Yield, chemical Composition and In Vitro digestibility of silages from five sorghum varieties in Golestan Province

This study aimed to investigate the nutritive value and in vitro digestibility of the silage from five varieties of sorghum involving (ICRISAT623×R165, ICRISAT632×R165, ICRISAT625×165, ICRISAT520×166 and speed feed) in a completely randomized design with five replicates. The dry matter(DM) and crude protein(CP) yield of the sorghum varieties were determined and then were ensiled in plastic buckets. The difference between sorghum varieties was significant in terms of DM and CP content before ensiling. ICRISAT520 ×R166 had the highest DM and CP yield and Speed Feed cultivar had the lowest yield. The results showed that silage cultivars had a significant difference in chemical composition (P <0.05). ICRISAT625 ×R165 had the highest content of fat, water soluble carbohydrates (WSC), and metabolism energy (ME) and Speed Feed had the highest amount of acid detergent fiber (ADF) and ammonia nitrogen (NH3-N). There was a significant difference between 5 cultivars in estimating of dry matter digestibility (DMD), organic matter digestibility (OMD) and metabolizable energy (ME). DMD and OMD in silage of ICRISAT625×625 (57.71% and 54.17%) and ICRISAT625×623 (56.30% and 55.04%) were higher than the rest of the cultivars. The highest ME was observed in ICRISAT625×165(7/8 MJ/Kg) and ICRISAT623 ×R165 (7/6 MJ/Kg). Generally, in terms of fresh consumption ICRISAT520×166 is recommended for cultivating in Golestan province due to higher DM and CP production than other cultivars (18487 and 1400 kg ha-1 respectively), but ICRISAT625 × R165 variety of sorghum silage is superior to other cultivars in terms of ME.