Prevalence of different dairy cattle diseases in selected dairy areas and farms of Bangladesh

: The present study was designed to have a comprehensive epidemiological data of the circulating diseases in Pubna cattle in Pubna and sirajgonj districts of Bangladesh. Two sites were selected for the study as the Nucleus Breeding Hard (NBH); which is located in the BLRI-RS, Baghabari, Sahjadpur, Siragjang and the community; consists of three villages of Bera upazila of Pabna district namely Khar-bagan, Hatail-aralia and Char-sabolla. The total cattle population was 576 (506 in the community and 70 in the NBH). The overall weather was hot and humid. A total of 965 clinical cases of cattle of different age and sex were diagnosed during the period from July, 2017 to June, 2018.The descriptive statistics suggested that endo-parasites (15.67%), FMD (27.51%), non-specific diarrhea (7.73%) and post-partum anoestrus (7.78%) are the most prevailing diseases in the community and endo-parasites (21.82%), foot-rot (15.15%), non-specific fever (7.27%), dermatochalasis (5.45%) and conjunctivitis (4.85%) are the most prevailing diseases in the NBH. Population data shows that there was an endemic outbreak of FMD in the community between March to May 2018 where almost 50% cattle were affected by the disease though calf morbidity was low (2.69%) but all the affected calf died. Non-specific diarrhea was more common in older individuals (14% in over 3years old cattle) mostly in cows (14.2%) and occurred in summer (9.84%) and winter (8.81%) may be because of the ignorance of the farmers to supply clean water to their animals. Although, we routinely de-worm our cows in the community and in the NBH round the year we found many cases of parasitic gastro-enteritis in both the locations which suggested that our de-worming practice is not working. Repeated study of the same kind can provide us a large set of data on cattle disease prevailing in the area which may provides valuable insight to design and implement priority based research on specific disease and to take efficient control strategies against that disease.


Introduction
Bangladesh is an over populated, rural and agrarian country in the world (BBS, 2008).It also has the highest density of livestock (cattle, goats, sheep and buffaloes) in the world with an estimated 145 large ruminants/km 2 compared with 90 for India and 20 for Brazil.Despite declining acreage of pasture land, the livestock population is growing steadily in the country.Livestock are an integral component of agriculture in Bangladesh that supplies food, draft power and manure.About 20% of the human population is directly and 50% is partly dependent on the livestock sector (Bangladesh Economic Review, 2009).Bangladesh earns foreign currency by exporting several byproducts such as hides, skin, bone etc and now biogas is also producing from cattle dung.The contribution of livestock in the magnitude of Gross Domestic Product (GDP) is about 16.23 % in Bangladesh (BBS, 2008).Cattle are very important component of the mixed farming system practiced in this country and health of cattle is one of the many factors that conspire against productivity of cattle production systems all over the world (Miranda, 2014).However, most of the animals in Bangladesh are weak and emaciated with non-satisfactory productive performance due to malnutrition and diseases.Among the various constrains in the development of cattle, both infectious and noninfectious diseases are the most important limiting factors that cause significant mortality of adult cattle and neonatal calves each year.It was reported that variation in different cattle breed, their sex and environmental factors greatly influence the disease prevalence in livestock of a specific area and cattle are of no exception (Islam et al., 2014).Economic losses are attributable to decreased animal growth and productivity as well as frequent death of affected cattle.

Materials and Methods
The study area and the study period-The NBH is located in the BLRI-RS, Baghabari and the community consists of three villages of Beraupazilla of Pubna district namely Kharbagan, Hatalaralia and Charsabolla.The cattle population was 576 (506 in the community and 70 in the NBH).The overall weather was hot and humid and the area was in the AEZ 4,7&11.A total of 965 clinical cases of cattle of different breed and sex were diagnosed during the period from July 2017 to June 2018.

The Diagnosis of diseases
Diagnosis of diseases was made by general physical examination of animals, clinical signs, gross pathology and laboratory procedures.During general physical examination animal's body condition, behavior, posture, gait, locomotive disturbance, pulse, respiration, temperature, abdominal distension, defecation etc were observed and/or recorded.Examination of different parts and systems of the body of sick animals were performed by using the procedure of palpation, percussion, auscultation, needle puncture and walking of animals.Owner's complaints were taken into account while performing general physical examination of a sick animal.Animal's breed, sex, age etc were also recorded in registered book.Specific bacterial, viral, and fungal diseases were diagnosed on the basis of specific clinical signs and gross lesions.In some cases, confirmatory diagnosis were made by cultural and biochemical characteristics of causative organisms following standard procedure.Parasitic infestations were diagnosed by faeces examination under microscope as described previously (Soulsby, 1986).Blood smears were prepared and examined under microscope after Giemsa's staining according to the methods described elsewhere to confirm hem protozoan infestation.The handling of animals in the study was performed in accordance with current Bangladesh legislation (Cruelty to Animals Act 1920, Act No.I of 1920 of the Government of the People's Republic of Bangladesh).Diagnosis of diseases was made by general physical examination of animals, clinical signs, gross pathology and laboratory procedures.In some cases, confirmatory diagnosis were made by cultural and biochemical characteristics of causative organisms following standard procedure.Parasitic infestations were diagnosed by faeces examination under microscope as described previously (Soulsby, 1986).Blood smears were prepared and examined under microscope after Giemsa's staining.

