RESUMO

With the expansion of livestock in the Amazon region, a high percentage of pasture areas are degraded and unproductive. Novel strategies are needed, including the use of native tree species, to simultaneously achieve economic and ecosystem benefits. This study aimed at assessing the effects of five multipurpose native tree species on soil fertility and forage quality of Urochloa brizantha pastures in the southern Amazon. Soil and forage samples were collected under the crown and adjacent to 25 isolated trees belonging to five species during a dry and a rainy season. The presence of native trees positively affected the level of potassium, calcium and manganese in the soil, as well as the mineral matter and crude protein of the forage, especially in the dry season, suggesting a protective effect against the seasonal drought. The tree species had variable effects on soil fertility and forage quality. Soil under Apeiba tibourbou had higher potassium levels, while the forage under Handroanthus serratifolius had higher protein and fiber content. Our results indicate that it is important to diversify silvopastoral systems in the Amazon through the use of native tree species, contributing to the design of novel silvopastoral strategies in the region. Common multipurpose tree species with widespread natural distribution could be used as a complementary aspect of pasture management to provide a protective effect against drought, contribute to enhanced nutrient cycling and even increase forage quality.

Com a expansão da pecuária na região amazônica, um alto percentual de pastagem está degradada e improdutiva. São necessárias novas estratégias, incluindo o uso de espécies de árvores nativas, para obter simultaneamente benefícios econômicos e ecossistêmicos. Este estudo objetivou avaliar os efeitos de cinco espécies arbóreas nativas multifuncionais na fertilidade do solo e qualidade da forragem em pastagens de Urochloa brizantha na Amazônia Meridional. Para isso, amostras de solo e forragem foram coletadas sob a copa e áreas adjacentes de 25 árvores isoladas pertencentes a cinco espécies durante uma estação seca e uma chuvosa. A presença de árvores nativas afetou positivamente o nível de potássio, calcio e magnésio no solo, bem como aumentou a matéria mineral e proteína bruta da forragem, especialmente na estação seca, sugerindo um efeito protetivo contra a seca sazonal. As espécies arbóreas tiveram efeitos variáveis sobre a fertilidade do solo e qualidade da forragem. O solo sob Apeiba tibourbou apresentou aumento nos teores de potássio, enquanto a forragem sob Handroanthus serratifolius apresentou melhor qualidade no que se refere a proteínas e fibras. Nosso estudo indica a importância da diversificação dos sistemas silvipastoris na Amazônia por meio do uso de espécies arbóreas nativas, contribuindo para o desenho de estratégias silvipastoris inovadoras na região. Espécies arbóreas multifuncionais comuns de ampla distribuição natural podem ser utilizadas como um aspecto complementar do manejo de pastagens para fornecer um efeito protetivo contra a seca, aprimorar a ciclagem de nutrientes e aumentar a qualidade da forragem.

Assuntos

RESUMO

With the expansion of livestock in the Amazon region, a high percentage of pasture areas are degraded and unproductive. Novel strategies are needed, including the use of native tree species, to simultaneously achieve economic and ecosystem benefits. This study aimed at assessing the effects of five multipurpose native tree species on soil fertility and forage quality of Urochloa brizantha pastures in the southern Amazon. Soil and forage samples were collected under the crown and adjacent to 25 isolated trees belonging to five species during a dry and a rainy season. The presence of native trees positively affected the level of potassium, calcium and manganese in the soil, as well as the mineral matter and crude protein of the forage, especially in the dry season, suggesting a protective effect against the seasonal drought. The tree species had variable effects on soil fertility and forage quality. Soil under Apeiba tibourbou had higher potassium levels, while the forage under Handroanthus serratifolius had higher protein and fiber content. Our results indicate that it is important to diversify silvopastoral systems in the Amazon through the use of native tree species, contributing to the design of novel silvopastoral strategies in the region. Common multipurpose tree species with widespread natural distribution could be used as a complementary aspect of pasture management to provide a protective effect against drought, contribute to enhanced nutrient cycling and even increase forage quality.(AU)

