Influência do estádio de maturação do sorgo forrageiro, Sorghum bicolor (L) Moench, sobre o rendimento e qualidade das forragens e respectivas silagens.

• Ano de defesa: 1983
• Autor(a) principal: Oliveira, José Aloísio de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Zootecnia
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/45689

This research was conducted at th.e experimental station of the Universidade Federal do Ceará, Fortaleza. The main objective was the determination of the optimal maturity stage of sorghum for processing into forage and silage. The cultivar chosen for this study was the EA-116, produced in this University. The following experimental treatments were tested: A - cut at 70 days (milky grain); B - cut at 80 days (early dough grain); C - cut at 90 days (hard dough grain); D - cut at 100 days (mealy grain). The material to be processed into silage was stored in concrete siles. The experimental design consisted of three completely blocks of four treatments each. The level of significance used in this experiment was 5%. The results showed that forage yield increased from treatment A to treatment D, from 5.4 to 7.0 ton/ha, with a dry matter content of the forage ranging from 26.7% to 34.7%. Total protein expressed as dry matter basis, decreased in treatments A to D, from 7.8% to 7.2%. The level of soluble carbohydrates in the forage, however, did not seem to be associated to maturity level of the plant. Silage yield increased with cutting time, from 3.7 to 5.1 ton/ha, dry matter content ranging from 26.6 to 34.6%. Soluble carbohydrates, expressed in a dry matter basis, increased with cutting time, from 6.7% to 7.9%. Crude protein level and pH showed no association with maturity time during the experiment. Lactic acid was significantly higher only in the silage processed with the plant cut at 70 days. Crude protein and soluble carbohydrate content of silage, expressed as yield per hectare, increased with cutting time. Treatment C showed the highest stability of dry matter content during silage. Crude protein and soluble carbohydrates losses showed inverse correlation with cutting time silage period. Digestible dry matter increased with cutting time, from 1.7 to 2.6 ton/ha for the silage. Crude protein and digestible energy levels, expressed per hectare, also increased with maturity time. In conclusion, the best time for harvesting forage sorghum for forage or silage feed, under the conditions used in this experiment, is between 90 and 100 days of age.