This study was conducted to determine the metabolisable energy (ME) levels of some concentrates and to investigate the differences between enzyme and gas techniques.

This investigation was carried out with totally 35 concentrate feed samples; oat (5), barley (5), corn(5), wheat (5) soybean meal (5), cottonseed meal (5), sun flower meal (5). All the 35 samples were collected from different regions of Turkey. Enzyme and gas techniques were used to identify the levels of metabolisable energy (ME) of the feeds. ME levels of oat, barley, corn, wheat, soybean meal, cottonseed meal, sunflower meal with the enzyme technique were determined as 2083.10, 2394.68, 2399.00, 2391.68, 1882.37, 1748.50 and 1847.24 kcal/ kg DM, respectively. ME levels of oat, barley, corn, wheat, soybean meal, cottonseed meal, sunflower meal with gas technique for 24 h incubations were found as 2880, 3060, 2940, 2450, 2250, 2090 and 2130 kcal/kg DM, respectively. The ME values of 48 h incubations of feedstuffs in gas techniques were found as 3370, 3580, 3460, 3060, 2740, 2690, 2320 kcal/kg DM, respectively.

According to the results of this study, gas technique was found more utilizable than enzyme technique to determine metabolizable energy levels of ruminant feeds.