The implications of the traditional breeding structure of Merino sheep are discussed. It is indicated that it is unacceptable that material from stud flocks have a greater genetic merit than animals from commercial flocks. A description of the scientific selection…
The object of this experiment was to find out whether ground supplements could be conveyed to the abomasa of sheep via the reticular grooves. If ruminal fermentation could be avoided in this way, suitable supplements would be more efficiently utilized…
The growth rate of medium-type pullets was manipulated by various quantitative and qualitative food restriction treatments in order to ascertain which of these methods produced the most satisfactory economic results. The results were based on food intake during the growing…
A total of 2 400 medium type pullets was used in an experiment to compare three methods of nutrient restriction from 2 to 20 weeks of age. The treatments consisted of the following: two quantitative food restriction treatments designed to…
In an experiment involving the feeding of different protein sources to one-week old chickens, no statistically significant differences occurred in the amino acid content of the chicken carcasses despite considerable differences in body mass changes as a result of the…
With the increasing shortages and costs of conventional protein-rich feedstuffs such as oilcakes and fish meal, and with the ever increasing cost of yellow maize, it was decided to investigate alternative protein and energy sources for use in cattle feedlot…
The purpose of this study was (1) to compare South African bred opaque-2 (or high lysine) maize with normal maize in pig diets that contain an equivalent sub-optimum protein percentage and (2) to determine the protein sparing effect of a…
The effect of progesterone synchronisation on the plasma progesterone and luteinizing hormone (LH) concentrations in sheep were studied. During their normal breeding season 10 Merino ewes were injected with l0 mg progesterone daily for 15 days to synchronise their oestrous…
The effect of underfeeding during autumn lactation, oestrogen priming and stage of the oestrous cycle on the release of LH in response to GnRH was studied in Merino ewes. The basal LH level prior to GnRH administration was not influenced…
The inheritance and interassociation of weaning traits of 1142 Afrikaner calves, the progeny of 27 sires, were studied over a period of 25 years. The estimates of heritability of the weaning traits were as follows: 0,184 ± 0.071 for birth…
A sensitive and reproducible double antibody radio-immunoassay for rat LH measurement, which requires at most 50 μl of serum or plasma per tube, is described for use with l25I and rabbit anti-rat LH serum. The assay has a sensitivity of…
The influence of medroxyprogresterone acetate impregnated intravaginal sponges and 300 IU pregnant mare serum (PMSG) , the latter injected at different times before sponge withdrawal, on the length of oestrus, the interval from sponge withdrawal to the commencement of oestrus…
Bulls and steers from Afrikaner and Friesland cattle fed ad lib. were slaughtered at different ages from birth to 24 months inclusive. Samples were taken from the M. semimembranosus and M. semitendinosus (dark and light) and histochemically treated with succinic…
Samples consisting of 1 262 and 2 291 pedigrees were employed in the analysis of the breed structure of the S.A. Mutton Merino for l961/62 and 1971/72 respectively. The breed structure was not stabilised in either analysis since the first…
The chemical composition of milk of Afrikaner cows kept under ranching conditions of feeding and management were determined. –The contents of non-casein and globulin nitrogen as well as phosphorus and calcium were statistically significantly influenced by age. Stage of lactation…
Poultry manure, potentially suitable as a ruminant f'eedstuff, was obtained from various sources Samples consisted of pure excreta from birds kept in batteries, broiler excreta on deep litter systems and pullet and breeder excreta on deep litter systems. Large variations…
