Colon Of Sheep Research Articles

Cactus cladodes cause intestinal damage, but improve sheep performance.

The objective of this study was to evaluate the effect of three varieties of cactus cladodes resistant to carmine cochineal on the animal performance and histology of the large intestine of sheep. Forty lambs (21.0 ± 2.0 kg body weight) were distributed in a completely randomized design, with four treatments and ten repetitions. The experimental treatments consisted of a control diet and three more diets in which part (750 g/kg) of the elephant grass hay, and all the corn were replaced by Miúda cactus cladodes, IPA-Sertânia cactus cladodes, or Orelha de Elefante Mexicana (O.E.M.) cactus cladodes. On the 60th day after the introduction of the tested diets, blood samples were collected to quantify serum magnesium (Mg2+) levels. After 63 days of experiment, the animals were slaughtered and fragments of the cecum and colon were collected for histopathological analysis. The inclusion of the Miúda and O.E.M. cactus cladodes in the diet caused inflammatory lesions in the cecum (100% of the animals) and in the colon (71.43% of the animals) of the sheep. The inflammation in the cecum caused by Miúda and O.E.M. cactus cladodes was considered accentuated (P = 0.009). Less voluntary water intake was observed for animals submitted to diets with cactus cladodes (P < 0.001), as well as higher water content in the feces (P < 0.001). The cactus cladodes, especially the Miúda and O.E.M. varieties, cause lesions in the tissue morphology of the cecum and colon of sheep, but improve productive performance.

A High Grain Diet Dynamically Shifted the Composition of Mucosa-Associated Microbiota and Induced Mucosal Injuries in the Colon of Sheep.

This study investigated the dynamic shifts in mucosa-associated microbiota composition and mucosal morphology in the colon of sheep fed a high grain (HG) diet. A total of 20 male sheep were randomly assigned to four groups (n = 5 for each). The sheep in first group received hay diet. The animals in other 3 groups were fed an HG diet for 7 (HG7), 14 (HG14), or 28 (HG28) days, respectively. Colonic digesta samples were collected to determine the pH and the concentrations of volatile fatty acid (VFA) and lactate. The colonic mucosa was sampled to characterize the bacterial communities using Illumina MiSeq sequencing and to determine mRNA expression levels of cytokines and tight junction protein genes using quantitative real-time PCR. As time advanced, results revealed that colonic pH linearly decreased (P = 0.007), and the concentrations of total VFA linearly increased (P < 0.001). Microbial analysis showed that an HG diet linearly reduced (P < 0.050) the diversity and richness of the colonic microbiota. The principal coordinate analysis results showed that the colonic mucosa-associated bacterial communities of the four groups significantly shifted with number of days fed an HG diet. At the genus level, HG feeding significantly increased the relative abundance of some taxa including Prevotella, Coprococcus, Roseburia, and Clostridium_sensu_stricto_1, and decreased the proportion of Treponema, and the percentage of these taxa was not affected by days fed an HG diet. The microscopic examination showed that HG feeding caused the mucosal epithelial injury. The RT-PCR results showed that the mRNA expression of claudin-1 (P = 0.038), IL-1β (P = 0.045), IL-6 (P = 0.050), and TNF-α (P = 0.020) increased linearly with number of days fed an HG diet. The correlation analysis revealed significant correlation between the colonic mucosal mRNA expression of cytokines and mucosal bacterial composition. Generally, HG feeding increased colonic fermentation and altered colonic mucosal bacterial communities, which eventually caused colonic mucosal damage and led to colonic dysfunction, and these changes occurred gradually over at least 4 weeks.