Com a expansão da pecuária na região amazônica, um alto percentual de pastagem está degradada e improdutiva. São necessárias novas estratégias, incluindo o uso de espécies de árvores nativas, para obter simultaneamente benefícios econômicos e ecossistêmicos. Este estudo objetivou avaliar os efeitos de cinco espécies arbóreas nativas multifuncionais na fertilidade do solo e qualidade da forragem em pastagens de Urochloa brizantha na Amazônia Meridional. Para isso, amostras de solo e forragem foram coletadas sob a copa e áreas adjacentes de 25 árvores isoladas pertencentes a cinco espécies durante uma estação seca e uma chuvosa. A presença de árvores nativas afetou positivamente o nível de potássio, calcio e magnésio no solo, bem como aumentou a matéria mineral e proteína bruta da forragem, especialmente na estação seca, sugerindo um efeito protetivo contra a seca sazonal. As espécies arbóreas tiveram efeitos variáveis sobre a fertilidade do solo e qualidade da forragem. O solo sob Apeiba tibourbou apresentou aumento nos teores de potássio, enquanto a forragem sob Handroanthus serratifolius apresentou melhor qualidade no que se refere a proteínas e fibras. Nosso estudo indica a importância da diversificação dos sistemas silvipastoris na Amazônia por meio do uso de espécies arbóreas nativas, contribuindo para o desenho de estratégias silvipastoris inovadoras na região. Espécies arbóreas multifuncionais comuns de ampla distribuição natural podem ser utilizadas como um aspecto complementar do manejo de pastagens para fornecer um efeito protetivo contra a seca, aprimorar a ciclagem de nutrientes e aumentar a qualidade da forragem.(AU)

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RESUMO

BACKGROUND: Precision Livestock Farming (PLF) is a promising approach to minimize the conflicts between socio-economic activities and landscape conservation. However, its application on extensive systems of livestock production can be challenging. The main difficulties arise because animals graze on large natural pastures where they are exposed to competition with wild herbivores for heterogeneous and scarce resources, predation risk, adverse weather, and complex topography. Considering that the 91% of the world's surface devoted to livestock production is composed of extensive systems (i.e., rangelands), our general aim was to develop a PLF methodology that quantifies: (i) detailed behavioural patterns, (ii) feeding rate, and (iii) costs associated with different behaviours and landscape traits. METHODS: For this, we used Merino sheep in Patagonian rangelands as a case study. We combined data from an animal-attached multi-sensor tag (tri-axial acceleration, tri-axial magnetometry, temperature sensor and Global Positioning System) with landscape layers from a Geographical Information System to acquire data. Then, we used high accuracy decision trees, dead reckoning methods and spatial data processing techniques to show how this combination of tools could be used to assess energy balance, predation risk and competition experienced by livestock through time and space. RESULTS: The combination of methods proposed here are a useful tool to assess livestock behaviour and the different factors that influence extensive livestock production, such as topography, environmental temperature, predation risk and competition for heterogeneous resources. We were able to quantify feeding rate continuously through time and space with high accuracy and show how it could be used to estimate animal production and the intensity of grazing on the landscape. We also assessed the effects of resource heterogeneity (inferred through search times), and the potential costs associated with predation risk, competition, thermoregulation and movement on complex topography. DISCUSSION: The quantification of feeding rate and behavioural costs provided by our approach could be used to estimate energy balance and to predict individual growth, survival and reproduction. Finally, we discussed how the information provided by this combination of methods can be used to develop wildlife-friendly strategies that also maximize animal welfare, quality and environmental sustainability.

RESUMO

BACKGROUND: Phenolic compounds are widely present in forage. However, few studies have been carried out to investigate the presence of these compounds in animal products such as milk. In this study, the total phenolic content (TPC) and ferric reducing-antioxidant power (FRAP) of milk produced under agroecological and conventional management systems in southern Brazil were determined. Three systems were compared: (a) agroecological, with intensive rotational grazing, also known as Voisin grazing (ECO); (b) semi-intensive conventional (SIC); and (c) conventional grazing (CGR) (n = 8 per group). Pastures with distinct and more diverse botanical composition were observed on the ECO farms. RESULTS: Significantly (P < 0.05) lower amounts of TPC were found in agroecologically produced milk in autumn and summer and the CGR system showed the highest FRAP value (P < 0.05) for the samples collected in autumn. Positive correlations where found between the TPC and FRAP values obtained for the milk samples (0.198, P < 0.05), milk FRAP and forage TPC values (0.344, P < 0.05), and the TPC and FRAP values obtained for the forage (0.70, p < 0.01). PCA applied to the UV spectra dataset (200-350 nm) clearly distinguished the samples collected from the ECO system in the winter. CONCLUSION: Our results revealed that, under the conditions prevalent in southern Brazil, since the cows were allowed to graze in all of the systems, the TPC and antioxidant capacity of the milk samples showed minimal variation. However, since the forage TPC and FRAP values for the milk were correlated, TPC appears to be a promising variable for the purpose of monitoring forage prior to its selection aimed at enhancing the antioxidant activity of milk.

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