Notes for the Poultry Farmer

New Zealand Journal of Agriculture, Volume 63, Issue 4, 15 October 1941, Page 344

Notes for the Poultry Farmer

Coccidiosis of Fowls

Coccidiosis is one of the most destructive diseases of poultry, and is probably the most prevalent infectious disease attacking poultry in New Zealand. This disease has been reported from many districts in both islands, and the annual loss among infected birds is heavy. It is, therefore, of considerable importance that poultrykeepers should be able to recognise an outbreak of coccidiosis and to know what steps to take to bring such an outbreak under control. How to Recognise Coccidiosis There are two main forms of coccidiosis among poultry. These forms may be distinguished by poultrykeepers according to the age of the

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F. C. BOBBY

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birds attacked. The first, or more acute, form attacks young chickens between the ages of approximately two to eight weeks. This is referred to as caecal coccidiosis, as the internal parasites causing this disease attack mainly the two caeca or blind guts. Often, the first sign of trouble is the presence of one or more dead chickens in a pen, and later the remainder become loose in feather, tend to huddle together, droop their wings, and close their eyes.

A careful examination of the pen will reveal droppings containing blood. If a dead chicken is opened the caeca will be found inflamed and distended with blood. In outbreaks where the disease is less acute, birds may not die so rapidly, and merely show ruffled feathers and general unthriftiness. On opening such birds it is often difficult to detect blood in the caeca, although they are usually enlarged. In these circumstances dead birds should be forwarded to the laboratory (see address at end of article) for examination, and a definite diagnosis of the trouble obtained. The second form of coccidiosis is encountered in older birds, and is not so easy to recognise. This form usually attacks well-grown pullets before coming into lay or when they have been in lay for a few weeks. Birds so attacked show signs of looseness of feather, a false moult, or a drying-up of the comb. These symptoms may be accompanied by lameness in one leg and a loss of eye colour. If such birds are left in the pen they lose condition and gradually “go light.” While mortality is not necessarily heavy, birds

affected in this way rarely recover, and are a big source of danger to healthy stock. This form of the disease is referred to as duodenal coccidiosis, as the parasites attack the lining of the small intestine or duodenum. Unfortunately, it is not always easy to recognise this disease by an inspection of the small intestine with the naked eye. It is therefore essential to send typically unhealthy birds to the laboratory for a microscopic examination whenever this disease is suspected. -. Of the forms described, the second is the most dangerous and should be brought under control as soon as possible. Duodenal coccidiosis may mean the loss of many valuable pullets, resulting in a serious loss in egg production. Cause of Disease J While it is not essential that a poultrykeeper should know the complete life history of the internal parasite.. causing coccidiosis, some knowledge is an aid to-understanding why certain sanitation methods are so important in the control of an outbreak of this disease. Such knowledge also

makes it easier to understand why the possibilities of successful medicinal treatment are so limited. Coccidiosis is caused by . an organism which is invisible to the naked eye. Coccidia are not confined to domestic fowls, but also occur in wild birds and most animals. Fortunately, those species found in animals and birds do not infect poultry, but wild birds will occasionally spread the disease by carrying coccidia organisms on their feet. This may account for some of the sudden outbreaks observed from time to time on new farms and on farms where the disease has not previously been observed. Coccidia pass through a complicated life history, but two main phases of this life cycle are of interest to poultrykeepers. The first stage is when the organisms are living and multiplying in the bodies of infected birds and thus setting up the disease, while the second stage must be completed outside the birds in litter or in the soil over which birds are running. This second stage occurs after the organisms have passed out of infected birds in their droppings. Healthy birds may now k pick up tnese coccidia-infested droppings when feeding, but these organisms must undergo a change, which takes from two to four days, while outside a bird’s body before they can infect a healthy bird. ; This is of

considerable importance, as , will be seen later. A further important fact is that during the second stage spent in the soil the organisms are well protected against cold, draught, and heat, and may, under favourable conditions, remain alive for as long as a year. It is also important for the poultrykeeper to realise that while the organisms are living and multiplying within an infected bird they are embedded in and destroying the delicate lining of the caeca or small intestine.