Stimuli-responsive lipid nanotubes in gel formulations for the delivery of doxorubicin

Lipid nanotubes (LNTs) are one of the most advantageous structures for drug delivery and targeting. LNTs formed by a specially designed molecule called AQUA (AQ-NH-(CH2)10COOH (AQ: anthraquinone group) is used for drug delivery, and doxorubicin (DOX) is the drug selected. DOX and AQUA have some similarities in their molecular structures, so a significant amount of DOX can be loaded to LNTs. The AQUA LNTs are pH responsive, and drug loading increased almost linearly by increasing the pH, reaching a maximum value (96%) at pH 9.0. In terms of drug release, lower pHs are preferred. Drug-loaded LNTs are also mixed with four different gels (chitosan, alginate, hydroxypropyl methylcellulose and polycarbophil) to use the advantages of these gels. The drug release efficiency is studied using a Franz diffusion cell in which sheep colon membranes and dialysis membranes are utilized. The amount of released DOX from the chitosan gel formulations was quite high. Sodium alginate gels had lower release and slower diffusion of DOX. The cytotoxic effect of DOX-loaded AQUA LNTs has also been determined on cell cultures. Our new lipid nanotubes are a non-toxic, effective, biodegradable, biocompatible, stable and promising system for drug delivery and can be used for colonic administration of DOX for the treatment of colorectal cancer (CRC).

Epithelial, metabolic and innate immunity transcriptomic signatures differentiating the rumen from other sheep and mammalian gastrointestinal tract tissues.

Background. Ruminants are successful herbivorous mammals, in part due to their specialized forestomachs, the rumen complex, which facilitates the conversion of feed to soluble nutrients by micro-organisms. Is the rumen complex a modified stomach expressing new epithelial (cornification) and metabolic programs, or a specialised stratified epithelium that has acquired new metabolic activities, potentially similar to those of the colon? How has the presence of the rumen affected other sections of the gastrointestinal tract (GIT) of ruminants compared to non-ruminants?Methods. Transcriptome data from 11 tissues covering the sheep GIT, two stratified epithelial and two control tissues, was analysed using principal components to cluster tissues based on gene expression profile similarity. Expression profiles of genes along the sheep GIT were used to generate a network to identify genes enriched for expression in different compartments of the GIT. The data from sheep was compared to similar data sets from two non-ruminants, pigs (closely related) and humans (more distantly related).Results. The rumen transcriptome clustered with the skin and tonsil, but not the GIT transcriptomes, driven by genes from the epidermal differentiation complex, and genes encoding stratified epithelium keratins and innate immunity proteins. By analysing all of the gene expression profiles across tissues together 16 major clusters were identified. The strongest of these, and consistent with the high turnover rate of the GIT, showed a marked enrichment of cell cycle process genes (P = 1.4 E−46), across the whole GIT, relative to liver and muscle, with highest expression in the caecum followed by colon and rumen. The expression patterns of several membrane transporters (chloride, zinc, nucleosides, amino acids, fatty acids, cholesterol and bile acids) along the GIT was very similar in sheep, pig and humans. In contrast, short chain fatty acid uptake and metabolism appeared to be different between the species and different between the rumen and colon in sheep. The importance of nitrogen and iodine recycling in sheep was highlighted by the highly preferential expression of SLC14A1-urea (rumen), RHBG-ammonia (intestines) and SLC5A5-iodine (abomasum). The gene encoding a poorly characterized member of the maltase-glucoamylase family (MGAM2), predicted to play a role in the degradation of starch or glycogen, was highly expressed in the small and large intestines.Discussion. The rumen appears to be a specialised stratified cornified epithelium, probably derived from the oesophagus, which has gained some liver-like and other specialized metabolic functions, but probably not by expression of pre-existing colon metabolic programs. Changes in gene transcription downstream of the rumen also appear have occurred as a consequence of the evolution of the rumen and its effect on nutrient composition flowing down the GIT.

