Animal Welfare Considerations in Food-Producing Animals

Animals play many important roles in humans’ lives. They are a source of food, companionship and wealth. Increasing global demand for food has resulted in the intensification of livestock production. Intensive production systems are aimed at maximising profits by rearing more animals on smaller pieces of land in order to produce more food. The other systems of animal production are semi-intensive and extensive production systems. Of the three systems, the semi-intensive system offers the best option for enhancing animal welfare in all species. Animal welfare can be defined in many ways depending on people’s views of animals. The underlying theme of animal welfare is to enhance physical and mental health of animals. Despite improvements in livestock farming techniques over the years, the welfare of farm animals remains a major concern. The major welfare concerns in the livestock industry relate to the rearing and management of dairy calves; the rearing of sows in gestation and farrowing crates; the housing of layer chickens in battery cages and the restriction of feed in broiler parent stock. Good animal husbandry is a basis for promoting the welfare of animals

Sero-prevalence of brucellosis in sheep and springbok (Antidorcas marsupialis) in the Karas Region of Namibia

Game farming developed in Namibia over the years as a result of constraints associated with livestock farming such as diseases and profitability. The development of this industry has brought livestock and game species into close contact. In the Karas Region, a major sheep producing area, sheep and springbok are reared together on commercial farms. The rearing of these species in close proximity may result in crosstransmission of zoonotic diseases such as brucellosis, enabling such diseases to enter the human population through meat and other livestock products. Game species may complicate the control of brucellosis by acting as reservoirs of infection after the disease has been controlled in sheep. Brucellosis due to B. melitensis has been reported in Namibia as a cause of reproductive failure in sheep. An outbreak of brucellosis occurred xvi in 2009 affecting sheep, goats and humans on a farm in the adjacent Hardap Region. Brucellosis outbreaks in sheep have the potential to disrupt Namibia’s foreign currency earning as the sheep industry contributes greatly to the economy of the country. This aim of the study was to estimate the prevalence of Brucella (B. melitensis, B. abortus, B. ovis).infections in sheep and springbok in the Karas Region and to find out if the outbreak of brucellosis which occurred in the Hardap Region in 2009 had spread to the Karas Region. Two experimental designs were used in this study. The first was a retrospective analysis of brucellosis testing results from 2008-2010 to indicate probable prevalence and to identify positive farms for follow-up sampling in sheep and springbok. Serological testing results of sera (n=22994) collected from 762 farms between 2008 and 2010 were analyzed and used to estimate apparent brucellosis prevalence. A total of 472 sheep sera and nine springbok sera were collected from eight farms that tested positive for Brucella antibodies between 2008 and 2010. The second part of the study was a prospective serological study in sheep and springbok reared together; sheep in the Tses and Berseba communal areas and in culled ewes at the regional abattoir. Sexually mature sheep and springbok were selected for the prospective serological study because they are more likely to show serological responses than younger animals. Prior to the serological study, eleven questionnaires were completed on the farms (n=11) that reared sheep and springbok together to gather information about farm management and risk factors for brucellosis. In the serological prevalence study, 332 sheep and 345 springbok sera were collected from the eleven commercial farms and 664 sheep sera were taken from the two communal areas. At the abattoir, 2302 sheep sera were collected from 40 farms in the region using the sample size for determining the absence or presence of disease. All sera were tested for Brucella (B. melitensis, B. abortus) antibodies using the RBT as a screening test and the CFT as a confirmatory test. B. ovis antibodies were tested for in sera from commercial farms only using the CFT test. Results from the retrospective study revealed an apparent sheep brucellosis prevalence of 0.14% (95% CI: 0.1%-0.2%) over the three years and an annual brucellosis prevalence of between 0.05% and 0.19%. At district level, apparent prevalence was between 0% and 0.49%. The prevalence of positive farms was between 0.72% and 1.82%. When apparent prevalence was adjusted for CFT sensitivity and specificity, the prevalence was zero in all cases, suggesting that the prevalence detected in this study may be due to false positive reactions. However, some of the positives serological reactions were from suspected brucellosis clinical cases which were also confirmed by the PCR test. At district level, brucellosis prevalence was shown to be rising in the Karasburg district and decreasing in the Keetmanshoop and Bethanie districts. However, statistical analysis of the data using Fisher’s exact test showed that the differences in brucellosis prevalence between districts was not significant, but that the differences in brucellosis prevalence between the three years was significant. All trace back sera collected in 2011 (using the sample sizes for proving disease freedom) from sheep (n=472) and springbok (n=9) on previously positive farms (n=8) identified by the retrospective study, tested negative for Brucella (B. melitensis, B. abortus, B. ovis) antibodies. The negative results provided strong evidence that brucellosis control measures implemented on the farms following the outbreak were effective and that these farms were now free of brucellosis. Results of questionnaire interviews showed that sheep and springbok were the main species on the farms and that the two species came into close proximity throughout the year especially at watering points in the summer. The interviews also revealed that the study population was naïve because farmers did not vaccinate sheep against brucellosis. All sera collected in the serological study on commercial farms (sheep and springbok), in the two communal areas (sheep) and at the abattoir (culled ewes) tested negative for Brucella antibodies (B. melitensis, B. abortus). The prevalence of B. ovis antibodies in rams on one farm was 10% (3/30). B. ovis antibodies were not detected in springbok. The role of springbok in the epidemiology of sheep brucellosis could not be inferred due to the negative results recorded in both species. Results of the retrospective and prospective serological studies confirmed that apparent brucellosis prevalence in sheep in the Karas Region was low. These results provided evidence that sheep and springbok reared together on the eleven commercial farms were not infected with Brucella. It was surprising that no positive reactors were found in sheep in the communal areas because the intermingling of sheep from different flocks enhances the spread of brucellosis. The absence of positive reactors at the abattoir confirms that the chances of contracting human brucellosis at the abattoir were low and confirms that the forty farms tested were free of Brucella infections.Dissertation (MMedVet)--University of Pretoria, 2013.Paraclinical Sciencesunrestricte

