Have falling tariffs raised wage inequality in South Africa?

Includes bibliographical references.This paper comments on a possible relationship between wage inequality and trade liberalisation in South Africa. Several unique contributions are made here: first, the above-mentioned relationship is tested using mandated-wage regressions that were based on the zero-profit condition; second, the impact of falling tariffs on factor returns is analysed directly; and third, the indirect impact of trade liberalisation on factor returns, through its effect on technology, is examined

The effect of slaughter weight on pig production efficiency

(South African J of Animal Science, 2000, 30, Supplement 1: 115-117

Effect of selection for lean growth on gonadal development of commercial pig genotypes in South Africa

A primary objective of commercial pig production is lean meat yield in order to satisfy consumer needs. The majority of the commercial pig breeds in South Africa have been selected for high lean growth potential and reduced backfat thickness. There are indications that selection for high lean meat yield may affect the gonadal development and possibly reproductive potential of commercial pig genotypes, because both testicular and ovarian growth appear to be important indicators of reproductive performance in boars and gilts, respectively. The effects of selection for lean growth on gonadal development were studied in five South African commercial pig genotypes (1, 2, 3, 4 and 5) from 116 to 214 days of age. Gonadal growth and development were measured and compared in 112 gilts and 112 boars. Differences between means were tested using genotype and age as fixed effects, while the relationships between gonadal parameters were evaluated by means of correlation analysis. Gilts from genotype 1 had a significantly shorter ovary length than those from genotypes 2 and 3. Gilts from genotype 3 also had heavier ovaries and larger ovary volumes than gilts from genotype 1. However, genotype did not influence ovary width or height. Correlations between P2 backfat thickness and gonadal development were generally poor in gilts. In boars, genotype 3 had significantly heavier testes than boars from genotype 1. Testes volume of genotype 1 also tended to be smaller compared to genotype 3. Correlations between gonadal measurements and P2 backfat thickness of boars were positive and moderately high (0.560 ≤ r ≤ 0.587). It is concluded from the study that there are differences between commercial pig genotypes in terms of gonadal development. These results suggest that selecting against backfat thickness may delay gonadal development and sexual maturation in boars, while the results are not conclusive in sows. Keywords: Pig; growth; backfat thickness; gonadal development; reproduction South African Journal of Animal Science Vol. 36 (5) 2006: pp.26-2

The effects of dietary soyabean oil-cake meal on performance and gut histology of piglets

The effects of four diets containing different protein sources on the performance and gut histology of piglets were compared. The diets contained as the main protein sources either: milk powder plus fishmeal, milk powder plus high-protein (48% crude protein) soyabean oil-cake meal, fishmeal plus high-protein soyabean oil-cake meal or high-protein soyabean oil-cake meal alone. No differences (p > 0.05) were observed between treatments for average daily gain, feed conversion ratio, intake or intestinal villus height. It was concluded that high-protein soyabean oil-cake meal can be utilised successfully in diets for weaner pigs either in combination with other protein sources or as main protein source without detrimental effects on production parameters or gut histology. These results apply to diets are formulated on the basis of digestible amino acids using soyabean oil-cake meal has been correctly processed. (South African Journal of Animal Science: 2000, 30(1): 62-66

Identification of Coliphages in the Aviary at Brookgreen Gardens and the Factors that Might Influence Coliphage Population Dynamics in this Cypress Swamp Environment

It has been understood that the presence of coliphages (bacteriophages specific for E. coli) in water is an indirect measurement of fecal contamination. Bacteriophages have been suggested to hold an important role in regulating the bacterial population. This pilot study analyzes the relationship between the presence of coliphages in the water in the aviary at Brookgreen Gardens and how environmental factors such as temperature, pH, and turbidity affect the presence of these viruses over the time period of three months (June 2017 through August 2017). Coliphages found in volary water sources were speculated to be deposited directly by birds that live in the Brookgreen Gardens aviary. These birds remain in an enclosed area, thus making the location a reservoir potentially rich in bacteriophage number and diversity. Plaque assays were conducted to look for the presence of the coliphages. Polymerase chain reaction (PCR) analysis was conducted on all samples collected in order to characterize any possible coliphages identified via plaque assays. The results gathered from both microbial (plaque assay) and molecular (PCR) methods varied immensely, with numerous positive results found at each site for each week of analysis over the three-month period. All PCR tests conducted on samples were deemed negative for coliphage presence, indicating that these coliphages are especially unique or may be RNA-based. These findings confirm that there are indeed bacteriophages present in the Brookgreen Gardens aviary, and that pH, turbidity, and temperature did not appear to play a prominent role in the presence of the coliphages. The location in the aviary which yielded the most positive results (Site 1) was the site at which the birds were most frequently observed defecating, providing indirect evidence that the fecal matter of the birds is the most important factor in bacteriophage presence

