Immunological study of an attenuated Salmonella Typhimurium expressing ApxIA,ApxIIA, ApxIIIA and OmpA of Actinobacillus pleuropneumoniae in a mouse model

Salmonella Typhimurium strain expressing the Actinobacillus pleuropneumoniae antigens, ApxIA, ApxIIA, ApxIIIA and OmpA, was previously constructed as a vaccine candidate for porcine pleuropneumonia. This strain was a live attenuated (∆lon∆cpxR∆asd)Salmonella as a delivery host and contained a vector containing asd. An immunological study of lymphocyte proliferation, T-lymphocyte subsets and cytokines in the splenocytes of a mouse model was carried out after stimulation with the candidate Salmonella Typhimurium by intranasal inoculation. The splenic lymphocyte proliferation and the levels of IL-4, IL-6 and IL-12 of the inoculated mice were significantly increased, and the T- and B-cell populations were also elevated. Collectively, the candidate may efficiently induce the Th1- and Th2-type immune responses.     

The experience of dog bites: A survey of veterinary science and veterinary nursing students

AIM: To investigate the circumstances of dogs biting people in New Zealand.

METHODS: Veterinary science and veterinary nursing students enrolled at Massey University in 2003 completed a questionnaire detailing their lifetime experience of dog bites and their opinions of dog control legislation.

RESULTS: The response rate was 100%. There were 228 completed responses to the survey, and 87 (38%) respondents had been bitten by a dog. Most bites caused minor injury, but 17 (20%) required medical attention. Male respondents were more likely to have been bitten. The highest proportion of respondents (27; 31%) had been bitten while between 6 and 10 years of age, and the hand was the part of the body most often injured. Eighteen (21%) bites involved a stranger's dog, but most bites were by a dog known to the victim. Respondents from rural areas were three times more likely to have been bitten than city dwellers. The victim's home was the place where most (31; 36%) bites occurred. Male dogs were responsible for a larger proportion of bites (38; 44%) than females (24; 28%); respondents were unsure about the sex of the remainder of the dogs (25; 29%) that bit them. Protecting the home, play, accidents, rough handling and pain were identified as the common reasons for dogs to bite. Most (46; 52%) respondents did not believe legislation could have prevented their bite. Only four (5%) bites were reported to authorities.

CONCLUSION: Rural dwellers, people with more experience of dogs, children <11 years of age, and male respondents were bitten by dogs most often. Only legislation relating to the fencing of dog owners′ properties may have prevented a reasonable proportion (25; 29%) of the bites reported here.     

A survey of public attitudes towards barking dogs in New Zealand

AIMS: To investigate public attitudes towards barking dogs in New Zealand in order to quantify the extent to which people perceive barking dogs to be a problem, to compare tolerance of barking with that of other common suburban noises, to assess the level of public understanding about the function of barking, to determine risk factors for intolerance of barking and to assess knowledge of possible strategies for the investigation and management of problem barking.

METHODS: A 12-page questionnaire was sent to 2,000 people throughout New Zealand randomly selected from the electoral roll. Risk factors for being bothered by barking were examined using logistic regression analysis.

RESULTS: A total of 1,750 questionnaires were successfully delivered; of these, 727 (42%) were returned. Among respondents, 356/727 (49.0%) indicated that frequent barking during the day would bother them while 545/727 (75.0%) would be bothered by barking at night. Barking and howling were ranked above other suburban noises as a cause of annoyance. Risk factors for being bothered by daytime barking were not being home during the day, not owning a dog, and considering a dog bite to be a serious health risk. Risk factors for being bothered by night-time barking were not being home during the day, marital status, considering dog bites to pose a serious health risk, and having been frightened by a dog. Overall, 510/699 (73%) respondents understood that barking was a form of communication.

Action likely to be taken by 666 respondents hearing frequent barking included notifying and offering to help the owner (119; 17.8%), complaining to the owner (127; 19.1%) or the authorities (121; 18.2%), or doing nothing (299; 48%). Possible responses by 211 dog owners if they had a barking dog included seeking help from dog trainers (59; 28%) or behaviourists (54; 26%), buying an anti-barking device (33; 15%) or getting rid of the dog (20; 10%).

CONCLUSIONS: Barking was considered to be potentially disturbing by respondents to this survey. Attitudes towards barking were most influenced by age, dog ownership, past experience with dogs and attitude towards dog bites. Public understanding of the possible reasons for barking and appropriate methods of managing the behaviour when it becomes a problem could be improved by better education and the provision of information through veterinary clinics and social media.     

