Experimental copper and manganese depletion by Phalaris minor and concurrent paramphistome infection in sheep

To confirm that staggers like nervous symptoms reported in sheep of Haryana and Uttar Pradesh states of North India, during winter months were due to Phalaris minor toxicity and also to see the effects of concurrent paramphistomosis on aggravation of P. minor toxicity symptoms and redistribution/deficiencies of certain trace-elements in P. minor fed sheep, the present experiment was planned. Three groups of four sheep each were kept on standard feeding schedule for 21 days. Then, all the animals except control group (Gp. III) animals were fed exclusively P. minor. Group-I sheep were infected with 6000 paramphistome metacercariae and Gp.-II animals were kept purely on P. minor. The blood samples were collected at fortnightly intervals to estimate copper (Cu) and manganese (Mn) for 45 days. At the end of the experiment, the animals were sacrificed and trace elements (Cu and Mn) in liver, spleen, heart, kidney, brain and spinal cord were analysed. Phalaris minor toxicity was produced successfully in sheep infected with paramphistomes. Lung haemorrhages were the consistent finding in almost all the animals. Copper levels reduced significantly in liver, spleen and spinal cord due to P. minor feeding. Paramphistome infection further reduced the Cu levels in the spinal cord. Manganese levels in heart and kidneys reduced significantly due to Phalaris feeding. An animal which showed the nervous signs was found to have very low levels of copper and manganese in the spinal cord. Thus, it is concluded that in addition to effects of alkaloids, low levels of copper and manganese appear to be predisposing factors for the development of stagger like symptoms in the affected animal.