Paper Details

Abstract

This study determined the effects of different harvesting intervals (45, 60, 75, and 90 days) on the dry matter (DM) yield and nutritive value of forage products from 7 tropical grasses during a field trial under subtropical conditions in Peshawar, Pakistan: Pennisetum glaucum, Setaria anceps, Panicum coloratum, Pennisetum purpureum, Sorghum almum, Panicum maximum, and Pennisetum orientale. The trial used a randomized complete block design (three blocks) arranged as a factorial (species × harvest interval). Factorial analysis revealed a significant main effect of harvesting interval on dry matter yield (p<0.001); however, the interaction between species and interval for yield was not significant (p = 0.739). Forage quality declined with advancing maturity, as evidenced by decreases in crude protein and In vitro dry matter digestibility (IVDMD), and by increases in crude fiber and cell wall fractions. The species × interval interaction was significant for dry matter (DM), ether extract, crude fiber, and IVDMD, indicating that the species differed in their rate of quality change with harvest timing. Relative feed value (RFV) ranged from approximately 52 to 74 and generally declined as the harvesting interval increased from 45 to 90 days. Therefore, RFV was used as a comparative ranking index rather than as an absolute forage grade. In general, higher digestibility and RFV values were observed in the earlier intervals (45–60 days), whereas delayed harvesting increased dry matter yield. Intermediate intervals (60–75 days) were frequently a manageable compromise for some species, but the best interval was species-specific

To Cite This Article