The purpose of this article is to review the development of breeding objectives in beef cattle breeding and the derivation of economic values. There seems to be general consensus that definition of breeding objectives should be the primary step in…
Impala (Aepyceros melampus) constitute one of the most commercially important species in game farming in South Africa. The purpose of this study was to compare the effects of day and night cropping on the meat quality characteristics of impala. Emphasis…
Thirty six Holstein bull calves were divided into six groups to determine the effect of protein degradability and rumen inert fat supplementation in starter and finishing diets on nutrient digestibility and veal production. Calves received low (LD) or high (HD)…
The purpose of the study was to evaluate the nutritive value of the forage legume species, Centrosema pascuorum, Lablab purpureus, Macroptilium bracteatum, Macroptilium gracile and Vigna oblongifolia as feed for ruminants in the Capricorn region of Limpopo Province, South Africa…
Oxygen (O2) consumption and carbon dioxide (CO2) excretion of ostrich embryos were studied on 45 ostrich eggs in various stages of development. A closed respirometry system was used for eggs subjected to < 10 days of incubation, while an open flow…
In an animal model evaluation of breeding values it is assumed that the base animals are all at the same genetic level. However, in the South African Holstein population, animals of different genetic levels were imported from foreign countries, thus…
The variation in, and often the disappointingly poor weight gains and the inability of lambs to achieve desirable carcass grades on ryegrass pastures have long been a concern to researchers, extension officers, advisors and farmers. The objectives of this study…
simulation study was carried out to compare the use of single and composite milk samples for the evaluation of milk composition in dairy cattle. The genetic correlation between the two sampling methods was estimated. Results showed a high genetic correlation…
The object of this study was to estimate heritabilities and sire breeding values for stayability and reproductive traits in a composite multibreed beef cattle herd using a threshold model. A GFCAT set of programmes was used to analyse reproductive data…
The object of this study was to estimate heritabilities and genetic correlations for reproductive traits in a composite multibreed beef cattle herd using multitrait analysis. A REML procedure fitting a multitrait animal model was used to analyse data. Heritabilities and…
The aim of this study was to evaluate the livestock production potential of Panicum maximum cv. Gatton cultivated under dry-land conditions and grazed at various stocking rates after various periods of re-growth. Treatments included a high stocking rate, fast rotation…
This study was conducted to assess the effect of greenleaf desmodium (Desmodium intortum) and sweet potato vine (Ipomoea batatus) supplementation of napier grass on dry matter intake, degradation and rumen fermentation in Friesian steers. Four fistulated steers were offered napier…
Experiment I was carried out with 220 one-day-old broiler chicks to evaluate the effect of 11 different levels of vitamin E supplementation (viz. 0 to 200 mg α-tocopheryl acetate/kg diet) on the production performance of broilers and oxidative stability of…
Genetic and phenotypic correlations were estimated between lamb and ewe traits in a flock of Sabi sheep reared at the Matopos Research Station. Direct additive estimates of heritability were: 0.28 ± 0.04; 0. 17 ± 0.00; 0.25 ± 0.01; 0.39…
Twenty Holstein-Friesian cows, two to four months postpartum, were randomly assigned to two groups. The control group received no monensin, whereas the treatment group received 300 mg monensin per cow per day. Cows grazed kikuyu pasture and received maize-based concentrates…
Three in vivo techniques were evaluated in terms of their suitability for determination of the apparent ileal amino acid digestibility (AID) of protein sources for piglets. The techniques were: ileo-rectal anastomosis (IRA), cannulation at the distal ileum and a slaughter…
The effect of night cropping (shooting the animal in the head with a light calibre rifle) on the pH45, pH24 and rate of pH decline in the M. longissimus thoracis of 10 Grey duikers was investigated. A mean pH45 of…
The yield, nutritional value and production potential of silage made from twenty one maize hybrids were compared. The digestibility of organic matter and predicted intake, mean retention time and milk production potential were found to differ between hybrids (p <…
Nineteen Holstein steers were randomly assigned to one of four treatments; no implant (CON); 36 mg zeranol (Ralgro) on d 0 and 20 mg estradiol benzoate plus 200 mg progesterone (Synovex S) on d 84 and 169 (RSS); Ralgro on…
Ewe lambs born to group pen-fed Karakul ewes in the summer (February), winter (June) or spring (October) respectively, were raised to study the influence of season of birth on the onset of sexual maturity. Lambs were exposed to fertile rams…
