OBJECTIVE The gastrointestinal tract of sheep contain complex microbial communities that influence numerous aspects of the sheep's health and development. The objective of this study was to analyze the composition and diversity of the microbiota in the gastrointestinal tract sections (rumen, reticulum, omasum, abomasum, duodenum, jejunum, ileum, cecum, colon, and rectum) of sheep. METHODS Thi...

Secretion of saliva as well as absorptive and secretory processes across forestomach epithelia ensures an optimal environment for microbial digestion in the forestomachs. Daily salivary secretion of sodium (Na+) exceeds the amount found in plasma by a factor of 2 to 3, while the secretion of bicarbonate (HCO3-) is 6 to 8 times higher than the amount of HCO3- in the total extracellular space. Th...

Herbivores face the dilemma that the level of feed intake is negatively related to factors that determine digestive efficiency, such as thoroughness of ingesta comminution by chewing, and retention of digesta in the digestive tract. Ruminants have evolved particular adaptations to solve this dilemma. Most ruminants share the characteristic of “digesta washing”: fluid moves through their digesti...

Digesta samples were collected from rumen, omasum, abomasum, upper small in tes t ine , middle small intestine, lower small intestine, cecum and colon to study the effects of dietary calcium levels on the concentration and solubility of minerals in the digestive tract of sheep. Ca lc ium c o n c e n t r a t i o n s in d ige s t a and supernatant increased and calcium solubilities tended to beco...

A 446-bp cDNA fragment encoding a peptide transport protein was cloned from sheep omasum and used as a probe to study the distribution of the peptide transport protein mRNA in various tissues of sheep, dairy cows, pigs, and chickens. Because the predicted amino acid sequence of this fragment was 85.8, 90.5, and 90.5% identical to rabbit, human, and rat intestinal peptide transporter (PepT1), re...

Alimet (Novus Inter., Inc., St. Louis, MO) feed supplement (an 88% aqueous solution of 2-hydroxy-4-(methylthio) butanoic acid; HMB) is a source of L-Met commonly used in nonruminants and ruminants. The absorption of HMB across ovine omasal and ruminal epithelia was evaluated in this study. Ruminal and omasal epithelia were collected from eight lambs (BW = 67.6 kg +/- 9.1) and mounted in parabio...

Purine analysis is widely used to estimate microbial crude protein (MCP) flow, and the method assumes that all purines contained in feed are degraded in the rumen and that purines detected are of microbial origin. The objectives of our experiment were (1) to determine if DNA from yeast (Saccharomyces cerevisiae) contained in dried distillers grains and solubles (DDGS) escapes degradation in the...

In Merino wethers, increasing the intake of cystine-S or inorganic SO,-S under steady state feeding conditions significantly increased ruminal sulphide concentrations and decreased the flow of soluble copper to the omasum. The curvilinear regression of soluble Cu outflow (y, mg/day) on ruminal S= levels (x, ,ug-ml) was y = 5.57 -2.36x+ 0.491x20.0333~3 (r = 0.95; P<O.OOl), but the flow of solubl...