A study on the occurrence of calf diseases in some selected dairy farms of Bangladesh

The objectives were to investigate the factors (age, sex, breed and season) affecting the occurrence of calf diseases. In this study 497 cases of 0 to 3 months of age from three different farms were investigated. Calf in Savar Dairy farm (n=249), Talbag Dairy Farm (n=85) and BAU Dairy Farm (n=163) were included from April 2011 to March 2012. The occurrence of diseases were classified on the basis of breed (Local and Cross), age (≤ 3 weeks and >3 weeks), sex (Male and Female) and season (Spring, Summer, Rainy and Winter). The overall diseases were diarrhoea (20.3%), anorexia (9.7%), fever (9.1%), naval ill (8.0%), malnutrition (7.7%), indigestion (6.7%), traumatic injury (5.4%), dysentery (5.0%), myiasis (4.6%), pneumonia (3.4%), alopecia (3.4%), atresia ani (3.2%), hernia (2.8%), constipation (2.6%), abscess (2.2%), conjunctivitis (2.2%), lameness (1.8%), FMD (1.2%) and blot (0.6%). The cases of diarrhoea was higher (20.5%) than that of other diseases. The occurrence of diseases was highly significant (p<0.01) in crossbred calves (77.3%) than that of local bred (22.7%). Cases of diseases were higher in male calves (51.7%) than that of female calves (48.3%) but the variation was insignificant (p>0.05). The effect of breeds on diseases were found significantly (p<0.05) higher in ≤ 3 weeks (55.1%) than that of > 3 weeks of age (44.9%). The occurrence of diseases in calves was significantly (p<0.05) higher in rainy season (36.0%) followed by the summer (31.0%), winter (22.1%) and lowest in spring (10.9%). The results demonstrate significant effect of breed, age and season on the occurrence of diseases in calves.


Introduction
Calf morbidity and mortality are perennial problems for dairy producers worldwide.Calf diseases that cause morbidity and mortality are the results of complex interaction of the management practices and environment, infectious agents and the calf itself.Scours in neonatal period and pneumonia in older calves are known to be responsible for most of calf hood morbidity and mortality (Olsson et al., 1993;Debanth et al., 1995;Sivula et al., 1996).Several environmental and managemerial factors act as risk factors for the occurrence of calf morbidity and mortality (Waltner-Toews et al., 1986;Lance et al., 1992;Bruning-Fann and Keneene, 1992).Crossbreeding program has been taken up as a national policy to develop dairy and livestock industries in Bangladesh.But the calf morbidity and mortality have been recognized as a serious concern affecting the replacement rate and thereby genetic improvement in dairy animals (Debnath et al., 1990(Debnath et al., , 1995;;Hossain et al., 1992a, b;Samad et al., 2001Samad et al., , 2002)).Calf mortality up to 12 months of age has been reported to be 9% under rural (Debnath et al., 1990) and 13.4% under a farm (Debnath et al., 1995) conditions in Bangladesh.Very limited data on the clinical aspects of calf diseases are currently available concerning the important constraints on calf health in Bangladesh.Most of the earlier reports on calf health in Bangladesh have been confined on retrospective studies on the incidence of morbidity and mortality (Hussain et al., 1983;Debnath et al., 1990Debnath et al., , 1995;;Hoque and Samad, 1996;Masuduzzaman et al., 1999;Samad et al., 2001).In addition, some reports on the etiology of calf diseases with especial emphasis to parasites (Ersaduzzaman et al., 1995;Samad et al., 2001) and microbes (Selim et al., 1991;Alam et al., 1994;Hossain et al., 2002) associated with calf morbidity and mortality have been done in Bangladesh.However, Das and Hashim (1996) studied the clinical aspects of some common surgical affection in calves.But the overall diseases occurrence from birth to 3 months of age in dairy farm condition of Bangladesh are lacking.Therefore, the objectives of the current study were to investigate the factors (age, sex, breed and season) affecting the occurrence of calf diseases in some selected dairy farms of Bangladesh.

