Pig husbandry plays an important role in socio economic development and livelihood of the rural people in North-East India, which accommodates 38.38% of country’s pig population (Livestock Census, 2012). Among the four registered pig breed of North East India, Assam possess only one pig breed known as  Doom pig. This unique germplasm is characterized by medium body size, short ears, black coat colour with thick line of hair (bristle) on the crest extending up to lumber region. They are mainly reared for meat and bristle under migratory scavenging system with minimum input from the farmer’s end and possess some valuable traits such as resistance to diseases and adaptability  to low input management system. However, till to date no field level post registration work has been done on Doom pig.  This  valuable  and  important  germplasm, therefore, needs to be studied in their native tract under the prevailing management system so as to gather information on different body measurements and bristle traits, which can be further utilized for planning suitable breeding strategies their genetic improvement as the body measurements traits can be used to predict body weight at different stages because they are said to have a positive correlation (Bordoloi et al., 1978; Morenikeji et al., 2013 and Oluwole et al., 2014). Therefore, the present study was designed to record the morphometric and bristle traits of Doom pigs under field conditions.

Materials and Methods                                                   

Data pertaining to 247 animals (115 males and 132 females) at different age (birth, weaning and adult) and 40 randomly chosen adult animals (20 males and 20 females) were utilized for the study of morphometric traits and bristle traits respectively covering the breeding tracts of Doom pigs, viz. Dhubri, Kokrajhar, Goalpara, Bongaigaon and South Salmara Mankachar  districts  of  Assam. The morphometric trait under study were recorded using calibrated measuring tape. The bristle length were recorded using measuring scale and the bristle diameter were measured using projection microscope (samples were send to Wool Research Association, Thane, Maharashtra for bristle fiber diameter analysis).

Table 1:  Description of morphometric and bristle traits under study

The morphometric trait and bristle length were expressed in centimeter and bristle diameter was expressed in micron. All the morphometric and bristle traits were recorded by same person to avoid individual variation (Table 1) and the data were classified according to the sex of the animals for morphometric traits and for bristle traits. The data were classified according to sex of animals and location of bristle on the bodynd the statistical analysis was carried out as per the methods described by Snedecor and Cochran (1994).

Results and Discussion

Morphometric Traits

The various morphometric traits of Doom pigs at birth, weaning and adult are presented in Table 2.

Body Length

The average body length of Doom pigs in the present study were 16.83±0.90, 42.06±0.32 and 71.01± 0.59 cm respectively at birth, weaning and adult age. Body length at birth were comparable to the findings reported by Khargharia et al. (2014) in Niang Megha pigs and Doom pigs. Kalita et al. (2018) also revealed comparable body length in Mizo local pigs at weaning and Subalini et al. (2010) in adult Sri Lankan local pig. In contrary, a lower body length at birth, weaning and adult as compared to present finding were reported by Savino et al. (2016) in Naga local pigs and Zaman et al. (2017) in Suwo pigs . However, Banik et al. (2016) revealed higher body length in adult Doom pigs as compared to present findings. The effect of sex on body length found to be non-significant at all the ages except at weaning where female animals exhibited significantly higher (P< 0.01) body length as compared to male. Non-significant effect of sex at birth and adult were also revealed by Banik et al. (2012) and Kalita et al. (2018) in Ghungroo and Mizo local pigs respectively. In contrary, Phookan (2002) reported significantly longer body length for males as compared to females at all ages in indigenous pigs of Assam.

Height at Withers

The average height at withers of Doom pigs were 12.77±0.17, 34.50±0.24 and 58.67±0.39 cm respectively at birth, weaning and adult age. The observed height at withers at birth was in accordance with the findings of Phookan (2002), Khargharia et al. (2014), Savino et al. (2016) and Zaman et al. (2017) in indigenous pigs of Assam, Niang Megha, Naga local pig and Suwo pig respectively.  However, they revealed lower averages for the trait at weaning and adult. Comparable height at withers at weaning in indigenous pigs of Assam and at adult in Doom pig were  reported  by  Deka  (1988)  and  Khargharia  et  al.(2014)  respectively.  However, higher averages for the trait at birth in Bareilly local pigs and at adult in Mali pigs were reported by Chauhan et al. (1992) and Dandapat et al. (2010) respectively. The effect of sex on height at withers  was  found  to  be  significant  (P<  0.01)  at  weaning  only.  Female animal revealed significantly higher height at withers than male in the present study. However, Banik et al. (2016) and Zaman et al. (2017) observed significantly higher height at withers in adult female Doom and Suwo pigs compared to male. Though significant effect of sex on height at withers was reported by Phookan (2002) in indigenous pigs of Assam at birth, weaning and adult which was contradictory to the present findings.

