Variability among Animals and Incubation Protocols for Ruminant In Situ Degradation Studies with Tropical Feeds

Simple Summary The knowledge on the nutritive value of feeds is essential to feed animals with adequate diets and to optimize production with minimal environment impact. In situ degradation is an important tool for nutritionists because it is a reliable, cheap, and fast way to assess information on feed digestion in ruminants. However, the lack of standards procedures for in situ trials with cattle in the tropics may compromise the reliability of information obtained from those studies. Thus, we aimed to generate useful information for animal scientists on how to perform that kind of study using adequate and minimal resources yet keeping accuracy to interpret feed characteristics. Our findings indicated an important variation among animals on the estimates of the rumen degradation rate of feeds, and taking into account that variation can allow for a more adequate comparison among feeds. On the other hand, we also found that an in situ trial cannot be performed using fewer than three animals, otherwise the risk of obtained biased and imprecise information increases. Minimum sets of incubation times were defined and evaluated. They can be used to decrease the costs and the labor when tropical feeds are evaluated through in situ trials with cattle. Our objectives were to evaluate the variability among animals regarding to the degradation rate of the potentially degradable fraction of dry matter, crude protein, and neutral detergent fiber, as well as to establish the minimum number of animals and provide a standardized design of sampling times for in situ ruminal degradation assays of tropical feeds with cattle. Seven feeds were evaluated, four concentrates and three forages. The incubations were performed using five rumen-cannulated Nellore heifers (328 +/- 9.8 kg of body weight). The complete sets of incubation sampling times encompassed 16 time points for forage samples (0-240 h) and 13 time points for concentrate samples (0-144 h). The profiles were adjusted using both fixed and mixed model approaches. When the variation among animals on the degradation rate was considered using the mixed model approach, the precision of the adjusted degradation profiles was increased. Moreover, the utilization of a low number of animals increases the probability to obtain biased estimates of degradation rate and increased random variances. A minimum of three animals is recommended for in situ trials with cattle. Minimum designs of sampling times regarding number and position of incubation times were proposed, discussed, and recommended to assess the dynamics of tropical feed degradation

DECOLONIALIDADE E EDUCAÇÃO ANTIRRACISTA

O texto objetiva trazer discussões sobre as marcas do colonialismo, do racismo e a possibilidade de pensarmos na escola em alternativas que trabalhem com uma educação antirracista desenvolvendo uma crítica à produção de conhecimento na modernidade, discutindo como conhecer, por meio da observação e explicação, produziu um modelo de ciência que, tornou-se hegemônico e dogmático, invisibilizando múltiplos conhecimentos e traduzindo-os como inexistentes. Propõe pensar um currículo que produza a crítica aos modos como o conhecimento é tratado na escola trazendo outras vozes e saberes por meio das narrativas, visto que elas permitem desinvisibilizar as experiências de opressão que estão, de modo dinâmico, sempre se relacionando e se sobrepondo entre si, sinalizando a inseparabilidade estrutural das questões de raça, gênero e classe e fazendo notar como o colonialismo deixou marcas profundas em múltiplas estruturas, exercendo suas colonialidades mesmo após a independência de suas colônias. Como aporte teórico-metodológico utiliza as pesquisas nosdoscom os cotidianos e a pesquisa narrativa, a fim de buscar uma compreensão de mundo mais ampliada, argumentando que o racismo é uma questão estrutural. Para isso, traz uma discussão sobre os currículos escolares numa perspectiva de valorização das diferenças e de um entendimento radical a favor da ideia de democracia social, buscando, por meio da narrativa de experiências, outras possibilidades de insurgência, de existência e de resistência

A Standard Procedure for In Vitro Digestion Using Rumen Fermenters: A Collaborative Study

