Animal cloning for food: epigenetics, health, welfare and food safety aspects

Is cloning horses ethical?

This paper assesses whether cloning horses is ethical by reviewing ethical arguments against cloning of nonequine species and determining whether they apply to horses, analysing ethical arguments about horse cloning which do not apply to noncompetitive species and considering the ethical dilemmas faced by veterinarians involved in horse cloning. The author concludes that concerns about the health and welfare of cloned horses render the technique ethically problematic and that the onus is on those providing commercial equine cloning services to collate data and provide a stronger evidence base for ethical decision-making.

Welfare in horse breeding

Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how positive welfare effects associated with breeding might be maximised. Further studies are needed to establish an evidence base about how stressful or painful various breeding procedures are for the animals involved, and what the lifetime welfare implications of ARTs are for future animal generations.

Plasma estrone sulfate, clinical biochemistry, and milk yield of dairy cows carrying a fetus from a bull or its clone

The aim of this article was to compare plasma estrone sulfate (E1SO4), clinical biochemistry, and milk yield of dairy cows carrying a female fetus from a bull (BULL) or from its clone (CLONE), evaluating also the relationship between the former variables and the birth weight of the newborn. Sixteen recipient dairy Friesian heifers (10 BULL and 7 CLONE) received a female embryo, obtained by in vitro embryo production and sexing by polymerase chain reaction with the semen of the BULL or the CLONE. Blood samples on all cows were obtained before feed distribution in the morning from jugular vein from 4 weeks before to 4 weeks after calving, to be analyzed for metabolic profile. The samples from late gestation were also analyzed for E1SO4 concentration. To separately assess the effect of calf birth weight (CBW), data were categorized as follows: low (<39 kg; BWT-A), mid (39-46 kg; BWT-B), and high (>46 kg; BWT-C). The plasma concentrations of β-hydroxybutyric acid (BHB, P=0.019), Na (P=0.002), Cl (P=0.026), strong cation-anion balance (P=0.020), total bilirubin (P=0.054), and α1-globulin (P=0.044) were higher in prepartum BULL recipients than those in CLONE, whereas BHB (P=0.021) and Mg (P=0.090) were higher in postpartum BULL recipients, while no differences were recorded in the remaining postpartum parameters. The CBW class had significant interaction with week of gestation on antepartum plasma estrone sulfate (P=0.021), whereas CBW per se affected antepartum plasma BHB (P=0.021), and nonesterified fatty acids (NEFA; P=0.011) being higher in BWT-C which also had the lower NEFA concentration during postpartum. Milk yield was unaffected by the sire used, both for quantitative and qualitative aspects. Cows carrying heavier fetus (BWT-C) had a different lactation affected by month compared with the other 2 CBW groups. From these results, there were no differences between BULL and CLONE recipients. Estrone sulfate, BHB, and NEFA may be used to predict CBW and provide different nutritional management during gestation.

Body growth, hematological profile, and clinical biochemistry of heifer calves sired by a bull or its clone

The aim of this paper was to compare body growth, hematological profile development, and clinical biochemistry in the female progeny of a sire with the female progeny of its clone. Sixteen Friesian female calves, 9 daughters from a tested bull (BULL) and 7 from its somatic cell nuclear transfer clone (CLONE) were monitored from birth to 60 wk of life. Body weight (BW), wither height (WH), hip height (HH), body length (BL), and hearth girth (HG) were measured at birth and 4, 8, 12, 16, 20, 24, 36, and 50 wk. Blood samples were taken from jugular vein at 12 to 48 h from birth and 1, 2, 3, 4, 8, 12, 16, 20, 24, and 36 wks of age, to be analyzed for hematological, serum protein, and metabolic profiles. At the same time, rectal temperature (RT) was recorded. Age at puberty was assessed on surviving heifers by measuring weekly plasma progesterone levels. Data were evaluated using a mixed model, taking into account the repeated measures in time on the calf. For each variable, different covariance structures were tested, choosing the best according to the Akaike's Information Criteria. Significant was set at P < 0.05, and a trend was considered for P < 0.10. At 24 wk of age, WH was lower in CLONE daughters than BULL daughters. Around 20 wk of age, there was a trend for lower BW in CLONE daughters than BULL daughters, confirmed from differences in HG. There was no difference in RT due to sire effect. Blood glucose concentration decreased in both groups during the first 4 wk of life; at birth, only a trend for higher blood glucose in CLONE daughters was recorded, whereas an opposite trend was observed for plasma creatinine. Total leukocyte count did not differ between progenies. Circulating lymphocytes tended to be lower in CLONE than BULL daughters. The neutrophil: lymphocyte ratio tended to be higher in CLONE than BULL calves. No difference was demonstrated for erythrocyte features, whereas mean platelet volume tended to be lower in CLONE than BULL progeny. From these results, there were no differences between progenies from BULL and its clone that suggest welfare problems in the first 6 mo of life.