Genetics and breeding of a black-bone and blue eggshell chicken line. 3. Visual eggshell color and colorimeter parameters in 3 consecutive generations.

The BG line, originated by crossing 2 Chinese indigenous breeds, Dongxiang blue eggshell and Jiangshan black-bone, has been bred for black carcass and blue-greenish eggs. Aiming to study the genetic parameters and selection aspects of these eggshell colors, the 4 colorimeter parameters (L*, a*, b*, SCI = L*-a*-b*) were measured on ∼5 eggs/hen/age (200 d and 300 d) from each hen in 3 generations (G4 = 452, G5 = 508, G6 = 498). Visual eggshell color was classified as either "Light," "Blue," "Green," or "Olive," and data from G4 and G5 indicated that visual eggshell color was more accurately determined by combining the classifications of single representative egg/hen by 4 independent observers.

Genetics and breeding of a black-bone and blue eggshell chicken line. 2. Laying patterns and egg production in two consecutive generations.

The BG line was originated from the cross between 2 Chinese indigenous breeds, Dongxiang blue eggshell, and Jiangshan black-bone, and has been bred to combine dark heavy black-bone body and high production of blue-shell eggs, into single dual-purpose line. Full-pedigree hens from 2 generations, G4 (n = 441) and G5 (n = 464), were reared in the same single-cage laying facility in 2019-2020 and 2020-2021, respectively. Starting from the first egg of each hen, its daily egg production was recorded until 300 days-of-age.

Genetics and breeding of a black-bone and blue eggshell chicken line. 1. Body weight, skin color, and their combined selection.

An experimental population of chickens was developed from the cross between 2 indigenous Chinese breeds, Dongxiang blue eggshell and Jiangshan black-bone. This breeding was aimed at eventually combining dark heavy black-bone body and blue eggshell, into a single dual-purpose breed. BW was recorded and skin L∗, a∗, and b∗ color parameters were measured by a Chroma Meter at several ages (56, 105, 150, 200, 250, and 300 d).

From broiler breeder hen feed to the egg and embryo: The molecular effects of guanidinoacetate supplementation on creatine transport and synthesis.

Supplementation of broiler breeder hens with beneficial additives bears great potential for affecting nutrient deposition into the fertile egg. Guanidinoacetate (GAA) is the endogenous precursor of creatine that is used as a feed additive for improving cellular energy metabolism in animal nutrition. In the present study, we have investigated whether GAA supplementation in broiler breeder feed affects creatine deposition into the hatching egg and molecular mechanisms of creatine transport and synthesis within hens and their progeny.

Dual-purpose production of genetically different chicken crossbreeds in Ethiopia. 2. Egg and meat production of the final-crossbreed females and males.

Females and males of 7 commercial (ComCb) and 3 experimental (ExpCb) crossbreeds were produced by 6 imported parent stocks (PS) and 1 local PS. The ComCb were Dominant Red Barred (DR), Dominant Sussex (DS), Lohmann Brown (LB), Lohmann-Dual, NOVOgen Brown (NB), NOVOgen Color (NC), and local Koekoek (KK). The ExpCb were (dams × sires) DR × KK (R × K), DS × DR (S × R), and KK × DS (K × S).