Sheep colon acellular matrix: Immunohistologic, biomechanical, scanning electron microscopic evaluation and collagen quantification

Colon decellularization provides three-dimensional biologic scaffold without any cell elements with preservation of extracellular matrix in order to enable autologous cell seeding for tissue augmentation without any immunological response. This study was performed to investigate the safety and feasibility of sheep colon decellularization as a first step of colon tissue engineering. The process of sheep colon decellularization was done in four stages which included scaffold preparation, histologic examination and microscopic investigations to reveal the remaining cellular deposits, biomechanical evaluation and collagen quantification studies by measurement of hydroxyproline content of normal and decellularized sheep colon. Decellularized colon scaffold revealed complete cell removal under a light microscope while 4',6-diamidino-2-phenylindole, di-hydrochloride (DAPI) staining confirmed no deoxyribonucleic acid (DNA) residues. Decellularized colon displayed preserved ultrastructure, comparable biophysical properties (resistance to unidirectional stretch forces) and higher hydroxyproline content. The results of biomechanical tests proved that the decellularized matrix did not bear any unexpected damages or structural changes which would make it unable to tolerate in vivo forces and stretches. The microscopic images captured after staining the tissue with Picro-sirius red also showed that the collagen in extracellular matrix is well preserved; this was confirmed by scanning electron microscopy. This implies that the scaffold prepared by this method is suitable for tissue augmentation or transplantation.

Potency of fibrolytic bacteria isolated from Indonesian sheep's colon as inoculum for biogas and methane production

Three fibrolytic bacteria were isolated from sheep’s colon using cellulose (b), xylan (c) and lignin (d) as selective substrates. The potency of fibrolytic was identified by Subbarao methods. These isolates were then used both in pure and mixed culture with cattle cellulolytic bacteria (a) from the previous research. The isolates were subsequently selected based on their ability to produce gas through biogas and methan measurement using in vitro gas test technique of Tilley and Terry methods. Based on the parameter, the potential isolates then were applied as inoculum for dairy cattle feces fermentation. The application research was based on Randomized Completely Design with inoculum concentration (0, 3, 6 and 9%) as the treatment with three replications. The result showed that the highest in vitro biogas and methane production was obtained from a-c-d co-culture addition. The a-c-d co-culture as inoculum for in vitro feces fermentation could increase gas production 56.36% and methane 18.09% compared to natural fermentation by feces microbes. Application of 3 to 9% of a-c-d inoculum at the fermentation scale was highly significant (P < 0.01) in increasing biogas production, however, addition of more than 3% of a-c-d inoculum decrease methane concentration. The fibrolytic bacteria from sheep’s colon were potential to increase the efficiency of biogas and methane production; thus, it should be considered as an inoculum for anaerobic fiber waste fermentation.

Morphologic and physiologic changes induced by Clostridium perfringens type A α toxin in the intestine of sheep

To evaluate the morphologic and physiologic changes induced by Clostridium perfringens type A (alpha toxin in the ileum and colon of sheep. 16 ligated intestinal loops in 4 Merino lambs and 18 explants of ileum and colon from slaughtered lambs. alpha Toxin-induced fluid accumulation was evaluated in ligated ileal and colonic loops of sheep. Tissues were evaluated morphologically by use of gross and histologic examination. Effects of toxin on in vitro intestinal net water transport were tested in modified Ussing chambers. Ovine ileal and colonic loops incubated with C perfringens type A alpha toxin retained more fluid than control loops. Histologically, in the ileum of lambs inoculated with 300 LD50 of alpha toxin/mL, there was a mild to moderate multifocal infiltration of neutrophils in the lamina propria and submucosa. The colonic loops of lambs inoculated with 30 or 300 LD50 of alpha toxin/mL had excessive mucus in the lumen, a moderate amount of neutrophils mixed with mucus in the intestinal lumen, and moderate multifocal infiltration of the lamina propria and submucosa with neutrophils; the blood vessels of these layers were engorged with neutrophils. In vitro measurements of water transport also revealed inhibition of net epithelial water absorption in ileum and colon incubated with alpha toxin on the mucosal side. These results indicate that alpha toxin induces alterations in sheep intestine. Clostridium perfringens type A organisms that produce alpha toxin could be responsible for diseases of intestinal origin in some ruminants.