Study area
This study was conducted from April 2011 to March 2012 in the following area: a) Central Cattle Breeding and Dairy Farm, Savar, Dhaka.b) Talbag dairy farm, Savar, Dhaka.c) Dairy Firm, Bangladesh Agricultural University, Mymensingh.

Calf selection
The diseased calf from birth to 3 months of age was considered.A total of 497 cases of calf diseases in three different farms were enlisted as 249 cases in Savar Dairy farm, 85 in Talbag Dairy Farm and 163 in BAU Dairy Farm.

Data collection procedure
For collection of information required a format that was developed for keeping the records of data (appendix).
The format contained the following information: a) Name of Disease of Calf b) Breed of Calf c) Age of Calf d) Sex of Calf e) Date of Disease Occurrence The data were collected from the monthly report of concern veterinarian of dairy farm.The recorded diseases were diagnosed by the clinical signs, and not confirmed by further laboratory diagnosis.

Case classification
Clinical case records of 497 calves from birth to 3 months old were considered.The recorded diseases were classified into two major diagnostic groups: 1) surgical diseases and 2) Non-surgical diseases.The total diseased calves were further classified based on age, sex, breed and season.

a) Classify of case according to breed
The study calves were divided into the two breeds.These were: (i) Local (Indigenous): Well developed hump.(ii) Cross: Predominant black and white colour, ranging from all black to all white.The hump is not developed.

b) Classify of case according to sex
The sex of study calves were divided into two groups.There were: (i) Male calf: Based on observing the testis.(ii) Female calf: Based on observing the vulva.

c) Classify of case according to age
The age of study calves were determined from the resister book of farm.From birth to 3 months of diseases calves were consider and divided into the following two groups: (i) Birth to 3 weeks: Based on birth record from resister books.(ii) 4 weeks to 3 months: Based on birth record from resister books.

d) Classify of case according to Season
The seasons of diseases occurrence were divided into following four groups: (i) Spring season (February to April) (ii) Summer season (May to July) (iii) Rainy season (August to October) (iv) Winter season (November to January)

Data analysis
The data generated from this study were entered in Microsoft Excel Worksheet and descriptive statistics were performed.The diseases occurrence rate in different analysis was expressed as percentage.Statistics was performed to calculate the percentages of different variant like age, breed, sex and season.The data were analyzed by chi square test using SPSS soft ware version 17.The variation was considered significant when the P value was less than 0.05 and 0.01.

