Cloning by somatic cell nuclear transfer (SCNT) involves replacing an egg’s nucleus with the nucleus of an adult cell (or that derived from an embryo or foetus) to be cloned, and then activating the egg’s further development without fertilisation.Provided that unhealthy clones would be detected at veterinary inspection and quality controls and thus be prevented from entering the food chain, the currently available data indicate that food products from clones of cattle and pigs and their progeny are as safe as food products of livestock derived by conventional breeding. None of the available studies have identified any differences outside the normal variability in the composition of meat (cattle and swine) and milk (cattle) between clones or clone progeny, and their comparators. After years of study and analysis it has been concluded that meat and milk from clones of cattle, swine and goats and the offspring of clones from species traditionally consumed as food, are as safe to eat as food from conventionally bred animals. Doubts have been expressed whether the current situation regarding the welfare and health of animal clones is ethically justified by the existing arguments in support of cloning for food.
Authors:B. Sas, G. Domány, Ilse Gyimóthy, Katalin Gaál Kovácsné and M. Süth
The effect of free-range versus cage management system on corticosterone transfer into the eggs was studied in laying hens. Hungarian Yellow laying hens (age: 21 weeks, body weight: 2.0 ± 0.5 kg) were divided into two groups in the spring: Group I, free-range keeping (n = 15 layers, density: ≯ 0.5 bird/m2) in outdoor runs, with continuous access to a commercial layer feed; Group II, hens kept in battery cages (n = 17 layers, density: 2 birds/m2, natural light, continuous access to feed and water). Eggs were collected after a one-week adaptation period on days 2, 7 and 16. Corticosterone (CST) was extracted from homogenised egg samples using an ASE-200 Accelerated Solvent Extractor and then assayed by liquid chromatography linked with tandem mass spectrometry (LC-MS/MS) [Thermo Quest Surveyor high-performance liquid chromatography (HPLC) interfaced via Atmospheric Pressure Chemical Ionisation (APCI) ion source to Finnigan/Thermo Quest LCQ Deca MS/MS] using dexamethasone as internal standard with positive APCI ionisation. CST concentrations of whole eggs laid by free-range hens on days 2, 7 and 16 were 0.370 ± 0.218, 0.259 ± 0.066 and 0.915 ± 0.745 ng·g-1, respectively, while those of eggs laid by caged hens were 0.206 ± 0.157, 0.223 ± 0.165 and 0.184 ± 0.110 ng·g-1 at the above sampling times. It is concluded that in free-range laying hens the sharp changes of environmental weather conditions significantly increased the corticosterone content of eggs, while the environmentally controlled and closed battery cage management technology resulted in relatively uniform corticosterone concentrations in the whole eggs.
After cannibalism had appeared in the reproductive units of a white mouse colony, treatment against confirmed Hymenolepis nana, a tapeworm with zoonotic potential, was performed on 67 mice in the reproductive and nursery units. Faecal droppings were evaluated by flotation and sedimentation methods. The sedimentation method revealed a higher number of positive results before, during and after the treatment, but the flotation method yielded some additional positive cases. In the reproductive unit, H. nana eggs were confirmed in 50% of the tested mice by the flotation and in 70% by the sedimentation method. In the nursery units, H. nana eggs were detected in 10.5% of the tested mice by the flotation and in 24.6% by the sedimentation method. A colony of mice was treated against the tapeworm H. nana with praziquantel and emodepside in doses of 2.574 mg praziquantel/100 g body mass and of 0.642 mg emodepside/100 g body mass. The content of the original pipettes (Profender®) was applied as a spot-on on the back of the neck in the area between the shoulders. The application was repeated three times at 14-day intervals. Seven days after the third therapy no H. nana was found in any of the tested mice in the reproductive or the nursery units. After the treatment, cannibalism was no longer observed. This treatment represented one of the steps aimed at improving animal welfare and preventing potential zoonotic disease. The public health significance of this cestode should receive more attention, especially among people who take care of mice, have them as pets, or feed them to reptiles.