The seasonal variation in diet selection and herbage intake of cattle and sheep and the effects on animal performance at various research centres are put into perspective, taking into consideration the annual rainfall and its distribution. The most important constraint…
Two trials were conducted to determine the effect of dietary molybdenum (Mo) on the fertility of young rams, when fed for ca. 14 weeks to prevent copper (Cu) toxicity. In the first trial, the sexual development of young weaner rams…
Elevated rumen ammonia levels in sheep on high nitrogen kikuyu (Pennisetum clandestinum Hochst) grass were indicative of a protein/energy imbalance in the grass. To correct the imbalance, grass containing 22% crude protein required maize meal supplementation of at least 20%…
Concentrations of plasma copper and zinc as well as blood selenium were determined in single and twin lambs and their dams for a period of 120 days from the birth of the lambs, using Merino, Dohne Merino and SA Mutton…
Influence of mastitis on milk production, somatic cell count, and concentrations of sodium, potassium and lactose in bovine milk. Milk production, somatic cell count, and concentrations of sodium, potassium and lactose of 32 pairs of normal equivalent quarters as well…
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…
Two trials were conducted to determine the milk production response to feeding a highly saturated free fatty acid supplement to grazed dairy cows in early lactation. The trials were conducted during spring and autumn, respectively. Sixty-five Friesian cows were supplemented…
Comparison of enriched barley, wheat, triticale and maize for the fattening of early-weaned lambs. Alkali-ionophoreenriched barley, wheat, triticale and maize were evaluated as diets for the fattening of early-weaned (ca 10 weeks) SA Mutton Merino lambs kept under feedlot conditions.…
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…
The allometric-autoregressive model describes growth accurately and is useful in the characterization of growth responses. Hence, the potential of the model for selection purposes was investigated. Rats were used in a selection experiment, where selection was practised for slope (b)…
The allometric-autoregressive model describes growth accurately and is useful in the characterization of growth responses. Hence, the potential of the model for selection was investigated. Rats were used in a selection experiment, where selection was practised for slope (b) and…
The efficiency of meat production with regard to kilogram of lamb weaned per kilogram metabolic mass of ewes at mating of six different Fl crossbred populations, viz. Finnish Landrace x Merino (FL x M), Border Leicester x Merino (BL x…
Lucerne hay (LH) was substituted by urea-ammoniated wheat straw (AWS) in four lamb-growth diets, all containing 60% roughage. The ratio of LH to AWS was 60: 0, 40: 20, 20: 40 and 0: 60 in the respective diets, which were…
The effect of different levels of winter nutrition on the subsequent performance of Simmentaler weaner (seven-month-old) heifers on summer veld at different stocking rates was evaluated in the Highland Sourveld of Natal. The data from 300 heifers over a three-year…
Utilization of enriched barley and a wheat/barley mixture in feedlot rations for early weaned lambs. Whole barley and a wheat/barley mixture (67: 33) were enriched with either a locally composed supplement (containing urea and minerals absorbed into the grain, with…
Oat, barley or triticale grain, enriched by addition of nitrogen, minerals, and an ionophore, was fed for 90 days as supplement at a level of 500 g per head per day to SA Mutton Merino ewes during late pregnancy and…
Effect of nutrition and active immunization against androstenedione on reproduction of SA Mutton Merino ewes: Two groups of SA Mutton Merino ewes, consisting of forty ewes each, were used to determine the effect of nutritional level and immunization against…
There are at least 15 breeds of beef cattle in the United States which have or are in the process of developing national genetic evaluation programmes. These 15 breeds represent over 600000 new registrations each year. The commercial cattle industry…
