A retrospective study on post-arrival mortality rate of Australian boer goats in a breeder farm in Malaysia

Post-arrival mortality pattern and the causes of those mortalities were studied in a Boer goat breeding farm in Malaysia. The farm was established in October 2005, following an importation of 597 breeder Boer goats from Australia. Further importations of 534 Boer goats were made in July 2007, and 166 goats in March 2008. Farm records covering the period between October 2005 and December 2008 were analyzed for monthly mortality pattern with special attention on the post-arrival weeks. Upon arrival, goats were provided with vitamins, anti-stress and antibiotic cover. They were fed with cut grasses and supplemented with goat pellets at 350g/goat/day. Drinking water was also available ad libitum. During the study period of 2005 to 2008, there were significantly (p<0.05) higher rates of annual mortality during rainy months (7%-14%) as compared to dry months (2%- 5%). Meanwhile, the post-arrival mortality showed an average of 27%, ranging between 13% and 43%, of the Boer goats died during the first 6 weeks of post-arrival. In particular, the goats arriving in the rainy months of October 2005 and March 2008 showed higher post-arrival mortality than those arriving in the dry month of July 2007. The post-arrival mortality pattern revealed a gradual but significant (p<0.05) increase as early as week 1, with an average of 5% mortality to reach peak at week 3 with 35% mortality before it gradually decreased to 6% at week 6 and 3% at week 7. The major causes of post-arrival mortalities were pneumonic mannheimiosis and helminthiasis, which were associated with the stresses of handling, loading and unloading during shipment

Major components of fish immunity: a review

Fish are fascinating creatures with a certain degree of immunity comparable to those of mammals. The fish's immune system consists of two major components, innate and adaptive immunities. Innate immunity is non-specific and acts as the primary line of protection against pathogen invasion while adaptive immunity is more specific to a certain pathogen/following adaptation. Innate immunity consists of the non-specific cellular and the non-specific humoral components. The non-specific cellular component consists of toll-like receptors (TLRs), macrophages, neutrophils, eosinophils and non-specific cytotoxic cell while the non-specific humoral component involves lysozyme, the complement, interferons, C-reactive proteins, transferrins and lectins. They work together at the initial stage to prevent pathogen invasion. On the other hand, the adaptive immune system consists of highly specilised systemic cells and processes that are separated into two main components: the humoral and cellular components. Three types of antibodies, the IgM, IgD and IgT, are the major constituents of the humoral immunity, which act on invaded extracellular pathogens. The cytotoxic T-lymphocyte cells are the major component of the cellular immunity that frequently kills virus-infected and intracellular bacterial or parasitic-infected cells. Both innate and adaptive immunities complement each other in the host's attempt to prevent infection

Reproductive performance of boer goats imported from Australia

Assessment of reproductive parameters of Boer goats imported from Australia were made in a Boer Breeding Farm and a mixed-breed farm in Sabah. Data between 2008 and 2009 were sampled randomly and used to calculate pregnancy rate, prolificacy rate and kid mortality rate. The performance was compared with that of a mixed-breed goat farm. The pregnancy rate of imported Boer goats and the mixed-breed goats was 48 and 80% respectively. The difference was significant (P<0.05). Pregnancy rate was influenced by the nutrition, buck-to-doe ratio, health status of the breeding goats and environmental associate stress. There was significant difference (P 0.05) difference in kid mortality rate between the farms. Kid mortality was attributed to inadequate nutrition, low birth weight, infectious diseases, helminthiasis, traumatic injury, poor mothering ability and lack of efficient management

Detection of Brucella melitensis in seropositive goats.

