-5 CNPq: 404169/2013-9

Made available in DSpace on 2019-10-06T16:41:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 In this study we conducted four field trials (two wet- and two dry-season) to quantify N2O and CH4 emissions, NH3 volatilization, and N2O emission factors (EF3PRP) following the application of cattle dung, urine, dung plus urine, and urea fertilizer on a palisade-grass pastureland in Brazil. The EF3PRP differed with treatment and season. Wet season EF3PRP were 0.36%, 1.02%, and 0.84% and dry season EF3PRP were 0.32%, 0.47%, and 0.34% for dung, urine, and dung plus urine, respectively. These emission factors are maybe lower than the default proposed by the Intergovernmental Panel on Climate Change (IPCC; 2%). Methane emissions also differed according to the treatment and season, and annualized dung emissions were 0.54 kg CH4 head−1 year−1. The fraction of total-N from animal manure and urine emitted as NH3 (FracGASM) in the wet season for dung, urine and dung plus urine was 7.2%, 6.3%, and 6.4%, respectively; lower than the rate of dry season volatilization from urine (14.2%) and dung plus urine (11.5%). Observed FracGASM is probably lower than the IPCC guideline (20%). Emissions of N2O, CH4, and the volatilization of NH3 after urea treatment were not influenced by season; N2O emissions from urea were 0.85%, CH4 emissions were 112 g CH4-C ha−1, and N-fertilizer lost as NH3 was 16.9%. The emission factors observed in this experiment differed from the IPCC Guidelines; observed N2O emissions were lower than the guideline (1%), and FracGASF was higher than the 10% guideline. Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias UNESP – Univ Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane s/n Universidade Estadual do Mato Grosso do Sul, Rodovia Aquidauana/UEMS - Km 12 Uberlandia Federal University, Rua João Naves de Ávila 2121, Uberlândia Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias UNESP – Univ Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane s/n

Made available in DSpace on 2019-10-06T16:31:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-01 A three-year-long field experiment was conducted in a continuous grazing system with a variable stocking rate to evaluate effects of increasing nitrogen levels in Marandu grass (Brachiaria brizantha Hochst ex A. Rich Stapf “marandu”) on herbage mass, forage accumulation rate (FAR), forage quality, stocking rate (SR), average daily gain (ADG), gain per hectare (GPH), and gain per kg of applied N. The experimental design was completely randomized with four treatments (control without application of N, and 90, 180, and 270 kg N ha −1 year −1 ) and three replicates (paddocks per treatment); nitrogen was applied in the form of urea. Herbage mass, crude protein (CP), FAR, SR, GPH, and the nitrogen nutrition index increased with increasing nitrogen level (P < 0.05), whereas the neutral detergent fibre (NDF), acid detergent fibre, and nitrogen usage efficiency decreased with increasing nitrogen level (P < 0.01). Crude protein was higher than 12% and NDF lower than 60% in all treatments. Nitrogen application rate affected ADG (P < 0.05) but did not fit any equation. The highest ADG was 90 kg N ha −1 year −1 (985 g animal −1 day −1 ). Increasing the nitrogen level is a promising way to improve Marandu grass production, nutritive value, and animal production. UNESP - Univ Estadual Paulista Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias UFRRJ - Univ Federal Rural do Rio de Janeiro Departamento de Produção Animal Instituto de Zootecnia Departamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias UNESP - Univ Estadual Paulista UNESP - Univ Estadual Paulista Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias Departamento de Ciências Exatas Faculdade de Ciências Agrárias e Veterinárias UNESP - Univ Estadual Paulista

