Ok, the breeding probability is fixed in java code and I will not violate somebody's code. However, I did some experimenting with the configs and achieved some improvements.
By changing a few parameters, one can increase productivity.
By increasing the amount of items dropped and and shortening the time interval between egg lays, one can dramatically increase production and at least use fewer chickens in the chicken farm.
Note: Contrary to popular logic inbreeding results in higher quality eggs(Strength:10,Gain:10,Growth:10) which will do the same thing but also takes a lot of extra time in addition to everything else required to set up a full chicken farm.
Recommend you save a copy of the original config file before editting.
In the example shown one would have to make these changes to each chicken the dev intends to use in a server or private single player modpack. Some chickens will be in chickens.cfg and morechickens.cfg.
SandChicken example in chickens.cfg file
sandchicken {
# Item amount to be laid/dropped. [range: 1 ~ 64, default: 2]
I:dropItemAmount=1 <-------------------------------------------------- change this amount larger
# Item amount to be laid/dropped. [range: -2147483648 ~ 2147483647, default: 0]
I:dropItemMeta=0
# Item name to be laid/dropped. [default: minecraft:sand]
S:dropItemName=minecraft:sand
# Item amount to be laid/dropped. [range: 1 ~ 64, default: 1]
I:eggItemAmount=1 <-----------------------------------------------------change this amount larger
# Item amount to be laid/dropped. [range: -2147483648 ~ 2147483647, default: 0]
I:eggItemMeta=0
# Item name to be laid/dropped. [default: minecraft:sand]
S:eggItemName=minecraft:sand
# Is chicken enabled? [default: true]
B:enabled=true
# Scale time to lay an egg. [range: 0.01 ~ 100.0, default: 1.0]
S:layCoefficient=1.0 <--------------------------------------change this amount smaller
# First parent, empty if it's base chicken. [default: ]
S
arent1=
# First parent, empty if it's base chicken. [default: ]
S
arent2=
# Chicken spawn type, can be: NORMAL, SNOW, NONE, HELL [default: NORMAL]
S:spawnType=NORMAL
}