Factors influencing the recalving rate of 2 165 lactating beef cows of four pure breeds (Afrikaner, Hereford, Bonsmara and Simmentaler) and three cross-bred types were investigated on the Mara Research Station between 1972 and 1982. Average recalving rate was 88.3%…
The effect of melatonin implants, flushing and teaser rams on the reproductive performance of spring-mated Dohne Merino ewes was investigated. The ewes (n = 534) were randomly allotted to four treatments, namely (1) no treatment (control), (2) melatonin implants (melatonin),…
Dietary conjugated linoleic acid (CLA) was reported to increase the levels of saturated fatty acids (SFA), to decrease monounsaturated fatty acids (MUFA) in egg yolk, liver and adipose tissue in chicken and quail. Hence, the objective of this study was…
The objective of this study was to determine the effect of inclusion of polyethylene glycol (PEG 8000) during in vitro incubation on gas production kinetics, organic matter digestibility (OMD) and the metabolisable energy (ME) content of foliage from the tannin…
The effect of restricted suckling and split weaning on the reproductive performance of dams and subsequent performance of their litters was studied in an experiment involving 48 Landrace x Large White sows of second and third parity. The sows and…
Two Merino lines were established in 1988 and were subjected to divergent selection for maternal ranking values on lambs weaned/ ewe joined (Lw/Ej). Replacements with high values were selected in the Reproduction `+` line, while progeny of low ranking ewes…
Components for a simulation model are described to predict feed intake, amino acid requirements and body composition changes over time on the basis of the inherent potential protein growth rate of pigs varying in genotype. The potential protein growth rate…
One hundred and thirty Merino ewes were used to test the efficiency of different doses of medroxyprogesterone acetate (MAP) progestagen to synchronize oestrus outside the breeding season. Three treatments, consisting of intravaginal progestagen doses (60 mg, 40 mg, and halved…
The effect of a shade structure on the behaviour of lactating Friesian cows in open camps (dry lots) was determined over two consecutive summer periods. The daily activities of cows were observed and recorded on 9 separate 24-h periods. Shade…
The in vitro ammonia production and ruminal in situ disappearance of dry matter, organic matter, protein and ether extract of heat-treated whole cottonseed were determined. Abomasal flow of nitrogen and ether extract and terminal ileal flow of lysine and methionine…
The study was conducted to determine the effect of whole cottonseed (WCS), heat-treated whole cottonseed (HWCS), and whole cottonseed plus lanolin (WCS + Q on feed intake, milk production and milk composition. Eight Holstein heifers in early lactation were fed…
A system of feeder–breeder dimorphism (large, fast growing offspring in feedlots obtained from small, low mainten¬ance cows on natural pastures) would be profitable in South Africa. The possibility of a genetic basis for feeder–breeder dimorphism was estimated by calculating genetic…
The diet of free ranging Angora goats in a False Upper Karoo veld type in the south-western Orange Free State is described. Angora goats are inherent browsers feeding on a wide variety of plants. Based on utilization frequency and feeding…
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,…
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…
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…
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…
