An experiment was conducted with 12 lactating dairy ewes and 12 goats with the objective to determine whether, under the same dietary treatments, the differences in their fatty acid (FA) profile with emphasis on cis-9 trans-11 CLA milk fat content, are reflected in the transcript levels of genes involved in FA and cis-9, trans-11 CLA biosynthesis. The animals were fed with two diets (A, B) in different days of milk (DIM) due to the different milk yield, body weight etc, in order to have the same food intake and to avoid dietary effects. Diet A was fed to the animals on a group basis as it is traditionally used in practice, while diet B was chosen to avoid individual feed intake variation which is usually observed in group feeding. The results showed that there are significantly lower mRNA levels of acetyl-CoA carboxylase (ACC) in sheep mammary gland compared with those of goats, independently from the diet fed. The same trend was observed with the mRNA level of FA synthase (FAS), but the results were significant only for diet A. The mRNA level of lipoprotein lipase (LPL) in the mammary gland did not differ between sheep and goats fed with diet A. In addition, the concentration of cis-9 trans-11 CLA content was significantly higher in sheep milk fat compared with those of goats. This is in accordance with the significant higher levels on mRNA of stearoyl-CoA desaturase (SCD) which were observed in their mammary adipocytes of sheep compared with those of goats, independently of the fed diet (A or B). In conclusion, these findings demonstrate that the differences between sheep and goats, concerning cis-9, trans-11 CLA and FA milk fat content, under the same dietary treatments could be explained in part by the differences in mRNA of SCD and lipogenic genes in their mammary gland.

The effect of sesame (Sesamum orientale) lignan preparation containing equivalent amounts of sesamin and episesamin on hepatic fatty acid metabolism was compared in rats, mice and hamsters. Animals were fed on either a diet free of lignan or a diet containing 2glignan/kg for 15d. The lignan preparation greatly increased hepatic activity and the mRNA levels of enzymes involved in fatty acid oxidation, while it strongly down-regulated those of enzymes involved in lipogenesis in rats. In contrast, lignan did not modify these variables in mice and hamsters. Changes observed, if any, were more attenuated in these mice and hamsters than in rats. Sesamin and episesamin concentrations in serum and liver of animals fed on lignan-containing diets were significantly greater (P<0·05) in rats than in mice and hamsters. Moreover, sesamin:episesamin values in tissues were far from that expected from the value in the lignan preparation given to the animals and were dependent on the animal species. Liver microsomes from each animal species degraded sesamin and episesamin in the presence of NADPH. The combined value of sesamin and episesamin degradation rates was lower in rats than in mice and hamsters. In addition, there was considerable diversity in the specificity of the enzyme reaction toward sesamin and episesamin among animal species. The differences in the amounts of lignan remaining in the tissues may account for the species dependence of the physiological activity of sesame lignan in affecting hepatic fatty acid oxidation and synthesis.

Which species will be intentionally preserved depends on societal perspectives regarding nature and species, but these have been little studied. In this study, it was hypothesized that in species-specific conservation, aesthetical perspectives, notably the appreciation of species characteristics as embodied in taxa, are important. However, this importance is changing due to variation in ecological (in particular, knowledge of species’ populations) and ethical perspectives (in particular regarding specific human-species relationships). The hypothesis was approached by assessing the relative involvement of different taxa in species-specific legislation on wild animals in the Netherlands over the period 1857–1995. Three objectives in this legislation were defined namely, ‘control’, ‘use’ and ‘protection’, based on purposes and potential levels of legally allowable taking. Over time, the number of species protected increased, whereas the numbers subject to ‘use’ and ‘control’ reached a peak and decreased again. The taxa included birds, mammals, amphibians, reptiles, fishes, bivalves, gastropods, cephalopods, insects, crustaceans and asteroids. Persistent differences were found in the relative involvement of taxa in the objectives as well as in the relative extent to which taxa were affected by long-term trends in numbers of species subject to the objectives. The results also show that species of one-and-the-same taxon were not regarded equally over time. It is concluded that the long-term changes in species’ legal status probably resulted from the combined effects of both the appreciation of species characteristics embodied in taxa and, in particular, changes in ethical perspectives regarding human-species relationships.