Desempenho e desenvolvimento ponderal de novilhas leiteiras alimentadas com dietas à base de cana de açúcar Performance and ponderal development of dairy heifers fed sugar cane based diets

O objetivo deste trabalho foi avaliar o desempenho e o desenvolvimento ponderal de novilhas alimentadas com dietas à base de cana-de-açúcar suplementadas com fontes de nitrogênio não-protéico (NNP) (uréia ou cama de frango, em substituição parcial da uréia) e, ou, adição de probióticos (sem probiótico, levedura ou microbiota ruminal). O custo e a margem bruta do uso destas dietas também foram analisados. Vinte e quatro novilhas, com idade e peso médio inicial de 15 meses e 247 kg PV, respectivamente, foram mantidas em baias individuais e alimentadas durante o período experimental de 84 dias. Os animais foram distribuídos em delineamento inteiramente casualisado, em esquema fatorial 2 x 3 (fonte de NNP vs fonte de probiótico), com quatro repetições. As novilhas foram pesadas e o perímetro torácico e a altura de cernelha e garupa foram determinados no início e no final do período experimental e a cada 28 dias. Os níveis de N-uréia plasmáticos das novilhas foram determinados em amostras de sangue coletadas imediatamente antes do fornecimento diário de alimento, zero hora, e às duas, quatro, seis e oito horas após a alimentação. Não houve interação entre fontes de nitrogênio e fontes de probióticos, para qualquer característica estudada. A suplementação da cana-de-açúcar com fontes NNP não apresentou diferença no ganho de peso diário dos animais. Entretanto, a adição de levedura ou microbiota ruminal promoveu ganhos semelhantes, porém superiores à sem adição de probióticos. A substituição parcial da uréia pela cama de frango não influenciou o desempenho das novilhas, mas as dietas suplementadas com levedura ou microbiota ruminal apresentaram maiores ganho de peso e desenvolvimento ponderal.<br>The objective of this work was to evaluate the performance, ponderal development of heifers fed sugar cane based diets, supplemented with non protein nitrogen (NPN) sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Cost and gross margin of the use of these diets were also evaluated. Twenty-four heifers, with age and average initial weight of 14 months and 247 kg LW, respectively, were maintained in individual stalls and ad libitum fed during the experimental of 84 days. The animals were distributed in a complete randomized design, in a 2 x 3 factorial arrangement (NPN source vs probiotic source), with four replicates. The heifers were weighed and their thoracic perimeter, hip and croup height were determined at the beginning and at the end of the experimental period and at every 28 days. The blood plasma N-urea levels of the heifers were also determined in blood samples collected immediately before the daily feed supply, zero hour, and at two, four, six and eight hours post feeding. There was no interaction between NPN sources and the probiotic sources, for any studied characteristic. The sugar cane supplementation with the NPN sources had no eefect on the average daily weight gain. However, the yeast or ruminal microbiota addition promoted similar weight gains, although, higher than without probiotic addition. The partial replacement of the urea for the broiler litter did not affect the heifers performance, but the diets supplemented with yeast or ruminal microbiota presented higher weight gain and ponderal development

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora