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The involvement of the hypothalamo-pituitary-adrenocortical axis in stress physiology and its significance in the assessment of animal welfare in cattle
2017
Brown, Emma J.(University of KwaZulu-Natal School of Life Sciences) | Vosloo, Andre(University of KwaZulu-Natal School of Life Sciences)
The intensification of cattle production has raised concern for animal welfare due to the stress that is associated with farming practices. The welfare of an animal is determined by the animal's ability to cope with or adapt to its continuously changing environment and the biological cost that is associated with this adaptation and maintenance. Stressors arise from various psychological, physiological and physical aspects of farming practices due to management and human-cattle interactions. Measuring the activity of the hypothalamo-pituitary-adrenocortical (HPA) axis with plasma cortisol levels is a useful method for determining the effects of stress on animals as it is stimulated at the onset of a perceived stress. The activation of the HPA axis affects various target tissues or systems and can result in suppression of the immune system, increased susceptibility to disease and adverse effects on reproductive success in prenatal and neonatal calves. Although some levels of stress associated with farming practices are unavoidable, improvements in farming methods need to be implemented in order to maintain or increase the efficiency of cattle production in a way that does not compromise the welfare of the animal.
Show more [+] Less [-]Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains
2017
Gitonga, Purity K.(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Ndung'u, Kariuki(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Murilla, Grace A.(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Thande, Paul C.(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Wamwiri, Florence N.(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Auma, Joanna E.(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Ngae, Geoffrey N.(Kenya Food Crop Research Institute) | Kibugu, James K.(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Kurgat, Richard(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute) | Thuita, John K.(Kenya Agricultural and Livestock Research Organization Biotechnology Research Institute)
African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.). In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6). We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP) periods were 8.4 ± 0.9 (range, 4-11) and 4.5 ± 0.2 (range, 4-6) for T. congolense and T. brucei isolates, respectively (p < 0.01). Despite the longer mean PP, T. congolense-infected mice exhibited a significantly (p < 0.05) shorter survival time than T. brucei-infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection-causing T. congolense EATRO 1829 and chronic infection-causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.
Show more [+] Less [-]The sero-prevalence and sero-incidence of African horse sickness and equine encephalosis in selected horse and donkey populations in Zimbabwe
2017
Gordon, Stuart J.G.(Massey University Institute of Veterinary, Animal and Biomedical Sciences) | Bolwell, Charlotte(Massey University Institute of Veterinary, Animal and Biomedical Sciences) | Rogers, Chris W.(Massey University Institute of Veterinary, Animal and Biomedical Sciences) | Musuka, Godfrey(Columbia University Mailman School of Public Health International Center for AIDS Care and Treatment Programs) | Kelly, Patrick(Ross University School of Veterinary Medicine) | Guthrie, Alan(University of Pretoria Faculty of Veterinary Science Equine Research Centre) | Mellor, Philip S.(The Pirbright Institute International Research Centre) | Hamblin, Christopher(The Pirbright Institute International Research Centre)
Sentinel herds and samples submitted by private equine practitioners were used to determine the sero-prevalence and sero-incidence of African horse sickness virus (AHSV) and equine encephalosis virus (EEV) in horse and donkey populations in the Highveld region of Zimbabwe. The sero-prevalence and sero-incidence of antibodies against these viruses were determined using the competitive enzyme-linked immunosorbent assay (ELISA) for the detection of serum antibodies. In donkeys, the median sero-prevalence of AHSV antibodies, across the three rainy seasons under study, was 75% (inter quartile range [IQR] 67-83), with a seasonal median sero-incidence of 45% (IQR 40-63). In horses, the median sero-prevalence of EEV antibodies was 63% (IQR 21-73), with a median seasonal sero-incidence of 10.5% (IQR 10-14), while in donkeys the median sero-prevalence of EEV antibodies was 80% (IQR 67-90), with a median seasonal sero-incidence of 50% (IQR 40-60). This study highlighted the significant levels of exposure of donkeys to AHSV and horses and donkeys to EEV in Zimbabwe despite equine encephalosis remaining unreported by Zimbabwean veterinarians to date. Most seroconversions in sentinel herd animals to AHSV and EEV occurred towards the end of the rainy season in March, April and May corresponding to the time of the year when the Culicoides vectors are in high abundance. In order to determine the clinical significance of these infections, blood and spleen samples, submitted by private equine veterinary practitioners over a 5-year period, from horses showing characteristic clinical signs of African horse sickness were tested for the presence of viral antigen using the antigen capture ELISA. The median sero-prevalence of AHSV antigen in horses recorded from these samples was 38% (IQR 33-88). The predominant AHSV antigen from these samples was serotype 7 (33%) followed by serotype 2 (26%) and serotypes 4 and 8 (16% each). African horse sickness virus serotypes 3 and 9, identified in this study, had not been previously reported in Zimbabwe.
Show more [+] Less [-]Assessment of a portable lactate meter for field use in the white rhinoceros (Ceratotherium simum)
2017
Cole, Georgina C.(University of Pretoria Department of Companion Animal Clinical Studies) | Tordiffe, Adrian S.W.(University of Pretoria Department of Paraclinical Sciences) | Steenkamp, Gerhard(University of Pretoria Department of Companion Animal Clinical Studies)
Blood lactate is a predictor of mortality in critically ill humans and animals. Handheld lactate meters have the potential to be used in the field to evaluate the condition of severely injured rhinoceroses but have not been compared with laboratory-based methods. Agreement between a handheld lactate meter and a laboratory method was assessed, as was the stability of rhino blood lactate in the anticoagulant sodium fluoride/potassium oxalate (fluoride/oxalate). Blood samples were obtained from 53 white rhinos that had been immobilised for management reasons. Lactate was measured by means of a handheld meter using whole blood in heparin (WBHEP), whole blood in fluoride/oxalate (WBFO) and fluoride/oxalate plasma (PFO). Results were recorded in both blood (BL) and plasma (PL) modes and compared to an established laboratory method for measuring plasma lactate. To assess the stability of lactate over time, blood lactate in fluoride/oxalate was measured on the handheld meter at intervals for up to 91 h. Agreement was best using WBFO in PL mode, with small bias (−0.16), tight 95% limits of agreement (LOA) (−1.46, 1.14) and a Pc (95% CI) of 0.97 (0.92, 0.99). The agreement was improved for all sample types when using the PL mode compared to the blood lactate (BL) mode. Blood lactate was stable in fluoride/oxalate for 91 h, with a mean change from baseline of 0.15 (−0.178, 0.478) mmol/L (mean, 95% CI). The handheld meter was found to be suitable for field use in white rhinos but provided more reliable results with the device in PL mode. Furthermore, rhino blood lactate was found to be stable in fluoride/oxalate for as long as 3 days.
Show more [+] Less [-]Seroprevalence and risk factors for Coxiella burnetii, the causative agent of Q fever in the dromedary camel (Camelus dromedarius) population in Algeria
2017
Benaissa, Mohammed H.(Scientific and Technical Research Centre for Arid Areas) | Ansel, Samir(Higher National Veterinary School) | Mohamed-Cherif, Abdallah(Higher National Veterinary School) | Benfodil, Karima(Higher National Veterinary School) | Khelef, Djamel(Higher National Veterinary School) | Youngs, Curtis R.(Iowa State University Animal Science Department) | Kaidi, Rachid(University of Blida LBRA Institute of Veterinary Sciences) | Ait-Oudhia, Khatima(Higher National Veterinary School)
Query (Q) fever is a globally distributed zoonotic disease caused by Coxiella burnetii, a bacterial agent for which ruminants are the most prevalent natural reservoir. Data regarding Q fever infection in camels in Algeria are limited. Therefore, a survey to detect seroprevalence of C. burnetii antibodies was conducted among healthy camel populations in a vast area in southeastern Algeria to determine distribution of the Q fever causative organism and to identify risk factors associated with infection. Between January and March 2016, blood samples were collected from 184 camels and serum samples were subsequently analysed using a commercial Enzyme-Linked Immunosorbent Assay (ELISA) kit. At the time of blood collection, a questionnaire investigating 13 potential predisposing factors associated with C. burnetii seropositivity was completed for every dromedary camel and herd. Results were analysed by a chi-square (χ²) test and multivariate logistic regression. The seroprevalence of C. burnetii at the animal level was 71.2% (95% CI: 65.2-78.3) and 85.3% (95% CI: 72.8-97.8) at the herd level. At the animal level, differences in seroprevalence were observed because of herd size, animal age, animal sex, presence of ticks and contact with other herds. A multivariable logistic regression model identified three main risk factors associated with individual seropositivity: (1) age class > 11 years (OR = 8.81, 95% CI: 2.55-30.41), (2) herd size > 50 head (OR = 4.46, 95% CI: 1.01-19.59) and (3) infestation with ticks (OR 2.2; 95% CI: 1.1-4.5). This study of seroprevalence of C. burnetii infection in camels in Algeria revealed a high seroprevalence of Q fever in camel populations in southeastern Algeria and provided strong evidence that Q fever represents an economic, public health and veterinary concern. Appropriate measures should be taken to prevent the spread of C. burnetii and to reduce the risk of Q fever in farm animals and humans in this agro-ecologically and strategically important region of North Africa.
Show more [+] Less [-]A serosurvey of bluetongue and epizootic haemorrhagic disease in a convenience sample of sheep and cattle herds in Zimbabwe
2017
Gordon, Stuart J.G.(Massey University Institute of Veterinary, Animal and Biomedical Sciences) | Bolwell, Charlotte(Massey University Institute of Veterinary, Animal and Biomedical Sciences) | Rogers, Chris W.(Massey University Institute of Veterinary, Animal and Biomedical Sciences) | Musuka, Godfrey(Columbia University Mailman School of Public Health) | Kelly, Patrick(Ross University School of Veterinary Medicine) | Guthrie, Alan(University of Pretoria Equine Research Centre) | Mellor, Philip S.(The Pirbright Institute) | Hamblin, Chris(The Pirbright Institute)
A convenience sample of sheep and cattle herds around the cities of Harare, Kwekwe and Bulawayo, located in the Highveld region of Zimbabwe, was used to estimate the sero-prevalence and sero-incidence of bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV) antibodies. A competitive enzyme-linked immunosorbent assay was used to identify serum antibodies against BTV and EHDV across three rainy seasons. The median sero-prevalence of BTV and EHDV antibodies in cattle was 62% (interquartile range [IQR]: 30-89) and 56% (IQR: 5-77), respectively. In sheep, the median sero-prevalence of BTV and EHDV was 41% (IQR: 19-63) and 0% (IQR: 0-21), respectively. Median sero-incidences of BTV and EHDV antibodies in cattle of 43% (IQR: 22-67) and 27% (IQR: 9-57) respectively were recorded. The median sero-incidence of BTV in sheep was 14% (IQR: 6-23). Based on these preliminary findings, animal health workers in Zimbabwe should continue to monitor the exposure rates of cattle and sheep to BTV and consider the possibility of strains emerging with increased pathogenicity. There are no previous published reports of antibodies against EHDV in Zimbabwe so the possibility of epizootic haemorrhagic disease existing in domestic livestock should now be considered by Zimbabwean animal health officials. Seroconversions to BTV and EHDV occurred predominantly at the end of each rainy season (March and April), which generally corresponds to high numbers of the Culicoides vectors. BTV isolations were made from three individual cows in two of the sentinel herds and all three were identified as serotype 3. This is the first time BTV serotype 3 has been recorded in Zimbabwe, although its presence in neighbouring South Africa is well documented.
Show more [+] Less [-]Gonadotropin-releasing hormone immunization and castration in male pigs: effects on growth, hormonal levels, antibody titer response, testicular function, back fat, and consumers' sensory perceptions
2017
Yamsakul, P., Chiang Mai University, Chiang Mai, Thailand | Patchanee, P., Chiang Mai University, Chiang Mai, Thailand | Yano, T., Chiang Mai University, Chiang Mai, Thailand | Boonma, T., Chiang Mai University, Chiang Mai, Thailand | Somkert, C., Chiang Mai University, Chiang Mai, Thailand | Sathanawongs, A., Chiang Mai University, Chiang Mai, Thailand
This study investigated the effects of gonadotropin-releasing hormone (GnRH) vaccine on pig growth, carcass quality, and sensory perceptions of pork meat by Thai consumers. Male crossbred pigs (n = 30) were separated into three groups of 10 pigs each: boars, immunocastrated pigs, and surgically castrated pigs. The immunocastrated group was immunized at 13 and 19 weeks of age with GnRH vaccine (400 킽/dose). All pigs were slaughtered at 24 weeks of age. Blood samples were collected and testes size determined. Testes weight and back fat thickness were recorded at the time of slaughter, and meat samples were collected for sensory assessment by Thai consumers. Testosterone and progesterone concentration levels decreased significantly two weeks after the second dose of GnRH (p less than 0.05), and the GnRH antibody titer of the immunocastrated pigs was significantly high two weeks after the second dose of GnRH (p less than 0.05). GnRH vaccine significantly reduced the weight and size of testes. Thai consumers reported no significant differences in odor or flavor among meat samples from the three groups. In conclusion, immunocastration improved growth performance, removed the need for castration surgery, and avoided "boar taint" in the meat. It has also no distinct trace of the boar taint same as pork that is currently produced from physically castrated pig which is making it acceptable to consumers.
Show more [+] Less [-]Virtual computed tomographic bronchoscopy: normal bronchial anatomy in six dogs
2017
Oh, D., Seoul National University, Seoul, Republic of Korea | Choi, M., Seoul National University, Seoul, Republic of Korea | Yoon, J., Seoul National University, Seoul, Republic of Korea
The aim of this study was to examine normal bronchi in dogs by using virtual bronchoscopy (VB) and to evaluate the utility of VB in clinical practice. The bronchi of six dogs without tracheobronchial disease were visualized by VB. Airways from the tracheal bifurcation to the lobar bronchi were well visualized in all dogs. Segmental and subsegmental bronchi were also well identified, but the degree and number of those varied with dog size. The mean numbers of segmental and subsegmental bronchi identified in the six dogs were 41.83 and 50.17, respectively, whereas, the mean numbers in medium- and large-sized dogs were 55.00 and 82.67, respectively, and in small-sized dogs, the means were 28.67 and 17.67, respectively. Although there were size-dependent differences in VB visualization of the bronchi, it was possible to identify peripheral airways to the subsegmental bronchi level, which can rarely be accomplished via conventional bronchoscopy. VB is the noninvasive method that can be used to examine bronchial anatomy, and our results suggest that VB can be useful for evaluating bronchi, including segmental and subsegmental ones that cannot be examined routinely by conventional bronchoscopy. Thus, VB has potential as an alternative to conventional bronchoscopy in the examination of bronchi in dogs.
Show more [+] Less [-]Identification of microbiome with 16S rRNA gene pyrosequencing and antimicrobial effect of egg white in bovine mastitis
2017
Kim, D., Seoul National University, Seoul, Republic of Korea | Kim, E.K., Seoul National University, Seoul, Republic of Korea | Seong, W.J., Seoul National University, Seoul, Republic of Korea | Ro, Y., Seoul National University, Seoul, Republic of Korea | Ko, D.S., Seoul National University, Seoul, Republic of Korea | Kim, N.H., Institutes of GreenBio Science Technology, Pyeongchang, Republic of Korea | Kim, J.H., Institutes of GreenBio Science Technology, Pyeongchang, Republic of Korea | Kwon, H.J., Seoul National University, Seoul, Republic of Korea
Bovine mastitis is an important microbial disease in the dairy industry. We investigated the frequencies of bacterial pathogens in 62 farms and pathogen antibiotic resistance from mastitis samples (n = 748). We tested the antimicrobial activity of chicken and duck egg white and lysozyme purified from chicken egg white. Moreover, we compared the microbiomes of normal and mastitic raw milk obtained by 16S rRNA gene pyrosequencing and culture methods. The results showed that the frequencies of Gram-positive pathogens (Enterococcus faecalis 37% and Staphylococcus aureus 36%) were higher than that of a Gram-negative pathogen (Escherichia coli 15%). Resistance frequencies to ampicillin and norfloxacin were lowest in Staphylococcus aureus (21%), Enterococcus faecalis (23%), and Escherichia coli (33%), and the antimicrobial activity of chicken egg white was higher than those of lysozyme and duck egg white. Pyrosequencing results revealed clear differences between the microbiomes of mastitic and normal raw milk samples and revealed a slightly similar, but clearly different, composition of pathogens compared to that from the culture method. Thus, pyrosequencing may be useful for elucidating changes in microbiomes during mastitis progression and treatment. A chicken egg white and antibiotic combination may help with mastitis treatment; however, further studies are needed.
Show more [+] Less [-]Candida glabrata infection of urinary bladder in a Chinchilla Persian cat
2017
Woo, S., Chungbuk National University, Cheongju, Republic of Korea | Kim, H.H., Chungbuk National University, Cheongju, Republic of Korea | Kang, J.H., Chungbuk National University, Cheongju, Republic of Korea | Na, K.J., Chungbuk National University, Cheongju, Republic of Korea | Yang, M.P., Chungbuk National University, Cheongju, Republic of Korea
A 5-year-old castrated male Chinchilla Persian cat weighing 4.84 kg was referred for hematuria. The cat had a history of urethrostomy and bacterial cystitis. In urine culture, Candida glabrata was cultured on Sabouraud dextrose agar. Based on these results, the cat was diagnosed with Candida cystitis. Subsequently, oral administration of fluconazole was initiated. Urine culture was negative at 31 days after administration. This case describes the diagnosis and treatment of Candida glabrata infection of urinary bladder in a cat with a history of urethrostomy.
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