scholarly journals Production, absorption, distribution and excretion of vitamin B12 in sheep

1970 ◽  
Vol 24 (4) ◽  
pp. 857-877 ◽  
Author(s):  
R. M. Smith ◽  
Late H. R. Marston

1. The efficiency of production and utilization of vitamin B12 was studied with sheep given a cobalt-deficient diet with and without supplementary Co (1 mg/d). Vitamin B12 to lignin ratios in rumen contents were used to estimate minimum rates of production and these were related to faecal and urinary excretion. Tissue distribution and excretion of vitamin B12 were studied with [58Co]cyanocobalamin and 5′-deoxyadenosyl[60Co]cobalamin.2. Labelled Co was rapidly sequestered by particulate material in the rumen and was largely excreted in the faeces. Most of the vitamin B12 in whole rumen contents was contained in micro-organisms, but was released on incubation at pH 2. Added cyanocobalamin was partly degraded in the rumen.3. The vitamin B12 to lignin ratio in rumen contents began to decline 1–3 d after cessation of a daily Co drench. Estimated ruminal production of vitamin B12 on full feed was not less than 400–700 μg/d with supplementary Co and 50–110 μg/d from the Co (0.01–0.05 μg/g dry weight) in the basal diet. Production of vitamin B12 appeared to be limited by food intake with or without additional Co.4. At full feed the efficiency of production of vitamin B12 from Co in the basal diet was about 13% while that from added Co was about 3%. Part of the vitamin B12 produced in the rumen was degraded before reaching the faeces and about 5% was absorbed. The minimum total requirements of sheep for vitamin B12 are assessed at about 11 μg/d.5. Injected 5′-deoxyadenosylcobalamin was better retained than injected cyanocobalamin, faecal excretion exceeded urinary excretion with both. Labelled cobalamin was selectively retained by liver (particularly by the mitochondria), kidneys and the walls of parts of the alimentary tract. Vitamin B12 was secreted into the duodenum and reabsorbed in the ileum, but little secretion occurred above the duodenum and little absorption below the small intestine.

1993 ◽  
Vol 69 (2) ◽  
pp. 455-466 ◽  
Author(s):  
E. J. Van Weerden ◽  
J. Huisman

In a study with twelve pigs of 60–70 kg live weight provided with a re-entrant cannula at the end of the ileum, and twelve intact, non-cannulated pigs, the fate of dietary doses of 100 and 200 g isomalt/kg during gastrointestinal passage was examined. From sugar analyses in ileal chyme it was calculated that 0.43 and 0.30 of the isomalt consumed was digested in the small intestine with the 100 and 200 g/kg doses of isomalt respectively. From findings on ileal energy digestibility it was calculated that, because of a secondary effect of isomalt on the digestion of the basal diet, isomalt digestibility in the small intestine was distinctly lower. In faeces no sugars were found, so faecal digestibility of isomalt was 1.00 for both doses. The bacterial fermentation in the large intestine of the isomalt not digested in the small intestine caused an increase in the faecal excretion of nitrogen and energy. This increased faecal excretion was hardly (nitrogen) or not (energy) compensated by a decreased urinary excretion.


1976 ◽  
Vol 27 (3) ◽  
pp. 437 ◽  
Author(s):  
FM Tomas ◽  
BJ Potter

The effect of magnesium chloride infusion to different sites in the gastrointestinal tract of sheep upon the net absorption of magnesium from different regions of the digestive tract has been examined. Four Merino wethers were each prepared with cannulas sited in the rumen, in the duodenum adjacent to the pylorus and in the terminal ileum. The basal diet provided 18.45 mmoles magnesium/ day and an additional 65 mmoles magnesium/day as magnesium chloride was continuously infused into (A) the rumen, (B) the rumen and duodenum in equal portions, (C) the duodenum and (D) the terminal ileuni. A continuous infusion of Cr-EDTA to the ruinen enabled digcsta and magnesium flow rates to be estimated from digesta samples obtained from the intestinal cannulas at 4 hr intervals over 3 days. For treatments A, B, C and D respectively, the mean net absorption of magnesium (mmoles/day) from the rumen was 20.4, 11.4, 1.4 and 3.4; from the small intestine –0.5, 1.7, –5.1 and –9.8; from the large intestine 4.6, 2.2, 12.7 and 12.3; and from the total gastrointestinal tract 24.6, 15.4, 9.1 and 4.9. In each case the effect of treatment was significant. The total net absorption of magnesium caudal to the pylorus was unaffected by treatment. Plasma magnesium levels were reduced during post-ruminal infusion of magnesium, but these changes were not obviously linked to the changed net absorption from the intestinal segments. The urinary and faecal excretion of magnesium, but not the magnesium balance, was strongly related to the total net absorption of magnesium. The results emphasize the major contribution of the stomach to the gastrointestinal net absorption of magnesium and show that although the amount absorbed from this region may influence separately the net absorption from the large and small intestine, it does not appear to influence the overall intestinal net absorption of magnesium.


