| dc.description.abstract | Previous research suggests that Bos taurus taurus cattle (BT) are less feed efficient when fed low-quality forage, produce more methane (CH4), and exhibit lower levels of N recycling than Bos taurus indicus cattle (BI), but the basis of these variations is not well characterized with regards to protozoal digestion of feeds. Differences in feed efficiency among other digestive functions in BT and BI may be closely associated with resident foregut (reticulorumen) protozoa populations, making this area of research valuable for future precision feeding techniques, management of the rumen microbiota, as well as aiding in the reduction of CH4 production. Samples of rumen fluid from six BT and five BI were analyzed over a period of time concurrent with varying levels of protein supplementation. Classification of two main categories of protozoa, entodiniomorph and holotrich, took place during the process of enumeration. Data for comparisons of BT and BI are presented in the form of protozoa concentration and proportion of holotrich and entodiniomorphs which are used for analyzing hourly data and data compiled for both cattle subspecies. Data collected showed no significant differences between BI and BT for total protozoa concentrations, entodinimorph concentrations, or holotrich concentrations. Proportional differences between BI and BT on the basis of subspecies was not significant, but differences related to time of collection were significant. Size differences were also observed, but not formally quantified with BI appearing to have larger entodiniomorphs than BT. Further research is planned for a deeper understanding of the protozoal population differences between BI and BT. | |
