Ovarian activity was studied in 36 dry, Bos taurus cows fed to achieve different rates of body mass loss and gain in a 2 x 2 factorial experiment. Cows were fed hay to supply either 70% (Treatments 1, 2) or…
Urea-supplemented wheat straw (UWS) was substituted stepwise by urea-ammoniated wheat straw (AWS) in diets fed to SA Mutton Merino ewes during late pregnancy and lactation. The experimental animals were fed ad libitum under zero grazing conditions over the last 8…
Problems relating to the anticipation and elimination of poor production due to mineral deficiencies in grazing livestock will be examined in this paper. Its concern is with subclinical problems rather than catastrophic clinical problems. The ways in which hypothetical models…
The protein degradability of various South African ruminant feed protein sources was determined in the rumen of cannulated lactating dairy cattle. The effective protein degradability was calculated at different fractional outflow rates, using the nylon bag technique. The degradability values…
Although the protein requirement of domestic ruminants may be calculated from a simple one-compartment model, this approach ignores factors such as microbial fermentation in the rumen and the non-equality of feed proteins. By examining digestion in each of the functional…
Growth rate, average daily gain, feed conversion ratio, muscle pH, backfat thickness, dressing percentage, drip loss, cooking loss, water holding capacity, and shear force were measured in 47 South African Landrace gilts of which 30 were…
The effect of age and parity of Afrikaner and Hereford cows on the weaning traits of their calves. Data from a registered Hereford herd and a registered Afrikaner herd were used to investigate the influence…
Acacia tortilis twigs with leaves or seedpods, from the Tugela valley, were milled and fed to five two-tooth wethers for 6 days in separate digestion trials, after a suitable adaptation period. The twigs with leaves contained 10,8% CP…
A group of slow-growing Landrace and a group of fast-growing Large White boars were used to study their patterns of feed intake, growth rate and feed utilization. The pigs were fed ad libitum on a high-energy diet of a high…
The digestible energy (DE) content of milled and whole class FH sunflower seed (SS) was determined in a digestion trial and found to be respectively 18,7 and 9,9 MJ/kg on an air dry basis. Two diets for early weaned piglets…
Twelve non-lactating Boer goat does with live masses ranging between 20 and 60 kg and of different body fatness were used to develop equations predicting body moisture, protein, ash and fat from tritiated water space. Calculated coefficients of variation, with…
Two studies involving 270 yearling steers were conducted to compare four growth promotants (three estrogenic and one androgenic). These represented short, medium and long-acting compounds and were implanted into steers that were grazing natural pasture and were finished…
The relationship between the chemical composition of kikuyu and the dry matter intake (DMI), digestibility of the chemical fractions and digestible organic matter (DOM) of kikuyu was investigated. The chemical composition and in vivo digestibility of kikuyu were determined throughout…
Genetic parameters of weaning traits of Hereford calves. The inheritance and interassociation of weaning traits for 912 Hereford calves, the progeny of 22 sires, collected over a period of 11 years, were studied. The estimates of heritability of the…
The effect of a copper deficiency on certain aspects of reproduction in ewes was investigated. An effective copper deficiency was induced by using the copper antagonists cadmium, calcium and sulphate. An average decline in the plasma copper concentration from 160…
The influence of body parameters on the reproductive performance of Karakul ewes. The influence of body mass, condition and size on the reproduction of mature Karakul ewes was investigated during the seasonal anestrum and breeding periods. Variation in body mass…
Six male and 24 female Cherry Valley Pekin ducklings were randomly allocated to each of 12 pens to test the effects of quantitative feed restriction during the rearing period on the subsequent reproductive performance. The three treatments were 50% of…
The effect of supplementation on the milk production of Boer goat ewes maintained under veld conditions (grass-/bush community) was studied over a 12-week lactation period. An average of 625 g concentrates was consumed per ewe per day. Supplemented ewes produced…
The potential of chemically treated common reed (Phragmites australis) hay in maintenance diets for sheep. 1. The effect of NaOH treatment and ensilage with urea on intake, digestibility and rumen kinetics. Untreated, NaOH treated and urea ensiled common reed…
The potential of chemically treated common reed (Phragmites australis) hay in maintenance diets for sheep. 2. A comparison between NaOH treatment and ammoniation with or without molasses with respect to digestibility, intake and nitrogen retention. A digestibility experiment was conducted…
