No abstract

No abstract

Lambs received 250, 1000 and 1750 mg Fe per kg concentrate dry matter. The Fe-supplementations caused the Fe-levels of spleen, liver, kidneys and ribs to rise significantly. Liver and spleen reflected most markedly the high Fe-supply. The Fe-supplementation reduced the Cu-content in the liver and the share of Zn in the kidneys. The Mn-content of all body parts analysed was not significantly influenced by Fe-supplementation.

2-Nitrotoluene (2NT) is an important commercial chemical intermediate. A recent National Toxicology Programme (NTP)-study demonstrated clear evidence of carcinogenic activity of 2NT in rats. In the present study male WELS-Fohm rats were dosed chronically with 2NT, 5 days a week for 12 weeks. Hemoglobin (Hb) adducts and hepatic DNA adducts were analyzed. After mild base treatment of Hb, 2-methylaniline (2MA) was released and quantified using gas chromatography/mass spectrometry. 2'-Deoxyguanosine (dG) and 2'-deoxyadenosine (dA) adducts of 2MA were found in hepatic DNA using electrospray-mass spectrometry (ESI-MS/MS). The dG adduct found in vivo did not co-elute with N-(2'-deoxyguanosine-8-yl)-2-methylaniline which is the expected adduct for arylamines. The dG adduct detected in the dosed rats was not present in calf thymus-DNA (ct-DNA) modified in vitro with N-acetoxy-2MA. The dA adduct detected in rats was a very minor product in ct-DNA modified in vitro. The dG and dA adducts found in the 2NT-dosed rats increased with the dose. The same increase was seen for the Hb adduct levels measured in the same animals. The increase of DNA and Hb adduct levels were supralinear. There was a very strong linear relationship between the level of dG-2MA adducts and dA-2MA adducts in hepatic DNA from rats administered 2NT over the whole dose range studied (r(2) = 0.9). A strong linear relationship also existed between the level of dG-2MA or dA-2MA adducts, in hepatic DNA, and Hb adducts, over the whole dose range (r(2) > or = 0.9). Thus, there was strong evidence to support the notion that Hb adducts were an effective surrogate marker for the hepatic DNA damage of rats chronically administered 2NT.

Diseases and losses were registered in dependence on vitamin A supply with 2,035 pigs (6.5-114 kg live weight). The histologic examinations comprised various organs of 72 animals. The content of the main protein fractions as well as antibody titre after supplementing antigenes were determined in the serum of 104 animals. The feeding of a vitamin-A- and carotinefree casein-starch-respectively a Vitamin-A-free cereal-soybeanmeal-diet led to deficiency symptoms after 7-8 respectively 16-19 weeks of experiment particularly in the shape of nervous disturbances and voice affectations. Histologically a hyperplasia and a metaplasia of the epithelium of the big ducts in the salivory gland could be proved. The repletion of a part of the avitaminotic animals by means of oral (500 I.U./kg feed) and parenteral (500,000 to 1,000,000 I.U. i.m.) vitamin A administration is proof of a lack of vitamin A. Vitamin A and provitamin dosage did not influence diseases and losses with the exception of the occurrence of deficiency symptoms. The protein content of the serum as well as that of the globulin fractions alpha, beta, gamma did not change, the albumin content was lower in the groups without vitamin A (p greater than 0.05). Antibody titre against the lipopolysaccharide of salmonella dublin and human gamma globulin were diminished in piglets and fattening pigs fed vitamin A free (p less than 0.05). Taking the criterion of animal health, a vitamin A requirement higher than for growth (250 I.U./kg feed) cannot be derived.