Treatment and Control No entirely satisfactory medicinal treatment for either caecal or duodenal coccidiosis has yet been found. Medicines which are strong enough in chemical action to destroy the coccidia will also destroy the delicate lining of the intestine itself. On the other hand, it is thought that if an acid condition is set up in the intestines of infected birds the multiplication of the coccidia is checked, while a mild scouring of the bird is set up which causes a large number of the organisms to be carried out in the droppings. It has been seen that these organisms are not able to infect healthy birds for two to four days after leaving the infected birds, so that if these coccidia are ' removed by the careful cleaning of the house they can be burnt before again becoming dangerous. It has been found that this method of attempting to overcome an outbreak is more effective against caecal than duodenal coccidiosis. While it is not intended to suggest that treatment for caecal coccidiosis in this manner is always effective, the following method has been found useful on a number of occasions under practical conditions. Success depends to a great extent upon noting an outbreak at an early stage and acting immediately.

Confine the young chickens to their brooder house pen and remove all. food for 12 hours. Next, supply a liberal amount in ample hopper space of a chicken mash containing 40 per cent, dried milk powder. Leave this special mash before the birds for 24 hours and then remove. Now feed in the ordinary manner for 24' hours, and clean • out the pen thoroughly at the end of this time. Starve again for 12 hours, give the 40 per cent, milk mash for 24 hours, and two days later give a second thorough cleaning to the pen. While carrying out this treatment kill off any birds which are obviously heavily infected with the disease. Such birds are unlikely to recover, and are the main source of danger to the healthy

ones. Remember, the whole chance of success depends upon cleaning the pen and equipment effectively after each feed of the milk mash. Properly soured milk may be used instead of the milk mash described. In this instance, the sour milk is given as the only drink available to the chickens for 24 hours, and then a thorough clean-out of the pen made 48 hours after giving the milk. This may be repeated twice, but because of the acid condition of the milk it should not be given in metal drinkers. It is claimed that treatment with vinegar or Epsom salts has a similar affect to the “milk flush” described above. While vinegar and Epsom salts. are cheaper than milk powder, the

latter has a very definite value as a food, and is particularly helpful to birds suffering from a check due to disease. The main point to note in this type of treatment is not so much whether milk, vinegar/or Epsom salts is used, but that success depends essentially upon the efficient and regular cleaning out at the times stated. Only by the removal of the coccidia which infect healthy birds can this disease be properly controlled. Medicinal treatment is rarely satisfactory in duodenal coccidiosis. Poultrykeepers must realise that the best method when well-grown pullets are attacked is that of rigid culling and strict sanitary measures. Any attempt to retain and treat infected birds is not a sound policy, and will in most cases result in greater total losses finally than iif an early attempt is made to cull out every sick bird. The infected flock should be confined to their house and the litter changed frequently until the infection dies down. Wire-netting must be placed in front of and under the perches to stop the birds having access to the droppings which accumulate during perching hours. Drinking and feeding equipment should be kept clean and thoroughly disinfected from time to time. Poultrykeepers who are in the habit of feeding dry mash are advised to use the wet mash system during an outbreak, and all troughs should *be picked up and placed out of the reach of the birds immediately a wet mash feed has been completed. Grain should be fed in a clean ' trough and not in the litter. Treatment of Housing and Runs \ As soon as a house can be freed of birds after an outbreak of coccidiosis whether caecal or duodenal floor and walls (for the first 18 inches up) should be scraped and thoroughly scrubbed with caustic soda. >lf the floor is wooden, this treatment should be followed by a coat of creosote. or a mixture of two-thirds creosote ; and one-third kerosene. Care must be taken to clean all dirt out of holes and cracks between boards. Where a grass or soil run outside the house is suspected of being contaminated, the area immediately around or in front of the house should be heavily dressed with quick lime and dug over. The run should then be spelled for as long as is possible. Prevention While all birds are liable to be attacked with coccidiosis. it is certain that birds of weaker constitution, whatever their age, are more prone to this disease and suffer most if attacked by it. Therefore, the first essential in prevention is the maintenance of constitution throughout the stock by sound breeding methods and good management. Breeding from poor stock,

