The absence of pullorum-contaminated wild birds inside sublines rather than red-legged young ones is worth discussing
Most likely, a man parents of those specimens was basically homozygous toward gene W. During the a dozen sublines regarding 20, in which male parents was in fact heterozygous (Ww), hens that have pullorum problem have been recognized. Choice about society will be achieved up against the recessive gene w (purple facial skin).
New Prohibited-and-Speckled Leghorn is actually a keen eggs-laying breed however it is too hefty. The new alive lbs out-of 150-day-old pullets is step 1.74 which of mature hens was 2.0-dos.1 kg. This new real time pounds regarding dicks is actually 2.5 kilogram. Ages of maturity is 165 months. Yearly development is actually 220 egg averaging 58 g. Champion layers provide 270-290 egg annually. Egg-shell is solution or white; options is happening getting solution colour. Virility of egg is actually ninety-95% and you can hatchability 80%. Survival rates of one’s young up to 150 times of age are 95%; inside people it’s 87%.
The characteristic feature of the new population is an excellent carcass appearance. In this trait they are superior to all known breeds of coloured chickens which carry the dominant gene E. Barred-and-Speckled hens, when mated with cocks of the C1C2 male parental form from the cross Hysex white, produce three-line hybrid layers, which are as good as four-way hybrids.
Barred-and-Speckled Leghorns is actually bred to own increased egg creation as well as consolidating ability on the mix that have male adult outlines regarding White Leghorns.
Black SPECKLED AUSTRALORP (Cherno-pestraya avstralorp)
An experimental population was created at the All-Union Research Institute of Farm Animal Breeding and Genetics by breeding inter se descendants of Black Australorps which had been injected intramuscularly with https://datingmentor.org/escort/orange/ blood from Barred Plymouth Rocks. The total volume of components injected during 11 months amounted to 330-380 ml per bird. The 1962 experiment resulted in 1093 offspring (F1). Among them were birds in which the juvenile moult produced, instead of black, a partially or completely white plumage. The number of chickens (F1) with depigmentation in groups which received injections of the whole alien blood, plasma, and blood elements was 4 (2.2%), 2 (1.9%) and 1 (0.9%). The control group had no specimens with white plumage.
Mendelian studies indicated that the brand new white shade of the newest plumage during the chickens obtained within this test is dependent on the result out-of the latest semi-dominating gene De- with 40% penetrance during the heterozygotes (Dede). The expression away from depigmentation ranged considerably within the private chickens.
Fresh chickens along with presented a considerable type about down colour of one’s embryo. In addition to black colored, which is typical to possess Australorps, almost light was observed, with many transitions among them. As long as it is good recessive reputation, the fresh mating off heterozygotes should bring twenty five% out of times. The departure of your noticed number (7) regarding officially asked (8-9) looked like not statistically extreme.
Wild birds that have white embryo off have been bred inter se and you may crossed which have birds having most other down colour. In the 1973-74, more 5000 particularly chicks was in fact hatched. Its decisive plumage is actually black having hook depigmentation. It was affirmed you to definitely white colour of the new embryo off try passed down due to the fact a beneficial recessive profile about black and that it’s controlled by new autosomal gene sp (spot). The latest gene sp inhibits melanin synthesis when you look at the homozygotes not only in various generations of plumage, in addition to on shanks. That it advances significantly the appearance of Black Speckled Australorp carcasses (dede spsp), compared to amazing breed – Black colored Australorps (dede SpSp).
Two F5 lady birds put 33 chicks eight (21%) from which were white having a little black spot into straight back
Next reproduction was conducted using this type of group and you will elevating of birds carrying the newest De allele is actually abandoned. Wild birds with white definitive plumage (DeDe SpSp) had eyesight problems followed closely by warning signs of exophthalmos and you may anexophthalmos.