POULTRY KEEPING.

Auckland Star, Volume LXIX, Issue 65, 18 March 1938, Page 15

POULTRY KEEPING.

CONTROL OF' PARASITES. UNDER INTENSIVE METHODS. (By ORPINGTON.) Undoubtedly intestinal infestation has become more prevalent, since the adoption of intensive and semi-intensive poultry keeping. Fowls continually running on limited areas eventually pollute the soil, and it becomes what is commonly known as "fowl sick." The average poultry man does not need to be told that the intestinal roundworm is a serious menace to his flock; more and more is he becoming fully aware of that fact. The name "roundworm" is commonly applied to the slender wire-like worms (Ascaridia lineata), from Hin to 3in long, that are commonly found in the intestines. Affected" birds become unthrifty in appearance, their plumage being bedraggled and soiled. Chickens becomo stunt-ed in growth. Unlike the tapeworms the roundworms require no small animal for transmission from one chicken to another. The eggs of the female roundworm pass to the ground. After two or three weeks of incubation the. worm egg. if swallowed by a bird, promptly hatches, and soon becomes a mature worm in the intestine. The female worm lays several thousand eggs daily. These eggs, being protected by a heavy shell, are very resistant to adverse conditions, and ha ve been known to live 100 days in shaded ground Eggs on the surface of the ground may be killed by a temperature of lOSdeg to llOdeg Fall, or by 20deg Fall, below zero. In a series of experiments carried out a<the Kansas (U.S.A.) Agricultural Experiment Station it was found that eggs of the large roundworm placed 011 the surface or buried to a depth of 4in in unshaded soil were killed by the heat of the summer sun. 111 a similar experiment in midwinter all eggs on the surface of the soil were killed at a temperature of 20 deg Fah. below zero, but remained alive at depths of 2in to 4in. Control of Roundworms. For the first ten or twelve weeks chickens should be kept in runs that getplenty of direct sunlight, that have 110 damp spots, and are free from adult birds. Experiments have proved that if thrifty chicks are kept free from worms until they are three months old they will have developed so much resistance that the worms they might get after that period will not seriously affect them. It goes without saying that the birds will have to be given a vermifuge, and although fairly good results have been reported of the tise of 2 per cent of tobacco dust mixed in the mash it really is a matter for individual treatment. Xema capsules have proved very effi- | cient. and another formula which has proved most satisfactory is made by

mixing 7.92 grams of Blackleaf 40 with 10 grams of alkaloidal reagent. After a thorough mixing the powder is then [lacked in No. 2 gelatine capsules in sufficient quantities to weigh, -when filled, :>.->O--100 milligrams. The dose is one capsule each bird. For badly emaciated birds and those under eight weeks of age only half or a quarter of this quantity should be administered. After treatment the poultry keeper must have a thorough clean-up all round to prevent reinfestation from worm eggs already 011 the premises. Chemical sprays are practically useless for this purpose. Reliance should be placed on a thorough mechanical cleaning of the floors of the poultry houses, and the yards should be dug well over or ploughed. One of the most important steps in sanitation is to eliminate "wet spots" in the runs. Marked results have followed the installation of gravel pits covered with narrow chats under all drinking receptacles. The object of this is to prevent birds having access to the usual wet soil surrounding the drinking fountains. Moist soil serves as an incnbatoß for worm eggs deposited in the droppings of infested birds. Caecum Worms. These are small parasites, measuring from Ain to Jin in length, and are found in the caeca or "blind guts" of the intestine. They are often overlooked on account of their size or mistaken for ! young roundworms, and their harmful effects are minimised. As a matter of fact they can be very serious where baby chicks arc concerned. The presence o'f these parasites 011 the walls of these organs interfere with their normal functioning, and may result in the death of the affected chick as early as the tenth day. Owing to the sheltered position they occupy these worms are distinctly diffi cult to eradicate. The same measures as those for dealing with roundworms will largely control these parasites and the microscopic eoccidia, which are minute parasites chiefly of the caeca.