Rumen microbial numbers in lambs as affected by level of feed intake and dietary diethylstilestrol

Effects of Chlortetracycline Rumen-Protected Granules on Rumen Microorganisms and Its Diarrhea Therapeutic Effect

Chlortetracycline is a broad-spectrum antibiotic used as an oral medication in ruminants. However, this antibiotic affects the rumen microbial population, thereby upsetting the normal microbiota of ruminants. This study determined whether our newly developed chlortetracycline rumen-protected granules are relatively harmless to rumen microorganisms while effective against lamb E. coli diarrhea. We used a qPCR assay to quantify selected rumen microorganisms from lambs treated with or without oral chlortetracycline. We also assessed bacterial diversity in the rumen by 16S rRNA gene sequencing. Lambs were divided into three groups: one group given with oral chlortetracycline granules for 7 days; one group with chlortetracycline premix; and one without treatment. Rumen fluid was collected on 0 d, 7 d, and 14 d of the experiment. In the therapeutic effect trial, cases of naturally E. coli-infected lamb with diarrhea were selected and divided into low, medium, and high dose groups of granules, premix, infection control, and healthy control groups. Treatments were continuously administered for 7 days, and animals were observed for 14 days after drug withdrawal to score and evaluate the treatment effect. Results of qPCR and 16S rRNA gene sequencing showed that the granules could diminish the impact of chlortetracycline on rumen microorganisms compared with the premix. The diarrhea therapeutic effect trial showed that the oral administration of the chlortetracycline rumen-protected granules at the dose of 30 mg/kg·bw/d for 7 days could effectively treat lamb diarrhea caused by E. coli. In conclusion, we provide a new drug preparation of chlortetracycline that can diminish the effect on the rumen microbiota while treating diarrhea caused by E. coli.

An investigation of the relationship between fecal and rumen bacterial concentrations in sheep

With no acceptable method for collecting fresh rumen fluid from zoo ruminants, it was proposed that fecal bacterial concentrations may be correlated with rumen bacteria. If so, fecal bacterial concentrations could be used to study both the effects of diet on rumen bacteria as well as rumen abnormalities. Total and cellulolytic bacterial concentrations were determined in whole rumen contents and feces of sheep using a most-probable-number (MPN) assay. In a Latin square design, four crossbred ewes were fed diets of 100% long or chopped orchardgrass hay (OH) and 60% ground or whole shelled corn plus 40% chopped OH. In a second trial, the sheep were fed a pelleted complete feed at varying levels of intake i.e., control at 2.0% of body weight and at 1.8, 1.6, and 1.2% of body weight. Higher total rumen bacterial concentrations (P<0.01) were found on the high concentrate diets as compared with the high forage diets. Grinding the corn also increased total bacterial concentrations (P<0.05). Fecal concentrations of total bacteria were higher (P<0.01) with the high concentrate diets. Chopping the forage decreased the concentration of fecal cellulolytic bacteria (P<0.05) but had no effect on their concentration in the rumen. An inverse linear relationship (P<0.01) was observed between total bacterial concentrations in the feces and diet intake. Although relationships were observed between the rumen and feces for total and cellulolytic bacterial concentrations, they were dependent on diet, particle size, and level of intake. Thus, fecal bacterial concentrations cannot be used to reliably predict rumen bacterial concentrations. Zoo Biol 27:100-108, 2008. (c) 2008 Wiley-Liss, Inc.

Rumen ciliates from Tanzanian short horn zebu cattle, Bos taurus indicus, and the infraciliature of Entodinium palmare n.sp. and Enoploplastron stokyi (Buisson, 1924)

Rumen ciliates of ten Tanzanian short horn zebu cattle were examined. A total of 15 genera and 46 species were identified, including a new Entodinium species. The ciliate density was 22.2 x 10(4)ml(-1). The number of species per host and the diversity index showed high values, 33.8 and 2.80, respectively. Rumen ciliates had a low percentage composition of the genus Entodinium (7.0-25.0%) and a slightly higher percentage composition of the genera, Eudiplodinium (19.3%), Diplodinium (14.1%), and Ostracodinium (13.1%). Entodinium palmare n.sp., Eudiplodinium kenyensis, and Enoploplastron stokyi were found in all cattle examined. The former two species have been found only in African zebu cattle. Entodinium palmare n. sp. has a characteristic right surface of the body like the "palm of a hand" because of the concave part on the postero-dorsal part of the body, and has the same pattern of infraciliary bands as in other Entodinium species. Enoploplastron stokyi has a characteristic pattern of infraciliary bands analogous to those of Epidinium ecaudatum and Ostracodinium mammosum; with the right side of the adoral polybrachykinety gradually tapering and a slender short vestibular polybrachykinety.