1982 ◽  
Vol 47 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Margareta Nyman ◽  
Nils-Georg Asp

1. The fermentative breakdown of dietary fibre from various sources in the intestinal tract was studied using rat balance experiments and gas–liquid chromatrographic analysis of dietary fibre monomers in feed and faeces.2. On a basal diet with 690 g maize starch/kg but no added fibre, small but detectableamounts of polymeric glucose, rhamnose, arabinose, xylose, galactose, mannose and uronic acids, i.e. sugars occurring in dietary fibre, were excreted in faeces.3. Dietary fibre in wheat bran was rather resistant to fermentation; 63% was recoveredin the faeces. Guar gum, on the other hand, was almost completely fermented, whereas 19 and 25% of the uronic acids in low and high methoxylated pectin respectively, were excreted in faeces. The various constituents of sugar-beet dietary fibre (approximately equal amounts of arabinose-based hemicellulose, pectin and non-starch glucan (cellulose)) showedquite variable availability for micro-organisms in that 6–12% of the arabinose, 17–25% of the uronic acids, and 52–58% of the cellulose were recovered in the faeces.4. Faecal nitrogen excretion increased on addition of any one of the dietary fibre preparations studied, resulting in decreased true and apparent protein digestibility values.5. The faecal dry weight increment was most pronounced when feeding bran and could then almost be accounted for by the remaining fibre and by protein. The less-prominent bulking effect ot guar gum and pectins, that were much more extensively fermented, could be only partly explained by dietary fibre and protein.


1976 ◽  
Vol 24 (3) ◽  
pp. 383
Author(s):  
VJ Williams

The dry weight of stomach, small intestine, caecum and colon was obtained from male and female rats from 8 to 184 days old weighing from 18 to 400 g. The length of the colon and small intestine was also measured. The length and dry weight of the small intestine of 35 merino sheep from birth to aged or 3 to 40 kg liveweight were also measured. Regressions between the logarithms of gut measurements and logarithms of the liveweights were calculated. The gut measurements were length, length/kg liveweight, DM, DM/kg liveweight and DM/m for the tubular small intestine and colon, and DM and DM/kg liveweight for the saccular stomach and caecum. For the rat, 2 relations were required to describe the data from all organs. A change in percentage increase or decrease relative to percentage liveweight increase occurred at about 70 to 80 g liveweight or 37 to 44 days old. This is the age range at which increase in metabolic rate relative to liveweight declines to about one-quarter of its previous rate. It is unlikely that there is a causal relation between the maturation of sex hormone output and gut growth and metabolic rate. One allometric regression coefficient adequately described growth of the small intestine of the sheep relative to weight gain.


1960 ◽  
Vol 199 (2) ◽  
pp. 289-291 ◽  
Author(s):  
Charles G. Moertel ◽  
Harold H. Scudamore ◽  
Charles A. Owen ◽  
Jesse L. Bollman

This study was undertaken to determine the site of maximal absorption of Co60-labeled vitamin B12 in the small intestine of the male albino rat. Animals were sacrificed at intervals after ingestion of the labeled vitamin. The highest concentration of radioactivity was found in the wall of the upper and mid-ileum 1/2–3 hours after ingestion. Accordingly, the absorption of tagged vitamin B12 was estimated by fecal and urinary excretion methods in animals with resections of portions of the small intestine, including the portion containing the ileocecal valve, and in normal controls. Resection of the middle half of the small bowel (the upper and mid-ileum) was found to produce significant impairment of vitamin B12 absorption. It is concluded that in the male albino rat the upper and mid-ileum is specifically adapted to most efficient absorption of vitamin B12.


