Características agronômicas e avaliação de silagens de 25 híbridos de sorgo

• Ano de defesa: 2006
• Autor(a) principal: Vera Lucia de Araujo
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: degradabilidade; conservação; forragem; Silagem Qualidade; Degradabilidade; Sorgo Silagem; Microscopia eletrônica
• Link de acesso: http://hdl.handle.net/1843/SSLA-7U2NL7

Agronomic traits and silage quality of twenty five sorghum hybrids for silage production wereevaluated. A block design was used for the agronomic traits experiment. A completely randomized block designwas used for the silage quality experiment. Skott-knott test was used to compare means (P<0,05). There weredifference among the hybrids for green matter and varied from 19,61 to 48,09 ton/ha. For the dry matterproduction Volumax hybrid had the greatest dry matter production. There were difference among the hybridshigher, stems, leaves, head, dry matter contents, crude protein and fibrous fractions (NDF, ADF and lignin). Therewere no difference among the sorghum silage for pH, ADF, hemicelluloses, cellulose, in vitro dry matterdigestibility and organic acids. Dry matter in situ degradability was no different among the silages. Volumax hadhad the greatest potential degradability, degradation rate and NDF disappearance. There were evaluated theruminal fermentations kinetics using the semi-automatic gas production technique. Incubations times used were 2,4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 e 96 hours. Volumax silage has had the greatest cumulative gasproduction and gas production outbreaks for hour. ATF54*9929036 silage has have the greathest pottencial gasproduction, and CMSXS217*9929012 silage has have the lower lag phase. The electronic microscopic evaluationsshowed that starch was not used during the silage fermentation, and that hemicelluloses was used by acid lacticbacteria inside the silo. The observation of forage degradation at the degradation time showed the tissuesdisappearance: primary parenchyma, secondary parenchyma, sclerenchyma e phloem. Still, showed that structuresclosely linked to lignin had higher resistance to degradation until at the latest ruminal incubation times