The study evaluated the integrated influences of red meat carcasses and product from red meat animals on price and supply of red meat carcasses. The purpose of the study was to assess the status of the South African red meat industry over five years and in comparison, to the status during the Apartheid era. The study resolved to establish in principle the relationships between the types of red meat carcasses (beef, mutton and lamb, and pork) on the purchase price (R/kg cold carcass mass) and carcass classes over a selected period, to establish in principle the relationships between the types of red meat carcasses (beef, mutton and lamb, and pork) on products from red meat animals (wool and hide) and to determine the effect of a red meat market on red meat producers. A great deal has changed since the Apartheid era with regards to red meat marketing and pricing. During the Apartheid era, the South African Livestock and Meat Industries Control Board (Meat Board) controlled the access of red meat to controlled areas and abattoirs. The system skewed the real picture of the supply, demand for and price of red meat. The last time a complete study of the South African red meat industry on supply and demand was completed by Du Toit in 1982, under the apartheid era. The study focused on external factors and not internal factors (carcass class) affecting supply and demand. There is no study on the effect of a specific red meat carcass class, according to the current South African red meat classification system, on price and supply of red meat carcasses. Market research has shown that there should be an interaction between the different types of red meat carcasses, meaning for example if the supply of beef were to increase, it could have an associated decrease on demand for pork meat. The supply and demand of the different red meat carcasses affect the price per kilogram of a particular red meat type. This study was designed to determine the effects of different meat carcass classes on each other concerning price, meat bought by the abattoirs and mass. The theory is that the different types of red meat carcasses would influence each other concerning price and number of carcasses bought by the abattoirs, the effect would be due to specific meat classes and not all the classes would be involved. It would be essential to know the effects of red meat production and price on the secondary and primary products from red meat animals. The concept is that there could be effects from some, but not all secondary and primary products from red meat animals. Data comprising 259 sets was obtained via the Red Meat Abattoirs Association (RMAA) for the period 2013 to 2017. The data was collected from abattoirs that voluntarily sent their information to the RMAA (RMAA, 2020). This data consisted of weekly data from the abattoirs on the number of carcasses bought, average mass, average purchase price, average selling price, and minimum and maximum selling price of each carcass class (pork, beef and sheep). The following variables were used for pork, sheep and beef carcasses: the number of carcasses bought, average purchase price and average mass per carcass price. The tonnage of meat was calculated by multiplying the average purchase price with the total number of carcasses bought for the specific red meat type. Data was analysed employing SAS® (Version 9.4). Linear regression analyses were used with a 95% confidence level. For each type of red meat carcass (pork, beef and sheep) and the average purchase price as compared to the tonnage of meat and the average purchase price of carcasses (R/kg) for pork, beef and sheep carcasses and carcass class. The influence of tonnage of pork, beef, lamb and mutton (sheep) per carcass class on the average purchase prices of pork, beef, mutton and lamb (sheep) respectively were analysed similarly. This process was followed in all the regression analyses for different explanatory variables. VI The third set of regression analysis addressed the relationship between each red meat carcasses average purchase price with red meat products (feedlot hide price, veldt hide price, SA wool price, US wool price, European wool price and Australian wool price). The data was sourced from Cape Wool SA and AWEX-EMI over the review period. The outcome of the study supported the hypothesis that carcass type and specific meat classes within carcass types were responsible for the differences in meat carcass prices. There was a differentiation in price between different meat classes, which affected the price of other classes, but some meat classes did not influence the dynamics of meat prices. The value in the analysis pointed directly to the classes that to a greater or lesser extent influenced price with an interactive effect between meat types. The analysis revealed that the influence observed was due to specific carcass classes and their specific factor (tonnage of meat, average mass, the average number of carcasses bought by abattoirs and average purchase price) and not all the carcass classes for price determination by buyers at the abattoir, processors and retailers as well as traders at the Johannesburg Stock Exchange (JSE), the different and combined influences of the different carcass classes on red meat price need to be considered. A great deal has changed since the Apartheid era and the study of Du Toit (1982). In order to offer producers optimal prices, all factors (including carcass classes and external factors) influencing red meat prices must be taken into consideration when determining the price. Currently, planning by red meat producers would not be influenced by the interactions of commodities and red meat, since their decision-making is not based on either carcass classes or the price of specific carcass classes. They base their decisions on the ratio between muscle and fat as well as the maximum profitability per animal based on input versus output cost. Producers are paid on a R/kg basis for carcasses and not according to the classification system. Negotiation of the price occurs before animals are brought to the abattoir according to contract or according to market information published by the JSE. Even though this study relates to the South Africa classification system, these principles apply to other countries and their specific classification or grading system. Further studies would be required to determine the combined effect on the price and supply, as well as on-demand about the internal factors and external factors affecting them. / Thesis (PHD (Animal Science))--University of Pretoria, 2020. / Animal and Wildlife Sciences / PHD (Animal Science) / Unrestricted