Retrospective analysis of the prevalence of Brucella antibodies in sheep in the Karas Region of Namibia

In this retrospective study, complete Brucella serology data from the annual national brucellosis testing program and disease investigation for the years 2008-2010 was collated and analyzed to estimate the prevalence of brucellosis in sheep in the Karas Region of Namibia. A total of 22994 serological results from 762 flocks screened using the Rose Bengal Test (RBT) and confirmed using the Complement Fixation Test (CFT) were analyzed. An overall prevalence of 0.14% was recorded over the three years. Yearly prevalence was 0.19% (2008), 0.05% (2009) and 0.18% (2010). At district level, brucellosis prevalence was estimated to be between 0% and 0.49%. On positive farms (n=32), prevalence was between 2.25% and 30%. True prevalence was zero at district level and in all the three study years. We concluded that the prevalence of Brucella antibodies in sheep was low taking into account that some farmers may have vaccinated against the disease. The low prevalence confirms the effectiveness of existing brucellosis control measures implemented by the official veterinary services.http://link.springer.com/journal/112502016-08-31hb201

Sero-prevalence of brucellosis among clinically suspect human cases presenting at health facilities in Namibia from 2012 to 2017

OBJECTIVE : This study estimated seroprevalence among human patients presenting with brucellosis-like symptoms in Namibia using serological test results from 2012-2017. METHODS : Presumptive cases were screened using a brucellosis commercial agglutination test kit. RESULTS : Apparent prevalence of human brucellosis was 11.64% (113/971, 95% CI: 9.77-13.81), while active infections were estimated at 6.90% (67/971, 95% CI: 5.47-8.67). Seropositive cases were clustered in the 30-40 year age group, and in females (64%) than males (36%) (z = -5.24, p < 0.01). Age (RR: 0.980 95% CI: 0.907-1.05) and gender (RR: 0.800, 95% CI: 0.598-1.069) were not risk factors for Brucella infection.http://www.elsevier.com/journals/biomedical-and-environmental-sciences/0895-3988hj2022Veterinary Tropical Disease

Assessment of knowledge, attitudes and practices relating to brucellosis among cattle farmers, meat handlers and medical professionals in Namibia

BACKGROUND : Brucellosis is a re-emerging zoonosis of significant socio-economic, animal and public health importance. It is principally a foodborne or occupation-associated infection of humans, whose effective control depends on maximum cooperation of high-risk populations. OBJECTIVES : The study assessed knowledge, attitudes and practices relating to brucellosis among cattle farmers (communal and commercial), meat handlers (abattoir and butchery workers) and medical professionals (nurses and doctors) in Namibia. METHODS : Between June 2019 and September 2020, self-administered questionnaires and questionnaire interviews were carried out in cattle farmers (n = 264), meat handlers (n = 143) and medical professionals (n = 124) in Namibia. RESULTS : Overall, 43.50% (231/531) of respondents were aware of brucellosis, with the highest awareness among medical professionals (73.39%, 91/124) and the least in meat handlers (13.99%, 20/143). Awareness of brucellosis was associated with tertiary education (p < 0.001) and the medical profession (p < 0.001). However, most medical professionals (98.39%, 122/124) did not consider brucellosis as a differential diagnosis in cases of persistent febrile illness. A proportion of communal (85.60%) and commercial (71.00%) farmers; abattoir workers (44.40%); butchers (53.50%); nurses (55.60%); and medical doctors (28.00%) consumed raw milk. CONCLUSIONS : The study identified the purchase of animals of unknown health status; assisting cow delivery; handling of aborted fetuses with no protective wear; consumption of raw milk, homemade cheese, cattle testes and undercooked livers, as risk factors for Brucella infection in cattle and humans. Thus, intensified risk communication, including public health education, is recommended, in particular, among meat handlers and communal farmers, to promote awareness and discourage risky practices.https://wileyonlinelibrary.com/journal/vms3hj2023Veterinary Tropical Disease