Data analysis
Diagnosed diseases were categorized as infectious disease, parasitic disease, digestive disorder, respiratory disease, metabolic disease and other diseases for statistical analysis.Obtained data were analyzed by using statistical software 'SPSS-16.0'where descriptive statistics was expressed as proportion with 95% confidence interval (CI).A paired t-test was also performed.

Results
Circulating diseases identification was our main aim.Table 1 contains different diseases and their prevalence percentage in our study area.Table 1 shows the prevalence of different dairy cattle diseases in community and on station (the NBH).The result of a paired t-test suggests that there is no significant difference in the pattern of disease occurrence in the two separate populations may be because in both the cattle population genotype is same (mostly local Pubna variety).The descriptive statistics suggested that Endo-parasites (15.67%),FMD (27.51%),Non-specific Diarrhea (7.73%) and Post partum anestrus (7.78%) are the most prevailing diseases in the community and Endo-parasites (21.82%),Foot-rot (15.15%),Non-specific fever (7.27%), Dermatochalasis (5.45%) and conjunctivitis (4.85%) are the most prevailing diseases in the NBH.Table .2shows that FMD is the most prevailing disease in the community.Population data shows that there was an endemic outbreak of FMD in the community between March to May where almost 50% cattle were affected by the disease though calf morbidity was low (2.69%) but all the affected calf died.Non-specific diarrhea was more common in older individuals (14% in over 3years old cattle) mostly in cows (14.2%) and occurred in summer (9.84%) and winter (8.81%).The incidence of post-partum anoestrus (14.43%) is the other important disease of the community may be because of the poor nutrition supply to the cows all through her life.Table .3shows the most important onstation diseases.Non-specific fever was common in lighter cows (7.88% in less than 250 kg b wt.cows) may be due to malnutrition and in summer and winter season may be due to acclimatization failure in weak cows.Conjunctivitis and dermatochalasis are mostly found in calves in winter may be due to low humidity.Foot-rot was the disease of older and heavy individuals as shown in Table .3.Captivity may be the other important cause of these diseases.Although we routinely de-worm our cow in the community and in the NBH round the year we found some cases of parasitic gastro-enteritis in both the locations.This need to be addressed and the causes should be explored.

Discussion
To investigate the prevalence of dairy cattle diseases at our working area, a total of 965 clinical cases were diagnosed and categories them in nine categories among which the prevalence of endo-parasitic diseases (15.67% in NBH and 21.82% in community) were the highest.Although other researchers like (Badruzzaman et al., 2015;Bhuiyan 2007 andMannan et al., 2009).Reported digestive disorder as the highest prevailing disease we did not find so may be because of the natural resistance of these types of cattle to the digestive diseases especially under rural production systems.Overall prevalence of infectious diseases was 39.44% in community and 28.49% on station but if we exclude FMD from community and foot-rot from on-station the prevalence stands 11.93% in community and 13.34% on-station.Furthermore FMD did not occur on station as the cattle there were vaccinated but the community cattle were not vaccinated.This information clearly suggests that vaccination can successfully prevent FMD in these cattle and these cattle were well tolerated against most other infectious diseases.Our results are in agreement with the findings of (Bhuiyan, 2007) and (Mannan et al., 2009;Sarker et al., 2011).reported prevalence of foot and mouth disease (25.07%) in Rajshahi district of Bangladesh which was in line with our 27.51% but (Badruzzaman et al., 2015).found 4.74% in Chittagong district of Bangladesh.This variation might be due to different geographical locations and related environmental factors.
In our study the prevalence of mastitis was 3.36% in community and 2.86% on station which is in line with the report of (Rahman et al., 2010 andPallab et al., 2012).In case of hem protozoan parasites, prevalence was 2.17% in the community and 2.86% on station respectively.(Alim et al., 2012) reported the overall prevalence of hem protozoan diseases as 12.02% in indigenous cattle, respectively where babesiosis and ana-plasmosis were predominant.A variation in hemoprotozoan disease prevalence with us is might be due to environmental factors, animal species and other related host factors.Females were more susceptible to infectious diseases than male cattle.Our results are in agreement with the findings of (Bhuiyan, 2007 andMannan et al., 2009).A good prevalence (25.91% in community and 15.72% on station) was recorded in digestive disease category of which non-specific diarrhea was the highest (13.64% in community and 7.14% on station) followed by anorexia (4.55% in community and 4.29% on station), blot (6.92% in community and 0% on station), constipation (0.2% in community and 4.29% on station).The prevalence of digestive disorders in our study was slightly lower than the report by (Pallab et al., 2012;Rahman et al., 1972;and Kabir et al., 2010).In our area, most farmers are poor and cannot supply adequate feed to their cattle so the prevalence of digestive disorders are lower.The prevalence of reproductive diseases was recorded as 19.77% in community and 20.01 on station which was lower than the report by (Pallab et al., 2012).Who reported 6.20% prevalence may be because of natural service offered to the cows at both the location.Overall prevalence of metabolic diseases (5.53% in community and 7.14% on station) in our study was higher than that reported by (Pallab et al., 2012).Who reported metabolic disease prevalence as 4.24%.Among the metabolic diseases, prevalence of weak calf syndrome was comparatively high on station which might be due to deficiency of micronutrients in stall feeding system.

Conclusions
According to our study, major diseases of cattle in our study area include FMD, digestive disorder, parasitic disease, skin disease of which FMD and parasitic diseases are predominantly prevalent diseases in both the location.Older female cattle are highly susceptible to most of the diseases.Our large set of data on cattle disease prevalence in the area may provides valuable insight to design and implement priority based research on specific disease and to take efficient control strategies against those diseases.