Breeding of beef cattle is changing, with more emphasis on efficiency of production. Feed cost is the highest expense, and reducing it has the potential to increase profitability. Common measures of efficiency are ratio traits such as feed conversion (feed…
The current study investigated the influence of selection for increased egg production on external and internal egg quality traits over five generations in Japanese quail. A total of 4325 fresh eggs from 1326 females were collected each week during the…
The aim of this article was to review the state of fertility of female dairy cattle in South Africa and to compare it with international efforts at improving fertility. Fertility in dairy cows is defined as the ability to conceive…
Objectives of the current study were to i) investigate effects of selection for bodyweight at four weeks old on bodyweight (BW) and bodyweight gain (BWG) across four generations; ii) estimate correlated response to selection for BW and BWG at different…
Sow longevity (sow productive lifetime) plays an important role in economically efficient piglet production. Direct selection for sow longevity is not commonly practiced in any pig-breeding program. In recent years, an increased number of peer reviewed articles addressing the economic…
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…
Much of the economic value of wildlife can be attributed to horn size, which is an important trait for trophy hunters. The main objective of the study was to estimate genetic parameters for the economically important horn traits of sable…
Subjectively assessed wool and conformation traits are widely used to select breeding ewes and rams in the sheep industry. Data from a Merino flock that is maintained at Elsenburg Research Farm were used to investigate animal model (co)variance components for…
Reproduction is important for sustainable lamb production in Merino sheep. Data from a Merino flock maintained at Elsenburg Research Farm in the Western Cape, South Africa, were used to investigate the genetic parameters for ewe reproduction traits and their relationship…
Accurate estimates of genetic parameters are essential for genetic improvement of milk yield in dairy cattle and for setting up breeding programmes. Estimates of genetic parameters from test-day models, particularly for Holstein Friesian cattle maintained in tropical environments, are scant…
The aim of this study was to identify single nucleotide polymorphisms (SNPs) associated with genomic region underlying variation in the binomial reproductive trait ‘wet-dry’ in sheep. The wet-dry phenotype was used to represent the reproductive status of the ewes, divided…
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…
Members of the Federation of Boxer Clubs in Southern Africa (FBCSA) have participated in official recording for many years. The aim of the study was to estimate genetic parameters and trends for pre-weaning survival and to assess inbreeding in the…
The main objective of this study was to estimate the genetic parameters for body measurement and yearling live bodyweight traits in the Makuie sheep breed. The data set consisted of 2 144 lambs from 122 sires and 984 dams recorded…
The review summarizes literature dealing with the effects of animal factors (breed, cow individuality, parity and stage of lactation) on fatty acid (FA) composition of milk fat. Genetic parameters affecting the composition of the FAs in milk are reviewed and…
Genetic parameters were estimated for body weight at scanning (SCW) and live animal ultrasound measures of rump fat thickness (P8FT), rib fat thickness (RBFT), rib eye-muscle area (REA) and intramuscular fat percentage (IMF) for South African Angus beef cattle. A…
The aim of this study was to estimate genetic parameters of some carcass characteristics in the Japanese quail. For this aim, carcass weight (Cw), breast weight (Bw), leg weight (Lw), abdominal fat weight (AFw), carcass yield (CP), breast percentage (BP),…
Calving interval (CI) is a fertility trait that can be used in selection programmes to minimize the negative effects that selection for production have on fertility. CI can be derived from milk recording data, therefore this fertility trait can easily…
Phenotypic and genetic parameters in a commercial Merino flock. A study was made of a commercial Merino flock on the farm Rietfontein near Soutpan in the central Orange Free State . The progeny of 43 rams and 542 ewes were…
The heritabilities of the parameters slope (b) and intercept (In a) of the allometric function: y = In a + bx [where y = In (body mass) and x = In (cumulative feed intake)] and for p, which is the…
