Identification and characterization of dwarf cattle available in Dinajpur district

The present study was undertaken from January to June, 2014 to investigate the morphometric, productive and reproductive characteristics of Dwarf cattle available in Dinajpur District. The data obtained from 200 Dwarf cattle of different categories (yearling bull, adult bull, heifer, cow, male calf and female calf). A wide variety of coat colors among the cattle of the selected areas were found. The head length and width, ear length and width, horn length and diameter, neck length and width, body length at shoulder, wither height, heart girth, fore leg and hind leg length, tail length and diameter, teat length and diameter, distance between fore teats and rear teats, length and width of testis, weight of testis, live weight, daily milk yield, lactation length, gestation length, calving interval, dry period, post partum heat period, age at first heat and service per conception were recorded. The Dwarf cattle in Dinajpur District are comparatively smaller in size than most of the recognized breeds or types of cattle, however coat color showed remarkable variation. The data generated for Dwarf cattle in Dinajpur District would be useful to characterize them.


Introduction
Livestock is one of the major components of agricultural output of Bangladesh which plays a vital role in national economy.In 2013, the contribution of livestock sub-sector to the GDP was 2.95%, which was estimated about 17.3% GDP to agriculture (DLS, 2014).About 36% of the total animal protein comes from the livestock products in our everyday life and 25% people are directly engaged in livestock sector, and 50% peoples are partly associated with livestock production (DLS, 2014).Livestock population in Bangladesh is currently estimated about 25.7 million cattle, 0.83 million buffaloes, 14.8 million goats, 1.9 million sheep, 118.7 million chicken and 34.1 million ducks (Banglapedia, 2012).In spite of a high density of livestock population, the country suffers from an acute shortage of livestock products like milk, meat and eggs.The shortage accounts for 85.9, 88.1 and 70.7% for milk, meat and eggs, respectively (Banglapedia, 2012).The shortage is so acute that alternative protein sources like rabbit meat is under research to fulfill the deficiency (Mobarak et al., 2015).However, the cattle population of Bangladesh is mostly of the indigenous type (Bos indicus) with high amount of Holstein-Friesian, Sindhi, Sahiwal, and Jersey crossbreds.Indigenous cattle posses late maturity, short lactation length, long calving interval and poor production of milk and draught power but are more disease resistant and capable of thriving in harsh conditions (Majid et al., 1992).Exotic breeds often lack of resistance to local diseases and climatic conditions, produce poorly and lack persistency without considerable high quality feed and management.Although milk production of non-descriptive cattle is low, it shows very high adoption to agro climatic condition of the respective region (Khirari et al., 2014).Depending upon the climate, soil type and availability of fodder, different varieties of cattle genetic resources are available in different parts of the country like non-descriptive Local Red Chittagong, Pabna, North Bengal Grey, Madaripur, Hilly and Munshigong (Bhuiyan et al., 2005).Another type of cattle is called Dwarf cattle found in Northern areas of Bangladesh which is very short in size and can produce milk almost throughout the year without sufficient grazing.The Dwarf cattle may be one of such promising variety of domestic animal genetic resource in Bangladesh.The history of the development of this variety is not clear.The productive and reproductive performance of Dwarf cattle has not yet been evaluated.The documented scientific information on various traits of these cattle were not available.Therefore, the present study was undertaken with the following objectives: a) To identify and characterize the Dwarf cattle reared in Dinajpur District of Bangladesh.b) To assess their productive and reproductive performances and comparing with other cattle available in Bangladesh.

Animal selection
In this study, a total of 200 animals were selected from different areas of Dinajpur District.Animals were selected randomly as milch cows, dry cows, heifers, bulls, bullocks and calves.In order to collect relevant information, an interview technique was used focusing on issues such as the livestock population, morphometric characteristics, production potential and reproductive performance.

Questionnaire development
Simple and direct questions were included in the questionnaire for the purposes of collecting information relating to the farmers such as age, production potential, reproductive characteristics, disease incidence, control measures and management of Dwarf cattle.In general, most farmers are not used to keeping any written information (records) on their livestock, so the researchers had to depend on the memory of the respondent for obtaining information.

Measurement procedure 2.3.1. Morphometric traits
Almost all the morphometric traits were measured by measuring tape and expressed as centimeters (cm) except coat color and weight of testicle.The measurement procedure of morphometric traits is shown in Figure 1.

Live weight
Body weight measurements were taken indirectly using Shaffer's method with the help of a measuring tape, i.e, Where, L is length (inch) from shoulder point to buttock and G is heart girth (inch).

Data analysis
The collected data of this study were analyzed and presented using simple statistical techniques.The raw data were entered and sorted into MS Excel spread sheet, then transferred to the analytical software SPSS (Statistical Package for the Social Sciences, version, 16) for descriptive analysis.Compare mean values under pair simple T-test to know different factors.All data were expressed as mean ± SEM.

Ear length and width
The average ear length and width of Dwarf cattle: yearling bull, adult bull, heifer, cow, male calf and female calf were 16.6, 10.1; 17.7, 10.6; 17.4, 9.73; 17.8, 9.89; 11.5, 7.29 and 12.3, 7.16 cm, respectively.The length and width of ear in North Bengal Grey cattle were 18.0 and 11.0 cm, respectively (Al-Amin et al., 2007), which is almost similar with the present results.The ear length of non-descriptive cattle in India (Khirari et al., 2014) was (18.1 cm) nearly similar with the present results.Kayastha et al. (2011) found almost similar ear length (18.1 cm) in indigenous cattle of Assam, India.