Heart Girth

The average heart girth of Doom pigs in the present findings were 22.75±0.27, 40.32±0.37 and 73.16±0.46 cm respectively at birth, weaning and adult age.  Phookan (2002) reported comparable heart girth at birth and weaning in indigenous pigs of Assam. In contrast to this, lower heart girth at birth, weaning and adult were reported by Khargharia et al. (2014), Savino et al. (2016) and Zaman et al. (2017) in Niang Megha, Naga local pig and Suwo pigs respectively. However, higher averages for the trait at adult were reported by Razmaite et al. (2009) in Lithuanian indigenous pigs and Dandapat et al. (2010) in Mali pigs. The present study revealed significant effect of sex on heart girth at all the ages except at birth. Female revealed significantly higher heart girth than male at weaning (P< 0.01) and adult (P< 0.05). These findings were supported by Banik et al. (2016) and Zaman et al. (2017) in adult Doom pigs and Naga local pigs. Phookan (2002) also reported significant effect of sex on heart girth at all the age where male were found to be significantly heavier than female that is contradictory to present finding. However, non-significant effect of sex on heart girth at different ages were reported by Banik et al. (2012), Borkotoky et al. (2014) and Kalita et al. (2018) in Ghungroo, Naga local and Mizo local pigs respectively.

Neck Girth

The average neck girth of Doom pigs were 16.35±0.25, 36.05±0.24 and 62.25±0.49 cm respectively at birth, weaning and adult age. Neck girth at birth and adult age in the present study were comparable to the findings of Khargharia et al. (2014) in Doom pigs.  However,  in accordance to the present findings, Khargharia et al. (2014) and Zaman et al. (2017) revealed lower  average  of  neck  girth  at  birth,  weaning  and  adult  in  Niang  Megha  and  Suwo  pigs respectively. The effect of sex on neck girth in present finding was found to be not significant at birth and adult, but at weaning, female pigs revealed significantly higher (P< 0.01) neck girth than male. Non-significant effect of sex on neck girth at birth was also reported by Zaman et al. (2017) and Kalita et al. (2018) in Suwo and Mizo local pigs respectively. However, Banik et al. (2016) and Zaman et al. (2017) reported significantly higher neck girth in adult female Doom and Suwo pigs respectively.

Head Length

The average head length of Doom pigs at birth, weaning and adult age were 5.96±0.09, 12.38±0.13 and 22.28±0.23 cm respectively. The present findings were comparable with the observations of Dandapat et al. (2010) and Ritchil et al. (2012) in Mali pigs of Tripura and indigenous pigs of Bangladesh at adult respectively. However, McManus et al. (2010) and Subalini et al. (2010) reported higher head length in adult pigs of Brazil and local pigs of Sri Lanka respectively. In the present findings, sex was found to have significant effect on head length at adult pig only, where female showed significantly higher (P< 0.05) values than male. On the contrary, McManus et al. (2010) reported significantly higher head length in adult male than female Brazilian pig.

Head Width

The  average  head  width  of  Doom  pigs  were  4.41±0.07,  9.67±0.10  and  13.97±0.14  cm respectively at birth, weaning and adult age. The present finding was in good agreement with the findings of Ritchil et al. (2012) in adult indigenous pigs of Bangladesh. However, shorter averages for head width as compared to the present findings was recorded by Subalini et al. (2010) in adult local pigs of Sri Lanka. Effect of sexhas no influence on head width at different age except at birth, where female exhibited significantly higher (P< 0.05) values as compared to male in present observation. The non-significant effect of sex was also observed by Subalini et al. (2010) in adult Sri Lankan indigenous pigs.

Ear Length

The average ear length of Doom pigs were 3.42± 0.07, 6.60±0.07 and 9.81±0.13 cm respectively at birth, weaning and adult age. Comparable values with the present findings at adult age were reported by Ritchil (2012) in indigenous pigs of Bangladesh and Banik et al. (2016) in Doom pigs. However, compared to the present findings; longer average value was reported by McManus et al. (2010)  in adult  indigenous pigs of  Brazil and shorter averages value was reported by Borkotoky et al. (2014) in adult Naga local pigs. The average ear length between the sexes did not differed significantly at different ages under study. Similar findings were also reported by Borkotoky et al. (2014) in adult Naga local pigs. However, McManus et al. (2010) revealed significantly longer ear length in male indigenous pigs of Brazil as compared to females.