Effects of nutritional supplementation and exposure to bulls on resumption of post-partum ovarian activity in Bunaji (Bos indicus) cattle

A total of 51 pluriparous post-partum Bunaji (Zebu) cows belonging to agropastoralists were involved in a 2 x 2 factorial experiment for a period of 180 days. The cows were assigned randomly at calving to four treatments: (1) grazing only (no supplementation) and exposure to bull (NSBE); (2) grazing only (no supplementation) and no exposure to bull (NSNE); (3) grazing plus feed supplementation (each cow received 600g of 20.8% crude protein of whole cottonseed supplement per day) and exposure to bull (FSBE); (4) grazing plus feed supplementation and no exposure to bull (FSNE). Cows with an increase in milk progesterone (P(4)) concentration of > or =1 ng/mL from the weekly milk samples were used to analyse the number of days from calving to the time of resumption of ovarian activity. The mean interval from parturition to cyclic ovarian activity for FSBE cows was 95 days, compared to 119 days for the FSNE cows. Intervals to onset of post-partum ovarian activity were 24, 33 and 39 days which were significantly earlier in the FSBE cows, than the FSNE, NSBE and NSNE cows, respectively. Intervals to cyclic activity were 9 and 15 days earlier in FSNE cows than in NSBE and NSNE cows. By 150 days post-partum, 100% and 92% of the cows in the supplemented groups (FSBE and FSNE), had resumed cyclic ovarian activity compared with 75% and 69% for the unsupplemented cows (NSBE and NSNE). It is concluded that nutritional supplementation and exposure to bulls synergistically shortened the length of post-partum anoestrus in zebu cattle. The economic benefits of using exposure to bulls and cottonseed supplementation in this study to enhance early resumption of post-partum ovarian activity of cattle may serve as a management tool in tropical areas where livestock production has some constraints.     

Use of Computed Tomography in Standing Position to Identify Guidelines for Screw Insertion in the Distal Phalanx of Horses: An Ex Vivo Study

Objectives— To compare the precision of radiography and computed tomography (CT) preoperatively in the standing position for identification of guidelines for screw insertion in the distal phalanx, and to identify whether standing CT might improve operative time compared with preoperative radiographic planning.
Study Design— Experimental ex vivo study.
Animals— Cadaveric equine thoracic limb pairs (n=10).
Methods— Insertion of a 4.5 mm cortex screw in lag fashion into an intact distal phalanx was evaluated in 2 groups (n=10) of cadaveric equine thoracic limbs. In 1 group, the site, direction, and length of the implant were determined by radiography, and in the other group, by CT. Accuracy of screw placement was verified by specimen dissection. Outcomes were (1) absence of penetration of the articular surface, the solar surface, or the semilunar canal (2) appropriate length and direction of the screw. Surgical time was also measured.
Results— No screw penetrated the articular surface, the solar surface, or the semilunar canal in either group. CT was more accurate to identify guidelines for screw insertion (U=23.50, P =.049). With CT, surgical time (mean, 7.7 minutes) was significantly shorter (U=0.000, P =.000) than with radiography (mean, 12.7 minutes).
Conclusion— Standing CT can be used to accurately determine anatomic landmarks for screw insertion in lag fashion in sagittal fractures of the distal phalanx.
Clinical Relevance— This study has a clear clinical relevance for improved internal fixation of sagittal fractures of the distal phalanx.     

Modulation of systemic and mucosal immunity against an inactivated vaccine of Newcastle disease virus by oral co-administration of live attenuated Salmonella enterica serovar Typhimurium expressing chicken interleukin-18 and interferon-α

Newcastle disease (ND) is a highly contagious disease of chickens causing significant economic losses worldwide. Due to limitations in the efficacy against currently circulating ND viruses, existing vaccination strategies require improvements, and incorporating immunomodulatory cytokines with existing vaccines might be a novel approach. Here, we investigated the systemic and mucosal immunomodulatory properties of oral co-administration of chicken interleukin-18 (chIL-18) and chicken interferon-α (chIFN-α) using attenuated Salmonella enterica serovar Typhimurium on an inactivated ND vaccine. Our results demonstrate that oral administration of S. enterica serovar Typhimurium expressing chIL-18 or chIFN-α provided enhanced systemic and mucosal immune responses, as determined by serum hemagglutination inhibition antibody and NDV Ag-specific IgG as well as NDV Ag-specific IgA in lung and duodenal lavages of chickens immunized with inactivated ND vaccine via the intramuscular or intranasal route. Notably, combined oral administration of S. enterica serovar Typhimurium expressing chIL-18 and chIFN-α significantly enhanced systemic and mucosal immunity in ND-vaccinated chickens, compared to single administration of S. enterica serovar Typhimurium expressing chIL-18 or chIFN-α. In addition, oral co-administration of S. enterica serovar Typhimurium expressing chIL-18 and chIFN-α provided enhanced NDV Ag-specific proliferation of peripheral blood mononuclear cells and Th1-biased cell-mediated immunity, compared to single administration of either construct. Therefore, our results provide valuable insight into the modulation of systemic and mucosal immunity by incorporation of immunomodulatory chIL-18 and chIFN-α using Salmonella vaccines into existing ND vaccines.     

Fertility in zebu cattle (Bos indicus) after prostaglandin administration and artificial insemination.

