Cochin is one of those breeds that has had every color variety bred to it. What that means is a color was introduced, Cochin breeding true to that color. Not many breeds have as many color varieties offered. Orpington, Wyandotte and Plymouth Rock have a lot of varieties to the breed too.
Line breeding is what breeders do to maintain a breed to standard. With your multi color varieties your best representation of a male will be from females that are not to standard and vice versa that poor standard of perfection males are needed to maintain perfect females. Dual mating is where you keep two lines. One being a male line and one a female line. These lines are not bred together. That takes considerable space to achieve. Most small breeders either attempt the best of both worlds (male and females) in one line or stick with female line. I forget what's needed for Partridge color. The color I breed is Silver Pencil. To get the best lacing pattern and complete pattern on females you'd keep males with white speckling on chest. The standard of perfection for males is a solid black breast but in keeping and breeding off standard males you improve the female coloring. Line breeding a female line. You'll never end up with show quality males but will have show stopping females.
Not sure why that was eluding me when submitting earlier. For best males in pattern birds like Partridge and Silver penciled use dark muted females.