Horn length and diameter
The average horn length and diameter of Dwarf cattle: yearling bull, adult bull, heifer and cow were 3.25, 8.67; 4.82, 10.2; 3.67, 9.83 and 5.74, 8.21 cm, respectively.The horn size of native cattle of Sylhet was (3.94 cm) almost similar with that of Dwarf cattle (Koirala et al., 2011).Horn length and diameter of non-descriptive cattle in India were 18.1 and 11.4 cm, respectively (Khirari et al., 2014).The horn length and diameter of North Bengal Grey cattle were 9.0 and 10.0 cm, respectively (Al-Amin et al., 2007).

Body length
The average body length of Dwarf cattle: yearling bull, adult bull, heifer, cow, male calf and female calf were 79.6, 86.1, 77.9, 89.7, 49.8 and 51.9 cm, respectively.Hadiuzzaman et al. (2010) reported that the body length of Red Chittagong cows at 60 months of age was 108.3 cm which was higher than the result (106.9 cm) obtained by Bag et al. (2010).Koirala et al. (2011) observed that the body length of native cattle of Sylhet was 119.9 cm.Body length of non-descriptive cattle in India was 97.3 cm (Khirari et al., 2014).

Wither height
The average wither height of Dwarf cattle: yearling bull, adult bull, heifer, cow, male calf and female calf were 85.6, 90.4, 82.8, 92.2, 63.1 and 63.3 cm, respectively.The wither height of indigenous cattle of Sylhet (Koirala et al., 2011) was (89.0 cm) almost similar with that of the present study.Al-Amin et al. (2007) and Khirari et al. (2014) observed almost similar wither height in North Bengal Grey cattle (91.0 cm) and non-descriptive cattle (84.6 cm) with Dwarf cattle.

Heart girth
The average heart girth of Dwarf cattle: yearling bull, adult bull, heifer, cow, male calf and female calf were 110.7, 116.8, 108.4, 120.3, 67.4 and 67.9 cm, respectively.The heart girth of North Bengal Gray adult cows was (127.0 cm; Al-Amin et al., 2007) almost similar with that of the present study (120.3cm).Khirari et al., (2014) also found similar heart girth (126.9 cm) in non-descriptive cattle.The heart girth observed in indigenous cattle of Sylhet region was 112.1 cm (Koirala et al., 2011).

Tail length and diameter
The average tail length and diameter of Dwarf cattle: yearling bull, adult bull, heifer, cow, male calf and female calf were 72.2, 11.0; 79.2, 12.7; 69.6, 11.1; 78.4, 11.7; 36.8, 7.71 and 35.8, 7.83 cm, respectively.The tail length (71.0 cm) of North Bengal Gray cattle (Al-Amin et al., 2007) was almost similar with the present findings.Kayastha et al. (2011) found that the tail length of indigenous cattle of Assam, India was 54.2 cm.

Teat characteristics
The average teat length and diameter of heifers and cows were 3. 25, 4.88 and 4.37, 5.20 cm, respectively.The teat length and teat diameter in North Bengal Gray cows (Al-Amin et al., 2007) were 5.0 and 6.0 cm, respectively.The average distance between fore teats and rear teats of Dwarf cattle (heifers and cows) were 5.88, 4.0 and 5.71, 4.28 cm, respectively.The distance between fore teats and between rear teats in North Bengal Gray cattle (Al-Amin et al., 2007) were 7.0 and 7.0 cm, respectively, which are slightly higher than that of the present results.

Testis length, width and weight
The average length and width of testis of Dwarf cattle: yearling bull and adult bull were 15.7, 11.1 and 16.6, 11.6 cm, respectively.The average weight of testis of Dwarf cattle: yearling bull and adult bull were 104.1 and 110.6 g, respectively.

Productive traits 3.2.1. Live weight
The average live weight of Dwarf cattle: yearling bull, adult bull, heifer, cow, male calf and female calf were 91.3, 109.1, 85.7, 120.8, 21.7 and 22.4 kg, respectively.The approximate live weight of indigenous cattle of Sylhet region (Koirala et al., 2011) was significantly higher (162.8kg) than the Dwarf cattle.Al-Amin et al. (2007) observed that the body weight of North Bengal Grey cow of Pabna District was 241.0 kg, which is higher than the present findings.

Daily milk yield
The average daily milk yield of Dwarf cows was 1.70 liter per day.The milk yield per day was lower (1.33 liter) in native cattle of Sylhet (Koirala et al., 2011) than that of Dwarf cows.Bhuiyan et al. (2007) also observed higher milk yield in Pabna cattle (2.81 liters).Khirari et al. (2014) found that the daily milk yield was 1.62 liters in non-descriptive cattle.Al-Amin et al. (2007) found daily milk yield in North Bengal Gray cattle was 3.0 liters.

Lactation length
The average lactation length of Dwarf cows was 240.0 days per lactation.Uzzaman et al. (2011) found almost similar lactation length (253.5 days) in Munshiganj cattle.The lactation length of native cows in Sylhet region (Koirala et al., 2011) was lower (187.9days) than that of Dwarf cattle.Al-Amin et al. (2007) observed that the lactation length of North Bengal Grey cattle of Bangladesh was 219.0 days, which is slightly lower than that of the present finding.

Reproductive traits 3.3.1. Gestation length
The average gestation length of Dwarf cows was 275.8 days.The gestation length of indigenous cows of Sylhet region (Koirala et al., 2011) was slightly higher (299.2days) than that of present result.Al-Amin et al. (2007) observed almost similar gestation length (281.0 days) in North Bengal Grey cows.Bhuiyan et al. (2007) observed almost similar gestation length for Red Chittagong and Pabna cattle (283.0 and 282.0 days, respectively).Uzzaman et al. (2011) found significantly higher gestation length (309 days) in Munshiganj cattle than that of the Dwarf cows.

Figure 1 .
Figure 1.Measuring of body length of a dwarf heifer.