This study reports an association of Brucella melitensis with pathological changes in sero-positive goats. 1,054 serum samples were subjected to the Rose Bengal Precipitation Test (RBPT) of which 27 were positive. Serum samples were re-collected from the 27 sero-positive goats 2 weeks later and subjected to RBPT for antibody titres. Uterii, mammary glands and supra-mammary lymph nodes were examined for pathological changes, immuno-peroxidase (IP) staining, bacterial isolation and PCR to detect B. melitensis. Results revealed that of the 27 goats tested, 41% were Category I (antibody titre = 2), 33% Category 2 (titre = 4) and 26% Category 3 (titre = >4). Goats in Categories 2 and 3 revealed more severe pathological changes with the latter being most severe. All goats in Category 3 showed positive reaction to IP compared with 56 and 18% in Categories 2 and 1, respectively. Three (33%) goats in Category 2 and 3 (43%) goats of Category 3 were B. melitensis positive either by isolation or PCR. There was strong correlation between the antibody titre, pathological lesions and presence of B. melitensis

The effect of dexamethasone on immune responses of calves to intranasal exposures to live attenuated gdhA derivative of Pasteurella multocida B:2

The effect of stress, created using dexamethasone on immune response by calves to intranasal exposures to gdhA derivative of Pasteurella multocida B:2 was studied. For the purpose of this study, twelve calves of 6 months old were selected and divided into 4 groups. At the start of the experiment, calves of groups 1 and 2 were intramuscularly injected with dexamethasone at the rate of 1 mg/kg body weight for 3 consecutive days. Then, the calves of groups 2 and 3 were exposed intranasal to 5 ml of the inoculums containing 106 cfu/ml of the gdhA derivative of P. multocida B:2. Calves of groups 1 and 4 remained unexposed control. Serum samples were collected prior to the start of the experiment and at weekly interval for a period of 7 weeks. At the end of the 7-week period, all the calves were sacrificed before the lungs were lavaged using 1 L of sterile phosphate buffered saline (PBS). The sera and lung lavage fluid were subjected to ELISA to determine the levels of IgG and IgA. Significant increase in both serum and lavage IgG and IgA were observed only in group 3, which were exposed without any dexamethasone treatment. The dexamethasone-treated and exposed group 2 failed to respond to the exposures when the levels remained insignificant to those of the control untreated and unexposed group 4. The calves of group 1, which were treated with dexamethasone but remained unexposed, failed to show any response at all. In conclusion, intranasal exposures to live attenuated gdhA derivative of P. multocida B:2 must be given only to unstressed calves, since stressful condition has been found to prevent calves from responding significantly to the antigen

Clinico-pathological changes in buffalo calves following oral exposure to Pasteurella multocida B:2.

Background and aim: Pasteurella multocida B:2, which causes hemorrhagic septicemia of ruminants, is believed to enter the host via respiratory and oral routes. While the role of respiratory route of infection has been established, the present study describes the clinical and pathological alterations following oral exposure of buffalo calves to live wild-type Pasteurella multocida B:2. Methods: Nine 8-month-old buffalo calves were selected and divided into three groups. Calves of group 1 were exposed orally to 50 mL of the inoculums containing 109 colony-forming unit (CFU)/mL of live Pasteurella multocida B:2. Calves of group 2 were exposed intra-tracheal to 5 mL of the same inoculums while calves of group 3 were exposed orally to 50 mL of phosphate-buffered saline. Results: Only one calf had to be euthanized at 48 h post-intra-tracheal exposure due to persistent clinical signs of hemorrhagic septicemia. The mean respiratory rate and rectal temperature had significantly increased in calves of groups 1 and 2. The pathological alterations included submandibular and brisket edema, generalized lymphadenopathy, acute fibrinous pneumonia, acute colitis and hemorrhagic typhilitis and proctitis. Nevertheless, oral infection with 109 CFU/mL of live wild-type P. multocida B:2 failed to produce a typical clinical disease. However, P. multocida B:2 was present along the gastro-intestinal tract, including the rectum of the calf that succumbed to the infection at 48 h post-intra-tracheal exposure. Conclusions: The presence of P. multocida B:2 along the gastro-intestinal tract is of concern since transmission via the gastro-intestinal tract of diseased animals is strongly possible

Histopathological changes in chickens infected with Pasteurella multocida and ducks infected with Riemerella anatipestifer