A total of 137 cycling zebu cows, each receiving a single dose of prostaglandin PGF(2alpha)were used in an oestrus synchronization programme on three different farms. Of the cows on the three farms, 60.6 and 90.5% showed overt oestrus and luteolysis, respectively. Pregnancy rate to fixed time inseminations following single injection of PGF(2alpha)was 61.4% for farm 1, significantly higher than the values of 45.7 and 46.9% for farms 2 and 3, respectively. The pregnancy rates to second service of rebred cows were 53.3, 50.0 and 50.0% for the three farms, respectively, with no significant differences between each.Fertility classification of the cows based on progesterone (P(4)) concentration showed that 6.6% of cows on the three farms were incorrectly diagnosed as having corpora lutea; 2.9% of them had incomplete luteolysis and 5.1% may have lost their embryos between days 21 and 45 post-insemination. The pregnancy rate was 10% higher in the rainy season than in the dry season. Cows with body condition scores of 3 and 4 had a higher overall pregnancy rates than those with a body condition score of 2. The findings of this study further confirm the luteolytic efficacy of prostaglandin in inducing oestrus in zebu cattle and indicate that the nutritional status of the cows must be satisfactory before embarking on oestrus synchronization programmes.     

Fertility of Bunaji (Zebu) Cows after Treatment with PRID with or without PGF2α

A study was undertaken to determine the oestrus response and fertility rates of zebu cows treated with PRID alone or in combination with PGF2alpha. A total of 184 non-suckled cycling Bunaji cows were allotted randomly to four treatment groups of 46 animals per group as follows: group 1 (PRID-12), PRID was inserted for 12 days; group 2 (PRID+7+PGF2alpha-6, PRID was inserted for 7 days and PGF2alpha was administered intramuscularly 1 day prior to PRID withdrawal; group 3 (PRID-7+PGF2alpha-7, PRID was inserted for 7 days and PGF2alpha was administered intramuscularly on the day of PRID withdrawal; group 4 (2 x PGF2alpha-13, two intramuscular injections of PGF2alpha 13 days apart. At the end of each treatment period, the cows were observed for 7 days for behavioural oestrus and were inseminated 12 h following detection of oestrus. Pregnancy was diagnosed by rectal palpation 30-40 days post-insemination. The respective oestrus response rates were 78.3%, 76.1%, 87.0% and 89.1% for groups 1-4. While the corresponding pregnancy rates were 39.1%, 41.3%, 52.2% and 52.2%, the conception rates were 50.0%, 54.3%, 60.3% and 58.6% for groups 1-4. Although individual variations in progesterone levels were observed, the progesterone profiles were generally typical and normal. The results of the study have confirmed the effectiveness of the four regimes in synchronizing and controlling oestrus and ovulation in Bunaji cows. However, groups 3 and 4 showed some superiority over the other treatments. The results of this study provide feasible options from which clinicians involved in intensive breeding programmes and herd health fertility programmes can choose.     

Hormonal interrelationships in postpartum suckled dairy cows.

Three cross-bred cows calved in March and April and were followed until day 62 after parturition. Each animal was suckled by 2 calves ad libitum. All calves were removed from the cows on day 55 after parturition. Blood was collected 3 times per day from the jugular vein by venipuncture. On 4 occasions after parturition--i.e. days 7-8, 21-22, 35-36 and 49-50, the cows were bled through a jugular venous catheter every 30 min during the 24 h. The plasma samples were analyzed for the content of 15-keto-13,14-dihydro-PGF2 alpha (main PGF2 alpha metabolite), LH, prolactin, cortisol and progesterone by radioimmunoassay methods. The concentration of PGF2 alpha increased from 280 to 730 pmol/l within the last 4 days before parturition. The highest geometric mean was 3106 pmol/l on the day of parturition. Thereafter a steady decrease of PGF2 alpha metabolite concentration was seen until day 21 when it reached plateau at 148 pmol/l. In all cows plasma LH concentrations increased significantly (P < 0.05) from about 1.6 micrograms/l on days 7-8 to 2.4 micrograms/l on days 21-22 post partum. The frequency of LH pulses showed no tendency to increase as the postpartum period progressed and averaged 6.5 pulses/24 h. Mean plasma LH concentrations increased from 2.1 micrograms/l 2 days before weaning to 3.2 micrograms/l 2 days after weaning (P < 0.05). LH peaks occurred less frequently in association with prolactin and cortisol peaks than in their absence. A partial positive correlation between PGF2 alpha metabolite and cortisol (r = 0.30) was found on days 7-8 post partum. Correlation between prolactin and cortisol on days 7-8 and 21-22 post partum was also positive (r = 0.20 and r = 0.27, respectively). There was a negative correlation between LH and cortisol on days 7-8 (r = -0.27) and days 49-50 (r = -0.21) post partum. The first and short progesterone increase observed after weaning was terminated in conjunction with PGF2 alpha metabolite peaks.