Effect of grain maturity stage on the quality of sorghum BRS-610 silages

The quality of sorghum BRS-610 silages in seven stages of grain maturity, between the milky and dry stage, for determination of the ideal moment of ensilage was evaluated. The silos were open after 56 days of fermentation. The values for dry matter of silages increased from 199 to 473g/kg or from 19.9 to 47.3%, with the advance of stage maturity of grains. As for the quality of fermentation, the silages may be classified as excellent quality in every stage of maturity. The lower values of neutral detergent fiber, 539g/kg or 53.9%, and acid detergent fiber, 307g/kg or 30.7%, were observed between the milky/dough to dough/dent stages. Regression analysis indicated an increase in values of lignin - 0.3 unit por stage - and reduction in values of in vitro dry matter digestibility - -2.5 units por stage - with the advance of the grain's stage maturity. The ensilage of sorghum BRS-610 between the milky/dough and dough stage ensure very good fermentation and nutritive value of silage

Parâmetros nutricionais da pastagem natural em diferentes tipos de solos na APA do Ibirapuitã, Rio Grande do Sul - Brasil Nutritional parameters of natural pasture in different soils at APA of Ibirapuitã, Rio Grande do Sul - Brazil

O desempenho de ruminantes domésticos é influenciado por fatores intrínsecos ao animal, ao alimento e pela interação entre animal e alimento. O trabalho foi realizado na Estância do 28, pertencente à Fundação Maronna, Alegrete - RS, dentro da APA do Ibirapuitã. Para representar o fator solo, foram escolhidos os três tipos predominantes da APA do Ibirapuitã: Basalto Superficial, Basalto Profundo e Arenito. As amostras da pastagem natural foram retiradas por simulação de pastejo, através de coleta manual. Os parâmetros nutricionais avaliados foram: proteína bruta, fibra em detergente neutro e taxa de degradação da matéria seca. A forragem da pastagem natural oriunda do solo Basalto Superficial apresentou diferença significativa (P<0,05) nos teores de proteína sobre aquelas obtidas dos solos Basalto Profundo e Arenito, os quais não diferiram entre si. O maior teor de fibra em detergente neutro (84,54%) foi obtido na pastagem oriunda do solo Arenito, em relação às originadas dos solos Basalto Superficial e Profundo, com valores de 74,53 e 77,98%, respectivamente. Para a taxa de degradação, também houve uma diferença significativa (P<0,05). A forragem da pastagem natural oriunda do solo Arenito apresentou valor intermediário de degradação 3,61% h-1, não diferindo dos demais solos. As pastagens naturais apresentam taxa de degradação semelhantes durante a primavera e o verão e durante outono e inverno. A forragem da pastagem natural oriunda do solo Basalto Superficial apresentou qualidade nutricional superior, comprovada pela taxa de degradação da matéria seca.<br>Intrinsic animal and food factors and the interaction between them influence the performance of domestic ruminants. This study was done at Estância do 28, property of the Maronna Foundation, Alegrete - RS, inside the Ibirapuitã Area of Environmental Protection. In order to represent soil as a factor, the three main soil types were chosen: Superficial Basalt, Deep Basalt and Sandy. Hand plucking methods were used to obtain samples of natural pasture. Nutritional parameters considered were crude protein, neutral detergent fiber and dry matter degradation rate. The forage from natural pasture of the Superficial Basalt presented significant difference (P<0.05) in crude protein rates over the other two types of soil, which did not differ amongst themselves. The highest rate of neutral detergent fibre (84.54%) was obtained in pasture originated from Sandy soil, in relation to Superficial and Deep Basalt, with values of 74.53% and 77.98%, respectively. There was also a significant difference in the degradation rate of dry matter (P<0.05). Sandy soil pasture presented an intermediate degradation value (3.61% h-1), not differing from other soils. The forage from natural pastures present similar degradation rates during summer and spring and for the period of autumn and winter. The forage from natural pasture of Superficial Basalt type soil presented superior nutritional quality, as could be proved by the dry matter degradation rate