scholarly journals The effect of antibiotics on rats receiving a vitamin B12-deficient diet

1970 ◽  
Vol 24 (2) ◽  
pp. 405-412 ◽  
Author(s):  
D. L. Williams ◽  
G. H. Spray

1. Rats fed on a vitamin B12-deficient or -supplemented diet were given either neomycin or a mixture of streptomycin and erythromycin by mouth for between 7 and 15 d. The urinary excretion of methylmalonic acid and the levels of vitamin B12 in plasma and tissues and of acetic and propionic acids in caecal contents were measured.2. Both treatments caused prompt reduction of methylmalonate excretion in the deficient rats. This was apparently due to depression of the production of some precursor of methyl-malonic acid, probably propionate, rather than to an immediate effect on vitamin B12 nutrition.3. After withdrawal of the antibiotics, neomycin-treated vitamin B12-deficient rats appeared to become partly repleted in vitamin B12, but the change in the vitamin B12 status of those which had received streptomycin and erythromycin was much smaller.

1973 ◽  
Vol 136 (2) ◽  
pp. 279-293 ◽  
Author(s):  
Richard M. Smith ◽  
William S. Osborne-White

1. Metabolism of folate was studied in six ewes in an advanced state of vitamin B12 deficiency as judged by voluntary food intake and in their pair-fed controls receiving vitamin B12. A group of four animals that were maintained throughout the experiment at pasture was also studied. 2. After 34–40 weeks on the cobalt-deficient diet urinary excretion of formiminoglutamate by four deficient animals was about 3.2mmol/day and this was not significantly decreased by injection of three of them with about 4.5μg of [2-14C]folate/kg body weight per day for 5 days. Three days after the last injection retention of [2-14C]folate by the livers of the deficient animals (5.5% of the dose) was lower than that of their pair-fed controls (26% of the dose) but there was no evidence of net retention of injected folate in the livers of either group. Urinary excretion of 14C indicated that renal clearance of folate may have been impaired in very severe vitamin B12 deficiency. 3. As estimated by microbiological assays total folates in the livers of animals at pasture (12.9μg/g) included about 24% of 5-methyltetrahydrofolate as compared with about 72% of a total of 12.5μg/g in three further ewes fed on a stock diet of wheaten hay-chaff and lucerne-chaff. Liver folates of vitamin B12-deficient animals (0.5μg/g) included about 88% of 5-methyltetrahydrofolate as compared with about 51% of a total of 5.2μg/g in pair-fed animals treated with vitamin B12. 4. Chromatography of liver folates of the pair-fed animals permitted quantitative estimates of the pteroylglutamates present. The results showed that the vitamin B12-deficient livers were more severely depleted of tetrahydrofolates and formyltetrahydrofolates than of methyltetrahydrofolates and that as the deficiency developed they were more severely depleted of the higher polyglutamates than of the monoglutamate within each of these classes. Results from animals injected with [2-14C]folate indicated an impairment of the exchange between pteroylmonoglutamates and pteroylpolyglutamates in the livers of deficient animals. 5. In vitamin B12-deficient animals with food intakes below 200g/day some of the liver folates were not completely reduced and some degradation of pteroylpolyglutamates was detected. The latter condition may have been associated with fatty liver. 6. The results are discussed in relation to current theories of vitamin B12–folate interactions.


2007 ◽  
Vol 58 (4) ◽  
pp. 367 ◽  
Author(s):  
S. C. Wiese ◽  
C. L. White ◽  
I. H. Williams ◽  
J. G. Allen

We measured methylmalonic acid (MMA) in plasma and succinate in the rumen during the depletion of sheep to a state of severe cobalt deficiency and repletion by various forms of supplementation. Groups of 10, cobalt-deficient weaners were allocated to one of 4 treatments: no supplement, 0.1 or 4.0 mg/day of cobalt as a solution of CoSO4.7H2O per os, or intramuscular vitamin B12. Plasma concentrations of MMA were elevated above the normal range (5 µmol/L) after 35 days on the cobalt-deficient diet, before a reduction in feed intake and while liveweights were still increasing. In all 3 supplemented groups of sheep, plasma vitamin B12 concentrations increased to normal levels within 10 days of supplementation (P < 0.001). Plasma MMA concentrations were reduced to normal levels within 10 days with vitamin B12 supplementation but took 31 days with oral cobalt supplementation (P < 0.001). Plasma MMA concentration in the unsupplemented group continued to rise and remain high for the duration of the experiment and did not show the peak and decline to levels indistinguishable from cobalt adequate levels as observed by others. Rumen succinate concentrations were elevated within 6 days of sheep being introduced to a cobalt-deficient diet and in the unsupplemented sheep remained elevated for the duration of measurement. This rise in rumen succinate was seen at a wider range of cobalt intakes than previously reported. In both oral cobalt treatments, vitamin B12 concentrations increased (P < 0.001) and succinate concentrations decreased (P < 0.001) in the rumen to normal levels within 6 days of supplementation. However, the vitamin B12 provided to the sheep by injection was not recycled to the rumen to any effective degree, as demonstrated by the persistence of high rumen succinate concentrations. The ability of the vitamin B12-supplemented sheep to maintain higher rates of wool growth than deficient sheep, while still exhibiting elevated succinate concentrations in the rumen, demonstrates that overcoming the blockage of the methylmalonyl CoA mutase pathway in the rumen is not essential for restoring metabolic pathways such as those responsible for wool growth. This work contributes to the knowledge of plasma MMA and rumen succinate as useful indicators of functional cobalt status and cobalt intake in sheep.


