Reproductive performance of rats supplemented with L-carnitine

It has been shown previously that supplementation of sows with l-carnitine increases their reproduction performance. The current study was carried out to investigate if feeding of l-carnitine also affects the reproduction performance of rats. Thirty female rats at 4 weeks of age were divided into two groups. The rats were fed diets with or without l-carnitine (1 g/kg diet) over a period of 34 weeks. After 8 weeks of feeding, the female rats were mated the first time. Two more reproductive cycles followed, with 3-week intervals in between. Body weight development of the females was similar in both groups during the whole experimental period. Number of pregnancies and number of total rat pups, pups born alive and stillborn pups were not influenced by l-carnitine. There was also no influence of dietary l-carnitine on the body weight of individual pups and the litter weights at birth. Weight development of litters differed between both groups on several days, but no uniform effect of l-carnitine was observed. Body weight development of weaned rats fed a commercial diet was different between both groups, but only in one reproduction cycle. In conclusion, this study shows that l-carnitine supplementation does not improve the reproductive performance of rats.     

The effect of elevated temperatures on food conversion efficiencies of Coccinella septempunctata and Harmonia axyridis young adults feeding on Sitobion avenae

Journal of Plant Diseases and Protection - An analysis of existing data gained in a set of climate chamber experiments was conducted to compare food conversion efficiencies of young Coccinella...     

Investigations concerning the sustainability of remediation by land deposition of tributyltin contaminated harbour sediments

Sediments often contain high concentrations of tributyltin, which is used as a biocide in antifouling paints. The aim of our project was to assess land deposition as an alternative in dealing with TBT-contaminated harbour sediments. Therefore, we followed the biological degradation of TBT under aerobic and anaerobic conditions at different temperatures using defined laboratory experiments and performing field measurements. With the data obtained, a risk assessment is performed. The biological degradation of TBT is faster under aerobic conditions and with increasing temperature. The half-lives found show the dependency of the degradation rates on the temperature between 5 to 55°C The degradation rate determined for water under the same conditions (just biological degradation, without photolysis) is almost 4 times higher than in the sediment. The field studies gave a degradation rate of around 10% per year in untreated sediment and 30% per year in restacked sediments. We did not observe any interference of released TBT with ground water or surrounding areas. The TBT uptake in plants was low. Based on our results, a multidimensional risk evaluation was done, concerning the TBT and its degradation products dibutyl tin (DBT) and rnonobutyl tin (MBT) released from the deposition area. The land deposition appears to be a sustainable solution for dealing with TBT-contaminated harbour sediments. Compared to other disposals, it is economically one of the cheapest and, from an ecological point of view, it is acceptable.     

Effect of short-term UVB exposure on vitamin D concentration of eggs and vitamin D status of laying hens

Vitamin D deficiency in humans is widespread, and only a few food items are important natural sources of vitamin D. This study investigated the effect of UVB exposure of laying hens on the vitamin D content in egg yolk. In a two-factorial design, hens fed a vitamin D-deficient (-D) or -adequate (+D) diet were nonexposed or exposed to UVB light over a period of 4 weeks. UVB exposure of the -D group caused nearly normal egg production rate and egg shell quality; exposure of the +D group did not further improve these parameters. UVB exposure tended to improve the concentration of plasma 25-hydroxycholecalciferol (25(OH)D(3)), but had no effect on 1,25-dihydroxycholecalciferol in plasma or on cholecalciferol and 25(OH)D(3) in egg yolk. The present study shows that a short-term exposure of laying hens to UVB light is not an appropriate way to improve the vitamin D content of egg yolk.     

Effects of Untreated and Thermally Treated Lupin Protein on Plasma and Liver Lipids of Rats Fed a Hypercholesterolemic High Fat or High Carbohydrate Diet

Lupin protein is capable of reducing plasma lipids in hypercholesterolemic man and animals. Whether lipid-lowering properties of lupin protein will be influenced by thermal treatment or by other nutrients has not been elucidated. In a two-factorial study, rats were fed hypercholesterolemic diets based on high amounts of carbohydrates (HC) or fat (HF), which contained either (20.4% of energy) untreated or thermally treated lupin protein (steam: 120 °C, 30 min) or casein as control protein. Lupin protein lowered plasma lipid concentrations in rats fed the HF diet but not in those fed the HC diet (P < 0.05). Among rats fed the HF diet, plasma and VLDL triglyceride concentrations were lower in rats fed thermally treated (−46% and −44%, P < 0.05) and untreated lupin protein (−47% and −46%, P < 0.05) than in those fed casein; whereas liver triglycerides were reduced only in rats fed untreated lupin protein (P < 0.05). Compared to casein, untreated lupin protein had slightly stronger cholesterol-lowering effects in plasma, LDL and HDL (−34%, −37%, −35%; P < 0.05) than thermally treated lupin protein (−23%, −29%, −31%, P < 0.10). In conclusion, the lipid-lowering effect of lupin protein strongly depends on composition of the basal diet, and thermal treatment is accompanied by a slight reduction of its hypocholesterolemic properties.