Perfil fermentativo das silagens de seis genótipos de sorgo (Sorghum bicolor L. (Moench.))

• Autor(a) principal: Gustavo Henrique Figueiredo Ibrahim
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMG
• Texto Completo: http://hdl.handle.net/1843/32006
• topic: Fermentação; Zootecnia; Silagem; Sorgo; Dieta em veterinária

It was evaluated the fermentation profile and the nutritional quality of the silages of six sorghum genotypes (Sorghum bicolor (L.) Moench) BR 700, BRS 610, 0249345, 0249351, 0249311 and 0249313. The genotypes had been planted in the dependence of the EMBRAPA MILHO e SORGO, located in the city of Sete Lagoas, Minas Gerais. For the analysis of the standard of fermentation and quality, PVC silos were confectioned. It was analyzed eight periods of ensiling, on time zero, was the forage before ensiling. The silos were opened with one, three, five, seven, 14, 28 and 56 days of fermentation. At the moment of opening, it was collected samples of silage juice for determination of pH, values of ammonia nitrogen and organic acids (latic acid, acetic acid, propionic acid and butiric acid). Dry matter (DM), crude protein (CP), fibrous fractions (neutral detergent fiber – NDF; acid detergent fiber – ADF; lignin – LIG ), in vitro dry matter digestibility (IVDMD) and soluble carbohydrates were evaluated for the silages and for the original material, forage before ensiling. The genotype BR 700 presented the highest perceptual of DM, 39,49%, while the genotype 0249311 was inferior (p<0,05), 26,77%. During the process of ensilage, it was observed the increasing of the DM content, 28,42% to 30,48%, for the original material and to the material of day 56, respectively. The genotype 0249345 was superior for the CP content, with 7,31%, while the genotype BRS 610, presented the lowest value of CP, 6,29% (p<0,05), when compared to the others. It wasn’t observed variation on the cell wall contents due to ensilage process on the genotypes composition. The NDF values ranged from 63,04% to 52,96%, the BR 700 was superior, and the BRS 610 was inferior (p<0,05) with values of 63,04% and 52,96% NDF, respectively. NDA values of BR 700 was superior to the others (p<0,05), with 31,30% NDA, while BRS 610 presented the lowest value of NDA, 26,50%, the others genotypes analyzed were similar (p>0,05) presenting values from 32,87% to 33,82% of NDA. The lignin values varied from 3,24 to 9,49% LIG, detailing the genotype BRS 610, with lowest value of this fraction, 3,24% LIG. The genotype 0249345 achieved the highest value of soluble carbohydrate (p<0,05), with a average value of 6,73%. The genotype BRS 610 presented the high value of IVDMD, 59,64%, in relation to the others that had oscillation from 50,16% to 53,86% in the DM (p<0,05). In relation to the others qualitatives parameters, the silages were classified as good to a very good quality, present values of ammonia nitrogen inferior to 10%, the pH values ranged from 3,78 to 4,03, the concentration of latic acid ranged from 4,99 to 6,31 mg%, propionic acid ranged from 0,29% to 0,33% and the values of acetic acid showed levels inferiors to 0,60 mg%, and during evaluation of organic acids it was not detected butiric acid in the tested silages.