1967 ◽  
Vol 21 (2) ◽  
pp. 309-314 ◽  
Author(s):  
B. K. Armstrong

1. Urinary excretion of total ether-soluble acids and of methylmalonic acid was studied in rats on vitamin B12-deficient diets with and without a vitamin B12 supplement.2. It was shown that urinary excretion of total ether-soluble acids and methylmalonic acid was increased in vitamin B12-deficient rats and that this increase was somewhat variable between individual animals, males and females, and rats from different litters.3. The increased excretion of these acids could readily be reversed by supplementing the diet with vitamin B12.


1983 ◽  
Vol 34 (2) ◽  
pp. 211 ◽  
Author(s):  
SO Mann ◽  
AB Wilson ◽  
M Barr ◽  
WJ Lawson ◽  
L Duncan ◽  
...  

In an attempt to clarify the reported relationship between cobalt deficiency and the incidence of cerebrocortical necrosis (CCN), sheep were fed on a diet deficient in cobalt. High levels of thiaminase activity were found regularly in rumen and faeces samples from cobalt-deficient animals, and also from controls supplemented with cobalt or vitamin B12. There was a poor correlation between thiaminase activity and viable counts of the thiaminase-producing organisms Clostvidium spovogenes and Bacillus spp. Urinary excretion of thiamine appeared normal. When the sheep were killed, normal concentrations of thiamine were found in the liver. The sheep were deficient in vitamin B12, as judged by the concentrations in serum and liver, by urinary excretion of methylmalonic acid, and by clinical condition. Twitching and weakness were observed, but clinical signs of CCN did not develop.


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.


1987 ◽  
Vol 38 (6) ◽  
pp. 1071 ◽  
Author(s):  
MF Quirk ◽  
BW Norton

An experiment was undertaken at Mt Cotton, south-east Queensland, to investigate the relationship between the cobalt nutrition of ewes and the occurrence of vitamin B12 deficiency in ewes and their lambs. Ewes received either no supplementary cobalt (C), 0.03 mg cobalt day-1 (LC), 0.06 mg cobalt day-1 (HC) or a cobalt bullet and grinder (CB). LC and HC ewes received their supplement as a weekly drench. Supplementation commenced prior to joining, and ewes subsequently grazed pangola grass pastures containing between 0.05 and 0.11 mg kg-1 cobalt.Cobalt supplementation of ewes increased their liveweight, reproductive and lactation performance. The milk production of ewes was influenced by the level of supplementation, with C, LC, HC and CB ewes producing 31.1, 41.5, 47.7 and 50.31. of milk respectively during the first 4 weeks of lactation. The lower productivity of C ewes was associated with concentrations of vitamin B12 in serum of less than 200 pg ml-1 and with the presence of detectable concentrations of methylmalonic acid (>80 8moles l-1) and formiminoglutamic acid (>30 8moles l-1) in their urine.The growth of lambs was influenced by the cobalt nutrition of their dams; the mean liveweight gain from birth to weaning (14 weeks of age) for lambs from C, LC, HC and CB ewes was 95, 158, 194 and 231 g day-1. Vitamin B12 deficiency was evident in lambs reared by C ewes from 4 weeks of age, but lambs from LC and HC ewes did not become deficient until 8 and 12 weeks of age respectively. Lambs from CB ewes remained free of signs of deficiency prior to weaning. Urinary formiminoglutamic acid concentration was a more reliable indicator of vitamin B12 status in young lambs than urinary methylmalonic acid concentration. The concentrations of vitamin B12 in the serum of lambs were low in all groups (< 150 pg ml-1) and were generally unaffected by the cobalt nutrition of their dams.A dietary cobalt intake of about 0.15 mg day-1 appeared to be necessary for optimal milk production from ewes. However, this level of dietary cobalt was inadequate for provision of sufficient quantities of maternal vitamin B12 to meet the requirements of lambs in the later stages of lactation.


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