Cobalt in the Nutrition of Ruminants: Influence of Cobalt on the Production of Factors possessing Vitamin B12-like Activity in the Fæces of Sheep

Dawbarn, Mary C; Hine, Denise C; Hughes, P. E.

doi:10.1038/170793a0

Cited by 10 publications

(4 citation statements)

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“…As noted by Dawbarn & Hine (1955), urinary excretion in animals fed on this diet 58-2 872 R. M. SMITH AND H. R. MARSTON I970 with or without supplementary C o was seldom more than I % of faecal excretion, but when cyanocobalamin was injected (50 pg/d) 30-36y0 was excreted in the urine and most of the remainder in the faeces. 500 pg [58Co]cyanocobalamin (13 p C i ) over 20 d into a vitamin B,,- [5sCo]cyanocobaZamin injected into a vitamin B12deficient sheep. A vitamin Bl,-deficient ewe (no.…”

Section: Vol 24mentioning

confidence: 67%

“…It is probable that faeces, rather than urine, is normally the major vehicle of excretion of vitamin B,, released from the tissues (Dawbarn & Hine, 1955), the balance between…”

Section: Discussionmentioning

confidence: 99%

“…I n Expts 5 and 6, both animals were restricted to the food intakes shown, and in periods without Co these animals were not seriously depleted of vitamin B,, in the tissues (Smith & Marston, 1970). Also reported by Dawbarn & Hine (1955) and shown in Table 5 are faecal and urinary excretion of vitamin B,, by a severely deficient animal (no. 5009) before and after treatment with 500,ug cyanocobalamin/d by mouth.…”

Section: Vol 24mentioning

confidence: 99%

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Production, absorption, distribution and excretion of vitamin B₁₂in sheep

Smith

Marston

1970

Br J Nutr

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I. The efficiency of production and utilization of vitamin BIZ was studied with sheep given a cobalt-deficient diet with and without supplementary Co (I mg/d). Vitamin B,, 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 Blz were studied with [58Co]cyanocobalamin and ~'-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 Blz 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 B,, to lignin ratio in rumen contents began to decline 1-3 d after cessation of a daily Co drench. Estimated ruminal production of vitamin B,, on full feed was not less than 400-700 pg/d with supplementary Co and 50-1 10 pg/d from the Co ( O O I -O .~~ pg/g dry weight) in the basal diet. Production of vitamin B,, appeared to be limited by food intake with or without additional Co. 4.At full feed the efficiency of production of vitamin Blz from Co in the basal diet was about 13 yo while that from added Co was about 3 yo. Part of the vitamin B,, produced in the rumen was degraded before reaching the faeces and about 5 % was absorbed. The minimum total requirements of sheep for vitamin B,, are assessed at about I I ,ug/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 B,, was secreted into the duodenum and reabsorbed in the ileum, but little secretion occurred above the duodenum and little absorption below the small intestine.Production of vitamin B,, in rumen contents of sheep depends on the presence of cobalt (Hale, Pope, Phillips & Bohstedt, 1950;Hoekstra, Pope & Phillips, 1952; Hine & Dawbarn, 1954;Kercher & Smith, 1956) and this is reflected in faecal excretion (Hale et al. 1950; Dawbarn, Hine & Hughes, 1952;Dawbarn & Hine, 1955). Little is known, however, either of the quantities produced or of the efficiency of absorption.Kercher & Smith (1955) The quantities of vitamin B,, in rumen contents of sheep given Co-deficient diets are not negligible, and it is not necessarily true that the efficiency of absorption is the same as that when additional Co is supplied or the same as that when crystalline cyanocobalamin is given orally. The work now described was aimed at estimating these rates and efficiencies and in addition at determining the tissue distribution and excretory pattern of injected cobalamins. The total requirements of sheep for vitamin B,, are assessed at about I I pg/d and, although the arguments leading to this estimate are not entirely rigorous, the results permit a reasonable description of the production, absorption a...

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Section: Vol 24mentioning

confidence: 67%

“…It is probable that faeces, rather than urine, is normally the major vehicle of excretion of vitamin B,, released from the tissues (Dawbarn & Hine, 1955), the balance between…”

Section: Discussionmentioning

confidence: 99%

Section: Vol 24mentioning

confidence: 99%

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Production, absorption, distribution and excretion of vitamin B₁₂in sheep

Smith

Marston

1970

Br J Nutr

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“…They started to lose weight at 14 weeks but started gaining weight if given Co by mouth. Dawbarn, Hine & Hughes (484) found that the ratio of coli to leichmanii factors in sheep faeces was markedly increased by oral Co. Phillipson & Mitchell (476) found that lambs in which the deficiency had been similarly produced could be cured by 100 jig.…”

Section: Cobalt and Vitamin B 1mentioning

confidence: 99%

Section A. Physiology of dairy cattle: Part II. Physiology and Biochemistry of Rumination

Owen

1954

Journal of Dairy Research

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Since the time of the previous review in this series by the present author it has been increasingly realized that the ruminant's adaptation to its herbivorous diet is very far-reaching. The biochemical consequences of its need for coarse roughage are still being worked out and have necessitated a reassessment of the causes of bovine ketosis, of the function of lower fatty acids in its blood and of the reasons for its large requirement of cobalt. Recent work on all these three aspects of ruminant metabolism is discussed in this review. The cow's chief function is to convert into milk vegetable materials, many of which are unsuitable for human consumption. Ac-, cordingly, some of the nutritional aspects of this conversion process have been discussed in the review. The literature on the subject has been reasonably well listed, but the author cannot claim that he has not perhaps inadvertently omitted certain pertinent new work. GENERAL Sherwood & Jones(l) found that alfalfa hay plus a mixture of wheat, barley and oats gave 20% more milk than the hay alone. Milk yield was also enhanced by adding the succulents squash and Jerusalem artichoke to the hay diet. Groups of cows receiving the concentrates needed 5-6 lb. more total digestible nutrients to produce 100 lb. milk, and the authors conclude that feeding of succulents is profitable only if they produce nutrients as cheaply as does hay. Watson, Davidson, Kennedy & Sylvestre(2) compared the digestibility of rations of hay plus increasing amounts of oats. As oats increased the digestibility decreased. This effect was most marked with barley, not so marked with oats and was only slight with linseed oil meal. Feeding standards are still the subject of informed criticism in Europe(3,4,5). Nehring(3) concludes that Kellner's starch equivalents cannot be used for pigs without prior respiration calorimetry. Blaxter(4) finds large discrepancies between different methods of computing rations for livestock, and Nicholls(5) enters a plea for food recording as a complement to milk recording. The trouble with all attempts to define standards for grazing animals is the extreme variability from year to year, from field to field, from treatment to treatment and from animal to animal of the nutrients provided by grass and hay or silage. Much current research all over the world is designed to measure more accurately the nutrient intake of cattle and sheep from pasture, with a view to striking a better balance between protein and fibre in the diet, always remembering that the content of fibre biologically best for maximal production per cow may not necessarily give the maximal production per acre. This may come from more cows per acre at somewhat more fibre per cow than would give maximal production per cow. In this connexion the observations of Hancock (6) are pertinent. He points out that the maximum production per animal does not necessarily yield the greatest net returns. In practice this can be achieved by a number of cows per acre too high for maximum productivity per cow or fo...

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