Investigations were made into the genetics of temperament in Merino ewes, with emphasis on those aspects which might have associations with maternal behaviour and postnatal survival of lambs. A data set of over 2000 animals and more than 20,000 records was analysed for estimation of genetic parameters. The heritability of ewe mothering temperament was 0.39 ± 0.02, indicating a moderate genetic ...

Direct and maternal components of variance for lamb survival to birth, 7 d, and weaning (110 d) were estimated by REML procedures in a flock of Australian Merino sheep. A total of 14,142 lambs, the progeny of 421 sires and 3,666 dams, born between 1975 and 1983 were available for analysis. The study has produced some of the most precise estimates of genetic parameters for lamb survival in the A...

Variance components for greasy fleece weight in Rambouillet sheep were estimated. Greasy fleece weight was modeled either as repeated measurements on the same trait or as different traits at different ages. The original data were separated according to the age of the ewe at shearing into three classes; 1 yr, 2 and 3 yr, and older than 3 yr. An animal model was used to obtain estimates of geneti...

Factors affecting ewe prolificacy (number of lambs born per ewe lambing) were evaluated using records on 9705 Targhee, 12,721 Suffolk, and 7231 Polypay lambings from flocks participating in the US National Sheep Improvement Program. Factors considered were ewe age and season of lambing. Prolificacy was affected by age of the ewe (P<0.001) and was highest for ewes lambing between 4 and either 7 ...

1Department of Hematology, University Medical Center, Utrecht, The Netherlands; 2HOVON Data Center, Erasmus Medical Center, Rotterdam, The Netherlands; 3Department of Pathology, Netherlands Cancer Institute, Amsterdam; 4Department of Hematology, University Medical Center, Nijmegen, The Netherlands; 5Department of Internal Medicine, Meander Medical Center, Amersfoort, The Netherlands; 6Departmen...

Chlorpyrifos, a well known organophosphorus insecticide and heavy metal lead, was challenged to Wistar rats to study their interactive effects on biochemical parameters (clinical pathology) after acute exposure via oral gavaging. Hematology and clinical chemistry parameters were estimated after 14 days of exposure. In addition, serum butryl and RBC cholinesterase was estimated on days 3 and 15 ...