RESUMEN
The effects on rumen kinetics after feed and water had been deprived for 72 hr were studied using four fistulated Bos indicus steers. The animals were assigned in a 2 × 4 crossover design with two treatments: feed and water ad libitum (control) and no feed and water for 72 hr (deprived) with four steers per treatment over two time periods. Feed and water deprivation caused decreases in the numbers of cellulolytic bacteria (1.4 vs. 0.4 cfu × 106 /ml; p = .001), live (23.7 vs. 0.8 × 109 /ml; p = .001), dead (12.7 vs. 0.5 × 109 /ml; p = .001) and total bacterial counts (36.4 vs. 1.4 × 109 /ml; p = .001) at day 0, compared with the control treatment. However, the deprived group had greater numbers of cellulolytic bacteria (2.7 vs. 50.1 cfu × 106 /ml; p = .001), live (18.3 vs. 42.2 × 109 /ml; p = .001), dead (6. 5 vs. 19.1 × 109 /ml; p = .001) and total bacterial counts (24.8 vs. 61.3 × 109 /ml; p = .001) from rumen fluid on day 4, compared with the control treatment. The numbers of protozoa in rumen fluid from the deprived group were less than (551.2 vs. 2.4 × 103 /ml; p = .001) the control group on day 0. However, the deprived treatment had fewer protozoa in rumen fluid than the control treatment on day 4 (p = .001) and day 9 (p = .001). Volatile fatty acids and in vitro gas production as functional measurements of rumen fluid followed the same trend as the bacterial and protozoa populations. These results indicate that feed and water deprivation would have a negative but transient effect on the rumen kinetics of Bos indicus steers.