Forage quality of tree species of rangeland plants (Astragalus gossypinus, Trifolium repens and Poa bulbosa) in different phenological stages in Sarab-Sefid Borujerd rangeland, Lorestan province

In the present study, forage quality of three range species including Astragalus gossypinus, Trifolium repens and Poa bulbosa at three phenological stages, (vegetative growth, flowering, seed maturity time) in Borujerd county of Loretan province were evaluated. Data were collected by random sampling using 10 individual plants on transect line in 5 replication. Qualitative indexes were measured and data were compared using ANOVA and Duncan test. Results indicated that DMD is not significant between different species, but it was significant differences (p< 0.01) among the various phenological stages. The highest and the lowest were 34.61 and 24.24% respectively for seeding and before flowering stages. The amount of crude protein was significant at (p< 0.05) in different species, phenological stages and their interactive effect. The highest and the lowest crude protein were obtained in 21.06 and 17.97% in Trifolium repens and Poa bulbosa respectively. The amount of crude fiber was not significant difference between species, on the other hand, in different phenological stages and their interaction was significant at (p< 0.05).The highest and the lowest of crude fiber were 94.30 and 20.86% in seeding time and before flowering phenological stages. The highest and the lowest of amount of ADF were obtained in Poa bulbosa and Trifolium repens with 57.6 and 31.26% respectively. According to obtained results, Trifolium repens, Poa bulbosa and Astragalus gossypinus had better forage quality respectively in before flowering stage where this issue indicates the best time for animal grazing is in May and June.