Caprinos na dispersão e germinação de sementes de leguminosas forrageiras tropicais

Abstract

This study was conducted with the objective of evaluate the dispersion and germination of leguminous seeds after passage through the digestive tract of goats. The first experiment was conduced with the objective on evaluate two methods for seeds scarification and determinate which species presented higher levels of germinated seeds. The leguminous species used were: Pueraria phaseoloides Benth (kudzú tropical), Clitorea ternatea (cunhã), Stylosanthes spp. (estilosantes), Macroptilium atropurpureum cv. Siratro (siratro) e Flemingia macrophylla (Willd.) Merrill (flemingea). The experimental design employed was completely randomised in a 5 x 3 factorial arrangement (five species, three treatments) and with five repetitions. The treatments were: scarification with sulfuric acid, passage through the digestive tract of goats and control, which was characterized by the absence of seeds scarification. The effect of passage through the digestive tract with one goat for each repetition. Each goat received 200 seeds of each specie administrated with the concentrate. The total collect of feces was realized in each 12 hours. All recovered seeds in feces were counted, and submitted to a germination test on the laboratory, like the seeds sulfuric acid scarificated and control treatment. The highest percentage of recovered seeds were of P. phaseoloides (48,3% of 1000 seeds), followed by F. macrophylla (42,5%) e M. atropurpureum (31,8%). The period that presented the higher percentage of seeds on feces was from 24 to 60 hours. F. macrophylla (65%) and P. phaseoloides (53%) presented seeds germinated percentage superior to the other species after passage through the digestive tract. The second experiment was conduced on a Brachiaria humidicola pasture shared in 20 paddocks. The experimental design employed was randomized complete block with seeds of four leguminous species (treatments) and five repetitions (paddocks), with two animals in each one. The treatments were represented by leguminous seeds of Flemingia macrophylla (Flemingia), Pueraria phaseoloides Benth (Kudzú tropical), Clitorea ternatea (Cunhã) and Macrotiloma axillare (Macrotiloma). The evaluation period started after the animals exit from paddocks. Four evaluations were made at 30, 60 and 90 days after seeds dispersion in each paddock. Macroptilium artropurpureum e Flemingia macrophylla species presented the better result of plants number on paddocks that shows the potential of these leguminous on this introduction method of seeds dissemination on pasture already constituted. The results of this study show that goats can be an alternative to scarification of some legume seeds and also can be used to dispersion for recuperate degraded pastures in Brazil. However, more studies must be conducted in field to validate this technique.