Rumen bacterial and protozoal populations in cattle being relocated in tropical Queensland

Abstract

Rumen microbial populations were measured in Brahman-cross steers that were relocated from spear grass (Heteropogon contortus) dominant pastures in northern Queensland to buffel grass (Cenchrus ciliasis) dominant pastures in central Queensland, to assess whether aspects of rumen function may contribute to the sometimes reported depressed growth rates following relocation. Nine genera of ciliate protozoa (Isotricha, Dasytricha, Entodinia, Epidinium, Diplodinium, Ostracodinium, Metadinium, Elytroplastron, and Eudiplodinium) were recorded in the rumen fluid of the steers. In most steers all genera were present at any time and the generic mix persisted throughout the 10 months over which the study was conducted. Protozoal population composition fluctuated only slightly over the sampling period. Entodinia were predominant, occupying 50-70% of the population. Population density varied according to season, with the highest density (4-8×105 /mL rumen fluid) occurring in the wet season. Bacterial and protozoal populations were remarkably stable and little affected by relocation. Again, the major impact on population density was the season, with all carbohydrate (soluble sugar, starch, xylan, and cellulose) utilising bacterial subpopulations reaching the greatest density with the onset of the wet season.

Microbial community compositions in the gastrointestinal tract of Chinese Mongolian sheep using Illumina MiSeq sequencing revealed high microbial diversity

“…In addition, the rumen is the most important segment of nutrient utilization (Kebreab et al 2009), which primarily involves protein metabolism and plant secondary metabolism. Nevertheless, main nutrients, particularly proteins, are absorbed in the small intestine (Klieve 2005). Importantly, the rapid uptake and conversion of simple carbohydrates help maintain the micro-ecological balance of the small intestine (Zoetendal et al 2012).…”

Genetic homogeneity and phage susceptibility of ruminal strains of Streptococcus bovis isolated in Australia

“…The collection of samples of rumen contents, storage and medium used have been described previously (Klieve et al 1989;Klieve et al 1998). Samples were thawed and dilution plated under anaerobic conditions on a rumen fluid based medium (Klieve et al 1989), modified to replace glucose and cellobiose with wheat starch (Sigma).…”

Diversity of methanogens in ruminants in Queensland

“…Merino wethers fed lucerne pellets (2) or fresh cut kikuyu grass (2) and two samples of fluid from a fermentor receiving Leucaena leucocephala leaf as a feedstock were collected. Samples of rumen fluid were collected either per os using a stomach tube and vacuum pump, or through a rumen canula, as previously reported (Klieve et al 1998(Klieve et al , 2003. Rumen fluid (50--100 mL) was collected and strained through nylon gauze into an openmouthed jar.…”