Effects of stocking density on growth and skin quality of grower Nile crocodiles (Crocodylus niloticus)

Intensive Nile crocodile (Crocodylus niloticus) farming operates with considerable variation in housing and stocking density. In this study, current commercial stocking densities for crocodilians were investigated using 261 grower-phase crocodiles (15 months old, average total body length 94.5 cm, and average weight 2.7 kg). Low (2.60 m2 per crocodile), medium (1.24 m2 per crocodile), and high (0.41 m2 per crocodile) stocking densities were tested. Growth, morphometric measures, Fulton’s condition scores and skin qualities were assessed over a six-month (May - November 2017) period. High stocking density had no adverse effects on the growth of grower Nile crocodiles. Crocodiles stocked at medium and high densities outperformed those that were stocked at low density in Fulton’s body condition scores, change in body condition from the start to the end of the trial, and feed conversion efficiencies. However, the high and, to a lesser extent, the medium stocking densities resulted in lower skin quality scores compared with those in the low-density treatment because of teeth marks from more aggressive behaviour. The results indicated that the medium pen density treatment is closer to the ideal than either the high or low stocking density groups. Stocking densities that provide 0.41 m2 per crocodile or less should be avoided because of lower skin quality scores, which weigh more heavily than growth and feed efficiency responses in the financial viability of commercial crocodile farming in typical South African production systems

Orbit spaces of free involutions on the product of two projective spaces

Let $X$ be a finitistic space having the mod 2 cohomology algebra of the product of two projective spaces. We study free involutions on $X$ and determine the possible mod 2 cohomology algebra of orbit space of any free involution, using the Leray spectral sequence associated to the Borel fibration $X \hookrightarrow X_{\mathbb{Z}_2} \longrightarrow B_{\mathbb{Z}_2}$. We also give an application of our result to show that if $X$ has the mod 2 cohomology algebra of the product of two real projective spaces (respectively complex projective spaces), then there does not exist any $\mathbb{Z}_2$-equivariant map from $\mathbb{S}^k \to X$ for $k \geq 2$ (respectively $k \geq 3$), where $\mathbb{S}^k$ is equipped with the antipodal involution.Comment: 14 pages, to appear in Results in Mathematic

The pharmacology of halogenated salicylanilides and their anthelmintic use in animals : review article

The halogenated salicylanilides are a large group of compounds developed mainly for their antiparasitic activity in animals. Several halogenated salicylanilides with potent antiparasitic activity have been synthesised of which only closantel, niclosamide, oxyclozanide, rafoxanide and resorantel are commercially available. Closantel and rafoxanide, which represent the most important drugs in the group, are used extensively for the control of Haemonchus spp. and Fasciola spp. infestations in sheep and cattle and Oestrus ovis in sheep in many parts of the world. Niclosamide is used extensively for its anticestodal activity in a wide range of animals. Antiparasitic activity of the halogenated salicylanilides has also been demonstrated against a large number of other internal parasites, in particular haematophagous helminths, and external parasites including ticks and mites, in a variety of animal species. Several cases of toxicity and mortality have been reported for closantel and rafoxanide in sheep and goats. Their unique pharmacokinetic behaviour appears to play an important role in the efficacy and safety of these compounds. The chemical and physical characteristics, mode of action, pharmacokinetics, antiparasitic activity and toxicity of the halogenated salicylanilides in animals are reviewed

Veterinary education in Africa : current and future perspectives : animal health management in the 21st century

Veterinary education commenced in South Africa in 1920 at the Onderstepoort Veterinary Institute in South Africa in association with the Transvaal University College, now the University of Pretoria. Sir Arnold Theiler, Director of Veterinary Research and Education, was the first Dean. Today there are 46 veterinary training institutions in Africa of which 21 are in sub-Saharan Africa.Veterinary services are indispensable to the sustained health and wellbeing of animals and humans, and agricultural economies of countries worldwide. Veterinary education, postgraduate training, and research, and adequate numbers of veterinarians, are essential to satisfy the millennium development goals, the objectives of NEPAD and the African Union, and the agreements regulating international trade

Supply of veterinary medicinal products to an emerging farming community in the North West Province of South Africa

A study was conducted in the Madikwe District of the North West Province to investigate the supply of veterinary medicinal products to small-scale, subsistence and emerging farmers. A combination of individual interviews, focus groups and direct observation was used to collect data. Stock remedies were made available to farmers within the district at Field Service Units that were managed by administrative staff of the Directorate of Field Services. The state veterinarian and animal health technicians were not directly involved with the sale of products. Most farmers still travelled to farmers' cooperatives in the larger centres outside the district to purchase the veterinary medicinal products they needed. Factors such as the quality of service provided, affordability and availability of required products as well as inaccessibility of outlets to all farmers contributed to the poor support of these outlets by the farmers of the district

