The global carbon emission rate, due to energy-driven consumption of fossil fuels and anthropogenic activities, is higher at any point in mankind history, disrupting the global carbon cycle and contributing to a major cause of warming of the planet with air and ocean temperatures, which is rising dangerously over the past century. Climate change presents challenges both direct and indirect for livestock production and health. With more frequent extreme weather events including increased temperatures, livestock health is greatly affected by resulting heat stress, metabolic disorder, oxidative stress, and immune suppression, resulting in an increased propensity for disease incidence and death. The indirect health effects relate to the multiplication and distribution of parasites, reproduction, virulence, and transmission of infectious pathogens and/or their vectors. Managing the growing crossbreeding livestock industry in Bangladesh is also at the coalface for the emerging impacts of climate change, with unknown consequences for the incidence of emerging and re-emerging diseases. Bangladesh is now one of the most vulnerable nations to global climate change. The livestock sector is considered as a major part of food security for Bangladesh, alongside agriculture, and with one of the world’s largest growing economies, the impacts are exaggerated with this disaster. There has been no direct study conducted on the impact of climate  change on livestock health and the diseases in Bangladesh. This review looks to explore the linkage between climate change and livestock health and provide some guidelines to combat the impact on livestock from the Bangladesh perspective. Keywords: Animal health, Climate change, Food security, Heat stress, Oxidative stress.

Aim:Mycoplasma gallisepticum (MG) is important avian pathogens responsible for chronic respiratory diseases of chicken and turkeys, which result in large economic loss for the poultry industry. The objectives of this study were determination of seroprevalence of MG antibody of commercial layer chicken at laying period in selected areas of Bangladesh.Materials and Methods:A total of 563 blood samples were collected randomly from selected commercial layer chickens at laying period during the period from July to December, 2013. Indirect enzyme linked immunosorbent assay (iELISA) and serum plate agglutination (SPA) test were performed to detect the presence of antibodies against MG.Results:Of 563 samples, 64.47% and 56.13% showed an overall prevalence of MG antibodies in iELISA and SPA test respectively. Prevalence of MG was recorded the highest (69.63%) at 50-55 weeks of age compared with lowest (53.26%) at 56-61 weeks of age (p<0.05). Significant (p<0.05) effect of breed were observed in the seroprevalence of MG infection in layer birds in the present study. The overall, 68.77%, 63.74% and 59.37% prevalence were found respectively in sonali, ISA Brown and White leg horn. The prevalence of MG antibodies was the highest (70.13%) in December followed by November (68%), October (65.67%), August (63.46%), September (58.54%) and July (51.78%) month. The seroprevalence of MG antibodies was higher (69.63%) in most of the large flocks and lower (56.82%) in small flocks.Conclusion:Therefore, might be suggested that the commercial layer farms should be routinely checked to monitor MG infection and the reactor birds should be culled since MG organism has the potential to transmit vertically. The correlation between MG antibody in month and flock size was not significant (p=0.359 and p=0.868, respectively).

Asian lineage A/H5N1 highly pathogenic avian influenza viruses (HPAIVs) have been responsible for continuous outbreaks in Bangladesh since 2007. While clades 2.2.2 and 2.3.4.2 HPAIVs have disappeared since poultry vaccination was introduced in 2012, clade 2.3.2.1a viruses have continued to be detected in Bangladesh. In this study, we identified A/H9N2 (n = 15), A/H5N1 (n = 19) and A/H5N1-A/H9N2 (n = 18) mixed viruses from live bird markets, chicken farms, and wild house crows (Corvus splendens) in Bangladesh from 2016-2018. We analyzed the genetic sequences of the H5 HPAIVs, to better understand the evolutionary history of clade 2.3.2.1a viruses in Bangladesh. Although seven HA genetic subgroups (B1-B7) and six genotypes (G1, G1.1, G1.2, G2, G2.1, G2.2) have been identified in Bangladesh, only subgroup B7 and genotypes G2, G2.1 and G2.2 were detected after 2016. The replacement of G1 genotype by G2 in Bangladesh was possibly due to vaccination and viral competition in duck populations. Initially, genetic diversity decreased after introduction of vaccination in 2012, but in 2015, genetic diversity increased and was associated with the emergence of genotype G2. Our phylodynamic analysis suggests that domestic Anseriformes, including ducks and geese, may have played a major role in persistence, spread, evolution and genotype replacement of clade 2.3.2.1a HPAIVs in Bangladesh. Thus, improvements in biosecurity and monitoring of domestic Anseriformes are needed for more effective control of HPAI in Bangladesh.

