Effects of Commonly Used Chemical Fertilizers on Development of Free-Living Stages of Haemonchus contortus in Experimentally Infected Pasture

Aim: The effects of N-P-K fertilizers in the form of urea, single super phosphate and muriate of potash on development of free-living stages of Haemonchus contortus were studied.

Materials and Methods: Five parasite free experimental plots of 1 m×1 m area, each of paddy leaves (15-day-old) and an equal number of Cynodon dactylon grass were infested with about 10×10⁴ eggs/ml phosphate buffer saline along with the application of the calculated amount of fertilizers solution. On the 10^th day of posttreatment, the pasture was cut, processed, larvae recovered by Baermann method and counted, which was expressed as number of L₃ per kg dry matter (DM) of pasture.

Results: The average recovered population of L₃ of H. contortus per kg DM varied significantly (p3 recovery per kg DM of paddy (19512.7±50.80) was more than that of Cynodon grass (16540.9±50.80). Larvae recovery per kg DM for different pastures under treatment were in decreasing order as follows: T-2 of paddy (6981.33±50.80, 35.77%), T-2 of Cynodon (5545.38±50.80, 33.52%), T-3 of paddy (317378±50.80, 16.26%), and T-3 of Cynodon (2218.72±50.80, 13.41%) which showed significant difference (p<0.05) among the treatments. In T-4 (paddy) and T-5 (Cynodon), the average number of recovery of larvae was nil implying no significant variation (p>0.05).

Conclusion: This study shown that when N-P-K fertilizers administered at recommended level, significantly reduced larval translation of H. contortus minimizing pasture infectivity for the free range grazing animals.