Changes

==Roles in the Body==

==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].   

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<ref name="Hurley">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.</ref>. 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<ref name="NRC">“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.</ref>.   

==Consequences of Manganese Deficiency==

==Consequences of Manganese Deficiency==

===Dog:===   

===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].  

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<ref>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.</ref>. Values for adult maintenance and pregnancy and lactation are based on similar estimations<ref>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.</ref><ref>Oftedal, O (1984). “Lactation in the dog: Milk composition and intake by puppies”. J. Nutr. 114:803-811. </ref><ref>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.</ref>.  

===Cat:===   

===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].

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<ref>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.  </ref>.

====Recognised Syndromes related to Manganese Deficiency====

====Recognised Syndromes related to Manganese Deficiency====

'''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:

'''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].

#'''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<ref name="Hurley"/>.

#'''Reproductive failure:''' A lack of manganese has serious effects on reproduction, including poor conception, increased rates of abortion and stillbirths. 

#'''Reproductive failure:''' A lack of manganese has serious effects on reproduction, including poor conception, increased rates of abortion and stillbirths. 

==Toxicity==

==Toxicity==

===Dog and Cat:===   

===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].

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"/>.

==Dietary Sources==

==Dietary Sources==