Results and Discussion
This study was conducted to investigate the occurrence of diseases in neonatal calves (birth to 3 months) and the effect of age, sex, breed and season on calf diseases.A survey was conducted in dairy farms.Data regarding the overall diseases occurrence in neonatal calves in three farms are presented in Table 1.The diseases were diarrhoea, anorexia, fever, navel ill, malnutrition, indigestion, traumatic injury, dysentery, myiasis, pneumonia, alopecia, atresia ani, hernia, constipation, abscess, conjunctivitis, lameness, FMD and blot.Among the diseases, highest number of diarrhoeal cases (20.3%) was recorded in calves.Similar result was reported by Samad et al. (2002).Diarrhea occurs due to enteritis.Although there are specific diseases in which enteritis is produced, a sudden change of diet or the feeding of unsuitable or fermentative material gives rise to diarrhea.The parasitic (Samad, 2001 b) and bacterial (Hossain et al., 2002) agents associated with diarrhoea were identified.However, dietary diarrhoea is more common in the neonatal animals which ingest sudden too much milk or a diet which is indigestible.Several studies reported that calf diarrhoea incidence was reduced from 36% to 11% within a year by the introduction of early colostrums feeding and improved housing hygiene (Cockram and Rowan, 1989;Lance et al., 1992).We observed 9.7% calves suffered with anorexia.This result is in support with the earlier report of Samad et al. (2002) who found second highest cases ( 11.0%) of anorexia.Moreover, results regarding the occurrence of other diseases like fever (9.0%), navel ill (8.0%), malnutrition (7.7%), indigestion (6.7%), injury (5.4%), dysentery (5.0%), myiasis (4.7%), and pneumonia (3.4%) are almost similar to the report of Samad et al. (2002).The effects of breeds on disease occurrence are presented in Table 2.This study showed significantly (p<0.01)higher occurrence of diseases in crossbred claves.Hailemariam et al. (1993a) also found higher calf morbidity in exotic breeds than locals.Taurine breeds and their crosses are generally more susceptible to diseases in tropical climates.The occurrence of diarrhoea found to be higher in crosbreed calves (17.3%) and variation was significant (p<0.01) between two breed groups.Similarly, dysentery, navel ill, anorexia, fever, malnutrition, alopacia, conjunctivitis, significantly (p<0.01)affected more crossbred calves.These results might be resulted from the availability of more high milk producing cross breed dairy animals in farm condition, which are more susceptible to the diseases occurrence compared to the local breed.Occurrence of calf diseases in regarding to sex is presented in Table 3. Considering the occurrence of diseases in regard to sex, insignificant (p>0.05)differences were found between two sex groups.Occurrence of diseases was higher in male calves (51.7%) than that of female calves (48.3%).The value of atresia ani was higher in male calves in comparison to female calves.Atresia ani is regarded to be hereditary and due to single, autosomal recessive gene.The diarrhoea, dysentery, navel ill, anorexia, indigestion, atresia ani were found relatively higher in male calves but the malnutrition, lameness, alopecia, abscess diseases were found higher in female calves.Variations were are not significant statistically (p>0.05).Effects of age of calves on diseases are presented in Table 4.The occurrence of overall diseases was significantly (p<0.05)higher in calves of ≤ 3 weeks (55.1%) than that of calves of ≥ 3 weeks (44.9%).This study supports the reports of Virtala et al. (1996a) who reported higher calf morbidity rate during the first month and decrease in mortality rate with the increase in age.Diarrhoea, dysentery, navel ill, atrasia ani were found significantly (p<0.05)higher in ≤ 3 weeks of calves.The malnutrition, fever, anorexia, indigestion etc. diseases found significantly (p<0.05)higher in ≥ 3 weeks of calves.Many calves do not acquire enough immunoglobulins during the first hours of life (Besser et al., 1991).This fact is probably the greatest risk factor for calf diarrhoea during the first weeks of life.Survey on the incidence of umbilical infection showed that the age of calves for its occurrence is usually in the first week of life (Virtala et al., 1996b).According to Britney et al. (1984), it is one of the disease conditions which has serious effect on future survival and productivity of calves.Occurrence of diseases in neonatal in relation to season is presented in Table 5.This study reported higher occurrence of diseases in rainy season (36.0%) compared to summer (31.0%), winter (22.1%) and spring (10.9%) and values differed significantly (p<0.05).This observation agrees with the findings of Haque and Samad (1996) who recorded diseases occurrences in rainy season (41.3%), summer (33.3%) and winter (25.2%).The cases of diarrhoea were recorded significantly (p<0.01)higher in rainy season in comparison to other seasons.This report supports the result of Samad et al. (2004) who recorded higher number of cases of diarrhea in rainy season.Similarly, more cases of dysentery, fever and myiasis was found in rainy season.The navel ill and conjunctivitis recorded significantly (p<0.05)higher in summer season compared to rainy, winter and spring.As the condition is seen commonly during the summer months, it is suspected that ultraviolet light, dust and flies act as predisposing factors (Watson, 2004).One of the most important external factors is the time of year, the number of cases being greater in summer than in winter (Rowlands et al., 1983;Cook, 2003) most likely reflecting the fact that most calf are housed in the winter.Wet weather conditions are also conducive to maintaining high bacterial levels.Lameness in calf tends to increase about three weeks after heavy rainfall (Williams et al., 1986).The pneumonia found significantly (p<0.05)higher in winter.There are seasonal differences in the absorption of immunoglobulins in newborn calves and this could be accounted for the variation in the occurrence of diseases in different seasons (Norheim and Simensen, 1985).