 |
Broad Leys Publishing - Poultry and Smallholding Books
|
The Bookshop
Bookshop Home Poultry Books Smallholding Books Livestock BooksAbout Us Poultry Articles Poultry Helpline Contact Us
Organisations
PoultryLivestockSmallholdingAgricultural CollegesPoultry SuppliersPigs, Sheep CattleAlpacas & LlamasBees etcPoultry HousingAnimal EquipmentTractors etcDairy & FoodHort SuppliersSmallholder
Poultry breeding
Effect of Light
Effect of Light |
 |
There are many misconceptions when it comes to breeding, if you'll pardon the pun. It's necessary to have good, fertile breeding stock, and to provide the best possible conditions for them. Having an accurate knowledge of the breeding cycle is a good place to start.
Through the winter, poultry have no interest in breeding. There are sound biological reasons for this because, in the wild, the cold weather conditions and general lack of food would mitigate against it. As spring approaches and the day length increases, it is a different scenario.
The effect of increased light has a galvanising effect. As it falls on the bird, it stimulates the pituitary gland of the brain to produce more of the hormone pituitrin. This is transported in the bloodstream to the ovary that is then stimulated to produce eggs.
Good healthy breeding stock is vital
Copyright © Katie Thear 2005
At one time, it was thought that the pituitary gland was affected by the reception of light through the eyes, but recent research has shown that even blind birds respond to increased daylight. It is now thought that the whole head and back area are affected.
Increasing the 'day' by giving a certain amount of artificial light in the house is a routine exercise with commercial flocks, so that the number of eggs does not dip in the winter. It is also a technique that is used by breeders to induce earlier laying so that the breeding season is extended. For best fertility, it is generally recommended to give the male birds extra light for two weeks before it is given to the hens. As with the females, the effect of light is to stimulate hormone production
The amount of extra light needed is not great, and involves two factors: day length and light intensity. The former is the provision of a total of 15 hours of light, made up of natural and artificial light as required. The latter is the degree of brightness and the unit of measurement is a lux. Around 10-lux is the minimum required for a house, and when you consider that 5-lux is the equivalent of side road lighting, it will be seen that the required intensity is not great.
Depending on the size of the house and the flock lighting could be from one 40-watt tungsten bulb, one 6 to 8 watt fluorescent bulb or tube, or one 25-watt bulb. One light source is enough for up to 100 birds. Power sources range from mains electricity to 12-volt car batteries or rechargeable NiCad batteries. Some houses have a photovoltaic (PV) panel so that solar energy is used to provide light inside. As far as controls are concerned, small-scale systems are available where a sensor 'reads' the amount of natural light available and automatically switches on the 12 volt powered source to make up the difference.
The need for light was well known even before the widespread availability of electricity. Traditionally, winter houses were painted white inside to maximise the amount of reflected light. Sometimes, a mirror was placed inside for the same purpose. It is interesting to see that many of the new, mobile houses now being designed for commercial free-range and organic flocks are also white inside. Their smooth interior panels are highly insulated and smooth for ease of cleaning, as well as not providing a haven for pests such as red mites.
Copyright © Katie Thear 2005