• Dr Ashok Santra

    Dr Ashok Santra
    Principal Scientist

    Eastern Regional Station National Dairy Research Institute, Kalyani– 741 235, WB

    • Current Research Area
      Animal Nutrition (Rumen manipulation)


    • M.V.Sc (Animal Nutrition)
    • Ph.D (Animal Nutrition)

    Major Research Accomplishments

    Rumen manipulation by defaunation and its influence on nutrient utilization, ruminal methane  production and rumen enzyme profile in growing buffalo calves was studied. Further, rumen fermentation characteristics, its enzyme profile and kinetic in cattle maintained on diets with varying levels of roughage and concentrate was studied. Experiments were conducted to study the comparative rumen fermentation characteristics with special reference to rumen ciliate protozoa in sheep and goats maintained under varying feeding regimen and physiological stages. The locally available feed ingredients particularly top feed resources and low grade roughages were screened for their rumen degradability in vitro, in sacco and in vivo in both sheep and goats.
    Considerable informations are available on growth performance of post-weaner lambs while the informations on influence of pre-weaning nutrition of lambs on its post-weaning gain is lacking. Organized studies on influence of plane of nutrition of lambs in pre-weaning phase on its post weaning growth indicated that 12 % DCP and 58 % TDN in creep mixture was adequate for 150 g average daily gain of pre-weaner lambs. A series of experiment indicated that a sheep (weaned at the age of sixty days) in active phase of growth on an average 150 g average daily gain with 15 – 20 % feed conversion efficiency under intensive feeding on 50 : 50 roughage and concentrate based ration attained 25 kg body weight at five months of age.
    The effect of defaunation on nutrient utilization and body metabolism have been extensively studied on growing lambs. Under a series of experiments conducted on the topic, the dosages of sodium lauryl sulfate as a defaunating agent for complete defaunation of sheep and goats was standardized. The time lag in reestablishment of rumen fauna in sheep and goats after defaunation in mixed herd management was identified. Growth study conducted on post weaner lambs indicated 12% improvement in growth and 18% improvement in feed conversion efficiency in defaunated lambs. Wool production also improved  in defaunated lambs.
    Attempts were made for manipulating rumen fermentation by using natural plant extract in different solvent (water, 50 % methanol and 50 % ethanol) and locally available vegetable oils. It was observed that sunflower oil and guava leave extract reduced the ruminal methane production and ciliate protozoal populations in vitro.

    Recent Projects :

    Project Leader :
    · Rumen Microbial manipulation for mitigation of Methane emission and productivity enhancement in dairy animals.(2007-2012)
    · Dietary manipulation of rumen fermentation to study the nutrient utilization and growth performance of calves. (2006-2009)
    Project Associate :
    · Studies on proximate composition and dietary protein & fiber fractions in concentrate ingredients and fodders at different stages of maturity(2007-2009
    ·  Studies on the effect of oviductal secretary proteins for in vitro maturation and fertilization of cattle oocytes (2008-2009)


    • Appointed as a member of Editorial board for the International Journal viz. Asian-Australasian Journal of Animal Sciences.
    • Awarded best young scientist award (1999-2001) in the field of Animal Nutrition and Feed Technology given by the Animal Nutrition Society of India.
    • Awarded BOYSCAST Fellowship 2001-2002, given by Department of Science and Technology, Ministry of Science and technology, Government of India.


    • Dietary manipulation of rumen fermentation for increased productivity and reduce methane production in ruminant” at Dairy Cattle Nutrition Division, National Dairy Research Institute, Karnal, Haryana, India, from 03.06.1996 to 22.06.1996
    • Technique for estimation of incriminating factor in feeds and fodder” at Animal Nutrition Division, Indian Veterinary Research Institute, Izatnagar, (U.P.), India from 10.09.1996 to 23.09.1996
    • Recent technique in nutritional microbiology and their application in livestock production” at Animal Nutrition Division, Indian Veterinary Research Institute, Izatnagar, (U.P.), India from 29.12.1998 to 23.01.1999
    • Isolation and characterization of rumen fungi and its feasibility for interspecies transinoculation to improve feed utilization” at Commonwealth Scientific and Industrial Organization (CSIRO), Perth, Australia from 04.09.2002 to 03.09.2003.
    • Advances in agricultural research project management” at National Academy for Agricultural research Management (NAARM) , Hyderabad, India from 01.06.2006 to 21.06.2006

    Patents, Technology, Methodology, Genetic Stock, Variety, etc.:

    • Fattening of lambs [In Technology from ICAR, page no. 249]
    • Fabrication of rumen cannulae for sheep and goats [Santra, A., Karim, S.A. and Prasad, R. (2001). Fabricated rumen cannulae to study fermentative digestion in sheep and goats. ICAR News : a science and technology newsletter. 7(3): 14-15. & Santra, A. and Karim, S. A. (2002). Rumen cannulation in sheep and goats: Fabrication of cannulae and surgical procedure for its implantation. Indian Journal of Animal Sciences. 72(11): 978- 980.]


    • Santra, A., Parthasarathy, S and Karim, S.A. (2007). Effect of defaunation on body confirmation changes, wool yield and fibre characteristics of growing lambs in a hot semi arid environment. Australian Journal of Experimental Agriculture 47: 789-795.
    • Santra, A., Karim, S.A. and Chaturvedi, O.H. (2007). Rumen enzyme profile and fermentation charaestersetics in sheep as affected by treatment with sodium lauryl sulfate as defaunating agent and presence of ciliate protozoa. Small Ruminant Research 67(2-3): 126-137.
    • Santra, A., Chaturvedi, O.H., Tripathi, M.K., Kumar, R. and Karim, S.A. (2003). Effect of dietary sodium bicarbonate supplementation on fermentation characteristics and ciliate protozoal population in rumen of lambs. Small Ruminant Research 47(3): 203-212.
    • Santra, A. and Karim, S.A. (2002). Influence of ciliate protozoa on biochemical changes and hydrolytic enzyme profile in the rumen ecosystem. Journal of Applied Microbiology 92(5): 801-811.
    • Santra, A. and Karim, S.A. (2002). Nutrient utilization and growth performance of defaunated and faunated lambs maintained on complete diets containing varying proportion of roughage and concentrate. Animal Feed Science and Technology 101(1-4): 87-99.
    • Santra, A., Karim, S.A. and Chaturvedi, O.H. (2002). Effect of concentrate supplementation on nutrient intake and performance of lambs of two genotype grazing a semiarid rangeland. Small Ruminant Research 44(1): 37-45.
    • Santra, A. and Pathak, N.N. (2001). The effect of dietary concentrate level on rumen enzyme profile and ciliate protozoa population in cattle fed wheat straw diet. Journal of Animal and Feed Sciences 10: 589-604.
    • Santra, A. and Karim, S.A. (2000). Growth performance of faunated and defaunated Malpura weaner lambs. Animal Feed Science and Technology 86(3-4): 251-260.
    • Santra, A. and Karim, S.A. (1999). Effect of protein levels in creep mixture on nutrient utilization and growth performance of pre-weaner lambs. Small Ruminant Research 33(2): 131-136.
    • Santra, A., Karim, S.A., Mishra, A.S., Chaturvedi, O.H. and Prasad, R. (1998). Rumen ciliate protozoa and fibre utilization in sheep and goats. Small Ruminant Research 30(1): 13-18.