Tail Length

The averages for tail length of Doom pigs at birth, weaning and adult age were 5.35±0.09, 12.50±0.20 and 20.22± 0.26 cm respectively. Similar to the present findings were also reported by McManus et al. (2010) in adult indigenous pigs of Brazil and Banik et al. (2016) in adult Doom pigs. However, longer averages for the trait at adult were reported by Dandapat et al. (2010) and Subalini et al. (2010) in Mali pigs and local pigs of Sri Lanka respectively. On the contrary to present finding, Borkotoky et al.  (2014)  revealed shorter tail length in adult indigenous pigs of Nagaland. There is no significant effect of sex on tail length for different age except at birth, where female revealed significantly longer (P< 0.05) tail length as compared to male pigs.  Non-significant effect of sex on tail length was also reported by Borkotoky et al. (2014) in adult Naga local pigs. Contrary to present finding, Subalini et al. (2010) observed significantly longer tail length in male than the female adult Sri Lankan pigs.

Table 2: Mean along with standard errors for body length(BL), height at withers(HAW), heart girth(HG),   neck girth (NG), head length(HL), head width (HW), ear length (EL) and tail length(TL) of Doom pig at birth, weaning and adult

Within parentheses are the number of observations; *: (P <0.05); **: (P<0.01)

Bristle Traits

The mean values along with standard errors for Bristle length (BL) and Bristle diameter (BD) of Doom pigs from different areas of the body are presented in Table 3.

Bristle Length

The bristle length of Doom pigs in the present study was comparable with Ghungroo pigs reported by Mohan et al. (2014). The present findings were also supported by Banik et al. (2016). However, a lower values were reported by Mohan et al.  (2014)  in  Niang Megha, Hampshire and Duroc pigs and Mohan et al. (2015) in crossbred (Hampshire X Ghungroo) pigs. Statistical  analysis  revealed  significant  (P<0.01)  effect  of  sex  on  bristle  length  and  non-significant effect of location on bristle length.  Male was found to have significantly higher bristle length than females. This finding was in consonance to the finding in Doom pig revealed by Banik et al. (2016).

Bristle Diameter

The average bristle diameter was found to be 368.30±6.50 micron in Doom pigs. The present finding was found to be in good agreement with the report of Banik et al. (2016) in Doom pigs of Assam. However, a lower value of bristle fibre diameter was reported by Mohan et al. (2014) in Ghungroo, Niang Megha, Hampshire and Duroc pigs and Mohan et al. (2015) in crossbred (Hampshire X Ghungroo) pigs. There is a significant effect (P<0.01) of sex and location on bristle diameter.  Males were found to have significantly higher diameter than females.  Location wise variation revealed significantly highest diameter in the bristle from withers region of males and neck region of females respectively.

Table 3: Mean along with standard errors for bristle length (BL) and bristle diameter (BD) of Doom pigs

Means with different superscript within a row (upper case) and within a column (lower case) differ significantly. Within parentheses are the numbers of observations

Conclusion

The various morphometric traits of Doom pig reported in the study may serve as baseline information for designing suitable conservation strategies for this native breed. The population of Doom pigs is declining; therefore scientific breeding strategies may be designed for proliferating their population. Study of bristle traits suggested that the bristle of Doom pigs are having unique characteristics in terms of length and diameter as compared to other breeds of pigs. Bristles can be very well utilized in commercial production of combs, brushes, brooms etc. Thus, these animals may be explored for bristle production to substantiate the income of poor farmers.