AUTOLOGOUS TRANSPLANTATION OF UROTHELIUM INTO DEMUCOSALIZED GASTROINTESTINAL SEGMENTS: EVIDENCE FOR EPITHELIALIZATION AND DIFFERENTIATION OF IN VITRO EXPANDED AND TRANSPLANTED UROTHELIAL CELLS

Purpose Our study established a technique for in vitro expansion and subsequent transplantation of autologous urothelial cells into vascularized seromuscular segments from stomach and colon in sheep. The proof of proliferation and differentiation of the transplanted urothelium in the absence of resident urothelium is considered to be a prerequisite for use of this technique in bladder augmentation. Materials and Methods Autologous sheep urothelial cells were expanded in vitro and grown on collagen membranes for sheet grafting. Using a vital stain, viability and confluency status of the urothelial graft were determined before transplantation into demucosalized segments isolated from the sheep stomach and colon gastrointestinal pouches. The gastrointestinal segments were sewn up and remained in the abdomen as small pouches stiched to the abdominal wall. Take and differentiation of transplanted cells within the pouch were assessed two and three weeks later using histological and immunohistological means. Results Urothelial cells grew well on collagen membranes. A confluency status > 40% and co-culturing with 3T3 feeder cells favored successful transplantation. Two weeks after transplantation a multilayered urothelial-like epithelium was found to line the lumen of the pouch. The epithelium was characterized by a distinct urothelium-typical distribution of basal and luminal keratins and the expression of the umbrella cell-specific marker uroplakin III. Moreover, the epithelium had an underlying basal lamina which focally contained collagen type IV. Conclusions The data indicate that in vitro expanded urothelial cells are capable of epithelializing demucosalized gastrointestinal segments forming a genuine, differentiated “neo” urothelium.

Nitrogen compounds and volatile fatty acids absorption from the caecum and colon of sheep

Nitrogen compounds and volatile fatty acids absorption from the caecum and colon of sheep

Secretion of nitrogen compounds into the isolated caecum and colon of sheep

Secretion of nitrogen compounds into the isolated caecum and colon of sheep

Mechanisms of intestinal phosphate transport in small ruminants.

In order to study the localization and mechanisms of intestinal phosphate transport in sheep and goats, unidirectional inorganic phosphate (Pi) flux rates across isolated stripped epithelial tissues were measured in vitro by applying the Ussing-chamber technique. In the first experiment the tissues were obtained from animals which had been kept on an adequate dietary P supply. In the second experiment the animals had either been kept on an adequate Ca and P supply or were Ca- and/or P-depleted. Significant net Pi absorption was measured in all segments of the small intestine and in the proximal colon of sheep and in the duodenum and jejunum of goats. Since the experiments were carried out in the absence of any electrochemical gradient, this clearly indicates the presence of active mechanisms for Pi transport in the intestinal tract of small ruminants. In sheep jejunum, reduction of mucosal Na concentration to 1.8 mM or serosal application of ouabain (0.1 mM) resulted in significant decreases of net Pi absorption of the same order of magnitude, indicating that about 65% of active Pi transport in sheep jejunum is mediated by a Na-dependent active transport mechanism. The mechanism for the remaining Na(+)-independent active Pi transport has not yet been identified. Dietary P depletion caused hypophosphataemia and induced a significant stimulation of net Pi absorption in goat duodenum and jejunum. This increase was independent of dietary Ca supply and was not associated with increased plasma calcitriol concentrations. This suggests substantial differences in hormonal regulation of Pi transport in small ruminants in comparison with single-stomached species.

The effects of Arctotheca calendula (capeweed) on digestive function of sheep

The effects of Arctotheca calendula (capeweed) on digestive function in the rumen, caecum and colon of sheep were studied. Three groups of 2-year-old Merino wethers were compared: 13 grazing capeweed-free pasture for 23 days; 8 fed 700 g of lucerne hay daily for 18 days, and 13 fed 6 kg of freshly cut capeweed (dry matter 11.3%) daily for 7 days. Capeweed did not cause diarrhoea and based on measurements of products of fermentation in the rumen, the plants were as nutritious as pasture containing grasses and clovers. The main disadvantage of capeweed in this single feeding trial was that sheep eating it lost body weight due to their inability, or lack of incentive, to consume enough dry matter.