Our objective was to propose and evaluate a standard procedure for the evaluation of in vitro dry matter digestibility for ruminant feeds, using artificial fermenters. A collaborative study was performed with seven feed analysis laboratories and four feeds (Tifton 85 hay, corn silage, soybean hulls, and soybean meal). Two types of artificial fermenters were evaluated (DaisyII Ankom and TE-150 Tecnal). Each laboratory received 80 sealed filter bags with samples (20 per feed), eight blank filter bags, a plastic bag with buffer solution reagents, and instructions describing how to conduct a 48 h in vitro assay using an artificial fermenter and how to collect bovine ruminal inoculum. On average, the contribution of laboratory effect to the total random variance was 24%, being less than the contribution of equipment (42%) and error (34%). The repeatability ranged from 3.34 to 5.79%, across feeds. The reproducibility ranged from 5.93 to 8.94% across feeds, which implied Horwitz ratios ranging from 2.94 to 4.10. Due to the specific characteristics of the analytical entity evaluated here, which is defined by the method itself, the proposed method was considered reproducible. The results highlighted that, if the method is followed exactly, its results are precise and present adequate levels of repeatability and reproducibility

Interfaces científicas

Número Temático organizado por: Josineide Siqueira de Santana, Marcia Terezinha J. Oliveira Cruz, Cristiano Ferronato, José Eduardo FrancoEsta edição temática trata da trajetória de brasileiras e portuguesas que, em diferentes tempos e espaços, foram educadas, educaram, romperam preconceitos e lutaram contra a opressão. Contempla textos que versam acerca de modelos pedagógicos, da educação escolarizada e não escolarizada, da educação por meio da escrita literária, jornalística e epistolar, das prescrições para o corpo feminino, assim como de mulheres às quais o direito de aprender foi negado, mas, ainda assim, letraram seus filhos e cuidaram dos negócios da família.info:eu-repo/semantics/publishedVersio

Contaminação proteica sobre os teores de lignina Klason em gramíneas e leguminosas tropicais

The objective of this work was to evaluate the extent of protein contamination on Klason lignin (KL) in tropical grasses and legumes, and to propose an equation to estimate the protein‑free content of Klason lignin (KLp). Five grass (30 samples) and 12 legume species (31 samples) were evaluated. Legumes had higher KL contents. Protein contamination was significant in both grasses and legumes, but greater in legume samples. The model to predict KLp was based on KL and crude protein (CP) contents, as follows: KLp = 0.8807KL ‑ 0.0938KL x D ‑ 0.00338CP (R2=0.935), in which D=0, for grasses, and D=1 for legumes.O objetivo deste trabalho foi avaliar a extensão da contaminação proteica sobre a lignina Klason (LK) em gramíneas e leguminosas tropicais, e propor uma equação para estimar o conteúdo livre de proteína da lignina Klason (LKp). Foram avaliadas cinco espécies de gramíneas (30 amostras) e 12 de leguminosas (31 amostras). As leguminosas apresentaram maiores teores de LK. A contaminação proteica foi significativa em gramíneas e leguminosas, mas maior em amostras de leguminosas. O modelo para estimar LKp foi baseado nos conteúdos de LK e de proteína bruta (PB), da seguinte forma: LKp = 0,8807LK ‑ 0,0938LK x D ‑ 0,00338PB (R2=0,935), em que D=0, para gramíneas, e D=1 para leguminosas

Nutritional performance of cattle grazing during rainy season with nitrogen and starch supplementation

The objective of this work was to evaluate the effects of supplementation with nitrogen and starch on the nutritional performance of grazing cattle during the rainy season. Five rumen cannulated Nellore steers, averaging 211 kg of body weight (BW), were used. Animals grazed on five signal grass paddocks. Five treatments were evaluated: control (forage only), ruminal supplementation with nitrogen at 1 g of crude protein (CP)/kg BW, ruminal supplementation with starch at 2.5 g/kg BW, supplementation with nitrogen (1 g CP/kg BW) and starch (2.5 g/kg BW), and supplementation with nitrogen (1 g CP/kg BW) and a mixture of corn starch and nitrogenous compounds (2.5 g/kg BW), thereby resulting in an energy part of the supplement with 150 g CP/kg of dry matter (DM). This last treatment was considered an additional treatment. The experiment was carried out according to a 5 ×5 Latin square design following a 2×2+1 factorial arrangement (with or without nitrogen, with or without starch, and the additional treatment). Nitrogen supplementation did not affect (p>0.10) forage intake. Starch supplementation increased (p0.10), NB obtained with nitrogen plus starch supplementation was greater than NB obtained with either nitrogen or starch exclusive supplementation. Supplementation with starch and nitrogen to beef cattle grazing during the rainy season can possibly improve digestion and nitrogen retention in the animal.

