초록
This study was conducted to determine the protein content, cell wall fractions, and mineral concentrations of some minor plant species collected for one year in pastures grazed by goats in the Philippines. An assessment of nutrient variability and a comparison of forage protein and mineral concentrations to the critical value of protein and minerals based on animal needs were also studied. The plant species were the following: grasses(Axonopus compressus, Eleusine indica, Rottboellia exaltata); legumes (Aeschynomene indica, Calopogonium muconoides, Desmodium tortousum); and herbs (Corchorus olitorius, Ipomea aquatica, Sida acuta, Synedrella nodiflora). The two seasons (dry and wet) were subdivided into Dry-1 (December to February, 132 mm total rainfall), Dry-2 (March to May, 25 mm total rainfall), Wet-1 (June to August, 1,138 mm total rainfall), and Wet-2 (September to November, 1,118 mm total rainfall). Results showed that significant differences were obtained on various nutrient fractions including those mineral concentrations across species. Across season, acid detergent lignin (ADL) had higher (p < 0.05) value at Dry-1. Legumes and herbs were higher in crude protein (CP) especially Sida acuta. Grasses showed the highest neutral detergent fiber (NDF) and acid detergent fiber (ADF) with the addition of Sida nodiflora (herb) for it contained high NDF. Aeschynomene indica contained the highest amount of ADL and the herbs (Ipomea aquatica and Sida acuta) had exceptionally high concentration of minerals. Coefficient variation of the various nutrient values ranged from 27.3 to 136.7%. Some forage minerals appeared to be deficient (sodium, phosphorus and copper) or excess (molybdenum) for the whole or part of the year. This study shows that some minor plant species could extend the range of concentration of some nutrients (i.e., CP and minerals) beyond that normally found in conventional pasture species.