Translation from Germany A.Z. Nachrichten. Organ der Austauschzentrale der Rogelliebhaber und Zuchter Deutschlands (AZ) e.V. by Brigitte Hilmer, U.K.
Disorders and diseases of the different parts of the female sexual organs (Ovaries) can lead to a stop of production of eggs and a complete cessation of the function of the ovaries. These disorders can be hereditary or develop later on, caused through changes of the glandular function responsible for internal secretion (Thyroid Gland).
The infertility of a female can be easily recognised by successively mating it with 3 different birds. If the female lays unfertilized eggs with every one of them, then it has been unquestionably proven that this bird is sterile.
Disorders of the ovary, hormone disorders, or disorders caused by a tumour (growth), but also infections, can prevent the ripening and loosening of the egg from the ovaries or produce infertilizable eggs. The same applies to infections or poisoning, to weakness and senility (sterility due to old age), as well as unfavourable environment. Females laying for the first time, show a considerable amount of unfertilized eggs, sometimes up to 50%. This initial infertility will cease quickly, however. Very often, unfertilized eggs are laid by older females, usually when the laying periods follow closely, i.e. when the female is ready to mate again quicker than the cock, who usually takes more care of the feeding of the young.
Looking at this quite common occurrence (which breeder has not been unhappy about the continued over-quick laying of some of his females) with a view to hormones, then we notice that in the females which are ready for mating too soon the hormone Prolaktine which is responsible for the hatching and feeding instincts, has reduced more quickly than it does in the cock, and the opposite force to the Prolaktine, the Prolan A, has taken over the reign of the female's sexual instincts too soon and given orders to the ovaries for a renewed laying too early.
Such females - with a short "Prolaktine Period" are also bad feeders of their young. Among the feed-factors, which play a significant role in the reproduction, total or part-deficiencies (probably Vitamin deficiencies) must be stressed.
The deficiency leads to a reduction or complete cessation of the functions of the sexual organs.
Overfeeding, something that surely every breeder has experienced is also disadvantageous.
The influence of Amino-acids, mineral and vitamin substances on the sexual sphere is well known. An insufficient amount of Vitamin B can lead to a degeneration of the sexual glands (ovaries and testicles will shrink). An addition of yeast (yeast contains Vitamin B) to the feed has therefore shown good results.
The same causes which are responsible for the female sexual malfunctions can also affect the sperm production by the cock. Scientists discovered that the absence of Vitamin B leads to the degeneration of the thin tubes in the testicles and to an abnormal growth of the cells in the tissues of the testes.
The total of partial absence of testicle-secretion, which is caused by feeding disorders, leads to a suppression of the sexual instinct, and coitus-difficulties during mating, e.g. the appearance of feathers around the anus which are stuck together with excrement, or the overcrowding of the breeding area in a colony aviary and the presence of a number of unmated birds (male and female), increase the percentage of unfertilized eggs.
Disorders of the ovaries of the female which prevent the spermatozoon from wandering upward inside the fallopian tubes also lead to fertility disorders.
There are many causes for the death of a young life inside the egg, and every bird-breeder has no doubt experienced these deaths quite frequently. The death of the embryo in the eggshell, equivalent to a miscarriage in mammals, can occur during any stage of the development, from fertilization to hatching. According to my observations there are 2 periods during which the life of the embryo is most endangered. These periods are between the 1st and 4th day (with the height of danger between the 2nd and 3rd day) and during the last 2 days of hatching time. The death of the embryo inside the egg can have several different causes.
These causes can be hereditary (fatal factor), physiological (composition of egg, retention inside tubes, hatching time), food (Vitamin deficiency) and physical damage (damaged tubes). Early fatality (1st to 4th day) is caused for example by genes within the structure of the egg, by the retention of the egg inside the tubes (retarded hatching) and by the hatching conditions (oxygen). The fatality at a later stage is usually due to unsatisfactory hatching conditions, like lack of humidity, wrong position of embryo inside the egg, paratyphoid through deformity, unnatural changes inside the fallopian tubes, mainly inside the shell chamber (too thick, too thin, or too rough).
The death of the embryo can also be due to incomplete hatching (hatching temperature as well as the oxygen content in the air being too low). A prolonged absence of the parents from the nest can have different reasons for instance this can be caused by hormone disorders, causing the deterioration of the hatching instinct, or the birds might suffer from parasites making them restless, or sometimes a bird having very long claws might, in his over-enthusiasm or shyness during mating, damage the eggs.
Embryos from sick, weak or old parents and those who do not have sufficient nourishment available in the egg, or who are the result of a failed inbreed-mating, often do not have the strength to crack the shell should this happen to be a little harder than normal. They will therefore die inside the egg, and we will find them completely developed when opening the egg later on. The dampening of the eggs with a very hard shell can assist the young birds to hatch. The cracking of the shell is extremely difficult or even impossible, should the embryo lie in the wrong position, or if it should be deformed, or in the case of a twin-egg (an egg with two yolks).
Vitamins are organic substances, mainly developed by plants and given to the birds with their feed. Even small amounts can be effective (as is the case with hormones). Vitamins are essential for life. Lack or deficiency cause specific diseases, the so-called Avitaminoses, or Vitamin Deficiency diseases. Vitamins often have a close relationship to hormones, and they act either in cooperation with, or in opposition to them.
Vitamins are also essential for ensuring a complete development of the embryo, to prevent its death inside the shell, and to guarantee a normal growth of the young.
Vitamin A - The simple addition of codliver oil to seeds will increase the number of hatchings. On the other hand, females who have received no or insufficient amounts of Vitamin A will lay eggs which do not hatch, even after they have been fertilized and have developed. So Vitamin A is essential in order to ensure the complete development, as well as the hatching of the egg. There will have to be at least 300 units of Vitamin A present in the egg. This minimum amount must be given to the bird by way of enriched diet before the mating.
Vitamin D - This is also contained in codliver oil but plays a different role to that of Vitamin A. It will give enough strength for hatching. It is not sufficient simply for an egg to be fertilized. It is also important that the embryo hatches out of the egg at the right point in time. Vitamin D gives the embryo enough strength to crack the shell and hatch out at the right time.
This vitamin is so essential that birds who do not receive any Vitamin D will lay eggs which later on cannot hatch, even when all other Vitamins and Minerals were given in the feed. The Vit D in the codliver oil can only take complete effect with UV treatment and if in addition raw milk, vegetables and greens are fed.
The Vitamin A in codliver oil (1 gramme normally equals 1000 units) is not very durable and is destroyed by heat, oxygen in the air and by light. Vitamin D (about 100 units in a gramme) on the other hand, is durable. In order to preserve Vitamin A the bottle containing the codliver oil should be stored in a cool and dark place. Therefore, codliver oil is being traded only in brown bottles. As the content of the bottle reduces, the remaining oil will be affected by the oxygen contained in the air-space above the oil in the bottle and the Vitamin A content will be reduced by oxydation.
It is therefore recommended to buy codliver oil in small quantities which can be used up quickly. It is not advisable to use codliver oil which has been left over from the previous year. The bottle to be newly filled, should be completely clean. It is in fact best to use a new bottle each time. Good, fresh codliver oil does not have a fishy taste and can even be used for baking!
If you want to give your birds additional codliver oil, then you should mix it just before feeding with the seeds, so that the birds get the benefit of the Vitamin A before it is destroyed by the oxygen in the air (oxydation)
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