POULTRY-KEEPING

New Zealand Journal of Agriculture, Volume 47, Issue 5, 20 November 1933, Page 325

POULTRY-KEEPING

Special Care for Late-hatched Chickens.

Although the current season for hatching chicks of any breed has now passed, it is safe to say that in many cases where poultry are kept in small numbers, and where broody hens were not previously available, hatching operations will be continued for some time yet; as in such circumstances it means late-hatched chicks or none at all. While it is true that the chicken ' brought out later than the end of October is always more or less undesirable as compared with the early - hatched : bird, yet where the majority of the adult stock kept are old, and have probably passed their best period of usefulness, the question of hatching out some chicks is worthy of consideration, as the late-hatched pullet, if given proper food and attention, can be depended upon to return a better profit than could an old worn-out hen.

The one and only way to counteract the drawbacks of late hatching is by judicious management, so that the birds will be encouraged to develop without check. The first thing necessary is to give a liberal supply of good palatable food, and if the chickens are to make • the best • growth the greater proportion of this food should be provided in moist- form. This applies to the early-hatched birds as well as the late ones. At this period of the year in particular, too much hard dry food tends to retard rather than to advance growth. Even where a prepared commercial food is being used the chickens will do better, except perhaps for . the evening meal, if it is moistened with milk (preferably) or hot water and left to swell before being fed.

The importance of placing late-hatched chickens on fresh ground whenever possible to do so cannot be urged too strongly. Too often these birds make poor growth, and a common cause of this is that . they have to follow stock hatched earlier in the season and are compelled to run on stale and tainted ground. The coop should be repeatedly shifted to fresh ground, and good shelter from wind and shade from summer heat should be arranged, while a constant supply of clean water, charcoal, and grit should be kept before the young birds, and green stuff should be fed in abundance. Cleanliness and the" protection of the birds from vermin are also requirements of special importance. Incubator Chicks dead in the Shell. Many complaints have reached me of late regarding the death of fully developed chicks in the shell. This is the problem of problems to advise upon in connection with the work of artificial incubation. A definite cause is apparently unknown, and indeed it is safe to say from a general standpoint that not one cause but a combination of causes is responsible for this common trouble. On close examination of such eggs for the failure to hatch, sometimes the chicks are found to be in such a position that it would be impossible for them to make the natural turn in order to cut their way out, while in others the chick may be so large that it cannot make the necessary movements to break the shell. Breeding from overfat hens that have' had insufficient exercise, or birds that have been forced for heavy egg-laying after being mated, are undoubtedly common causes of the trouble. . ; •

Probably, however, more fully developed chicks die in the shell owing to the air-cell not being dried down to the right degree than from any other cause. If the air-cell dries down too rapidly in the incubator the lining membrance of the. shell becomes too tough, while the' membrane between the air-cell and the chick is also hardened, hence the condition of the air-cell is such that the chick cannot get through, and as a consequence it dies in the shell. On the other hand, if through improper management of the incubator the moisture in the eggs has .not been absorbed sufficiently the beak of the chick comes in contact with fluid when turning, and consequently it becomes smothered or drowned. The management of the air-cell is therefore a matter of vital importance, for upon . this being brought down to the correct degree, and the membrane at the same time being of the desired condition, the success of the incubation process largely depends.

With the hen there is a natural force always in operation to provide the eggs with just the amount of moisture they need for safe incubation. If there is an excessive supply of moisture in the surrounding atmosphere the hen is capable of restricting the supply of this to the eggs ; whereas, notwithstanding any dearth of humidity in the atmosphere, or moisture in the grass and surroundings, she appears to be quite capable of controlling just the amount of moisture needed by the eggs. With the artificial system it is left entirely to the operator to decide the amount of moisture that should be supplied, and, being devoid of the natural instinct of the hen mother, it is not to be wondered at if he sometimes fails to gauge correctly the moisture required at all stages of the incubation process, especially where the climate is variable and the degree of atmospheric moisture is difficult to determine. .

Artificial incubation, being merely a substitute for a natural process, requires . generally, to be better understood, than it is, and this can only be done by much study and investigation, as even the best makes of incubators require to be managed in accordance with different local and .surrounding conditions. A study, however, of the moisture and the ventilation process appears to be the only means . of improving our knowledge of incubation and of making it a more reliable means of Matching chicks. In view of these facts, and considering that local climatic conditions and the room in which an incubator is being worked play such an important part in incubation work, operators would be well advised to keep a strict record of weather conditions, the ■ range of temperature both in and outside of the incubator, the amount of moisture supplied and the time, and the process of the air cell from day to day. In saying this, I quite realize that nothing can counteract a weak germ due to lack of vigour in the parent stock. The breeding birds should have ample exercise, and the freer the range the better the results. Deformed Incubator Chicks. . Not ■ only is the excessive drying down of the air-cell, and the consequent effect of making the shell membrane tough, a frequent cause of chicks failing to hatch, but it is probably responsible for more deformed chicks being hatched in an incubator than all other causes put together. When the membrane, or the skin on the inside of the shell, becomes tough and the chick has difficulty in piercing it, the constant working in the shell during the effort to get out, and. being too long in the shell, cause the delicate legs and feet, and sometimes the beak, to become injured. To the observant person, a chick thus affected will usually show an inflamed condition surrounding the hock joints for at least a day after being hatched, indicating that undue pressure was necessary during the final effort to break out of its shell.

Once a chick becomes affected in this way little or nothing can be done for it, and usually the limbs will become more and more deformed as the

bird grows older ; therefore the wise course is to destroy it at the outset. The only way of dealing with this trouble is -to prevent it, and the great essential is to prevent, by the application of added moisture, the air-cell from drying down beyond a desired line. It will generally be found that if the air-cell dries down in accordance with the diagrams. contained in the book of instructions supplied with incubators the desired moisture is being obtained. Where washed and unwashed eggs or those of different ages are put into the same incubator it is often a difficult matter to secure uniform air-cells, as obviously the older the egg the larger will be the air-cell. If washed and unwashed eggs or those of different ages are used in the same incubator, a more uniform air-cell can be struck by placing moisture in the machine. for the first . three or four days.

F. C. Brown,

Chief Poultry Instructor, Wellington