The effect of inbreeding on the 305-d yields of milk, fat and protein, and the percentages of fat and protein in the first three lactations was estimated using records on the South African Jersey cows that participated in the National…
This paper describes the responses of two genotypes of male broilers to constant 8- and 16-h photoperiods, and to an abrupt transfer from 8 to 16 h at 10, 15 or 20 d. Body weight, feed intake, and feed conversion…
Fully developed rigor mortis in muscle is characterised by maximum loss of extensibility. The course of post mortem changes in ostrich muscle was studied by following isometric tension, shortening and change in pH during the first 24 h post mortem…
A 2 x 2 factorial experimental design was used to evaluate effects of ovariectomy and implantation (200 mg trenbolone acetate and 28 mg estradiol benzoate; Synovex-Plus) on the performance, serum urea nitrogen, serum insulin like growth factor -1 (IGF-1), and…
The direct short-term impact of three rates of stocking (4, 8 and 16 Small Stock Units/ha) on arid Nama Karoo vegetation (shrub/grass) was quantified in terms of dung distribution and trampling. Grazing, by mature Merino wethers took place for one…
This trial was conducted to test the hypothesis that early lactation cows grazing ryegrass pasture and receiving maize and mineral supplementation could respond to additional supplementation with a protein source such as fish meal. Multiparous Jersey cows in early to…
Samples of kikuyu foggage (standing hay) were collected in northern KwaZulu-Natal from five adjoining paddocks to measure the changes in nutrient composition of the foggage as winter progressed. Leaves and stems were separated. The first samples collected on the 18th…
Longevity reflects the ability of a cow to avoid being culled for low production, low fertility or illness. Longevity can be used in breeding programmes if genetic parameters are known. Various measures are used for longevity. In this study survival…
Reproductive performance of experimental commercial Dalland sows (n = 87) maintained under a constant photoperiod (10 h light and 14 h darkness) and control sows (n = 187) maintained under natural daylight length (10.4 h light in winter and 13.4…
Twenty-four sets of full-sib ram lambs, each born from a different sire, were kept individually in pens and hand-reared from birth up to 50 kg live mass. Feed intake and mass of each lamb were determined every third day. Growth…
Records of the Elsenburg stud where the Dormer sheep breed originated in 1941, were analysed from 1941 to 1990 to investigate non-genetic factors contributing to early growth traits. The fixed effects, identified as having a significant (P < 0.01) effect…
Non-ammonia nitrogen (NAN) passage to the small intestine and disappearance of NAN in that organ have been studied in multi-cannulated sheep on pasture or fed indoors. Forages under investigation included a number of subtropical grasses, foggages and hay, temperate grasses,…
Effects of intratesticularly administered zinc tannate (ZT) on growth performance, sexual development, slaughter, carcass and meat quality characteristics of young bull calves (-225 kg, 7 months old) were investigated. Comparisons were made across a three (treatments: ZT animals, intact bulls…
The experiments reported in this series were designed to investigate the metabolism of lysine, leucine and methionine in lambs fed roughage diets supplemented with various levels of protein. and to compare these amino acids as tracers of whole-body protein metabolism…
A selection and line x environment interaction study with grade Afrikaner cattle was established in 1956 at Matopos Research Station, Zimbabwe. Two selection lines of 100 cows each were reared in different management environments. The non-supplemented (NS) line relied on…
A selection and line x environment interaction study with grade Afrikaner cattle was established in 1956 at the Matopos Research Station, Zimbabwe. Two selection lines of 100 cows each were reared in different management environments. The non-supplemented (NS) line relied…
In order to describe the response of broiler breeder hens to dietary amino acids and to develop an effective model for the precise feeding of these birds after sexual maturity, accurate estimates of the amounts of each amino acid required…
Genetic parameters were estimated for birth weight (BWT), weaning weight (WWT) and pre-weaning average daily gain (ADG) using Restricted Maximum Likelihood (REML) procedures. Four different animal models were fitted, differentiated by including or excluding maternal effects. The direct heritability estimates…
Two experiments were conducted to test whether young pigs are capable of discriminating against a feed based on its nutrient balance (or protein value) and/or the presence or absence of anti-nutritional factors and whether there is an order of preference…