Made available in DSpace on 2021-06-25T11:02:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The intensification of pasture production has increased the use of N fertilizers—a practice that can alter soil greenhouse gas (GHG) fluxes. The objective of the present study was to evaluate the fluxes of CH4, CO2, and N2 O in the soil of Urochloa brizantha ‘Marandu’ pastures fertilized with different sources and doses of N. Two field experiments were conducted to evaluate GHG fluxes following N fertilization with urea, ammonium nitrate, and ammonium sulfate at doses of 0, 90, 180, and 270 kg N ha−1 . GHG fluxes were quantified using the static chamber technique and gas chromatography. In both experiments, the sources and doses of N did not significantly affect cumulative GHG emissions, while N fertilization significantly affected cumulative N2 O and CO2 emissions compared to the control treatment. The N2 O emission factor following fertilization with urea, ammonium nitrate, and ammonium sulfate was lower than the United Nations’ Intergovernmental Panel on Climate Change standard (0.35%, 0.24%, and 0.21%, respectively, with fractionation fertilization and 1.00%, 0.83%, and 1.03%, respectively, with single fertilization). These findings are important for integrating national inventories and improving GHG estimation in tropical regions. Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias UNESP—Universty Estadual Paulista Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias UNESP—Universty Estadual Paulista FAPESP: 2015/16631–5 FAPESP: 2017/02914–0 FAPESP: 2017/11274–5 FAPESP: 2017/20279–0 CNPq: 431713/2018–9

Made available in DSpace on 2021-06-25T11:54:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-03 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R. D. Webster cv. Marandu] is widely used in Brazil and is typically managed with little or no N fertilizer, which often leads to pasture decline in the long-term. The current relationship between beef price and fertilizer cost in Brazil does not favor fertilizer use in pastures. Legume inclusion is an alternative to adding fertilizer N, but often legumes do not reach a significant proportion (> 30%) in pasture botanical composition. This study evaluated herbage responses to N inputs and pasture species composition, under intermittent stocking. Treatments included palisadegrass-forage peanut (Arachis pintoi Krapov. & W.C. Greg. cv. Amarillo) mixture (mixed), unfertilized palisadegrass (control), and palisadegrass fertilized with 150 kg N ha(-1) yr(-1) (fertilized). Treatments were applied over two rainy seasons with five growth cycle (GC) evaluations each season. Response variables included herbage biomass, herbage accumulation, morphological components, total aboveground N of forage peanut (TAGN(FP)), and contribution of biological N-2 fixation (BNF). Herbage biomass was greater for fertilized palisadegrass [5850 kg dry matter (DM) ha(-1)] than for the palisadegrass-forage peanut mixture (3940 kg DM ha(-1)), while the unfertilized palisadegrass (4400 kg DM ha(-1)) did not differ from the mixed pasture. Nitrogen fertilizer increased leaf mass of palisadegrass (2490 kg DM ha(-1)) compared with the control and mixed treatments (1700 and 1310 kg DM ha(-1), respectively). The contribution of BNF to the forage peanut ranged from 79 to 85% and 0.5 to 5.5 kg N ha(-1) cycle(-1). Overall, benefits from forage peanut were minimal because legume percentage was less than 10%, while N input in the system by N-fertilizer increased palisadegrass herbage biomass. Sao Paulo State Univ, Dept Anim Sci, Jaboticabal, SP, Brazil Embrapa Agrobiol, Antiga Rodovia Rio Sao Paulo, Seropedica, RJ, Brazil Univ Florida, North Florida Res & Educ Ctr, Marianna, FL USA Sao Paulo State Univ, Dept Anim Sci, Jaboticabal, SP, Brazil FAPESP: 2016/11086-1 FAPESP: 2017/11274-5 FAPESP: 2015/16631-5 CNPq: 404169/2013-9

Intensification of tropical grassland can be a strategy to increase beef production, but methods for achieving this should maintain or reduce its environmental impact and should not compromise future food-producing capacity. The objective of this review was to discuss the aspects of grassland management, animal supplementation, the environment, and the socioeconomics of grassland intensification. Reducing environmental impact in the form of, for example, greenhouse gas (GHG) emissions is particularly important in Brazil, which is the second-largest beef producer in the world. Most Brazilian pastures, however, are degraded, representing a considerable opportunity for the mitigation and increase of beef-cattle production, and consequently increasing global protein supply. Moreover, in Brazil, forage production is necessary for seasonal feeding strategies that maintain animal performance during periods of forage scarcity. There are many options to achieve this objective that can be adopted alone or in association. These options include improving grassland management, pasture fertilization, and animal supplementation. Improving grazing management has the potential to mitigate GHG emissions through the reduction of the intensity of CO2 emissions, as well as the preservation of natural areas by reducing the need for expanding pastureland. Limitations to farmers adopting intensification strategies include cultural aspects and the lack of financial resources and technical assistance.

Made available in DSpace on 2018-11-26T16:01:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Embrapa Federal Rural University of Rio de Janeiro We aimed to quantify nitrous oxide (N2O) and methane (CH4) emissions as a function of the addition of different quantities of bovine faeces and urine on soil under pasture. Two experiments were performed in randomised complete blocks with five replicates. In the first experiment, the emissions of CH4 and N2O were evaluated for 14 days after the addition of four amounts of faeces (0.0, 1.2, 1.8 and 2.4 kg of fresh faeces per plot), and in a second experiment, N2O emissions were evaluated for 43 days after addition of four volumes of urine (0.0, 1.0, 1.5 and 2.0 L). Urine and faeces came from crossbred (Fresian x Gir) dairy cows fed on pasture and concentrates. N2O emissions from faeces did not alter the emission factor (EF) according to the faeces weight (P = 0.73). N2O-N EF from faeces-N averaged 0.18% (+/- 0.05) of total applied N. The volume of urine applied influenced N2O losses. The EF decreased linearly (P = 0.015) with increasing volumes of urine, being 4.9% (+/- 0.75), 3.36% (+/- 0.7) and 2.43% (+/- 0.46) of N applied emitted as N2O for the 1.0, 1.5 and 2.0 L volumes of urine respectively. The EF from urine was significantly (P < 0.0001) higher than the EF from faeces. There was no change to the CH4 emissions per kilogram of excreta when the amount of faeces added was varied (P = 0.87). However, the CH4 emitted increased linearly with the amount of faeces (P = 0.02). The CH4 EF was estimated to be 0.95 (+/- 0.38) kg/head.year. Sao Paulo State Univ, Dept Anim Sci, Via Acesso Prof Paulo Donato Castellane, BR-14884900 Jaboticabal, SP, Brazil Embrapa Agrobiol, Antiga Rodovia Rio Sao Paulo,Km 47, BR-23891000 Seropedica, RJ, Brazil Sao Paulo State Univ, Dept Anim Sci, Via Acesso Prof Paulo Donato Castellane, BR-14884900 Jaboticabal, SP, Brazil

Ammonia (NH(3)) is a large source of environmental contamination from nitrogen usage. The objective of this study was to evaluate NH(3) losses from urine and dung of cattle grazed in Marandu-grass pastures (Brachiaria brizantha cv. Marandu) with different sources of nitrogen. The experiment consisted of two factors (pasture management and excreta type) in a randomized complete block design, with 5 replicates. The pastures were: 1) CONTROL: Marandu-grass pastures without nitrogen or legume; 2) FERT: Marandu-grass pastures fertilized with nitrogen (150 kg N ha(-1) year(-1)); 3) MIXED: Marandu-grass pastures intercropped with Pinto peanut (Arachis pintoi cv. Amarillo). The excreta types were dung (1.6 kg/ treatment) and urine (1.0 L/ treatment) from heifers (353.1 ± 24.1 kg BW) grazing in the pastures. Ammonia volatilization was evaluated using semi-opened free static chamber and nitrogen determination by steam distillation. Sampling were performed on 1, 3, 5, 9, 14 and 21 d after treatments being applied to the area. ANOVA was performed for total ammonia volatilized; when differences were observed among means, they were compared using the LSD test. For dung, NH(3) losses differed among pasture treatments (P = 0.046). Volatilization losses was greater for FERT pastures (1.04% of applied N) compared with CONTROL (0.83% of applied N) and MIXED (0.81% of applied N) pastures. No differences were observed for urine among treatments for FERT (3.69 of applied N), MIXED (3.63 of applied N) and CONTROL (2.78 of applied N). The NH(3) emission factor differed between excreta type (P < 0.0001). Urine averaged 3.40% and dung 0.89% of volatilized N-applied. Urine was the main source of ammonia volatilization, and all estimates of volatilization losses were among the lowest reported in the literature.