Effects of Fat Sources on Digestibility and Rumen Fermentation in Crossbred Thai Native X Brahman Bulls

Four rumen-fistulated crossbred Thai native x Brahman bulls were allotted to receive total mixed ration at 2% BW. The ration contained cracked cottonseed (cCS) or cotton oil (CO) or cracked sunflower seed (cSFS) or sunflower oil (SFO) as fat sources. The cattle were randomly assigned according to a 4 x 4 latin square design. Each period of feeding lasted for 21 days. The results revealed that supplementation of fat from different sources did not affect feed intake. However, supplementation of cCS and cSFS trended to improve the digestibility of dry matter (DM) andorganic matter (OM) as compared with the supplementation of CO and SFO. The values of rumen pH and ammonia-nitrogen (NH 3 -N) ranged from6.61-6.86 and 42.44-51.09 mg/dl respectively, these did not differ significantly (P>0.05) between the dietary treatment groups. In addition, acetic acid concentration was higher in TMR containing cCS than in TMR containing CO, cSFS and SFO. It was concluded that using cCS as fat source in diet improvesthe nutrient digestibility without any change in rumen fermentation.