Biofixation of CO2 by microalgae has been recognized as an attractive approach to CO2 mitigation. The main objective of this work was to maximize the rate of CO2 fixation ( [Formula: see text] ) by the green microalga Chlorella vulgaris P12 cultivated photoautotrophically in bubble column photobioreactors under different CO2 concentrations (ranging from 2% to 10%) and aeration rates (ranging from 0.1 to 0.7 vvm). Results showed that the maximum [Formula: see text] (2.22 gL(-1)d(-1)) was obtained by using 6.5% CO2 and 0.5 vvm after 7 days of cultivation at 30°C. Although final biomass concentration and maximum biomass productivity of microalgae were affected by the different cultivation conditions, no significant differences were obtained in the biochemical composition of microalgal cells for the evaluated levels of aeration and CO2. The present study demonstrated that optimization of microalgal cultivation conditions can be considered a useful strategy for maximizing CO2 bio-mitigation by C. vulgaris.

The aim of this study was to evaluate diets substituting corn grain with passion fruit peels on the consumption, ingestive behavior, digestibility of diets and sheep performance. A total of 20 sheep were used, confined in individual pens, fed twice a day, with diets which included passion fruit peels in the proportions of 0; 25; 50; 75 and 100% replacing corn grain. The corn grain represented 70% of the dry matter of the diet and the passion fruit peels were supplied in dehydrated form. The experimental design was completely randomized with five treatments and four replicates. The data were submitted to analysis of variance and regression analysis at the significance level of 5%. There was a linear increase in dry matter consumption with an increase of 3.89 g for each inclusion level of passion fruit peel. The apparent digestibility of dry matter decreased and neutral detergent fiber increased linearly with the substitution of corn grain with passion fruit peels. The feeding, rumination, leisure and water intake times presented averages of 3.74; 2.92; 16.92 and 0.42 hours, and were not influenced by the diets (P>0.05). The average daily weight gain was similar for the animals in the different diets and consequently the final weight presented average values of 0.226 kg day-1 and 32.1 kg, respectively. The inclusion of passion fruit peels in the sheep diet is an interesting alternative because even with the reduced dry matter digestibility, it increased the consumption and promoted similar weight gains.

Due to the importance of dairy activity in the municipalities of the state of Rondônia, the objective was to characterize milk production in the properties of the municipality of Nova Brasilândia D'Oeste - RO. The methodology was composed by the application of a questionnaire containing questions related to the production chain, using a sample of dairy farmers distributed through the municipality's vicinal lines. The analysis was performed with the aid of Microsoft Office Excel spreadsheets®. The results obtained show a low technological level in dairy activity in the municipality, with an average daily production of 4.73 L per cow. The animals are kept in pastures of tropical grasses, in which the genus Brachiaria stands out, present in 100% of the properties. The supply of bulky and concentrated source for supplementation of animals is not significant, causing seasonality in dairy production in dry periods because it does not meet the nutritional requirements of the herd. In relation to herd health, producers carry out mandatory vaccines of foot-and-mouth disease and brucellosis. Milking hygiene deserves attention for the low level of use of hygiene techniques such as pre- and post-dipping and diagnostic tests and mastitis control. Manual milking is performed in 92% of the evaluated properties. The low productivity of the municipality is related to non-specialized animals, the low technological level employed in the properties and the low adoption of technical assistance by producers. The data obtained were important to know and characterize the profile of dairy properties in this region and visualize the need for investment of the activity.

