This study evaluated the effects of different inclusion levels of cactus pear (Opuntia stricta) (at 0%, 15%, 30% or 45% on fresh matter basis) ensiled with shoots of cassava (Manihot esculenta) on ...

The environmental changes in the Caatinga biome have already resulted in it reaching levels of approximately 50% of its original vegetation, making it the third most degraded biome in Brazil, due to inadequate grazing practices that are driven by the difficulty of monitoring and estimating the yield parameters of forage plants, especially in agroforestry systems (AFS) in this biome. This study aimed to compare the predictive ability of different indexes with regard to the biomass and leaf area index of forage crops (bushveld signal grass and buffel grass) in AFS in the Caatinga biome and to evaluate the influence of removing system components on model performance. The normalized green red difference index (NGRDI) and the visible atmospherically resistant index (VARI) showed higher correlations (p < 0.05) with the variables. In addition, removing trees from the orthomosaics was the approach that most favored the correlation values. The models based on classification and regression trees (CARTs) showed lower RMSE values, presenting values of 3020.86, 1201.75, and 0.20 for FB, DB, and LAI, respectively, as well as higher CCC values (0.94). Using NGRDI and VARI, removing trees from the images, and using CART are recommended in estimating biomass and leaf area index in agroforestry systems in the Caatinga biome.

The aim of this study was to evaluate the effect of different water restrictions on the thermoregulation and blood hematological and metabolite parameters of crossbred Santa Inês ewes in a semi-arid climate. Thirty-two ewes were subjected to four water supply levels (100%, 80%, 60%, and 40%), in a completely randomized design with eight replications. The confinement period lasted 77 days, with 14 days allocated for adaptation. Respiratory rate, heart rate, and rectal temperature exhibited a quadratic response. There was an increase in red blood cells and urea. The enzyme alanine aminotransferase decreased linearly with water restriction. Urinary creatinine decreased along with water supply. Regarding urine color characteristics, all groups showed different colors, ranging from clear to cloudy. For the chemical characteristics of urine, a quadratic effect was observed for pH, with the highest value (8.75) at 60%. An increase was observed in total urine proteins and urobilinogen. Crossbred Santa Inês ewes in a semi-arid climate exhibit physiological adaptations to water supply reduction up to 40%. Following an 80% reduction in water supply, animals exhibit mild dehydration, characterized by increased serum urea levels and decreased alanine aminotransferase activity.

The aim was to evaluate the effect of the cactus pear levels (0, 15, 30, and 45%) in cassava shoot silages on the fermentation profile, chemical composition, and aerobic stability. Four treatments were tested with five repetitions, totaling 20 silos. The inclusion of cactus pear in cassava shoots silages promoted an increase in gas losses (P < 0.001), buffering capacity (P < 0.001), pH (P = 0.033), mineral matter (P < 0.001), total carbohydrates (P < 0.001), non-fiber carbohydrates (P < 0.001) and a decreasing in dry matter (P < 0.001), organic matter (P < 0.001), ether extract (P = 0.002), and crude protein (P < 0.001) content. A quadratic effect was observed for effluent losses (P < 0.001), with greater effluent losses (94.78 kg/t natural matter) obtained with the inclusion of 30% cactus pear in cassava shoots silages. Cactus pear inclusion in cassava shoots silage promoted a reduction in the pH during oxygen exposure (P = 0.008). Including cactus pear in up to 45% of cassava silage, shoots cause changes in the fermentation and nutritional characteristics. However, values found in the silages are by good quality standards.

O semiárido brasileiro tem passado por extensos processos de degradação ambiental, principalmente devido a impactos causados pela atividade agropecuária, desmatamentos e queimadas, apresentando como seu bioma predominante, a Caatinga, o qual possui cerca de 50% da sua paisagem original modificada. O uso de sistemas agroflorestais (SAFs) tem sido abordando na literatura destacando-se como uma forma de exploração sustentável, adotados em diversas regiões ao redor do globo, contudo no semiárido brasileiro, apesar do crescimento de áreas destinadas aos SAFs ter ocorrido no Brasil nos últimos anos, adoção desses sistemas na região semiárida ainda é pouco difundida. Considerando-se os benefícios da adoção dos SAFs onde se destacam a assimilação de carbono e nitrogênio, conservação do solo, redistribuição hidráulica, ciclagem de nutrientes e biodiversidade, e a importância da preservação de áreas do semiárido brasileiro e garantia de segurança alimentar dos produtores, e assim a abordagem econômica e ecológica dos sistemas agroflorestais, objetivou-se com essa revisão enriquecer as discussões sobre esses sistemas, seus benefícios e sua viabilidade, como forma de produção agrícola sustentável e fonte de renda a ser adotada no semiárido brasileiro.