Show simple item record

dc.contributor.authorAnderson, Robert Donald
dc.date.accessioned2014-01-30T00:48:50Z
dc.date.available2014-01-30T00:48:50Z
dc.date.issued1974
dc.identifier.urihttp://hdl.handle.net/10179/5064
dc.descriptionText on several pages including the Abstract is not clear.en
dc.description.abstractA total of 8,684 first-lactation records produced in the region in the dairying seasons 1966-67 to 1972-1973, inclusive were assembled. Based on weighted and unweighted intra-sire regressions of progeny performance (deviation from within and within-year contemporary average) on time, a series of estimates of the genetic trend in production for the period were obtained. Variable estimates, allied with large standard precluded reliable conclusions on the nature of the genew By applying a mixed model solution method of sire-eva but only to restricted sub-sample of the data (2,155 records breeding values of 47 sires were estimated unbiased by The numbers of records involved were too few to allow a comparison of these estimates with estimates of the f the same sires obtained by the Farm Production D N.Z. Dairy Board using its method of sire evaluation. Based on variance component estimated obtained of Henderson's Method I, heritability of milk yield and was estimated to be 0.43 and 0.36 respectively. The agree well with estimates reported elsewhere. Additional estimates of the genetic trend were obtaine dregressing the solutions for the fixed effects (sire-group of the sire evaluation model on time.en
dc.language.isoenen
dc.publisherMassey Universityen_US
dc.rightsThe Authoren_US
dc.subjectDairy cattleen
dc.subjectBreedingen
dc.titleA study of biases in dairy sire evaluation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey Universityen
dc.typeThesisen
thesis.degree.disciplineAnimal Scienceen
thesis.degree.grantorMassey Universityen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Agricultural Science (M.Agr.Sc.)en


Files in this item

Icon
Icon

This item appears in the following Collection(s)

Show simple item record