Collated data showed that the concentration range of bromide (Br-) in groundwater (GW) was between 0 – 132mg/L in selected provinces in South Africa where livestock production occurs. The no observed adverse effects level (NOAEL) of 0.01 mg/L was proposed and validated using the chicken embryo model. The objective was to investigate the effect of a range of 0 – 1 mg/L Br- on the pre-hatch growth and development of the chicken embryo to demonstrate the risk that Br- exposure may pose to livestock and humans residing in the regions where livestock production depends on GW as main drinking water source. The chicken embryo model was used to investigate the effects of Br- on the growth and development of the heart, liver and brain because the thyroid hormone (TH) receptors are similar to that in mammals and the effects on TH are independent of maternal TH fluctuations. A volume of 200 μL NaBr at concentrations of 0, 0.01, 0.05, 0.5 and 1 mg/L was administered by in ovo injection and the wet mass of the whole embryo and the heart, liver and brain were measured on embryonic day (ED) 14 and 20, and on hatch day (HD) using a sensitive balance. The relative organ mass for each organ was calculated as individual organ mass over whole embryo mass and expressed as a percentage. Crown-rump (CR) and shank length were measured on ED 14, 20 and HD using callipers. These were not found to be reliable measures of pre-hatch growth. Data were analysed using the GLM and REML procedures of SAS®. There was a significant treatment effect of Br- on the relative heart mass, with the relative mass decreasing with increasing concentrations of Br- (P ≤0.1). It appeared that Br- may have interfered with the pre-hatch growth of the heart. The null hypothesis that different concentrations of Br- do not have an effect on pre-hatch growth and development was rejected. The implication of this conclusion is that Br- concentrations present in GW in excess of 0.01 mg/L could potentially pose a risk to livestock and human populations that are chronically exposed to the element in their drinking water. / Thesis (PhD (Animal Science))--University of Pretoria, 2020. / Animal and Wildlife Sciences / PhD (Animal Science) / Unrestricted

The interactions between host and gut microbiota are a rapidly developing field with a plethora of implications. Recent developments in identification and quantification methods of gut microbes allow for a better understanding of said interactions. For the local broiler production industry, studying the microbiome of the gastrointestinal tract (GIT) is imperative to ensure ease of transitioning into an antibiotic-free feeding practice. Clostridium perfringens infections are a major burden for the global poultry industry and can lead to necrotic enteritis (NE). The economic losses induced by NE in the South African broiler industry are estimated to be $68.81 million per annum. In this trial, day-old Ross 308 broiler males were randomly placed in an environmentally controlled house and subjected to eight dietary treatments with 12 replicate pens each containing 23 birds. The antibiotic growth promoter (AGP), zinc bacitracin (ZB), was used as the positive control, and three additional feed additives were used either alone or in combination. The three feed additives are classified as a direct fed microbial (DFM), an essential oil mixture (EO), and finally a mixture of EOs and organic acids (OAs). To induce C. perfringens infection, birds received a coccidial vaccine (Immunocox, Ceva) of 10x the prescribed dosage at 10 days of age and were orally inoculated with a broth of C. perfringens at 14 days of age. Both ileal and caecal digesta samples were collected at 21 and 35 days of age. Bacterial 16S rRNA sequencing was performed on these samples using a customized chip containing 100 selected intestinal bacteria. Age had the most significant effect on microbial abundance in both the ileum and the caeca. The dominant bacterial phylum regardless of age was Firmicutes, followed by Bacteroidetes and Proteobacteria. The ileum samples showed that microbial diversity increased with age, whereas the caecal samples revealed a reduction in diversity in the older samples. For the 35-day samples, the DFM and EO treatments increased ileal Lactobacillus and Lachnospiraceae respectively when compared to the negative control (no additives). Increased Lactobacillus and Lachnospiraceae are beneficial for broiler health and production. No significant differences were observed between the positive control (AGP) and the other treatment groups except for the EO + AGP combination group. Further research on the microbiome of the chicken’s intestinal tract is necessary. / Dissertation (MSc)--University of Pretoria, 2019. / Cargill / Animal and Wildlife Sciences / MSc (Agric) / Unrestricted

