Influence of type of diet and incubation time on in sacco release of Cu, Fe, Mn and Zn from Italian ryegrass, untreated and ammonia treated wheat straw.

Artificially dried ryegrass, untreated and ammonia-treated wheat straw were ground and incubated in nylon bags in the rumen of three sheep each fed with diets based on roughage or concentrate. Dry matter degradability, the concentration and the release of the trace elements Cu, Fe, Mn and Zn from the incubated feeds were measured after 0 (washing loss), 6, 12, 24, 48 and 72 h rumen incubation time. Dry matter degradability, trace element concentration and their release were significantly influenced by the kind of incubated feeds, incubation time and feeding of sheep. Cu- (1.8-6.9 mg kg-1 DM) and Zn concentrations (36-103 mg kg-1 DM) of straw residues in the bags were much higher than those of original straw (1.2-1.6 and 8.1-9.9 mg kg-1 DM resp.). The inflow of Cu and Zn in the bags containing straw residues was higher than their release. The Cu-, Fe- and Mn-release from ryegrass was similar to the dry matter degradability, but the Zn-release was much lower.

Nickel--an essential element.

Nickel is necessary for the biosynthesis of the hydrogenase, carbon monoxide dehydrogenase, and of factor F 430, found in a number of genera of bacteria. Urease from jack beans and several species of plants is also a nickel protein. These plant enzyme systems can affect animals via the microbiological digestion of food in the rumen. Nickel is a constituent part of all organs of vertebrates. Its absorption can be controlled. Low nickel offers reduce growth; this is particularly true of intra-uterine development. Such offers also decrease the life expectancy of reproducing animals. Nickel deficiency is accompanied by histological and biochemical changes and reduced iron resorption and leads to anaemia. It can disturb the incorporation of calcium into skeleton and lead to parakeratosis-like damage, which finds expression in disturbed zinc metabolism. Nickel deficiency results in lower activities of different dehydrogenases and transaminases and, above all, of alpha-amylase, and particularly affects carbohydrate metabolism. A marked decrease in metabolism was observed in the case of the energy sources fat, glucose, and glycogen. Nickel therefore performs a vital function in metabolism: it is an essential element. The nickel requirements of human beings and animals amount to less than 500 micrograms/kg and are probably even considerably lower. It therefore follows that, in view of the available nickel offer, primary nickel deficiency in human beings and animals can be excluded, at least in the present state of knowledge. On the other hand, it should be remembered that, 25 years after the discovery of the essentiality of manganese, this element was included among the trace elements of academic importance only, whereas today it is a feed additive.

[The supply of wild ruminants with major and trace elements. 1. The cadmium content of winter grazing and the cadmium status of red deer, fallow deer, roes and moulons]. / Die Mengen- und Spurenelementversorgung der Wildwiederkäuer. 1. Mitteilung: Der Kadmiumgehalt der Winteräsung und der Kadmiumstatus des Rot-, Dam-, Reh- und Muffelwildes.

The Cd-determination of 10 different winter grazings for wild ruminants in seven different biotopes showed significant differences of the habitats resulting from the previous Cd-emission of metallurgy smelting non-ferrous metals. The winter grazing of the Tharandt Forest and the Harz mountains contained significantly more Cd than that of the Lower Flaming hills, the western Erzgebirge and the northern agrarian areas. The bark and the tips of conifer twigs, twigs of oak and mountain ash, bilberry and heather plants, i. e. perennial plants resp. parts of plants proved to be particularly rich in Cd. On an average, wild ruminants consume more Cd than domesticated ruminants, which do not consume parts of perennial plants. The rumen contents of all wild ruminants contained, with 0.20 to 0.25 mg/kg dry matter more Cd than could be expected from the content of the grazing. In the Cd-contaminated areas the amount of Cd in the rumen contents too showed the Cd-load. The kidneys, livers and the covering hair of a total of 172 head red deer, roes and mouflons reflected the Cd-load and the dependence of the Cd-level on the age. The Cd-concentration ascertained in the organs of the wild ruminants was compared with that of sheep and cattle. The, on an average, higher Cd-load of the wild ruminants was confirmed. The kidneys of wild ruminants older than five years should, as a general principle, not be eaten and neither should the livers of animals from Cd-contaminated biotopes. The limb defects of mouflons from Cd-contaminated areas are discussed in connection with Cd-induced secondary Cu-deficiency resp. Mn- and Zn-deficiency. A reference is made to further works.

[The supply of wild ruminants with major and trace elements. 2. The manganese content of winter grazing and the manganese status of red deer, fallow deer, roes and mouflons]. / Die Mengen- und Spurenelementversorgung der Wildwiederkäuer. 2. Mitteilung: Der Mangangehalt der Winteräsung und der Manganstatus des Rot-, Dam-, Reh- und Muffelwildes.

The winter grazing of wild ruminants on mantles of slate waste in the Harz mountains and in Gera county were richest in Mn whereas those on mantles of granite waste in the Erzgebirge were poorest. The flora of the shell-limestone, keuper and loess areas contains much less Mn than that of those acid habitats. The Mn-requirement of the wild ruminants grazing in the forests is met however, since bilberry plants (2,080 mg/kg), spruce twigs (984 mg/kg), spruce bark (827 mg/kg), oak twigs (791 mg/kg) and heather (754 mg/kg dry matter) in addition to many other plant species store extremely high amounts of Mn. Solely sallow twigs were poor in Mn (28 mg/kg). Based on 601 samples examined, the Mn supply of wild ruminants is extensively described. The rumen content reflected the plentiful Mn-supply of the wild ruminants living in forests (greater than 400 mg/kg) and the far worse one of field roes, particularly in Mn-deficiency areas for domesticated ruminants (mantle of shell-limestone waste 37 mg Mn/kg dry matter of rumen content). The indicator organs of the Mn-status (liver, covering hair, kidneys) verify the statements made concerning red deer, fallow deer and mouflons, of which a total of 170 head from 14 biotopes were examined. An Mn-deficit of field roes in Mn-deficiency habitats in winter cannot completely be excluded. Mouflons have not yet been able to adapt themselves to the excessive Mn-supply of the acid forest habitats in Central Europe. They stored significantly higher amounts of Mn in liver, covering hair, kidneys, cerebrum and ribs than the other wild ruminants and sheep and cattle. The normal Mn-content of the liver and the cerebrum of red deer, fallow deer and roes corresponds to that of sheep and cattle. Roes and fallow deer have winter covering hair poor in Mn (less than 4.0 mg/kg) in comparison to sheep and cattle.