A description and evaluation of histopathological changes in organs of chickens infected with three different serotypes of Pasteurella multocida and ducks infected with Riemerella anatipestifer were carried out. Seventy-five 4-week old chicken and 25 ducks were selected for the study. The chickens were divided into 3 groups of 25 chickens each while the ducks were not divided. At the start of the experiment, all chickens of group 1 were infected intramuscular with 0.5 mL inoculums containing 109 cfu/mL of live Pasteurella multocida A:1. Chickens of groups 2 and 3 were similarly infected with Pasteurella multocida A:3 and A:1, 3 respectively while all ducks were infected with Pasteurella multocida A:1 followed by Riemerella anatipestifer. All animals were observed for clinical signs and the survivors killed on day8 post-infection. The lungs, liver and kidneys were collected during postmortem and histology examinations, and the lesions were described and severity objectively scored. Intramuscular inoculation of chickens with Pasteurella multocida A:1, A:3 and A:1,3 killed most chickens at the rate of 92, 96 and 86%, respectively. The gross lesions consisted of generalised congestion of internal organs with occasional haemorrhages. Histology revealed severe pulmonary, hepatic and renal congestions with occasional haemorrhages and focal hepatitis. Based on rate of mortality and histology lesion scoring, Pasteurella multocida A:3 was found to be most virulent while Pasteurella multocida A:1,3 the least virulent of the three serotypes. Infection by Pasteurella multocida A:1 followed by Riemerella anatipestiferin ducks resulted in similar lesions with 94% mortalityrate

Status and effect of fascioliasis in buffaloes kept extensively in a farm in Sabah, Malaysia

This study was carried out to determine the status and possible effect of fascioliasis among buffaloes kept extensively in the Buffalo Breeding and Research Centre at Telupid, Sabah, Malaysia. Forty adult four-year old buffaloes from a herd of 250 animals were selected for the study. Faecal samples were obtained from the animals and subjected to sedimentation technique to determine the presence of Fasciola sp. ova. Blood sample from each animal was collected into a plain tube and serum obtained for determination of AST and albumin concentrations. The helminth burden was determined in these animals to obtain information on the prevalence of gastrointestinal helminthiasis in the farm. None of the faecal samples had Fasciola sp. ova. However, the serum ALT concentrations in these animal were significantly (p<0.05) higher than the upper limit of the reference range. The study suggests that that the buffaloes may have been exposed to diseases that caused liver damage

Effects on of dexamethasone on vaccination responses against pneumonic pasteurellosis in goats

A study was conducted to compare the effect of dexamethasone treatment prior to, during and post-vaccination on antibody response and protection against experimental challenge with Mannhaemia haemolytica. Sixteen goats of about 7 months old were divided into 4 equal groups. All goats were vaccinated twice intranasally with 1 ml inoculum containing 106 colony forming unit (cfu) of formalin-killed Mannhaemia haemolytica A2/ml. The two doses were administered at 2-week intervals. Goats in group 1 were treated with dexamethasone prior to vaccination, group 2 was treated during vaccination, group 3 was treated at 1 week-post vaccination while group 4 remained as the vaccinated control. Serum samples were collected weekly for a period of 5 weeks to detect antibody using an ELISA. Two weeks post-vaccination, all goats were challenged intratracheally with 4 ml inoculum containing live Mannhaemia haemolytica at a concentration of 109 cfu/ml before slaughtering at 2 weeks post-challenge. The extent of pneumonic lung lesions was determined. Generally, animals without dexamethasone treatment had significantly (p<0.05) high antibody response compared to other groups while the extent of pneumonic lung lesions was significantly (p<0.05) lowest. Although group 1 showed the second highest antibody response and a lower percentage of lesions, the differences were significant (p<0.05) compared to the control group. Group 2 which showed the second lowest antibody response recorded significantly (p<0.05) extensive lung lesions while group 3, which showed the lowest antibody level had insignificantly (p<0.05) more extensive lung lesions. There were strong correlations between the antibody response and the severity of lesions. The results emphasise that vaccination will not be efficient if carried out when the animal is under stressful conditions