Moving beyond a limited follow-up in cost-effectiveness analyses of behavioral interventions

Background Cost-effectiveness analyses of behavioral interventions typically use a dichotomous outcome criterion. However, achieving behavioral change is a complex process involving several steps towards a change in behavior. Delayed effects may occur after an intervention period ends, which can lead to underestimation of these interventions. To account for such delayed effects, intermediate outcomes of behavioral change may be used in cost-effectiveness analyses. The aim of this study is to model cognitive parameters of behavioral change into a cost-effectiveness model of a behavioral intervention. Methods The cost-effectiveness analysis (CEA) of an existing dataset from an RCT in which an high-intensity smoking cessation intervention was compared with a medium-intensity intervention, was re-analyzed by modeling the stages of change of the Transtheoretical Model of behavioral change. Probabilities were obtained from the dataset and literature and a sensitivity analysis was performed. Results In the original CEA over the first 12 months, the high-intensity intervention dominated in approximately 58% of the cases. After modeling the cognitive parameters to a future 2nd year of follow-up, this was the case in approximately 79%. Conclusion This study showed that modeling of future behavioral change in CEA of a behavioral intervention further strengthened the results of the standard CEA. Ultimately, modeling future behavioral change could have important consequences for health policy development in general and the adoption of behavioral interventions in particular

The effect of protein inclusion level in diets formulated to contain an ideal amino acid composition for growing pigs

The aim of the study was to determine the optimum protein inclusion level in diets containing an ideal amino acid balance for growing pigs. The performance of commercial crossbred grower-pigs was studied in two trials in which the experimental animals were housed either in commercial-type group housing (experiment1) or in individual pens (experiment 2). Treatments consisted of diets containing 14%, 16%, 18% or 20% crude protein. Lysine, tryptophan, threonine and total sulphur-containing amino acids were included in all diets at levels equivalent to that supplied by the 18% crude protein diet. In experiment one, 144 pigs (72 boars and 72 gilts) of initial mass 30 kg were fed until slaughter at 70 kg. In experiment two, 80 pigs (40 boars and 40 gilts) of live masses ranging from 17.5 to 31.1 kg were fed until slaughter at masses between 64 and 105.5 kg. There were no differences between treatments (p > 0,05) for daily gain, feed conversion ratio, daily intake or carcass classification, but feed conversion ratio differed between sexes in experiment two (p < 0.05). It was concluded that protein inclusion levels in pig growth diets could be decreased from 18% to 14% without any detrimental effect on performance, provided that the digestible essential amino acid composition is adjusted to meet requirements. This practice is however not economically viable for South African pig producers at the prevailing price of synthetic amino acids. (South African Journal of Animal Science: 2000, 30(1): 57-61

Investigating the Lytic Staphylococcus aureus Bacteriophage Reservoir Amongst a South Carolina University Population: Discovery, Characterization, and Identification of a Potential Bacteriophage Treatment for Methicillin-Resistant Staphylococcus aureus

Bacteriophages are viruses that only infect bacterial cells and can be used to treat antibiotic resistant bacterial infections. This study focused on the isolation and characterization of bacteriophages lytic to Staphylococcus aureus at Coastal Carolina University (CCU) in Conway, South Carolina, as a means to isolate bacteriophages that can potentially be used to treat methicillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant S. aureus variant. From 2014 to 2018, collection of ear and nose samples from 225 randomly selected CCU volunteers was conducted. Filter sterilization, amplification, microbial tests, and PCR analyses were performed in order to identify and characterize bacteriophages. Coliphage populations were also monitored as an indicator of temporal competition and fecal contamination. A pilot study was initiated in 2017 in which 15 CCU volunteers were sampled once a month from October 2017 through March 2018 in order to investigate coliphage and S. aureus phage population dynamics. The purpose of this study was to gain insight into the lytic Staphylococcus aureus phage repository found in the CCU community, and to explore S. aureus phage dynamics amongst the CCU populace. Results indicated that a considerable S. aureus and E. coli phage reservoir exists amongst the CCU population. Most phages could not be characterized via PCR analysis, suggesting high diversity. The preliminary study indicated that S. aureus and E. coli hosts potentially exhibit temporal competition, of which might be explanatory of phage population fluctuations