References

1. Banik, S., Naskar, S., Pankaj, P. K., Sahoo, N. R., Tamuli, M. K. and Das, A. (2012). Effect of different body measurements on body weight in Ghungroo pigs. Indian Journal Animal Science, 82(9), 1094-1097.
2. Banik, S., Naskar, S., Zaman, G., Sarma, D. K., Tamuly, M. K. and Gandhi, R. S. (2016). Doom Pig, An Indigenous Pig Germplasm of Assam. Monograph, published by ICAR-National Research Centre on Pig, Rani, Guwahati, 781131.
3. Bordoloi, T., Raina, B. L. and Bhat, P. N. (1978). Prediction of body weight from linear body measurements in pigs. Indian Journal of Animal Health, 27(2), 149-154.
4. Borkotoky, D., Perumal, P. and Singh, R. K. (2014). Morphometric attributes of Naga local pigs. Veterinary Research International, 2(1), 08-11.
5. Chauhan, V. P. S., Chhabra, A. K., Arora, A. L. (1992). Heritabilities, genetic and phenotypic correlation among body measurement of indigenous pigs. Livestock Adviser, 17(1), 14-
6. Dandapat, A., Dev Choudhury, K. B., Debbarma, C. and Das, M. K. (2010). Phenotypic characterization of Mali pig in Tripura, India. Livestock Research for Rural Development,22(4): http://www.lrrd.org/lrrd22/4/dand22083.htm
7. Deka, A. C. (1988). Performance of local, exotic and crossbred pigs under farm and village conditions. M.V.Sc. Thesis, Assam Agricultural University, Khanapara, Guwahati-22.
8. Kalita, G., Sarma, K., Rahman, S., Talukdar, D. and Ahmed, F. (2018). Morphometric and reproductive attributes of local pigs of Mizoram. International Journal of Livestock Research, 8(2): 173-177.
9. Khargharia, G., Zaman, G., Laskar, S., Das, B., Aziz, A., Roychoudhury, R. and Roy, T. C. (2014). Phenotypic characterization and performance studies of Niang Megha and Doom pigs of North eastern India. Asian Academic Research Journal of Multidisciplinary, 1(27), 2319-2801.
10. Livestock census (2012). Department of Animal Husbandry, Dairying and Fisheries, Ministry of Agriculture, Government of India, New Delhi.
11. McManus, C., Paiva, S. R., Silva, A. V. R., Murata, L. S., Louvandini, H., Cubillos, G. P. B., Castro, G., Martinez, R. A., Dellacasa, M. S. L. and Perez, J. E. (2010). Phenotypic characterization of naturalized swine breeds in Brazil, Uruguay and Colombia. Brazilian Archives of Biology and Technology, 53(3), 583-591.
12. Mohan, N. H., Debnath, S., Mahapatra, R. K., Nayek, L. K., Baruah, S., Das, A., Banik, S.and Tamuli, M. K. (2014). Tensile properties of hair fibres obtained from different breeds of pigs. Biosystem Engineering, 119, 35-43.
13. Mohan, N. H., Debnath, S., Sarma, D. K. and Talukdar, B. (2015). Physical and microscopic characteristics of fiber obtain from crossbred (Hampshire x Ghungroo) pigs. https://www.researchgate.net/publication/303382447.
14. Morenikeji, O. B., Chineke, C. A., Adu, O.A. and Aro, S.O. (2013). Genetic correlation and heritabilities of performance traits among three pig genotypes. International Journal of Scientific & Engineering Research, 4(3), 2229-5518.
15. Oluwole, O. , Tiamiyu, A.  K., Olorungbounmi, T.  O., Oladele-Bukola, M. O. and Akintoye, N. A. (2014). Pre-weaning growth traits in Nigerian indigenous pig crossbreds. Agricultural Science, 5, 891-896.
16. Phookan, A. (2002).  Studies  on  certain  growth,  reproduction  and  biochemical  traits  in indigenous pigs of Assam. M.V.Sc. Thesis, Assam Agricultural University, Khanapara, Guwahati-22, Assam.
17. Razmaite, V., Kerziene, S. and Jatkauskiene, V. (2009). Body and carcass measurement and organ weight of Lithuanian indigenous pigs and their wild boar hybrids. Animal Science Paper and Report. Institute of Genetics and Animal Breeding, Jastrzebiec, Poland, 27(4), 331-342.
18. Ritchil, C. (2012).  Phenotypic and morphological characterization and reproduction attributes of indigenous pig in Bangladesh. M.V.Sc. Thesis, Bangladesh Agricultural University, Mymensingh.
19. Savino, N., Chusi, Z. and Perumal, P. (2016). Growth performance of Naga indigenous pig. Indian Veterinary Journal, 93(05), 19-21.
20. Snedecor, G. W. and Cochran, W. G. (1994). Statistical Methods. 7^th The Lowa State University Press, Ames.
21. Subalini, E., Silva, G.   L.  P. and Demetawewa, C.  M.  B.  (2010).  Phenotypic characterization  and  production  performance  of  village  pigs  in  Sri Lanka.  Tropical Agricultural Research, 21(2), 198-208.
22. Zaman, G., Aziz. A. and Kiba, H. Z. (2017). Body weights and body measurements of Suwo pigs of Nagaland at different ages. The North-East Veterinarian, XVӀӀ (1), 6-8.