Grande parte do rebanho de bovinos do Brasil se encontra em sistemas a pasto em áreas intertropicais, como a Amazônia. Visto a necessidade de buscar maior sustentabilidade ambiental e econômica da pecuária, este trabalho teve como objetivo discutir a introdução e os benefícios do componente animal em sistemas integrados de produção agropecuária. A revisão baseou-se no referencial da pesquisa bibliográfica coletados através do levantamento das produções científicas sobre sistemas integrados de produção agropecuária (SIPA), produzidas entre os anos de 2000 a 2020. Os SIPAs consistem na implantação de diferentes atividades (pecuária, agricultura e silvicultura) na mesma área, em consórcio, sequencial ou rotacionado, manejados com ênfase no contexto de produção e sustentabilidade. A inclusão do componente animal traz diversos benefícios para o sistema, seja pelo estímulo à produção de biomassa, aumento da ciclagem de nutrientes, aumento da massa e diversidade microbiana, melhoria nas condições físicas, químicas e da fertilidade do solo. Além de beneficiar o sistema, o componente animal se beneficia com a inclusão, especialmente pelos melhores valores nutricionais das forrageiras e conforto térmico oferecido por alguns arranjos. Outro fator benéfico dos sistemas integrados para a pecuária, seria a sua utilização em métodos alternativos na recuperação e renovação de pastagens em áreas degradadas. Diversas são as modalidades/arranjos que podem ser empregados na integração, em que são montados visando aproveitar as sinergias existentes entre as atividades, as quais, possuem seus benefícios particulares ou mútuos quando bem conduzidos.

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Objetivou-se avaliar a suplementação proteica ou proteica-energética e a substituição da quirera de milho pela casca de maracujá na suplementação proteica, para novilhas durante a recria, no período de seca, além do estudo da viabilidade econômica dessas suplementações. O delineamento experimental utilizado foi inteiramente casualizado, com três tratamentos e oito repetições. Foram utilizadas 24 novilhas, divididas em três lotes: lote 1, suplementação proteica à base de núcleo proteico e quirera de milho (1:1), fornecida na quantidade de 1 g por kg de peso corporal; lote 2, suplementação proteica-energética, à base de núcleo proteico e quirera de milho (1:2), fornecida na quantidade de 3 g por kg de peso corporal; e lote 3, suplementação proteica à base de núcleo proteico e casca de maracujá (1:1), na quantidade de 1 g por kg de peso corporal. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey, ao nível de 5%. Os pesos, inicial e final, foram semelhantes para as suplementações. O ganho de peso médio diário foi semelhante entre os animais que receberam a suplementação proteica com quirera de milho e a suplementação proteica-energética e superior em relação aos animais que receberam a suplementação proteica com casca de maracujá. Mesmo apresentando diferenças no ganho de peso, o lucro diário por animal foi semelhante. O ganho de peso de novilhas na recria é influenciado pelo tipo de suplementação, durante o período de seca, porém a lucratividade pode ser semelhante.

Toxoplasma gondii and Neospora caninum are obligate intracellular intestinal coccidia distributed worldwide, and are causative agents of toxoplasmosis and neosporosis, respectively. The aim of this study was to evaluate the prevalence of anti-T. gondii and anti-N. caninum antibodies and the factors associated with infections in beef cattle intended for human consumption in an Amazonian area of North Brazil. We collected blood samples of 387 cattle from 50 herds located in different municipalities of the State of Rondônia. An epidemiological questionnaire was distributed to farmers, with regard to nutritional, sanitary and reproductive herd management. The samples were identified, refrigerated and sent for serological analyses via IFAT (Immunofluorescent Antibody Test). Among the 387 analyzed animals, 91 (23.5%; CI 95%: 18.8–27.2) were positive for anti-T. gondii antibodies, with titers varying from 1:64 (75.8%) to 1:512 (2.2%). For anti-N. caninum antibodies, only four animals (1%; CI 95%: 0–2.7) were positive, with titers ranging from 1:400 (50%) to 1:1600 (25%). We observed a significant rate of anti-T. gondii antibodies in the variables “pure breed” and “contact with free-range chickens” (p < 0.2). There were no risk factors associated with the presence of anti-T. gondii or anti-N. caninum antibodies. In conclusion, there was a high prevalence of anti-T. gondii antibodies in beef cattle intended for human consumption in the State of Rondônia, Brazil, and a low prevalence of anti-N. caninum antibodies. Longitudinal studies can better elucidate the cause of these prevalence levels and how they could be better prevented and controlled.

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