1969 ◽  
Vol 20 (5) ◽  
pp. 899 ◽  
Author(s):  
M Somers ◽  
EJ Underwood

Dry matter digestibilities and nitrogen and sulphur balances were compared in ram iambs fed on a zinc-deficient diet containing 2.4 p.p.m. zinc and showing clinical signs of zinc deficiency and in pair-fed ram lambs consuming the same basal diet supplemented with 30 p.p.m. zinc. Dry matter digestibility was similar for the two treatments but both nitrogen retention and sulphur retention were significantly lower in the zinc-deficient animals, although they were consuming and digesting the same amounts of food. Faecal excretion of nitrogen and sulphur was similar in the two groups but the urinary excretion of both these elements was significantly elevated in the zinc-deficient animals. These findings provide further evidence that protein utilization is impaired in zinc deficiency in sheep. *Part I, Aust. J. agric. Res., 1969, 20, 889.


1999 ◽  
Vol 69 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Hayakawa ◽  
Iida ◽  
Tsuge

To investigate how dietary fiber in the diet affects vitamin B-6 nutriture of rats which have been deprived of vitamin B-6, rats were made vitamin B-6-deficient by feeding a vitamin B-6-deficient 70% casein diet. They were fed 2% cellulose powder-based vitamin B-6-deficient diets supplemented with 3% of additional dietary fiber sources (agar, konjac mannan, pectin and cellulose powder) for subsequent 18 days. Vitamin B-6 status was evaluated according to several biological criteria (weight gain, urinary excretion of xanthurenic acid after tryptophan loading, plasma pyridoxal 5’-phosphate, apparent pyridoxal 5’-phosphate-saturation of liver kynureninase, urinary excretion of 4-pyridoxic acid and fecal output of vitamin B-6). Vitamin B-6 status evaluated by these criteria was considerably improved in the konjac mannan-fed group, when compared with the respective data of the vitamin B-6 supplemented group. The relative mean effect of the konjac mannan diet was about 40% of the vitamin B-6 supplemented diet. In conclusion, konjac mannan was effective for improving the vitamin B-6 nutritional state in vitamin B-6-deprived rats.


1996 ◽  
Vol 75 (3) ◽  
pp. 461-469 ◽  
Author(s):  
Inge Tetens ◽  
G. Livesey ◽  
B. O. Eggum

abstract:The hypothesls was tested that fermentable dietary fibre (DF) sources elevate faecal N excretion at the expense of urinary N without affecting N retention. DF that substantially increase fermentation (pectin, Sugarbeet and soya bran) or are poorly fermented (crystalline cellulose and maize bran) were fed as supplements to a basal DF-free diet a t three dose levels: 0,50 and 100 g supplement/kg basal diet. The diets were fed to juvenile male Wistar rats for 2 weeks before a 7 d period when faeces and urine were collected. Faecal excretion of N was significantly increased, dose-dependently, by all DF supplements and was positively correlated to faecal bulking. Urinary excretion of N was lower at the high doses of the DF supplements but reached significance only with the highly fermentable (0·68) sugarbeet- supplementeddiets. Regression analysis showed that the major part (0·75) of the increase in faecal N excretion due to DF supplementation was balanced by a reduction in urinary excretion; N retention was therefore, at the dose levels used, only affected to a small extent. Only in the maize-bran-supplemented diets were the reductions in N retention significant. The shift in N excretion from urine to faeces can be explained largely by the degree of microbial fermentation in the large intestine caused by the addition of DF supplements and emphasizes the modifying role that certain DF supplements may have on the enterohepatic cycle of N. Possible implications of these findings for patients with liver or renal failure or for conditions when the intake of dietary protein is marginal are discussed.


1992 ◽  
Vol 15 ◽  
pp. 169-171 ◽  
Author(s):  
G. E. J. Fisher ◽  
A. MacPherson

It has been suggested (Mills, 1981) that there was a lack of research on the effects of cobalt (Co) deficiency on the reproductive performance of sheep. Duncan, Morrison and Garton (1981) reported that clinically Co-deficient ewes produced fewer lambs with a higher incidence of stillbirths and neonatal mortalities than Co-sufficient animals. Garton, Duncan and Fell (1981) related these findings to the vitamin B12 and methylmalonic acid status of dams. However, their investigations used few animals and were therefore inconclusive. The objectives of this work were to investigate the effects of subclinical Co deficiency in pregnant hill sheep on reproductive performance and neonatal lamb viability.Experiment 1 (1985/86) comprised 60 Scottish Blackface × Swaledale ewes, while experiment 2 (1986/87) included 30 of these animals plus 30 pure Scottish Blackface sheep. In both experiments the ewes were housed and bedded on sawdust and a Co-deficient diet of timothy hay, micronized maize, maize gluten, dibasic calcium phosphate and sodium chloride was offered. Skimmed milk powder was introduced to the diet during lactation. The Co content of the diet was 0.06 mg Co per kg dry matter.


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