A linear discriminant function (LDF) was used to estimate the level of milk progesterone which allowed the best overall classification of dairy cows into pregnant and non-pregnant groups (confirmed by rectal palpation). Progesterone levels were measured in milk samples drawn…
Two of the many factors which may affect the accuracy of pregnancy diagnosis using milk progesterone levels are day of sampling and number of samples taken per cow. These two aspects were analysed using information obtained from progesterone profiles encompassing…
The use of a mathematical programming model for determining optimal nutritional strategy for a dairy cow is described. Mixed Integer Programming (MIP) may be used to fit curvilinear functions, such as the changes in the nutrient requirements of the cow,…
The chemical composition and in vitro dry-matter digestibility (IVDMD) of manure collected from steers fed on a high-concentrate diet were investigated. The influence of the time interval between excretion and freeze drying of manure on its chemical composition and IVDMD…
The use of intravaginal progestagen sponges (MAP or FGA), 300 or 500 IV PMSG, and implementation of one or two inseminations following synchronization, were evaluated in 600 Merino ewes with a mean body mass of 30,6 kg, outside the normal…
Concentrations of plasma copper, plasma zinc and blood selenium in sheep, goats and cattle, grazing together on natural pastures, were determined at two- to three-monthly intervals over a two-year period. Cattle had the lowest plasma copper concentrations, but no definite…
The relationship between nitrogen and other components in kikuyu grass (Pennisetum clandestinum) from long-established pastures was investigated. Leaf material, when compared to stem tissue, was higher in total organic nitrogen and protein content, but lower in non-protein organic nitrogen, nitrate,…
Problem areas in the production of Cherax tenuimanus, a freshwater crayfish (the 'marron') introduced to South Africa from Australia , are outlined. The high juvenile mortality rate problem is discussed. With reference to the morphology of the mouthparts of the…
Milk progesterone levels were measured on a daily basis for 44 dairy cows from calving to conception in order to use the progesterone profiles in diagnosing and treating reproductive disorders related to the oestrous cycle. Some of the profiles could…
The effect of supplementing a diet of wheat straw plus urea with either 0, 100 or 200 g/d cottonseed oilcake meal .(CSM) in combination with either 0, 100 or 200 g/d whole maize on wool and carcass growth of SA…
The effect of selecting for growth, size and efficiency on fitness (fertility and survival rate) and body composition was investigated by surveying a number of selection experiments which have appeared in Animal Breeding Abstracts since 1938. In the case of…
Data of lambing records from 1984 to 1989, which comprised 914 ewe lambing years and 1522 lambing opportunities, were used to investigate overall productive performance of Dohne Merino ewes under an accelerated lambing system. Ewes were exposed to three fixed…
Afrikaner, Nguni and Pedi weaner bulls (15 per breed) were fed individually from initial masses of 168, 159 and 160 kg to predetermined target masses of 290, 340 and 390 kg respectively. Feed and water were freely available. The diet…
Textural evaluations were conducted on the longissimus thoracis muscles from carcasses of young Afrikaner, Nguni and Pedi bulls fed intensively and slaughtered at 160, 290, 340 and 390 kg. Carcasses were stimulated electrically (500 V, 12,5 Hz) for 2 min,…
Female Boer goat kids were randomly allocated (post weaning) to 2 X 3 factorial design experiments for two observation periods, to monitor puberty and the induction thereof. Treatments for each period (December and April weaning seasons respectively) included three male…
Effect of feed restriction in the early life of young Merino sheep on growth performance and wool characteristics. The effect of feed restriction on the relative performance of young Merino sheep was investigated. Lambs were separated from their mothers between…
The effect of starch fermentation in the rumen on the kinetics of roughage digestion, was studied using 12 sheep fed three roughages, viz. lucerne hay, maize cob leaves and wheat straw. The amount of starch infused per day was increased…
Digestibility or diets containing cottonseed and the effect or supplementary lanolin thereon in sheep. The apparent digestibility of nutrients in four diets (A, B, C and D) containing 0, 10, 15 and 20% whole cottonseed respectively, was determined in sheep…
This experiment was conducted to determine apparent and true amino acid digestibilities of untreated (BPS), heat-treated (HBPS) and thermal-ammoniated (NH3BPS) high-tannin sorghum with pigs both intact and with an ileo-rectal anastomosis (IRA). The mean endogenous protein secretion for the surgically…
An experiment was conducted to evaluate a hetero-yellow endosperm sorghum cultivar (G766W) in comparison to a low-tannin (GL) sorghum cultivar as well as maize in a growth trial using pigs. The digestible energy (DE) content of the experimental diets as…
