"Experientia docet" - Experience is the best teacher
The effect of shearing pregnant ewes prior to a winter-lambing season on ewe and lamb performance in the southern Cape (Short Co
About half of the 505 winter-lambing SA Mutton Merino ewes were shorn at four or fewer weeks prior to lambing at the Outeniqua Experimental farm near George in July-August 1991 and 1992. The remaining ewes, with a 6 – 7-month…
The performance of lambs on kikuyu as influenced by stocking rate and grazing system
Stocking rates of 20, 35 and 55 seven-month-old wethers/ha were used to determine the stocking rate/sheep performance relationship on kikuyu under continuous and rotational grazing, considering the stress placed on the animals by decreasing the availability of herbage with higher…
The effects of long-term variation in rainfall and dry matter production of veld on the financial position of a beef weaner ente
Four simulations (RANGEPACK Herd-Econ) of a beef weaner enterprise, each subjected for a period of 30 years to a different rhythm of the long-term variation in rainfall and simulated dry matter production (PUTU 11) of veld at Glen, were compared…
Blood, rib bone and rumen fluid as indicators of phosphorus status of grazing beef cows supplemented with different levels of ph
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…
Studies on small ruminant breeds with inherent differences in fibre production and ewe productivity 1. Relationship between ewe
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…
Genetic parameter estimates in the South African Jersey breed
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…
Effects of genetic variants in milk protein on yield and composition of milk from Holstein-Friesian and Simmentaler cows
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…
Dietary influences on lutein pigments and carcass fat quality in wethers of different maturity types
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…
An investigation into genetic evaluation using an animal model when paternity is uncertain
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…
Protein degradability of several South African feedstuffs by the artificial fibre bag technique
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…
Preliminary report on a novel straw semen freezing method for ram spermatozoa (Short Communication)
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.
Model comparisons and genetic and environmental parameter estimates of growth and the Kleiber ratio in Horro sheep
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)…
The effects of phosphorus supplementation on body mass and reproduction of grazing beef cows supplemented with different levels
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…
A note on the occurrence of mycotoxins in cereals and animal feedstuffs in Kwazulu Natal, South Africa 1984-1993 (Technical Note
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 use of acid detergent insoluble nitrogen to predict digestibility of rumen undegradable protein of heat processed plant prot
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…
The inclusion of herd-year-season by sire interaction in the estimation of genetic parameters in Bonsmara cattle
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…
