The long-term effect of selection for the parameters of the allometric model on fitness is investigated to evaluate the allometric model for long-term selection purposes. Fitness is defined as the number of mature animals / female mated / 100-day period,…
The use of three media to support growth and development in headfold Sprague-Dawley rat embryos cultured for 48 h, for possible use in a teratogen assay, was investigated using sheep serum (SM) and sheep serum mixed with rat serum (80%…
Malignant hyperthermia (MH) genotype, as expressed by the halothane genotype, was determined on a random sample of 100 pigs originating from the Western Cape. The pigs were slaughtered to investigate the effect of MH genotype on certain carcass characteristics and…
Four simulations (RANGEPACK Herd-Econ) of a beef weaner enterprise, each subjected for a period of 30 years to a different rhythm of the long-term variation in rainfall and simulated dry matter production (PUTU 11) of veld at Glen, were compared…
Heritability estimates and breeding value predictions of Dormer sires for litter size and lamb mortality were obtained using a threshold model. Heritability estimates on the underlying scale were 0.24 and 0.12 for litter size and mortality, respec¬tively. Breeding value predictions…
Direct and maternal variance components and resulting heritabilities were estimated by DFREML-procedures for clean fleece weight (CFW), body weight (BW) and mean fibre diameter (MFD) in the Grootfontein Merino stud. Direct heritabilities were estimated as 0.381, 0.289 and 0.626 for…
Simmentaler cattle of the Highveld Region Development Institute were used in this study to determine the genetic and envi¬ronmental effects on birth mass, weaning mass and the mass gain from birth to weaning. During winter the animals were kept in…
Data collected from calves born at the Bartlow Combine Breeding Station were analysed to estimate direct and maternal additive genetic variances and resulting heritabilities for weight at birth, 205, 365 and 540-days of age. The estimates of direct heritability were…
Stocking rates of 20, 35 and 55 seven-month-old wethers/ha were used to determine the stocking rate/sheep performance relationship on kikuyu under continuous and rotational grazing, considering the stress placed on the animals by decreasing the availability of herbage with higher…
About half of the 505 winter-lambing SA Mutton Merino ewes were shorn at four or fewer weeks prior to lambing at the Outeniqua Experimental farm near George in July-August 1991 and 1992. The remaining ewes, with a 6 – 7-month…
Grains from five triticale cultivars on the South African market (Usgen 7; 10; 14; 18; 19) were compared with each other and to maize in enriched mixtures for lambs in a feedlot. The grain was enriched by adding 12% of…