Aim: The present study was aimed to determine the prevalence of infectious bronchitis virus (IBV) as well as virus isolation, identification, and molecular characterization of various strains circulating in Bangladesh. Materials and Methods: A total of 371 swabs and organ samples were collected from four types of chicken including layer, Sonali (local), broiler, and broiler breeder under eight districts (Rangpur, Bogura, Tangail, Dhaka, Gazipur, Mymensingh, Jamalpur, and Cumilla) during 2014-2016 in Bangladesh. Results: Out of 371 samples, 65 samples were positive in reverse transcriptase polymerase chain reaction (RT-PCR) for molecular identification of IBV. The overall prevalence was 17.52% recorded and among the selected types of chicken, the highest prevalence of IBV was found in layer that was 42.22% followed by 17.24% in Sonali, 14.93% in broiler breeder, and lowest prevalence was 11.94% in broiler chicken, respectively. Moreover, the prevalence of IBV was recorded highest in aged chicken at 41-60 weeks, which was 54.55% in layer, 27.27% in Sonali, and, afterward, 14.68% was found in broiler breeder, respectively. Frequency of IBV more frequently in winter (22.67%) followed by rainy (15.87%) and summer season (11.58%). The highest prevalence of IBV was found Tangail district (41.67%) followed by Mymensingh (24.42%), Gazipur (19.32%), Dhaka (15.38%), Jamalpur (16.67%), Bogura (13.68%), Cumilla (5.88%), and Rangpur (9.26%), respectively. Samples that were found high positive in IBV RT-PCR (Ct value below 30) were subjected to inoculation into chicken egg embryo to observe characteristic changes in chicken embryo. Swabs and organ samples were processed and passaged in 9-day-old embryonated chicken eggs through allantoic cavity route. IBV virus suspected samples inoculated into chicken egg embryos after 3-5 passages showed dwarfing and curling of the embryos which are characteristic lesions of IBV. Allantoic fluid was collected from all inoculated eggs and performed partial sequencing of S1 gene for three isolates. After sequencing, the phylogenetic tree was constructed from the nucleotide sequences of IBV isolates. Two of the isolates are 4/91 IBV and another one matched with QX-like IBV. Conclusion: The results revealed that the three isolates from different places in Bangladesh were identified for the 1st time as which will help for IBV control strategy.

Objective:The study was conducted to investigate the effect of mastitis on postpartum conception in crossed cows (Local x Friesian or Sahiwal x Friesian) in Chittagong area of Bangladesh. Materials and methods: A total of 100 lactating cows were randomly selected from thirteen small and medium size commercial dairy farms. The cows were reared under traditional feeding and management systems. Age and number of parity of the cows were 2.5 to 6 years and 1-5, respectively. On-farm California Mastitis Test (CMT) and Whit Slide Test (WST) were performed with the milk samples to diagnose mastitis. Besides, productive and reproductive data were recorded by examining the animals and interviewing the farmers. Results: The incidence of mastitis was significantly (P=0.037) higher (76% for CMT and 62% for WST) in 3.5-4.5 years old cows and lower (P=0.037) (47% for CMT) in 2.5-3.5 years old cows. The highest percentage of CMT (72%) and WST (59%) positive cases were found in cows having parity number 2. The CMT (71%) and WST (53%) test results were similar in third parity cows. The first parity cows were less prone to mastitis (47%). Mastitis had significantly (P=0.002) negative effect on days required to first heat after parturition. Mastitis was also negatively correlated with calving interval (CI) (P=0.030). More the incidence of mastitis prolongs the calving interval and the highest percentage (85% for CMT and 71% for WST) of mastitis was found in cows having 380-400 days calving interval. Lowest mastitis (54% for CMT and 48% for WST) incidence detected cows' lowest calving interval. Significantly, more number of Service per Conception (SPC) was also required in cows having more incidence of mastitis (P=0.03). SPC was 4 for subclinical to clinical cases and 3 for clinical cases. Conclusion: Significant correlation between mastitis and post-partum conception is recorded in this study that may hamper reproductive performances.

