SHEEP AND PARASITES.

King Country Chronicle, Volume XXXIII, Issue 4800, 21 June 1939, Page 3

SHEEP AND PARASITES.

CAUSE OF MOST LOSSES

CHANGE OF GRAZING GROUND

It is contended by the best authorities that of all sheep troubles at least 75 per cent, of all losses are traceable to parasites. Hidden from view, unseen and unsuspected by the unenlightened sheep owner, they carry on their life of robbery and poisoning. They take the sheep’s blood, its food, and also pollute the victim with their toxins. The warm woolly covering is appreciated by the parasites just as much as it is by the sheep, in that it keeps the parasites warm, supplies part of their living, and is an excellent place in which to rear other generations of parasites. The blood vessels of the sheep’s thin skin and underlying tissues supply an everrunning fountain of food, always in easy reach of the blood-sucking proboscis of the parasite. Nothing could be easier for the parasite—food, shelter, and warmth supplied free, little wonder parasites flourish. Internally conditions also favour the parasite. The first duty of ownership is protection. An understanding of the life history of each parasite is invaluable to the sheep owner if he is to do his part in properly caring for his animals. Pastures become heavy seeded with worm eggs and young worm larvae, due to the fact that all eggs and larvae must pass from the body of the host animal, with the natural discharges. Eggs and larvae do not complete the life cycle in the host animal in which they were released by their parent, but must reach the outride and some under the influence of a temperature lower than that of the host animal. Conditions of moisture must also be favourable if the development of the hatching worm egg is to take place. Danger of Moist Places. The common knowledge that hill land is the safest sheep pasturage is explained by the fact that the lower lands offer better condition for worm egg or larvae development than do the hillsides, which are washed free of contamination with every storm. The dampness of the valleys and the heavy vegetation favour the young worm, in that they afford protection from the wind and sun.

The surface run-off of water from the hills carries with it the worm eggs deposited with the natural discharges from the sheep as they graze the higher ground, this tends to concentrate parasitic troubles on the low areas. Any field with water pools all the time, or only after rains, is an aid in bringing the lambs and parasites together, because the worm eggs or larvae may be washed into such pools, contaminate the water and thereby infest the sheep. The menace of old pastures, where sheep have been running for years, is not generally recognised by sheep owners. The soil surface and grass blades of such places are heavily infested with the young worms or eggs of whatever internal parasites the sheep or lambs may be carrying. The sheep, with its cleft lip, grazes close, the latterly placed eyes do not permit it to see the exact spot from which it is cropping the grass. The worm eggs and worm larvae are too minute to be seen, so the sheep is apt to pick up more than grass when feeding.

The route to the stomach, the intestine and the lungs is short for the parastite that is stealing its way. Give the sheep a chance by allowing them to graze on land free from contamination of the droppings of wormy sheep. Pollution comes quickly; one

sheep heavily infested with stomach

worms will distribute in her discharges not less than 3,000,000 worm eggs each day. This will indicate the necessity for frequent change of grazing ground, the resting of old pasture areas, and the use of care and judgment in the purchase of sheep.