A bioequivalence and pharmacokinetic evaluation of two commercial diminazene aceturate formulations administered intramuscularly to cattle

The bioequivalence of the diminazene formulation Veriben (Centaur) was determined in cattle (n = 10) by means of a single-dose, randomized cross-over experiment. The results of nine statistical procedures\ud commonly used for bioequivalence evaluation are discussed. Veriben was found to be equivalent to Berenil (Hoechst) with respect to the area under the plasma concentration versus time curve, but not in terms of the maximum plasma drug concentration and the time to maximum plasma drug concentration. Pharmacokinetic parameters were calculated in which bioequivalence data (n = 10) together with data from an additional four cattle were used. A two-compartment model best described the pharmacokinetic behaviour of diminazene in cattle. Peak concentrations of diminazene (3,24 ± 0,16 flg/m~) were reached 49,8 (± 7,6) min after intramuscular injection of 3,5 mg/kg drug, with absorption proceeding rapidly (t'lha = 1,93 ± 0,95 h). Diminazene was slowly eliminated (t'lhJl = 222 h), resulting in a mean residence time of 13,27 d. The safe interval necessary between successive treatments of diminazene or before live babesia vaccines should be administered, and a recommended pre-slaughter withdrawal period are also discussed

Towards the establishment and standardization of a veterinary antimicrobial resistance surveillance and monitoring programme in South Africa

The objective of this study was to establish a repeatable, standardized laboratory procedure for monitoring the development of antimicrobial resistance in bacteria isolated from animals and food of animal origin in South Africa, with reagents prepared in-house. The emergence of resistance and the spread of resistant bacteria can be limited by implementing a veterinary antimicrobial drug policy, in which inter alia systematic monitoring and prudent use play essential roles. The bacteria included in this study represented three different categories, namely zoonotic bacteria (Salmonella), indicator bacteria (Escherichia coli, Enterococcus faecalis and Enterococcus faecium) and veterinary pathogens (Mannheimia haemolytica). Thirty isolates of each species were collected with the aim of standardizing the laboratory methodology for a future national veterinary surveillance and monitoring programme. Susceptibility to ten selected antimicrobial drugs was determined by means of minimum inhibitory concentrations (MICs) using the microdilution method. The method according to the National Committee for Clinical Laboratory Standards was used as the standard. Multi-well plates containing varying dilutions of antimicrobial drugs and prepared in-house for MIC determinations, yielded repeatable results. Storage of plates for 2 months at -70 oC did not influence results meaningfully. Within this limited sample of bacteria, MIC results did not indicate meaningful resistance against any of the ten selected antimicrobial drugs. The findings of the study will be used to establish a national veterinary antimicrobial resistance surveillance and monitoring programme in South Africa. To allow for international comparison of data, harmonisation of the surveillance and monitoring programme in accordance with global trends is encouraged. Ideally it should be combined with a programme monitoring the quantities of antimicrobial drugs used. The aim is to contribute to slowing down the emergence of resistance and the problems associated with this phenomenon by means of the rational use of antimicrobial drugs

Use of ethnoveterinary medicinal plants in cattle by Setswana-speaking people in the Madikwe area of the North West Province of South Africa

Rapid Rural Appraisal (RRA) methods were employed to document the use of ethnoveterinary medicinal plants in cattle by Setswana-speaking people in the Madikwe area of the North West Province of South Africa. The study indicated that Setswana-speaking people in the North West Province have a rich heritage of ethnoveterinary knowledge, which includes all aspects of ethnoveterinary medicinal plant use. Information was gathered from informants through individual interviews, group interviews, guided field walks and observations. Ethnoveterinary uses in cattle of 45 plant species representing 24 families were recorded. Plants were used in 84 % of the total number of recorded ethnoveterinary remedies. These plants were used alone (64 %) or in mixtures (36 %) for 29 indications. The most important indications were retained placenta, diarrhoea, gallsickness, fractures, eye inflammation, general ailments, fertility enhancement, general gastrointestinal problems, heartwater, internal parasites, coughing, redwater and reduction of tick burden. Plant materials were prepared in various ways including infusion, decoction, ground fresh material, sap expressed from fresh material, charred and dried. The most common dosage formwas a liquid for oral dosing. Other dosage forms included drops, licks, ointments, lotions and powders. Liquid remedies for oral dosing were always administered using a bottle. Medicinal plant material was preferably stored in a dried form in a cool place out of direct sunlight and wind. Lack of transfer of ethnoveterinary knowledge to younger generations puts this knowledge at risk. RRA was found to be a successful method of investigation for the study of ethnoveterinary medicine