Ontogeny, distribution and structure of aggregated lymphoid follicles in the large intestine of sheep

Aggregates of lymphocytes were demonstrated from 70 days gestation (term 150 days in sheep) in the proximal colon and rectum. Immunoperoxidase staining for 5′-bromo-2′-deoxyuridine incorporation and IgM, indicated that the lymphocyte population of lymphoid follicles in fetal sheep colon was actively dividing and surface IgM positive. Enzyme histochemistry for 5′-nucleotidase showed that the lymphocytes developed in a meshwork of positive reticular cells, suggestive of developing follicles. Follicle aggregates were distributed in a characteristic pattern in lambs, with major accumulations in the ascending colon and in the rectum. In adult sheep a partial atrophy of follicle aggregates was observed. The microscopic structure of large intestinal aggregates showed similarities to the jejunal Peyer's patch (PP), with broad follicles containing a prominent corona and wide interfollicular areas in older lambs. The apparent deep penetration of crypts into the lymphoid tissue proper, which is a frequently reported phenomenon for colon follicles, was dependent on the contractile state of the mucosa, as judged from its absence in specimens where the intestinal wall had been stretched before fixation.

Studies of the large intestine of sheep. 2. Kinetics of liquid and solid phase markers in the caecum and proximal colon.

1. Experiments were undertaken to examine the errors associated with the use of indigestible markers, the 51Cr-labelled complex of chromium ethylenediaminetetra-acetic acid (51Cr-EDTA) and 103Ru-labelled tris-(1,10-phenanthroline)-ruthenium(II) chloride (103Ru-P), to measure liquid- and solid-phase digesta kinetics in the caecum and proximal colon of sheep.2. First-order kinetics of markers were observed following either single injection or termination of continuous infusion. There were no differences between the half-times (T½) of marker in the caecum plus proximal colon whether calculated from marker concentration in caecal digesta or in faeces. There were also no differences in the T½ values calculated for the liquid- and solid-phase markers. When pool sizes calculated from the marker kinetics were compared with the volume of digesta present in the caecum and proximal colon at slaughter, it appeared that the 51Cr-EDTA and 103Ru-P caecal pools described the digesta contained in the entire caecum and proximal colon.3. The flow-rates of dry matter (DM) through the caecum of sheep given 694 g lucerne (Medicago sativa) DM/d were similar whether estimated from total collection of faeces, by single injection of marker, or by the ratio, marker concentration: DM in either caecal digesta or faeces during continuous infusion of marker into either the rumen or the caecum.4. In sheep given 553 g brome grass (Bromus inermus) DM/d the coefficient of variation of estimates of the plateau of 51Cr-EDTA marker during continuous infusion into the caecum was greater when 130 ml infusate/d were administered than with 1000 ml/d.5. In the sheep given brome grass the lines of best fit of decline in In 51Cr-EDTA marker concentration v. time following termination of the continuous infusions described previously and following single injection of marker in 20 or 2 ml into the caecum were examined. The variation was least when 1000 ml infusate/d had been administered and was unacceptably large following a single injection of 2 ml.6. These experiments showed that tracer techniques could provide unbiased estimates of trace kinetics in the caecum and proximal colon.

The electrical potential difference, short circuit current and Na + and Cl − transport across different segments of sheep colon

1. 1. The electrical potential difference (pd) and short circuit current (Isc) across the sheep colon descendens was significantly higher than across the sheep colon ascendens. 2. 2. The ion equivalent of the Isc and the net Na + transport from the mucosal (m) to the serosal (s) side of the short-circuited sheep colon descendens were identical, while the net Na + transport across the colon ascendens exceeded the ion equivalent of the Isc. 3. 3. There was a net m-s Cl − transport across both short-circuited colon segments, indicating that Cl −, like Na +, is absorbed by active transport. 4. 4. The results suggest that active Na + transport across the sheep colon descendens occurs entirely by an electrogenic mechanism, whereas active Na + transport across sheep colon ascendens probably occurs by both an electrogenic and an electrically silent mechanism.

