Susceptibility of yak (Bos grunniens) to copper deficiency

EFFECT OF SUSTAINED-RELEASE TRACE ELEMENT RUMINAL BOLUS ON PLASMA TRACE MINERAL PROFILES IN CAPTIVE BLESBOK ANTELOPES (DAMALISCUS PYGARGUS PHILLIPSI)

Nutritional deficiencies in mineral metabolism have been described or suspected in managed and wild ungulate populations. In blesboks (Damaliscus pygargus phillipsi), clinical signs of copper deficiencies have been described in the wild as well as in captivity. Plasma concentrations of cobalt (Co), copper (Cu), iodine (I), manganese (Mn), selenium (Se), and zinc (Zn) were measured over a 6-mon period by inductively coupled plasma mass spectrometry in two groups of five apparently healthy blesboks from a single zoological collection. The control group did not receive any treatment, whereas animals from the treatment group were given an oral drench in October with two sustained-release trace element ruminal boluses (Oligovet ovin-caprin 6 g bolus, Vetalis, 16100 Château Bernard, France). Plasma samples were obtained prior to the start of treatment (October) and in November, February, and April following treatment. No significant differences were found between treatment and control groups for any of the measured minerals over the course of the study. The plasma concentrations of Co, Cu, Se, and Zn were significantly different (P < 0.05) over time for all individuals, but this effect could not be linked to a change in the diet or husbandry. Copper plasma values fluctuated between deficient and normal ranges for cattle. Zinc plasma values were within a range consistent with deficiency in cattle. The great variability of these results should prompt caution in the interpretation of the efficacy of oral trace mineral intake or the expected effect of a dietary modification on trace mineral status based on plasma values.

Ruptured hepatic artery aneurysm in a domestic yak

A 19.5-y-old, male domestic yak ( Bos grunniens) with a history of sudden unexpected death was submitted for autopsy. The yak had hemoabdomen, and a large blood clot was attached to the liver and forestomachs. The hepatic artery had a saccular aneurysm with a 1-cm tear. The arterial wall at the site of the rupture was thin, and the luminal surface was roughened with yellow streaks. The arterial wall adjacent to the rupture was thickened, white, firm, and less elastic than normal arterial walls. Cause of death was concluded to be acute exsanguination. Similar cases with sudden death have been reported in domestic cattle and humans. No risk factors, such as nutritional deficiencies, genetic predisposition, or blunt trauma, were identified in this case, and there was no gross or histologic evidence of generalized vascular disease.

Health and mineral nutrition status of yaks in southern Mustang, Nepal

Biochemical values and mineral concentrations in blood plasma were investigated to evaluate the statuses of health and mineral nutrition among yaks in Mustang District, Nepal. In total, 118 plasma samples of female yaks collected in April and September/October of 2013-2015 were offered. Seventy-four percent of yaks showed lower plasma total-cholesterol concentrations than the lowest limit of reference range (100 mg/dL) and the values in spring (83.41 mg/dL) were lower (P < 0.05) than those in autumn (95.05 mg/dL). All the yaks had lower plasma albumin concentrations than the lowest limit of reference range (3.0 g/dL) and 66% of yaks showed lower plasma inorganic phosphorus concentrations than the critical level of phosphorus deficiency (4.5 mg/dL). Thirty-five percent of yaks showed lower plasma calcium concentrations than the lowest limit of normal range (8 mg/dL) and the concentrations were lower in spring than in autumn (P < 0.01). Seventy-five percent of yaks presented lower copper concentrations than the critical level (0.65 mg/L) and the concentrations were lower in spring than in autumn (P < 0.01). Since the low plasma total-cholesterol might have indicated shortage of dry matter and energy intake, attention should be paid to the nutritional statuses of energy, phosphorus, calcium and copper in winter and early spring.

Preliminary evaluation of selected minerals in liver samples from springbok (Antidorcas marsupialis) from the National Zoological Gardens of South Africa

Limited information is available on the mineral nutrition of captive antelope in South Africa. Zoo animals are usually offered a very limited array of feeds, which may result in nutritional imbalances. As a pilot study to investigate the presence of myopathy in antelope at the National Zoological Gardens of South Africa (NZG), stored liver samples from six springbok (Antidorcas marsupialis) and seven other antelopes from the NZG, as well as selected food items, were submitted for analysis of selenium, copper, manganese and zinc content by spectrophotometry. Springbok liver levels of copper were 23.07 mg/kg ± 0.72 mg/kg, whilst manganese, selenium and zinc levels were 6.73 mg/kg ± 0.22 mg/kg, 0.14 mg/kg ± 0.05 mg/kg and 135.02 mg/kg ± 1.26 mg/kg, respectively. Liver mineral levels in the other species were very variable. Food item copper levels ranged from 4.00 mg/kg (Eragrostis tef) to 17.38 mg/kg (antelope cubes), lucerne (Medicago sativa) and E. tef contained no detectable selenium. The highest zinc levels were in antelope cubes (147.00 mg/kg) and the lowest were in lucerne (20.80 mg/kg). Interpretation of these results was hampered by the small number of samples and a paucity of information on liver mineral levels in free-ranging and captive antelope; however, results suggested that, in the springbok, whilst copper and manganese intake are likely adequate, selenium nutrition is probably insufficient and may account for the myopathy diagnosed. Zinc liver levels are possibly within the toxic range, perhaps as a result of the high levels of zinc in the antelope cubes. This pilot study highlighted the need to establish baseline mineral nutrition data for captive and freeranging antelope under South African conditions.

Copper deficiency and neurological disorders in man and animals

Copper metabolism in the brain is far from being completely understood and further studies are needed on the role of copper in the CNS, starting with careful measurements, metal and biological speciation of metabolites on the molecular level, and combining copper concentration in different brain areas with morphological as well as biochemical alteration after Cu-depletion/deficiency. So far a pathological role for copper has been clearly demonstrated in some human genetic diseases (e.g., Menkes' and Wilson's diseases), but other pathological features connected with metal depletion are under investigation in several laboratories. The metabolic interaction between copper and other metal ions in some neurological disorders is also discussed in this contribution.

Studies of a naturally occurring molybdenum-induced copper deficiency in the yak

The clinical signs of a disorder known locally as "shakeback disease" in yaks in the North of the Qing Hai-Tibetan Plateau of China were defined: they included emaciation, unsteady gait, a 'shivering' back and deprived appetites. Coat colour was not affected. The mineral composition of soil and forages, and samples of blood and hair from yaks in affected ranches in this region were compared with those of 20 samples from unaffected areas. The mean concentration of molybdenum (Mo) in soil and forage was 4.85+/-0.21 and 4.96+/-0.25 microg/g (dry matter), respectively; the mean copper (Cu) to Mo ratio in the forage was only 1.34+/-0.36 compared to 8.12+/-1.31 for unaffected areas. The mean concentrations of Cu in blood and hair from the affected yaks were 0.29+/-0.17 and 3.51+/-1.12 microg/g, respectively, compared with 0.85+/-0.24 and 6.42+/-1.21 microg/g, for controls. The highest value for Cu in the blood of affected yaks was 0.58 mug/g and the lowest 0.03 microg/g (the corresponding highest values for unaffected yaks were 1.03 mug/g, the lowest 0.56 microg/g). There was a hypochromic microcytic anaemia and a low level of ceruloplasmin in the blood. The Cu deficiency in yaks was most severe during pregnancy and lactation, but oral administration of copper sulphate prevented and cured the disease. We conclude that "shakeback disease" of yaks in this region is probably caused by a secondary Cu deficiency, mainly due to the high Mo content in soils and forage.