When learning about how Gold and Silver genes work in poultry, it can be very gratifying to realise that much can be made of the sex-linked cross (Gold male over Silver female). This produces sex-identifiable progeny in the day-old offspring (yellow males and brown females).
When it comes to colour, the Silver gene is dominant over Gold and so beneath a Silver Pencilled Wyandotte lies a Partridge Wyandotte, for example. A pure Silver Pencilled Wyandotte male has 2 doses of Silver and the female only has 1. This is because she can only carry a single copy of the gene (on her male sex chromosome).
However, this is not the end of the story. A good job too, otherwise some of the beautiful colours and varieties wouldn't be possible. I'm talking about a kind of Gold that's unaffected by the Silver gene, and this can be found in the breast of the Silver-Grey Dorking female. It can also be observed on the backs of Salmon Faverolles females and other varieties.
Photo Right: Silver-Grey Dorkings with the Ap gene clearly visible in the breast of the female
As I alluded to in a recent article on the subject, there are many factors that got me interested in colour genetics of poultry. One of the main sources was the book 'Bantams in Colour' first published in 1984 by Gold Cockerel books. Little did I know at the time that both Michael and Victoria Roberts would one day become good friends of mine, or that Gold Cockerel would go on to publish 2 of my books!
This book was my 'Bible,' as I referred to it. I was obsessed with all the different colours and patterns of poultry available. Before that, I had only known of hybrids and the odd pure breed such as the Rhode Island Red or Light Sussex.
I was obsessed with certain pages in Bantams in Colour - particularly the Wyandottes and Hamburghs. The different plumage patterns were stunning, and I couldn't help but question if, or how they were all interlinked.
Grant Brereton is a published author and frequently contributes to poultry magazines on a monthly basis. He is editor of UK magazine, Fancy Fowl. He is regarded as the leading authority on poultry plumage genetics in the UK and has produced a number of E-Books on the subject. Here, Grant looks at what is achievable when you focus your efforts...
Whether you are an experienced poultry breeder or relatively new to the hobby, there are some common factors which have to be learnt in order to improve your stock. The principle factor in breeding is the 'art of selection.' This basically means acquiring the knowledge to understand what is and what isn't desirable when assessing the stock you will keep, and what will be moved on to the less 'picky' among us. For example, garden poultry keepers are more than happy to pay a little less (or quite considerably less) for a reasonable example of a breed but which is not quite good enough for the show pen.
Grant Brereton, a lifelong poultry breeder, is an internationally acclaimed authority on poultry plumage genetics and has written a book and several e-books on the subject. Here in part one of his series on poultry plumage, he looks at where it all began...
|The Red Jungle Fowl (Male)|
When learning about poultry plumage there is only one starting point: the Red Jungle Fowl, assumed to be the ancestor of all domesticated fowl.
Although there have been recent studies to suggest that other Jungle Fowl such as the Grey and Green varieties contributed certain attributes, the 'Red' best resembles poultry as we know it and was likely the original ancestor; a theory first put forward by Charles Darwin.
There are only two types of pigment when it comes to poultry: black and red. Black is quite obviously black, but the term 'red' describes a host of tones from the lightest lemon to the darkest mahogany; something to keep in mind.
If you are familiar with showing and breeding then you will almost certainly recognise the reference to a 'line' or a 'strain' and this becomes immediately obvious when you start to look at show winners.
A particular exhibitor will have a row of birds all appearing exactly the same, and in fact the average member of the public visiting the show would be hard pressed to spot even the smallest difference.
This range of related birds will all have been bred in a specific way to maximize the preferred features and minimise or even eradicate those physical traits which fall 'foul' of the breed standards. The line is fixed to such an extent that a judge will recognise instantly a specific breeder's stock, and would even be able to tell which line a new exhibitor's bird originates from.
Following on from Making your Own Line of birds, Laurence Beeken looks at how to fix specific traits into your line, and how to introduce fresh blood when necessary.
So you've selected your birds and your first season has gone well, and now you're ready to look to the future and create the line that, hopefully, will be associated with you and become sought after by those who show and by those who wish to start off.
You are now ready to start fixing the good and eliminating the bad. Remember that the sole point of all of this breeding is to improve the quality of your birds year on year without losing the vigour of the line - both in terms of how robust the birds are and how well they reproduce - a poor doer is unlikely to produce good offspring as weak birds invariably produce weak chicks which are then prone to disease.
Autosexing is when pure bred day old chicks can be sexed by their different appearances when they have hatched. This is a characteristic that is highly desirable so that chicks can be raised as guaranteed pullets, keeping food costs down. There are a number of birds (note: that are pure bred birds) that will autosex, the Cream Legbar being an example. The offspring will breed true and remain autosexing.
If blue birds (genetic code Bb) are mated together, they throw a percentage of ‘off' colours in their progeny (youngsters), the probability being 25% blacks (BB), 25% blue splashed whites (bb) as well as 50% blues (Bb). You need to breed a sufficiently large number to achieve this percentage - since this is a probabilty.
Black and blue splashed whites are homozygous and the blues are heterozygous - i.e. they produce equal number of black and blue splashed white gametes. This can be tested by breeding the blacks or the blue splashed whites with themselves and each will breed true to its respective type. This means they will breed true. The blues will not breed true, they carry two colour genes and no amount of breeding selection will ever make them breed true.
Many years ago, a group of scientists in Cambridge discovered that certain characteristics are passed down from parent birds to their sons and not their daughters and vice versa.
Some of these characteristics are down colours and markings that can be used to identify male and female chicks when they hatch. This is a very useful characteristic for commercial or hobby producers of hybrid laying hens, it effectively halves the rearing costs since unwanted cockerels need not be grown on un-necessarily.