WORM INFESTATION

Wairarapa Times-Age, 23 December 1939, Page 3

WORM INFESTATION

TREATMENT OF LAMBS ROTATION IN FEEDING. POINTS OF SOME IMPORTANCE. The signs of worms in lambs are that they handle badly, their coats are dry, and lack bloom and they usually scour. Even more characteristics than leanness, is the fact that they lack vigour and are much too easy to catch. It should be noted that there are other diseases which'give rise to symptoms not unlike worm infestation. For example, lambs suffering from nutritional deficiences, such as pine, tend to lose their flesh and bloom in much the same way as worm-infested lambs. From external appearances, it is often difficult to say whether they are, or are not, suffering from worms. In these circumstances, the wisest procedure is to have a lamb slaughtered and the stomach and intestinal contents examined by an expert, and the number and kind of worms present actually ascertained. This information, combined with the condition and grazing history of the lambs themselves, will usually give the information required. There are several points that should be kept in mind in dealing with the problem of worm infestation in sheep. In the first place, all sheep have worms, and it is impossible to rear grazing sheep free of them. Investigations have shown that even a fat lamb will carry over 4000 stomach worms without showing any signs of ill-health. It is necessary for lambs to carry tens of thousands of roundworms before signs of ill-health and disease are shown. Worms do not multiply within the body. If a lamb contains 10,000 worms, then each of these has been taken in with the grass. on which they have been waiting their chance to gain entrance to the sheep’s intestines. Worms reproduce by laying enormous numbers of eggs which pass out in the droppings, and go through several stages of free-life development, finally reaching a stage, known as infective larvae, at which they are ready to infect other sheep.

RESISTANCE TO DISEASE. The infective larvae cannot live indefinitely on the grass in the absence of sheep. It ha‘s been shown that very few can survive a period of twelve months, so that pasture which has been kept free of sheep for a year, is practically worm-free. If the infective larvae are taken in by horses, cattle, rabbits, or any other animal, they will perish in the animals’ intestines. Once the sheep has reached maturity, it develops a strong resistance to worms, so that most of the infective larvae taken in are destroyed in the sheep. It is well to note however, that this resistance may be broken down if the sheep is under-nourished or grazing on poor pasture. The methods for avoiding losses from worms may be summarised as follows: Avoid overcrowding. Never be tempted to keep more sheep because the grass is plentiful. If the grass is abun-' dant and must be eaten, then stock it with cattle or make it into hay or grass silage. Avoid continuous stocking. Pastures which have been sheeped for several years and are unable to produce healthy sheep should be ploughed up and put under rotation. Applications of lime, salt, or kainit to kill the worms on the grass are useless. In order to produce any appreciable effect, these substances would require to be applied in such large amounts that the grass would be destroyed. The ewes and their lambs should be

given the cleanest and the best grazing on the farm. First year’s grass may be regarded as worm-free, provided sheep have been kept off it during the winter. Resting pastures for a period of say, a month, is distinctly beneficial as it reduces the degree of infection. It follows that the more fields or grazing shifts there are available for the lambs, the less chance have they of becoming heavily infested. In one experiment. worm-free lambs were produced by shifting them on to clean pasture every ten days, for a period of three months. '

VALUE OF GOOD FEEDING. Every precaution should be taken to maintain the standard of the diet. Experiments have proved that a well-fed lamb is not only better able to resist the harmful effects produced by worms, but will actually prevent them from developing within the body. Good feeding, therefore, is one of the best preventives against worms and, in its absence, treatment is seldom effective. Probably more outbreaks of worm diseases take place through un-der-nourishment than any other cause, and it is significant that losses from worms occur mostly after weaning, or the beginning of the autumn, when the quality of pasture is greatly reduced.

The addition of extra feed in the form of concentrates at this period,therefore, will do more to prevent serious loss than any other method. Adopt mixed grazing rather than grazing with sheep only. Grazing cattle along wtih sheep improves the grazing and reduces the number of worms. Worms swallowed by cattle or other animals are unable to devolop and ultimately die.

Where all other methods have failed to effect an improvement, the use of a drench containing copper sulphate and nicotipe sulphate is advised. Experiments have shown that copper sulphate and nicotine sulphate are the best drugs to. use and that they will destroy a large proportion of the roundworms inhabiting the fourth stomach and small intestine.

APPLICATION OF DOSE. The ingredients of the drench arc as follows: — Copper sulphate, crystals (Bluestone), 3oz. Nicotine sulphate, 40 per cent, 3 fluid o'z. Water, 1 gallon. Heat the water in an enamelled vessel and dissolve the copper sulphate as it nears boiling point. This solution of copper sulphate will keep indefinitely in a glass, earthenware or enamleled container, but the nicotine sulphate must not be added until immediately before use. as the mixture will not keep. The doses are as follows: —Adult sheep, 2 fluid oz; well-grown lambs. 1 fluid oz; smaller lambs. A to J-fluid oz. Most farmers find their own method in administering the dose. Three men —one drenching, one preparing the doses and one catching the animals —can complete the treatment of a hundred lambs in an hour. It is not necessary to starve the animals before dosing. Lambs may be dosed every three weeks to a month from the time they are two months old. On ni account give a lamb a larger dose because it appears to be in more need of it than the others.