The small foreigner: new laws will promote the introduction of non-native zooplankton in Brazilian aquatic environments

Abstract Non-native species of zooplankton have been introduced in Brazilian continental aquatic environments for a variety of reasons (e.g., non-native fish stocking, aquaculture), but many pathways of zooplankton introductions remain unknown. Recently, the governor of the State of Amazonas passed Law No. 79/2016, which allows for aquaculture operations using non-native fish in that state. This change in policy will likely result in the species introduction or propagule pressure of non-native zooplankton such as: Mesocyclops ogunnus Onabamiro, 1957; Kellicottia bostoniensis (Rousselet, 1908); Daphnia lumholtzi Sars, 1885; Lernaea cyprinacea (Linnaeus, 1758); Lamproglena monodi Capart, 1944. Of further concern is federal law No. 5989/09, which proposes the use of non-native fish in Brazilian aquaculture nationwide. We believe that both laws will intensify the introduction of non-native zooplankton. Once established in aquatic environments, non-native species of zooplankton could result in negative impacts (e.g., a loss of ecosystem services, food web alterations). Therefore, Brazilian authorities should incentivize the use of local native species rather than pass laws that threaten the environment

Substituição do milho e farelo de algodão pelo milheto no concentrado da dieta de novilhos em confinamento

Objetivou-se identificar possíveis efeitos da substituição do milho e do farelo de algodão por milheto na digestibilidade dos nutrientes da dieta e no desempenho de bovinos em confinamento. As dietas, com relação volumoso:concentrado 65:35, foram compostas de silagens de milho e milheto como volumoso (50:50, com base na matéria natural) e cinco níveis de milheto em substituição ao milho e ao farelo de algodão (0; 23; 49; 80 e 96% da matéria natural) no concentrado. O delineamento de blocos ao acaso foi adotado em ambos os experimentos. Utilizaram-se cinco repetições no estudo de desempenho e quatro na avaliação do consumo e da digestibilidade in vivo. O consumo de matéria seca (MS) expresso em porcentagem do peso vivo (PV) e g/kgPV0,75, diminuiu linearmente com a introdução de milheto na dieta, registrando-se 2,91% e 108,5 g e, 2,5% e 92,53 g para dietas exclusivas de milho e milheto, respectivamente. As digestibilidades de MS, proteína bruta e carboidratos totais não foram afetadas, enquanto a digestibilidade do extrato etéreo diminuiu e a de fibra aumentou linearmente sem afetar os teores de nutrientes digestíveis totais. O ganho de peso vivo diário, o consumo de MS e a conversão alimentar também não foram afetados pela adição de milheto, portanto, é possível substituir o milho e o farelo de algodão por milheto em rações para bovinos em confinamento.The objective of the present study was to identify possible effects of replacing corn and cottonseed meal by pearl millet on digestibility of nutrients in diets and on performance of cattle in feedlots. Diets with a 65:35 roughage:concentrate ratios were composed of corn and pearl millet silages as roughage (50:50, based on natural matter) and five levels of pearl millet replacing corn and cottonseed meal (0; 23; 49; 80 and 96% natural matter) in the concentrate. It was used random block designs in both experiments. Five replicates were used to evaluate performance and four replicates for evaluating intake and in vivo digestibility. Dry matter (DM) intake, expressed in body weight (BW) percentage and g/kg BW0.75 linearly decreased when pearl millet was introduced into the diet, thus 2.91% and 108.5g and, 2.5% and 92.53 g were registered for diet exclusively with corn and pearl millet, respectively. Digestibility of dry matter, crude protein, and total carbohydrates were not affected, whereas digestibility of ether extract reduced and fiber digestibility linearly increased without affecting contents of total digestible nutrients. Daily body weight gain, dry matter intake and feed conversion were not affected by adition of pearl millet, either, therefore, it is possible to replace corn and cottonseed meal by pearl millet in rations for cattle in feedlot