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Condensed tannins are a potentially important treatment option to mitigate N

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

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 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

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 2018-12-11T17:07:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-11-01 The present study had the primary objective of evaluating clinical, hematological and biochemical parameters, as well as observing anatomical and histopathological characteristics of abomasums, from calves prime-infected with Haemonchus contortus or H. placei. Ten male Holstein newborns were subdivided in three groups (GI placebo; GII infected with H. contortus; GIII inoculated with H. placei). Eye mucosa staining was evaluated. Hematological and biochemical tests were performed on animals. The euthanasia of all ten experimental calves was performed on the 42nd day post-inoculation. Fragments were collected from each of all 10 abomasums for histopathological analysis. Discrete submandibular edema was diagnosed in animals from both infected groups (H. contortus or H. placei). However, there were no significant changes (P > 0.05) in the color of the ocular mucosa of calves from all three experimental groups across the entire experimental period. Hematological and biochemical changes diagnosed on animals could not be linked to infections by species of Haemonchus spp. Regarding histopathological exams, it was possible to diagnose hypertrophy, hyperplasia, binucleated cells, inflammatory infiltrate, multifocal hemorrhage and edema in abomasums from calves of both groups infected with H. placei and H. contortus. It can, thus, be concluded that not only are calves susceptible to infections by both Haemonchus species, but they can also present clinical changes and similar anatomic histopathological lesions independent of being infected by Haemonchus placei or Haemonchus contortus. These results reflect a negative effect on helminth control by mixed grazing between sheep and cattle, especially when using calves. Faculdade de Ciências Agrárias e Veterinárias UNESP/CPPAR, Via de acesso Prof. Paulo Donatto Castellane, s/n Instituto de Patologia Tropical e Saúde Pública Universidade Federal de Goiás Universidade Camilo Castelo Branco (Unicastelo), Av. Hilário da Silva Passos, 950 Faculdade de Ciências Agrárias e Veterinárias UNESP/CPPAR, Via de acesso Prof. Paulo Donatto Castellane, s/n