Authors : Ismail Gul , Ramazan Demirel , Numan Kilicalp , Mehdi Sumerli and Hasan Kilic
Abstract: The effect of different harvesting times on yield and some silage quality of maize, sorghum and sorghum�sudangrass hybrids grown as in a split plot design with 3 replicates during second crop in semi arid condition were evaluated. In this research, whole plant silage chemical composition and DM digestibilities on different times, measured in vivo were determined. For this purpose, 2 maize (DK 711, TTM 815), 2 sorghum (Sucro sorgo 506, FS 5) and 2 sorghum-sudangrass hybrids (P 988, Grazer N2) cultivars were harvested at 3 different maturity stages (mid-flowering-MF, milkline-ML and hard dough-HD). The chopped materials were ensilaged in 10 L anaerobic jars, for 60 days. Silage samples were dried (CP, FP, pH, ADF, NDF contents were measured) and incubated in fistulated 3 Holstein Friesian heifers for determining dry matter digestibility. Significant differences were found between plant cultivars and harvesting stages for DM yields, CP, DM and WSC. The dry matter yields varied between 12654.2 and 25340.1 kg ha 1. The highest dry matter yield was obtained from Sucro Sorgo 506 with ML and HD. Dry matter content of silages were changed from 20.63% (in silage sorghum cv. FS 5) to 27.36% (in sorghum-sudangrass hybrids cv. Grazer N2), pH (3.84 in FS 5 and 3.98 in TTM 815), Fleig point (FP) (90.87 in TTM 815 and 104.6 in Grazer N2 ), Crude Protein (CP) was 3.92% in Grazer N2 and 6.64% in FS 5, ADF was 44.56% in DK 711 and 49.33% in SS 506, NDF was 59.56% in DK 711 and 65.70% in P 988, whereas in vivo DM digestibility at 12 h was 32.82% in SS 506 and 38.91% in TTM 815. Crop maturity increased satistically significantly, silage DM varied from 20.43-25.92% and in vivo digestibility of DM at 12 h varied from 32.56-37.66%, however significantly decreased. ADF decreased from 50.17-42.56%, NDF decreased from 64.71-59.62%), WSC (Water Soluble Carbohyrates) increased from (24.59-30.24%). CP decreased from 5.59-5.05%. pH was between 3.78-4.10 and Fleig point was between 94.66-97.58. These values were not changed statistically, when crop maturity increased. Incubation periods were 0, 12, 24, 48 and 72 h for determining dry matter digestibility by using nylon bag technique. Silage NDF values were decreased from flowering to milkline stages. It was concluded that silages in vivo DM digestibility were increased with maturity at 12 h rumen incubation.
Ismail Gul , Ramazan Demirel , Numan Kilicalp , Mehdi Sumerli and Hasan Kilic , 2008. Effect of Crop Maturity Stages on Yield, Silage Chemical Composition and In vivo Digestibilities of the Maize, Sorghum and Sorghum-Sudangrass Hybrids Grown in Semi-Arid Conditions. Journal of Animal and Veterinary Advances, 7: 1021-1028.