| A total 300 blood samples were randomly collected (150 crossbred and 150 local cattle) in three consecutive seasons (summer, rainy and winter) from four selected areas, namely Nasirabad, Patia, Bayezid and Jointika under Chittagong district of Bangladesh. The effects of topography, season, age and gender were tested in both crossbred and local cattle. The PCR was performed after consequence screening by light microscopy, which exhibited that 22 samples (14 Anaplasmaspp, 6 Babesia spp and 2 for mixed infections) were positive. The overall prevalence of haemoprotozoan diseases were 9.33% in crossbred and 5.33% in local cattle, among these babesiosis, anaplasmosis were recorded 2.66% and 6.00% in crossbred cattle and 1.33% and 3.33% in local cattle, respectively. The highest prevalence of anaplasmosis was found in Patia (9.33%) followed by Bayezid (4.00%), Nasirabad (2.67%) and Jointika (2.66%) and babesiosis was recorded in Bayezid (4.00%) followed by Jointika (2.66%) and Patia (1.33%). Among three seasons the highest prevalence of anaplasmosis was recorded 12.00% in crossbred cattle followed by 6.00% in local cattle in summer whereas babesiosis was highest in summer (4.00%) in crossbred cattle followed by 2.00% in local cattle. Prevalence of anaplasmosis increased significantly (P<0.05) with the increase of age in crossbred cattle. The highest prevalence of anaplasmosis was 13.72% and 6.94% in adult crossbred and local cattle, respectively. Occurrence of babesiosis was the highest in adult (5.88%) in crossbred than young (2.78%) in local cattle, respectively. It was revealed that haemoprotozoan diseases were more common in female cattle, among these highest prevalence of anaplasmosis was recorded (6.11%) in female crossbred cattle and (4.00%) in local cattle, respectively. Positive samples were analyzed by PCR, where 9 samples were amplified among these 4 samples (1.33%) of Babesia spp and 5 samples (1.67%) of Anaplasma spp.

How to cite: Bhuiyan ZA, Ali MZ, Moula MM, Bary MA, Arefin N, Giasuddin M, et al. Seroprevalence of major avian respiratory diseases in broiler and sonali chicken in selected areas of Bangladesh. J Adv Vet Anim Res 2019; 6(4): ABSTRACTObjective: This study was conducted to investigate different respiratory diseases in broiler and sonali birds in some selected districts of Bangladesh. Materials and Methods:We were collected a total of 460 blood samples from 46 farms with 36 broiler farms and 10 sonali farms (cross-breed) from 2015 to 2017. All the collected serum samples were tested for determining specific antibodies of avian rhinotracheitis (ART) virus, infectious laryngotracheitis (ILT) virus, infectious bronchitis (IBV) virus, and Ornithobacterium rhinotracheale (ORT) infection using commercially available enzyme-linked immunosorbent assay kits. Results: The overall seropositivity was highest in ORT (45.9%), followed by IBV (37.6%), ART (2.6%), and ILT (0.4%). Out of 360 broiler samples, highest seropositivity was recorded in ORT (43.3%) and lowest in IBV (31.4%). Surprisingly, no broiler samples were found positive for ART and ILT. In case of sonali, the seropositivity was highest in IBV (60%) and lowest in ILT (2%). With respect to types of birds and age groups, the seropositive percentage of all four pathogens was found higher in sonali than broiler. Between two age groups of sonali, the seropositive percentage of ART (12%), ORT (55%), ILT (2%), and IBV (60%) was highest at 21-60 weeks of age compared to 5-20 weeks of age. However, based on location, the seropositive of ORT and IBV was highest in Jamalpur (63.3%) and Fulbariya and Trishal (50%) and lowest in Sreepur (16.7%) and Jamalpur (3.3%). Conclusion:The four pathogens are ubiquitous in nature for the sonali chickens, and the prevalence of ORT and IBV was the most prevalent viruses in the study areas. This study indicates a need for improved surveillance and characterization of ORT and ART circulating in all types of poultry in Bangladesh. ARTICLE HISTORY

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