West Nile Virus Seroprevalence in a Selected Donkey Population of Namibia

West Nile Virus (WNV) is a mosquito-borne virus enzootically maintained in birds. However, it can incidentally infect other species, leading to sometimes severe clinical consequences like in horses and especially human beings. Despite the topic relevance, the presence and distribution of WNV are currently unknown in Namibia. Several countries implement surveillance systems based on virus detection in birds, mosquitoes, and vertebrate species including horses. The present study aimed to fill this knowledge gap by serologically evaluating WNV exposure in Namibian donkeys, whose population is remarkably bigger than the horse one. Forty-seven out of 260 sampled animals showed neutralizing antibodies against WNV (18.07% [95% CI = 13.59–23.30%]), demonstrating its circulation in all country territory, although, with apparent regional differences. On the contrary, no association with animal age or sex could be identified. The present study demonstrates the widespread presence of WNV in Namibia as well as the practical utility and effectiveness of donkeys as sentinels for infection surveillance. Due to clinical relevance, vaccination campaigns should be considered for horses of high economic or genetic value. Additionally, the burden of WNV infection on human health should be carefully evaluated

Serological prevalence and public health significance of brucellosis on a dairy farm in Namibia from 2011 to 2014

Abstract Objective The main objective of this study was to determine the serological prevalence of brucellosis on a dairy farm with no past history of abortions, but where Brucella control measures including test and slaughter and vaccination of heifers at 4–8 months of age was practiced. Secondary data from 2011 to 2014 obtained from the Epidemiology Section of the Directorate of Veterinary Services was used. Results Mandatory annual brucellosis testing results for mature dairy cows on a dairy farm for the period 2011–2014 were collated and analyzed. Results of a total of 6912 cows were analysed. The data comprised of the year of testing, number of cows tested for Brucella antibodies and the number of cows that tested positive. Serological testing was carried out using the Rose Bengal Test (RBT) as a screening test and the Complement Fixation Test as a confirmatory test for results that tested positive on the RBPT. Over the 4-year period, one dairy cow tested positive for Brucella antibodies in 2013 giving an apparent prevalence of 0.05% and an overall prevalence of 0.01%. When apparent prevalence was adjusted for RBPT test specificity and sensitivity of 71 and 78% respectively, true prevalence was determined to be zero

Assessment of knowledge, attitudes and practices relating to brucellosis among cattle farmers, meat handlers and medical professionals in Namibia

Abstract Background Brucellosis is a re‐emerging zoonosis of significant socio‐economic, animal and public health importance. It is principally a foodborne or occupation‐associated infection of humans, whose effective control depends on maximum cooperation of high‐risk populations. Objectives The study assessed knowledge, attitudes and practices relating to brucellosis among cattle farmers (communal and commercial), meat handlers (abattoir and butchery workers) and medical professionals (nurses and doctors) in Namibia. Methods Between June 2019 and September 2020, self‐administered questionnaires and questionnaire interviews were carried out in cattle farmers (n = 264), meat handlers (n = 143) and medical professionals (n = 124) in Namibia. Results Overall, 43.50% (231/531) of respondents were aware of brucellosis, with the highest awareness among medical professionals (73.39%, 91/124) and the least in meat handlers (13.99%, 20/143). Awareness of brucellosis was associated with tertiary education (p < 0.001) and the medical profession (p < 0.001). However, most medical professionals (98.39%, 122/124) did not consider brucellosis as a differential diagnosis in cases of persistent febrile illness. A proportion of communal (85.60%) and commercial (71.00%) farmers; abattoir workers (44.40%); butchers (53.50%); nurses (55.60%); and medical doctors (28.00%) consumed raw milk. Conclusions The study identified the purchase of animals of unknown health status; assisting cow delivery; handling of aborted fetuses with no protective wear; consumption of raw milk, homemade cheese, cattle testes and undercooked livers, as risk factors for Brucella infection in cattle and humans. Thus, intensified risk communication, including public health education, is recommended, in particular, among meat handlers and communal farmers, to promote awareness and discourage risky practices

Cadmium and Lead concentration in Fish

Cadmium and lead concentrations in fresh water fish (tigerfish, catfish and three-spotted tilapia). Fish lengths and weights are given