I'm going to say it might be detrimental to wait so long. Breeding a goat at three years old means she won't kid until she is four, which is fully mature. One thing about younger animals is that their ligaments are much softer and stretchier than older ones. Breeding once they are already fully mature means it may be harder for those ligaments in the pelvis to stretch for the first time and allow kids to pass. I think you're also more likely to encounter problems like cystitis, dry mastitis, and precocious udder. Goats are naturally designed to start having babies at around 1-2 years old. When they wait much longer they tend to be like wethers and pack on weight which can interfere with their ability to come into heat. I haven't bred too many of them so maybe my experiences have been outliers, but I always seem to encounter a grab bag of weird of breeding and birthing problems with older maiden does.
Interesting! Maybe I won’t wait another year to buy a buck. I did notice my maiden doe is rather fat from being an only child to a high producing ff who refused to wean her until 9 months old even after my multiple attempts to intervene. I didn’t know weight could make breeding harder. It might do her good to put her to work, then.
Older maiden does often freshen with poorer quality udders from having low grade dry mastitis along with the other issues listed by [mention]Damfino [/mention]
They are much more likely to have reproductive complications, often from getting too fat.
There are reasons that goats, cows, pigs, sheep, and horses all have pretty standard ages at which they are bred. The time lines are set around what has the least complications and the best for the long term reproductive health of the animals.