Nutritional evaluation of bamboo cultivars in sub-Himalayan region of India by chemical composition and in vitro ruminal fermentation

Bamboo leaves at similar maturity from 12 different species, namely Sasa auricoma, Bambusa nutans, Bambusa bambos, Phyllostachys aurea, Bambusa tulda, Dendrocalamus asper, Bambusa ventricosa, Dendrocalamus strictus, Melocanna baccifera, Dendrocalamus hookerii, Bambusa vulgaris and Dendrocalamus hamiltonii growing at the bamboo fields of Himachal Pradesh, India were selected for evaluation of their nutritive value based on their use as cattle feed at different places in India. The evaluation parameters were chemical composition, in vitro gas production (IVGP) and its kinetic parameters, in vitro dry matter (IVDMTD) and organic matter true degradability (IVOMTD), partitioning factor (PF), ammonia N production, methane and short chain fatty acids production. The compositional value (g kg⁻¹ DM) of bamboo leaves with respect to crude protein from 146 (B. tulda) to 204 (D. hamiltonii), acid detergent lignin from 49 (M. baccifera) to 94 (B. ventricosa), acid insoluble ash from 44 (D. hookerii) to 110 (B. vulgaris) and other constituents and their correlation with various in vitro ruminal degradability parameters, suggested that M. baccifera, D. hookerii, D. hamiltonii and D. asper could be promising fodder species. Among the promising ones, Melocanna baccifera had higher μ (maximum rate of gas production at the point of inflection of the gas curve) and lower t₁/₂ (halfway time to the maximum gas volume), higher IVDMTD (482 g kg⁻¹ DM), IVOMTD (548 g kg⁻¹ OM), and microbial mass (19.6% of DM), and less contribution of substrate to ammonia N production and narrower acetate: propionate ratio with increased metabolizable energy concentration (7.92 MJ kg⁻¹ DM). Thus, Melocanna baccifera may be ranked as the best cultivar. Above all the bamboo cultivars, M. baccifera, D. hookerii, D. hamiltonii and D. asper were considered as promising fodder for the ruminant livestock.