Difference between revisions of "Manganese - Nutrition"
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==Toxicity== | ==Toxicity== | ||
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| − | There is no information on the effects of excess manganese in dogs or cats. It is considered to be '''one of the least toxic of the trace elements''' and from investigations in other mammals a maximum tolerable dietary content of around 1000 mg/kg of food on a dry matter basis is assumed<ref name="NRC"/>. | + | There is no information on the effects of excess manganese in dogs or cats. It is considered to be '''one of the least toxic of the trace elements''' and from investigations in other mammals a maximum tolerable dietary content of around 1000 mg/kg of food on a [[Nutrition Glossary#Dry Matter Basis|dry matter basis]] is assumed<ref name="NRC"/>. |
==Dietary Sources== | ==Dietary Sources== | ||
Revision as of 07:57, 22 May 2015
What is Manganese?
Manganese does not occur naturally as a free element, but is often found in combination with iron and in many minerals. It is one of a group of metals or minerals that are essential nutrients in dogs and cats. It only occurs in very small amounts in animal tissues; it is referred to as a trace element because the requirement for this mineral is relatively small.
Why is it Important?
Manganese is an essential component of certain metalloenzymes, and as an activator of many other enzymes that are required for normal metabolic function.
Roles in the Body
Manganese is a component of a diverse group metalloenzymes including arginase, pyruvate carboxylase and manganese superoxide dismutase that are important regulators of the urea cycle, gluconeogenesis and lipogenesis, and detoxification of oxygen radicals. Manganese is also a metallic activator for other enzymes such as hydrolases, decarboxylases, kinases and transferases[1]. It is known to be important for normal bone development and neurological function. The bioavailability of manganese is affected by several factors. Calcium, phosphorus, and phytate all have an adverse effect on manganese absorption whereas iron seems to act by increasing faecal manganese losses. In contrast, the amino acids cysteine and histidine enhance the uptake of manganese[2].
Consequences of Manganese Deficiency
Dog:
There is no information on manganese deficiency in dogs. Information on requirements comes from studies of the concentration of manganese in bitches’ milk and the consumption of milk by puppies[3]. Values for adult maintenance and pregnancy and lactation are based on similar estimations[4][5][6].
Cat:
As with dogs, there is no information on manganese deficiency in cats and estimates of requirement come from studies on the manganese content of queens’ milk[7].
Dog and Cat:
Although there are no specific data on dogs and cats, from studies in other mammals there are basically two main aspects of manganese deficiency:
- Retarded bone growth: Manganese deficiency affects new-born and growing animals where it causes shortening and bowing of the forelimbs. In adult animals lameness and enlarged joints can occur. In poultry it causes slipped tendon or perosis. These effects appear to be due to faults in bone formation resulting from dysfunction of manganese-containing enzymes involved in cartilage synthesis[1].
- Reproductive failure: A lack of manganese has serious effects on reproduction, including poor conception, increased rates of abortion and stillbirths.
Toxicity
Dog and Cat:
There is no information on the effects of excess manganese in dogs or cats. It is considered to be one of the least toxic of the trace elements and from investigations in other mammals a maximum tolerable dietary content of around 1000 mg/kg of food on a dry matter basis is assumed[2].
Dietary Sources
Manganese in dog and cat foods is found in a number of ingredients, in particular cereal grains and animal raw materials. Supplemental sources of manganese are often added to manufactured pet foods as inorganic salts such as sulphate, chloride and carbonate.
References
- ↑ 1.0 1.1 Hurley, L, Keen, C (1987). “Manganese” in Trace Elements in Human and Animal Nutrition, 5th edn., Vol. 1. ed. by W. Mertz, Academic Press, San Diego, California, USA: p 185-223.
- ↑ 2.0 2.1 “Manganese” In: Mineral Tolerance of Animals, 2nd Edition. (2005) National Research Council, National Academy of Sciences. The National Academies Press, Washington DC: p 235-247.
- ↑ Kienzle, E, Meyer, H, Dammers, C, Lohrie, H (1985). “Milk intake, weight gain, milk digestibility and nutrient retention in suckling puppies”. Adv. Anim. Physiol. Anim. Nutr. 16:26-50.
- ↑ Meyer, H (1984). “Mineral metabolism and requirements in bitches and suckling pups” in Nutrition and Behaviour in Dogs and Cats, ed. by R. S. Anderson, Pergamon Press, Oxford, UK: p 13-24.
- ↑ Oftedal, O (1984). “Lactation in the dog: Milk composition and intake by puppies”. J. Nutr. 114:803-811.
- ↑ Hill, R, Burrows, C, Ellison, G, Bauer, J (2001). “The effect of texturized vegetable protein from soy on nutrient digestibility compared to beef in cannulated dogs”. J Anim. Sci. 79:2162-2171.
- ↑ Keen, C, Lonnerdal, B, Clegg, M, Hurley, L, Morris, J, Rogers, Q, Rucker, R (1982). “Developmental changes in composition of cats’ milk: Trace elements, minerals, protein, carbohydrate and fat”. J. Nutr. 112:1763-1769.