Absorption of Na, H ions and short chain fatty acids from the sheep colon.

The interrelationship between the absorption of Na, H ions and short chain fatty acids (SCFA) and the secretion of HCO3 in the sheep colon was studied using an in vivo perfusion technique. 1. Under control conditions net SCFA absorption was 62.9 +/- 6.1 mmol . h-1, net Na absorption 49.8 +/- 7.6 mmol . h-1. HCO3 accumulated in the colon lumen at a rate of 5.1 +/- 2.9 mmol . h-1. 2. When 30, 50, or 70% of the Na in the perfusion solution were replaced by Li, Na transport was gradually inhibited and even abolished when 70 mmol . 1(-1) of Li were present. SCFA absorption also decreased, however, to a lower degree. 3. Net Na transport was higher in the presence than in the absence of SCFA. This difference disappeared when Na transport was inhibited by Li. 4. HCO3 accumulation in the colon lumen significantly increased with increasing Li concentrations up to a maximum of 21.7 +/- 7.1 mmol . h-1 when 50% of Na were replaced by Li, however, only in the presence of SCFA. 5. Neither increasing Li concentrations nor the presence or absence of SCFA influenced the H ion disappeared from the perfusion solution. 6. These results indicate that net absorption of Na and SCFA in sheep colon are closely linked to the availability of H ions.

The nutritive value of silages. Digestion of organic matter, gross energy and carbohydrate constituents in the rumen and intestines of sheep receiving diets of grass silage or grass silage and barley.

1. Two experiments were conducted to study the digestion of organic matter, gross energy and carbohydrate constituents in the rumen, small intestine and caecum and colon of sheep given grass silage diets. Three silages made from perennial ryegrass (Lolium perenne) with formic acid as an additive were used. One was made from first-harvest grass in the spring and the others from regrowth grass cut from a single sward in either early autumn or late autumn. Expt 1 involved a comparison between the spring silage given alone or supplemented with barley (silage:barley, 4:1 dry matter (DM) basis). Expt 2 involved a comparison between the early-cut and late-cut autumn silages. 2. In Expt 1, supplementation of the silage with barley resulted in a non-significant (P > 0.05) reduction in the proportion of digestible energy (DE) and digestible organic matter digested in the rumen and an increase in the proportions digested in the small intestine. There were also pronounced effects of barley on ruminal cellulolysis and the proportion of digestible cellulose broken down in the rumen was reduced (P < 0.05) from 0.90 to 0.77. There was an increased passage of alpha-linked glucose polymers to the duodenum but even with the supplemented diet 0.91 of the dietary polymers were digested in the rumen. The molar proportion of propionic acid in the rumen tended to be reduced and there were increases in the proportions of butyric acid (P < 0.01) and acetic acid. 3. Expt 2, the digestibility of organic matter, gross energy and cellulose in the early-cut silage was higher (P < 0.01) than in the late-cut silage but there were no significant (P < 0.05) differences between silages in sites of digestion of these constituents. However, the molar proportion of acetic acid in the rumen was higher (P < 0.01) and the molar proportion of propionic acid was lower (P < 0.01) with the late-cut silage than the early-cut silage. 4. The results are discussed in relation to the voluntary intake and utilization of high-digestibility silages.

The nutritive value of silages. Digestion of nitrogenous constituents in sheep receiving diets of grass silage and grass silage and barley.

