Study on caloric value of forages and crop straws in Tibetan Autonomous Region

The caloric value of forages and common crop straws in Tibetan Autonomous Region were studied. The results showed that the gross caloric value (GCV) and ash free caloric value (AFCV) of 69 forages ranged from 16.06 to 20.68 kJ/g and 17.83 to 22.47 kJ/g, respectively. Cultivated forages showed higher caloric value than natural forages. AFCV of all the 69 forages were relatively higher than that of the terrestrial plants in the world. 95.65% of the forages belonged to medium or high caloric value forage. The arrangement of AFCV differed within families, which could be explained by the difference of ash content. The average AFCV of graminaceous forages, which were the main feed resources for livestock, was 20.46 kJ/g. Meanwhile, the caloric value content of the forages was higher than that of the crop straws, whose AFCV was 17.75 kJ/g on average, close to the average caloric value of terrestrial plants in the world. GCV of the crop straws showed negative correlation with ash contents.