The aim of this experiment was to evaluate the use of neem seed extract for controlling common cattle ticks of the Ixodidae species. Three bulls and three cows of the Tswana, Brahman and Simmentaler breeds were cleared of ticks using…
Kikuyu (Pennisetum clandestinum) is a summer growing tropical pasture species well adapted to the Midlands of KwaZulu-Natal. Kikuyu foggage (standing hay) could play an important role in a fodder flow programme to sustain dry ewes during late winter after their…
Seventy-seven mature Tswana goats were used to investigate the effect of supplementation on reproduction of wet season kidding animals. Treatments groups with similar weights were: Unsupplemented Control (UC), Continuous Supplementation (CS), Before Rain Supplementation (BRS) and After Rain Supplementation (ARS).…
Field data for the period 1976 to 1998 from South African and Namibian Afrikaner, Drakensberger, SA Angus and Simmentaler beef cattle breeds was used to investigate two fertility traits, calving rate (CR) and calving success (CS). Calving rate, a lifetime…
The variation in, and often the disappointingly poor weight gains and the inability of lambs to achieve desirable carcass grades on ryegrass pastures have long been a concern to researchers, extension officers, advisors and farmers. The objectives of this study…
Weaning performance of calves sired by Charolais and Hereford on dams of Angus, Bonsmara and Hereford and various crossbred dam combinations was compared. Charolais sired calves were on average 5 kg heavier at birth and 20 kg heavier at weaning…
simulation study was carried out to compare the use of single and composite milk samples for the evaluation of milk composition in dairy cattle. The genetic correlation between the two sampling methods was estimated. Results showed a high genetic correlation…
The n alkane marker (dosed marker, dotriacontane, C32, herbage markers C31, C33 and C35) technique was evaluated for use in feed intake and digestibility studies with horses. The mean retention time of digesta in the digestive tract was determined in…
Timing of birth and birth site selection were investigated in two lines of grazing Merino sheep that had been divergently selected for multiple rearing ability. Time budgets in the neonatal phase were also compared between the two lines. Parturition was…
Genetic parameters were estimated for birth weight (BWT), weaning weight (WWT) and pre-weaning average daily gain (ADG) using Restricted Maximum Likelihood (REML) procedures. Four different animal models were fitted, differentiated by including or excluding maternal effects. The direct heritability estimates…
Genetic parameter estimates for scrotal circumference (SC), testis diameter (TD) and two-tooth liveweight (LW) were obtained for 1380 two-tooth Merino rams born from 1986 to 1998 on the Tygerhoek Experimental Farm. The effect of SC of service sires (n =…
The chemical composition and in vitro dry matter digestibility (IVDMD) of untreated and ammoniated crop residues, sampled at various sites in the North West Province of South Africa, were investigated. The mean IVDMD of maize residues obtained by means of…
Data used for this study were collected on the Carnarvon Afrino flock from 1986 to 1998, and include data records on several subjectively assessed traits, body weight and fleece traits of 3291 animals, the progeny of 127 sires and 772…
The objective of this experiment was to test the proposition that fatter pigs, when fed a high crude protein (CP) diet, would attempt to correct the effects of excess fattening on body composition by returning to a state that is…
The nitrogen (N) retention response to the abomasal infusion of amino acids in South African Mutton Merino ram lambs fed a standard finishing diet was investigated. The basal diet consisted of (g/kg air dry weight): 300 lucerne, 80 wheat straw,…
Five populations with varying percentages of animals in full-sib families were simulated. For each population, three combinations of additive and dominance genetic variances of different relative magnitudes were considered, thereby creating fifteen sub-populations. Constant residual variance was used in all…
Oxygen (O2) consumption and carbon dioxide (CO2) excretion of ostrich embryos were studied on 45 ostrich eggs in various stages of development. A closed respirometry system was used for eggs subjected to < 10 days of incubation, while an open flow…
In an animal model evaluation of breeding values it is assumed that the base animals are all at the same genetic level. However, in the South African Holstein population, animals of different genetic levels were imported from foreign countries, thus…
Two experiments were conducted to test whether young pigs are capable of discriminating against a feed based on its nutrient balance (or protein value) and/or the presence or absence of anti-nutritional factors and whether there is an order of preference.…
Two broiler feeding trials (1-31 days of age) were carried out to determine the effect of fortifying grain amaranth diets with lysine, methionine, casein and ethylene diamine tetraacetate (EDTA) on performance, amino acid availability, plasma amino acids, nitrogen and mineral…