1. Two experiments were conducted to study the digestion of nitrogenous constituents in the rumen, small intestine and caecum and colon of sheep given diets of grass silage or grass silage and barley. Three silages were used. One was made from first-harvest grass in the spring and the other from regrowth grass cut in either early autumn or late autumn. All were of perennial ryegrass (Lolium perenne) and were preserved with formic acid. 2. Expt 1 involved a comparison between the spring silage given alone (644 g dry matter (DM)/d) and the spring silage supplemented with barley (151 g DM/d). The intakes (g/d) of total nitrogen for the silage diet and for the supplemented diet were 14.89 and 17.36. Corresponding values (g/d) for N passage were 15.55 and 18.53 (P < 0.01) and the duodenum, 6.01 and 7.09 at the ileum and 5.06 and 5.52 in the faeces. The barley supplement had no significant (P < 0.05) effect on rumen ammonia-N concentration. 3. Expt 2 involved a comparison between the two autumn-cut silages each offered at a level of feeding of approximately 700 g DM/d. The intakes (g/d) of total N for the early-cut silage and for the late-cut silage were 21.67 and 15.62 respectively. Corresponding values (g/d) for N passage were 17.10 and 16.96 at the duodenum, 6.65 and 6.80 at the ileum and 4.5 and 5.22 in the faeces. The concentration of NH3-N in the rumen was significantly (P < 0.001) higher with the early-cut silage than with the late-cut silage. 4. In both experiments the rates of bacterial crude protein (N x 6.25) synthesis in the rumen, estimated using alpha, epsilon-diaminopimelic acid as a marker, were low, 142 and 161 g crude protein/kg organic matter apparently digested in the rumen for the spring silage and the spring silage and barley diets respectively, and 68 and 103 g crude protein/kg organic matter apparently digested in the rumen for the early-cut autumn silage and the late-cut autumn silage respectively. For all diets there was a relatively low contribution of bacterial crude protein to the duodenal passage of crude protein and the amounts of individual amino acids ingested in the diets had a marked influence on the amino acids passing to the duodenum and as a consequence on the mixture of amino acids taken up from the small intestine. 5. The results are discussed in relation to the nutritive value of silage N for ruminants.

Secretion and absorption of phosphorus in the gastrointestinal tract of sheep fed on four diets

The effects of three phosphorus supplements on the metabolism of phosphorus in the gastrointestinal tract of sheep were examined. One group of sheep was fed on a low phosphorus (P-L) diet and three other groups on diets supplemented with monosodium orthophosphate (P-MSOP), meat and bone meal (P-MBM) or bran (P-ORG). The total phosphorus (TP), ultrafilterable phosphorus (UP) and nucleic acid phosphorus (NP) in the digesta were measured. There was a large net secretion of phosphorus into the rumen and the first quarter of the small intestine, and net absorption from the remainder of the small intestine of all sheep. The relative concentration of phosphorus in the omasum suggested considerable omasal secretion and a subsequent abomasal absorption of phosphorus, but this was considered to be largely an artefact. There were no consistent differences between diets in the net secretion and absorption of TP at sites along the gastrointestinal tract. Sheep fed on the P-L diet secreted more phosphorus per unit of phosphorus intake than sheep on the other diets. Most UP was present in the abomasum and cranial small intestine where the pH was lowest. The concentration of UP fell precipitously in the small intestine, which suggested that this was the major form of phosphorus absorbed and that there was a high degree of complex formation at the higher pH. The concentration of NP was relatively constant, and the lowest NP/TP ratios were found in the cranial small intestine. NP formed in the rumen was mainly degraded in the cranial small intestine. NP represented half the TP in the colon of sheep fed on diet P-L. The results indicate that the form of phosphorus supplement did not influence phosphorus metabolism in the gastrointestinal tract.

The effect of Lantana camara on intestinal motility in sheep

Pressure changes occurring in the duodenum, jejunum, caecum and spiral colon of sheep were recorded to assess the affect of lantana on intestinal motility. Lantana did not affect the responses of the duodenum to pentagastrin given intravenously or to hydrochloric acid given into the duodenum. It was possible to demonstrate contractions of the jejunum, caecum and spiral colon after lantana was given. The results of these experiments do not support an hypothesis that lantana causes intestinal paralysis.