The effect of different levels and combinations of Ca and P consisting of nine treatments as CaoPo, Car, Pr, ~, Pd, (CaP)r, CadPr, (CaP)d and CarPd were investigated with an unrestricted semi-purified diet (r= to the rumen; d = to…
Twenty-eight Friesland bull calves, four days of age, were allotted to four groups and were offered milk diets which supplied 147 g to 444 g butterfat per calf per day for 21 days. Mean daily ME intakes increased from 10,6…
A comparative study on voluntary feed intake during different months of the year under natural grazing conditions, was conducted with three sheep breeds namely, the Merino, S. Afr. Mutton Merino and Dorper. The selective grazing behaviour of the Merino and…
Protein sources in the diets of growing pigs. 1. A comparison between fish meal and heated full-fat soyabean mealTwo trials, one with porkers and one with baconers were conducted to determine the influence of heated full-fat soyabean meal as protein…
Approximately 50% of Rhodesia is covered by veld types of which Heteropogon contortus constitutes a significant proportion of the grazing. If' sheep other than the smooth coated indigenous types are introduced in these areas, the seeds of H. contortus. through…
The plasma LH level of ewes which did not exhibit oestrus during lactation was not significantly different from the inter-oestrus level of ewes showing regular oestrus. The LH level in the plasma of ewes kept isolated from rams was significantly…
Blood levels of luteinizing hormone (LH) were measured, using a radioimmunoassay, during the oestrous cycle and during the postpartum period in 14 Brangus and 5 Friesland cows. Except during pre-ovulatory surges, basal blood levels of LH ranged between 0,2 and…
The possibility that the pineal exerts a regulatory influence on the gonadotrophic function of the adenohypophysis was investigated using in vitro techniques. Additionally, since a direct negative feedback of pituitary LH onto the hypothalamus occurred when adenohypophysial and hypothalamic tissues…
The oestrous cycles of cows and/or heifers were synchronized in six herds by the intramuscular administration of progesterone. In order to exclude those cows that were in the latter third of their cycles at the onset of treatment, the herds…
Ewes with single lambs received either sufficient feed to maintain body condition during lactation (high plane) or the quantity of feed was reduced so as to result in an average loss of approximately 20% in body mass (low plane). The…
Two comparable groups of three- to four-year-old Dorper-type ewes were fed a protein-rich supplement in addition to veld grazing to make either small mass gains (6,56%) or substantial mass gains (14,45%) during the gestation period. The quantitative milk production was…
This study was concerned with the cellular growth of muscle tissue in rats during the early stages of recovery from undernutrition. Groups of animals were undernourished either pre- or post-weaning and realimentated on either unrestricted intakes or on a restricted…
The efficiencies of small (<420 kg), medium (455 - 490 kg) and large (>525 kg) size grade Africander cows were compared for reproductive performance of cow, survival rates, growth of progeny and overall profitability. Cow efficiency index (C.E.I.) calculated by…
A technique is described which allows automatic collection of jugular venous blood from tethered cows. In this system, blood is pumped continuously from an intravenous cannula which has a double lumen while an anticoagulant is pumped through the second opening…
Opaque -2 maize gave significantly better nett protein utilisation (NPU) values than normal maize varieties in trials performed with rats and chickens. Altogether seven varieties of maize were tested of which three carried the opaque -2 gene and these proved…
The vitamin a-status of cattle at Elsenburg The B-carotene concentrations in feeds and feed mixtures used for calf- and heifer feeding were determined and a survey of the B-carotene and vitamin A concentrations in the plasma and livers of calves…
The effect of nitrogen fertilization on the yield and feeding value of Eragrostis curvula hay: Twenty-eight fistulated Merino wethers were used to investigate the feeding value of fertilized E. curvula. The different grasses were grown after fertilization with nitrogen varying…
A comparative study on the voluntary feed intake of lactating and dry cows under natural grazing conditions was undertaken with two breeds the Simmenthaler and the Africander. The trial was carried out over a 6 month period from November 1971…
Dairy animals received silage made from pineapple plants as their only source of roughage for a prolonged period. Results indicated that this reduced both milk yield and live mass and resulted in abnormalities such as rough hair coat and pica…
Eighty Dohne Merino lambs were divided into 4 groups to investigate the effect of different succulent feeds and concentrates given to ewes and lambs on veld grazing. From the time of lambing ewes received the following supplementary rations per head…
