An understanding of genetic information and relationships among traits is required for an improvement programme to be successful. Therefore, this study aims to estimate certain (co)variance components for bodyweights Mecheri sheep collected at various ages. The data consisted of 2…
The objectives of this study were to evaluate statistical models of potential utility for genetic evaluation of feed intake and to estimate the (co)variance components and genetic parameters that would be necessary for their use in a national cattle evaluation…
The wildlife industry in South Africa has shown immense growth since the 1990s, which was brought about by the private game segment of the industry. In recent years, trophy quality Cape buffalo breeding animals have achieved extremely high prices. Much…
The purpose of this study was to evaluate alternative expressions of genetic merit for cow efficiency. Weights of Pinzgauer cattle taken at birth, weaning, and maturity were extracted from the South African National Database. Average daily gain from birth to…
Infestation with gastrointestinal nematodes is probably among the most pervasive problems in small-stock production worldwide. Faecal worm egg count (FWEC) has been reported as an indirect measure of parasite resistance in livestock production. Environmental and genetic factors of FWEC were…
The SA Dairy Swiss population could not previously be incorporated into the National Dairy Genetic Evaluation System, owing to inadequate population numbers and data structures. However, in recent years participation in Milk Recording has improved sufficiently to allow for genetic…
The data used for this study consisted of 27 485 kid records, the progeny of 599 sires and 10 077 dams, and were collected on the 2000- to 2009-born kids of 11 Angora goat studs. Variance and covariance components and…
Genetic parameters of weaning traits of Hereford calves. The inheritance and interassociation of weaning traits for 912 Hereford calves, the progeny of 22 sires, collected over a period of 11 years, were studied. The estimates of heritability of the…
Genetic and phenotypic parameters were estimated in the control line of the Klerefontein Merino sheep selection experiment. The heritability estimates of 0,247 for body mass, 0,229 for clean fleece mass and 0,369 for fibre diameter are generally lower than other…
Investigation of selection criteria for Afrino sheep. Genetic parameters of growth and wool traits: The data used in this study were obtained from the Carnarvon Afrino stud. The genetic and phenotypic parameters for the various growth and wool traits were…
Data involving monthly records of egg production (EP), chick production (CP), hatchability (H), mean egg weight (MEW) and mean day-old chick weight (MCW) were analysed using REML procedures. All traits were treated as hen traits. Egg production of young birds…
Genetic parameters for production and reproduction traits in the Elsenburg Dormer sheep stud were estimated using records of 11743 lambs born between 1943 and 2002. An animal model with direct and maternal additive, maternal permanent and temporary environmental effects was…
Dispersion parameters for number of piglets born alive (NBA) were estimated using a random regression model (RRM). Two data sets of litter records from the Nemscak farm in Slovenia were used for analyses. The first dataset (DS1) included records from…
Repeated records (n = 58,295) of Bonsmara cows were used to evaluate mature cow weight (CW), using random regression animal models (RRM). Cows (n = 11,847), age two to 11 years (AY), were weighed at weaning of their calves. Data…
The objective of this study was to estimate dominance variance for number born alive (NBA), 21- day litter weight (LWT21) and interval between parities (FI) in South African Landrace pigs. A total of 26223 NBA, 21335 LWT21 and 16370 FI…
Selection accuracy for resistance to mastitis may be increased by combining somatic cell score (SCS) and udder type into an udder health index, using genetic parameter estimates among them. A multi-trait animal model was used to estimate genetic parameters among…
Accurate genetic parameters are vital for genetic prediction, selection on breeding values and creation of selection objectives. Consequently, records for birth weight (BW), 200 (WW), 400 (YW) and 600 (FW) day weight were analyzed to obtain heritability estimates. These records…
A total of 79687 (after editing) first lactation records for milk (MY), butterfat (BFY) and protein (PRY) yield, as well as butterfat (BFP) and protein (PRP) percentages were obtained from the South African Holstein Society for animals that were registered…
The purpose of this study was to estimate genetic and phenotypic parameters for gestation length and birth weight in Bonsmara cattle in South Africa. A total of 26962 gestation length and birth weight records for the period 1989 to 2000…