A Standard Procedure for In Vitro Digestion Using Rumen Fermenters: A Collaborative Study

Our objective was to propose and evaluate a standard procedure for the evaluation of in vitro dry matter digestibility for ruminant feeds, using artificial fermenters. A collaborative study was performed with seven feed analysis laboratories and four feeds (Tifton 85 hay, corn silage, soybean hulls, and soybean meal). Two types of artificial fermenters were evaluated (DaisyII Ankom and TE-150 Tecnal). Each laboratory received 80 sealed filter bags with samples (20 per feed), eight blank filter bags, a plastic bag with buffer solution reagents, and instructions describing how to conduct a 48 h in vitro assay using an artificial fermenter and how to collect bovine ruminal inoculum. On average, the contribution of laboratory effect to the total random variance was 24%, being less than the contribution of equipment (42%) and error (34%). The repeatability ranged from 3.34 to 5.79%, across feeds. The reproducibility ranged from 5.93 to 8.94% across feeds, which implied Horwitz ratios ranging from 2.94 to 4.10. Due to the specific characteristics of the analytical entity evaluated here, which is defined by the method itself, the proposed method was considered reproducible. The results highlighted that, if the method is followed exactly, its results are precise and present adequate levels of repeatability and reproducibility

Identification and characterization of expressed retrotransposons in the genome of the Paracoccidioides species complex

Background: Species from the Paracoccidioides complex are thermally dimorphic fungi and the causative agents of paracoccidioidomycosis, a deep fungal infection that is the most prevalent systemic mycosis in Latin America and represents the most important cause of death in immunocompetent individuals with systemic mycosis in Brazil. We previously described the identification of eight new families of DNA transposons in Paracoccidioides genomes. in this work, we aimed to identify potentially active retrotransposons in Paracoccidioides genomes.Results: We identified five different retrotransposon families (four LTR-like and one LINE-like element) in the genomes of three Paracoccidioides isolates. Retrotransposons were present in all of the genomes analyzed. P. brasiliensis and P. lutzii species harbored the same retrotransposon lineages but differed in their copy numbers. in the Pb01, Pb03 and Pb18 genomes, the number of LTR retrotransposons was higher than the number of LINE-like elements, and the LINE-like element RtPc5 was transcribed in Paracoccidioides lutzii (Pb01) but could not be detected in P. brasiliensis (Pb03 and Pb18) by semi-quantitative RT-PCR.Conclusion: Five new potentially active retrotransposons have been identified in the genomic assemblies of the Paracoccidioides species complex using a combined computational and experimental approach. the distribution across the two known species, P. brasiliensis and P. lutzii, and phylogenetics analysis indicate that these elements could have been acquired before speciation occurred. the presence of active retrotransposons in the genome may have implications regarding the evolution and genetic diversification of the Paracoccidioides genus.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Minas Gerais, Inst Ciencias Biol, Dept Microbiol, BR-31270901 Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Programa Posgrad Bioinformat, BR-31270901 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, SP, BrazilUniv Brasilia, Inst Ciencias Biol, Lab Biol Mol, BR-70910900 Brasilia, DF, BrazilUniv Fed Goias, Inst Ciencias Biol, Lab Biol Mol, BR-74001970 Goiania, Go, BrazilFIOCRUZ Minas, Ctr Pesquisas Rene Rachou, Grp Informat Biossistemas, BR-30190002 Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Dept Biol Geral, BR-31270901 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, SP, BrazilFAPEMIG: APQ-01661-13CNPq: 301652/2012-0CNPq: 486618/2013-7Web of Scienc