Heat stress is a cause of great economic loss in poultry production throughout the world. Many methods have been researched to find a solution to alleviate the negative effects of heat stress. Methods include but are not limited to: adequate ventilation and facility orientation, the acclimation of birds to elevated temperatures, electrolyte and acid-base balance to maintain body fluid homeostasis, water management to aid in evaporative cooling, feed management by means of fasting and nutrition to ensure a balance diet during reduced intake and non-nutritive feed additives to improve performance. Previous research has shown that the inclusion of virginiamycin (VM) in poultry diets during periods of heat stress may improve growth rate, feed intake, feed conversion ratio, survivability and carcass weight. This was tested by conducting an experiment on 1408 male broilers. A randomised block design was used with 32 pens in each side of the house. Chicks were randomly assigned to four treatments with 16 replications, each containing 22 broilers. Data was statistically analysed as a randomised block design with the GLM model and mortality data by Chi-square. The broilers were subjected to a temperature profile which simulated a cyclic heat wave with high temperatures during the day and lower temperatures at night. From day 16 to 32, house temperature was gradually increased from 8:00-11:00 until the set maximum temperature of the profile was achieved and decreased at 18:00 to 24 °C. The control group received a diet without antibiotic growth promoters. The second group which was a positive control group received a diet with zinc bacitracin 15% (334 g/ton). The third group received a diet with VM (20 g/ton) in all feeding phases whilst the fourth group received VM (20 g/ton) in all feeding phases with exception of the post-finisher phase. Broiler performance, intestinal morphology and carcass and blood composition of birds were measured. The addition of VM to the feed of broilers subjected to heat stress had no significant (P<0.05) effect on body weight or carcass and blood composition. Mortality within the third and fourth group was significantly lower, both before and after the onset of high cyclic temperatures. Supplementation of VM could be beneficial to lower the mortality rate of birds subjected to heat stress. / Dissertation (MSc)--University of Pretoria, 2019. / Animal and Wildlife Sciences / Msc / Unrestricted

No description available.

No description available.

No description available.

For almost a century both toxic and beneficial qualities have been ascribed to fluorine. During this time emphasis has been placed on many aspects of fluoride metabolism by different groups of workers. Farm animals are exposed to dietary fluorine from small amounts in most natural feedstuffs, from their water supply, from rock phosphate used as a mineral supplement, and from foliage grown in the vicinity of certain industrial operations. [...]

Certain types of infertility found in various animal populations may be due to genetic causes. This type of lowered reproduction becomes increasingly important in the male as the use of artificial insemination extends to more species. The extensive use of affected males tends to increase the frequency of these deleterious alleles in a population and thus lower the rate of reproduction of the species. [...]

"It is not surprising that in their impatience to transform the animal populations under their control, experimenters and practical husbandmen, may have consciously or unconsciously tended to minimize the fact that they were pitting their short-term efforts against a phylogenetic history extending for many generations," Lerner (1954). [...]