small for the breed they represent, and lacking in real vitality, is the first step towards encouraging an outbreak of this disease. It is also a well-established fact that damp litter and floors give ideal conditions for coccidea, so that for the prevention and control of coccidiosis it is important to avoid dampness at all times in both brooder and laying houses. This rule particularly applies to areas around drinking vessels. As droppings are a source of danger, it will be realised that the large quantities which collect under the perches must intensify this danger where the flock are allowed unrestricted access to such droppings. It is therefore suggested that where coccidiosis has once occurred and may easily break out again, the . area under the perches should be wired off against the birds'

in the house. Floor space may be lost, but greater safety is attained. As a safeguard against contaminated runs, annual dressings of quick lime, applied in the winter when the run can be spelled, are advised. The draining of wet runs is a further safeguard against outbreaks. Where farms have been free from outbreaks of coccidiosis, special care should be taken at any time when fresh stock or hatching eggs are introduced. The eggs should be dipped in methylated spirits and allowed to dry before setting, while fresh stock should be placed in a quarantine pen for at least a fortnight and be kept under .close observation. Where Help Can Be Obtained The need for recognising the disease as soon as possible and then of acting

quickly has already been stressed as, an essential in effective control. It has also been stated that difficulties arise in recognising the disease if it is 1 not present in an acute form. For these two reasons poultrykeepers are strongly recommended to forward suspected birdstwo or three if possible to the Chief Diagnostic Officer, Animal Research Station, Wallaceville. A thorough examination will be . made and a report sent back to the poultrykeeper without delay. If serious losses are occurring it is also recommended that the poultrykeeper seek the services of the local Poultry Instructor by writing him at the Department of Agriculture, Auckland, Wellington, Christchurch, or Dunedin, according to the district. Delay is dangerous—act immediately.

Cool Storage Notes

Examination of Stocks in Storage

A T this time of the year the cool storage stocks have been reduced, storage stocks have been reduced, and a number of chambers are holding only relatively small quantities of fruit. It would be advantageous if these small quantities could be transferred to one or more chambers so that these chambers may be filled with fruit, as by this means the correct flesh temperature can be more easily maintained and fluctuating temperatures detrimental to the fruit may be avoided. The Sturmer variety should be placed in a separate chamber owing to the necessity for holding them at a higher temperature. Other varieties, such as Granny Smith, Delicious, and Dougherty, may be held together in another chamber at a lower temperature. The cool storage stocks of apples and pears now being held to supply the market requirements until the end of the year should have been thoroughly examined. Varieties of apples such as Sturmers, Granny Smith, Tasma, Dougherty, and Delicious may be held for a longer - period provided they were picked and placed in cool storage at the correct state of maturity and held under favourable ' cool storage conditions. This also applies to pears still held. The Winter Nelis variety should be carefully inspected, as rots are subject to develop from injury and cause loss by contact with surrounding fruits in the case. Winter Cole and P. Barry should also be carefully examined, as excessive wilt or rots may develop. During August the Dougherty and Frimley Beauty varieties held at un-

suitable storage temperatures developed superficial scald. This form of scald is brought about by the accumulation within the apple tissues of certain gases which are produced by the apples themselves as a result of respiratory activity. Therefore, the lowest temperature at which the variety can be safely held is the best temperature to check respiratory activity and the advancement of maturity, which eventually bring about the accumulation of gases which cause this form of deterioration. Superficial scald will develop '■ more readily on poorly-grown fruit and on fruit which is immature when it is held at unsuitable storage temperatures. ' Faulty or insufficient , ventilation and close stacking of fruit will increase the percentage of loss. Open stacking which will provide air circulation will contribute to the prevention of superficial scald in storage by assisting to maintain the fruit at a low, even, flesh temperature. The Dougherty and , Frimley varieties need to be matured and well coloured when picked and placed in cool storage, and should be held at 33 degrees F. flesh temperature. . . ' The Granny Smith variety is responding to a delay of from 10 to 15 days after picking and before cool storage, as superficial scald is not developing on the fruits either during cool storage or after removal. The use of the oil wraps is also assisting in the prevention of scald and the development of lenticel- rots on this variety.

To prevent wilt development in fruit held in cool storage, and also to preserve its natural bloom 1 and appearance, 90 per cent, relative humidity is desirable in the rooms. An accurate check of the relative humidity of the storage atmosphere throughout the season would greatly assist in improving the results obtained with fruit, particularly when the varieties are . susceptible to wilt development and are being held for long storage. —A. A. POWELL, Cool Storage Officer, Wellington.