Sixty-six grazing beef cows at Armoedsvlakte were supplemented per fistulam with different levels of phosphorus (P) from 1984 to 1989. Supplementation was provided according to a 3 x 2 factorial of three levels of P (Low, Medium and High), in…
Ewe productivity, as affected by varying wool production potential in different environments was studied in three woolled sheep flocks. Production and reproduction data collected in the Carnarvon Afrino Flock (AC) between 1979 and 1992, as well as data of the…
Data obtained from the INTERGIS for Jersey breeders participating in the NationalDairy Cattle Performance and Progeny Testing Scheme were analysed. The registered and grade records commenced in test year 1977 through 1992 (incomplete) and consisting of lactations between 240 and…
Milk samples from 237 Holstein-Friesian (HF) and 177 Simmentaler cows in six herds were typed for genetic variants of aS1-, b- and k-caseins (Cn) and b-lactoglobulin (-Lg) using ultrathin-layer polyacrylamide isoelectric focusing in the presence of carrier ampholytes (3-10 pH). The…
The aim of this research was to study the effect of high-maize diets and pelleting on the accumulation of lutein pigments and appearance of the subcutaneous fat in Dorper and SA Mutton Merino wethers. High and medium energy maize diets…
A study was conducted to examine the effect of using Henderson`s (1988) `average numerator relationship matrix` (ANRM) on the prediction error variance (PEV) of breeding values obtained using an animal model with maternal effects. Genetic trends with and without using…
The protein degradability of 13 South African ruminant feed protein sources were determined by the artificial fibre bag technique. Three sheep fed ad lib. on a basal diet of lucerne hay were used. Estimates obtained by two methods of calculation…
A straw (0.25 ml French) semen freezing method for ram spermato¬zoa using a temperature controlled stainless steel plate is described to possibly replace the conventional static liquid nitrogen vapour freezing method.
Genetic and environmental parameters were estimated for pre- and post-weaning average daily gain (ADG1, ADG2) and Kleiber ratio (KR1, KR2) using the ASREML program. Twelve models, formed with inclusion or exclusion of the maternal genetic, permanent environmental and common (litter)…
In an attempt to quantify the requirement for supplementary phosphorus (P) of grazing beef cattle at Armoedsvlakte (which is notorious for its P deficient pastures), 66 cows received supplementary P per fistulam from 1984 to 1989. Supplementation was provided according…
During the period 1984-1993 just over 1600 samples of agricultural commodities, comprising maize, compound animal feeds, oil seeds, soyabean, fishmeal and forage were examined for fungi and over 20 mycotoxins using a multi-screen augmented with individual assay. Aflatoxin had the…
The usefulness of acid detergent insoluble nitrogen (ADIN) to predict digestibility of rumen undegradable protein (UDP-D) of heat processed and unprocessed plant proteins was investigated. A series of drum roasted protein sources, sunflower, cottonseed and soybean oilcake meals, in addition…
Weaning weight records of 24 758 Bonsmara calves produced by 503 sires in 30 herds, from 1980 to 1993, were used to examine the importance of the inclusion of herd-year-season by sire interaction in the estimation of genetic parameters. Three…
The essential amino acid composition of carcasses from South African Mutton Merino ram lambs fed a standard diet was investigated. Twenty lambs were randomly allocated to four pre-assigned average slaughter weights (30, 35, 40 and 45 kg live weight). The…
The Kuri is a rare, little known breed of cattle of the Hamitic Longhorn (Bos Taurus longifrons) type which is found on the islands and shores of Lake Chad Basin in the area covering the common borders of Cameroon, Chad,…
The influence of the pre-ovulatory oestradiol-17ß (E2) surge on yield of viable embryos was studied in 28 oestrus synchronized SAMM ewes. Ewes were super ovulated either with FSHo (88 units in 6 divided doses) or PMSG (1200 IU). Blood samples for…
The effect of immunization against oestradiol-17â (E2) on fertilization rates and of human chorionic gonadotrophin (hCG) in reducing the proportion of unovulated follicles from super ovulated ewes was examined. Forty South African Mutton Merino ewes were divided into four treatments…
Spring-hatched broiler breeders housed in non-lightproof facilities are frequently maintained on long daylengths to prevent precocity, but controlled-feeding and delayed dissipation of photorefractoriness retard sexual maturation. Trials were conducted to determine the appropriate growth for birds maintained on 14-h photoperiods,…
