Effects of palm kernel cake substitution for ground corn in concentrate on nutrient utilization and rumen ecology of Thai indigenous cattle | ผลการใช้กากเนื้อในเมล็ดปาล์มน้ำมันทดแทนข้าวโพดบดในอาหารข้นต่อการใช้ประโยชน์ได้ของโภชนะ และนิเวศวิทยาในกระเพาะรูเมน ของโคพื้นเมืองไทย

This experiment aimed to study the effects of palm kernel cake (PKC) substitution for ground corn (GC) in concentrate on the utilization of nutrients and on the rumen ecology in Thai indigenous cattle. Five rumen-fistulated native bulls, with an average live weight of 317±21 kg were randomly assigned according to a 5×5 Latin Squares Design to receive five diets containing different levels of PKC (0, 25, 50, 75 and 100%) substitution for GC. Plicatulum hay was offered ad libitum. Based on this experiment, the amount of plicatulum hay intake was linearly increased while the amount of concentrate intake and the total dry matter intake were linearly decreased as a result of an increase in level of PKC substitution for GC in the diet. Digestibility coefficients of dry matter and organic matter of cattle fed with concentrate containing 0, 25 and 50% PKC substitution for GC were not significantly different (P> 0.05) but the digestibility coefficients of dry matter and organic matter of cattle fed with concentrate containing 75 and 100% PKC substitution for GC were slightly decreased. Ammonia – nitrogen concentration, total volatile fatty acid and total protozoa population in the rumen of cattle fed with concentrate containing 75 and 100% PKC substitution for GC were slightly lower than those of 0, 25 and 50% PKC substitution for GC group. However, there were no significant differences (P>0.05) among treatments regarding ruminal fluid pH, the amount of acetic (C2), propionic (C3) and butyric (C4) acid in rumen fluid, bacterial population and fungal zoospores in rumen fluid (P>0.05). Furthermore, nitrogen balance, the amount of ruminal microbial nitrogen supply and the efficiency of microbial nitrogen supply in the rumen were not significantly different when compared with other treatments. Therefore, the level of PKC substitution for GC in the concentrate for indigenous cattle fed with plicatulum hay should not be more than 50%.