While the genetics of many traits have been studied and are well understood, other traits are influenced by multiple genes and are more difficult to predict. This can be especially evident in the coat colors of cross-bred Boer kids.
The traditional Boer color pattern (red head, white body) is a dominant trait, so that solids bred to traditionals will almost always result in traditional kids, unless the traditional carries a gene for the solid pattern.
With Boers, red is usually dominant to black, so a recessive black gene can be carried for generations until it is matched with another black gene to produce the black color. Many red Boers can be carriers of black but not show it. Rock and Rocket (Reference page) are examples of reds who are black carriers. (There is a dominant black gene which seems to be dominant over most other colors. It is rare.)
The chocolate color results when an otherwise black Boer inherits a modifier gene from both parents, in which case the coat color looks like a very dark reddish brown with black points (legs, tail, ears). Chocolates usually do not have a darker dorsal line like reds.
When bred to reds, chocolates usually produce reds which carry for both chocolate and black.
The red color in Boers appears to be modified by other sets of yet-unidentified genes, so reds can vary from a golden tan to a dark mohogany. Some researchers have called these genes "plus and minus" factors, since some seem to act as diluters of color, while others intensify the color.
Once Boers are bred with other breeds, the possible color combinations are astounding and very hard to predict. The solid white of Saanens and Savannas seems to be dominant to the traditional Boer pattern, although crossbred kids may show a faint tan on their heads and necks. Nubians come in many colors and can produce some interesting kids when bred with Boers. Nubian/Boer crosses are desireable because both breeds have floppy ears, large frames and Roman noses. Nubian milk is high in protein and milk fat.
Spots and dapples have become very popular. The genes which produce these patterns seem to show a partial dominance. A solid red doe bred to a spotted or dappled buck may produce offspring with just a few spots. If those kids are bred to spots or dapples, the resulting kids usually show more spotting and dappling. However, it is possible to get solids from matings between spots or dapples. See photos of dapples & spots below.
Paints are also highly variable and somewhat unpredictable. The paint pattern where the head, neck, shoulders, and hips are colored and a wide white belly band is present seems to be predominant over other patterns.
Crosses of Boers with dairy breeds such as Toggenbergs and Alpines can produce kids with modified color patterns which resemble their dairy parent. You can see examples of frosted ears, facial stripes, dark bellies & light tops, tri-colors, etc.
Breeders wishing to raise meatier goats or does with greater milking and mothering ability are wise to take into consideration which traits are highly heritable and which traits are of low heritability. Here are some production-related traits with their estimated heritability:
High Moderate Low
Mature Weight - 65% Birth Weight - 40% Birth Interval - 5%
Milk Fat - 55% Weaning Weight - 30% Number Born - 15%
Frame - 50% Cannon Bone Width - 45% Udder Support - 20%
Conformation - 50% Yearling Weight - 40% Rear legs - 15%
Milk Protein - 50% Teat Placement - 30%
Carcass Weight - 50% Quality Grade - 40%
Scrotal Circumf. - 50% Feed Conversion -40%
Mothering Ability - 40%
Milk Yield - 25%
Muscling - 45%
Ribeye Area - 45%
Temperament - 25%
Many of the most important traits for producing nice meat goats have high to moderate predictability, so it is to a breeder's advantage to seek out herd sires which are strong in those traits. A herd sire is said to be half of the herd, so an outstanding sire can rapidly improve a meat goat herd if he is selected for his high and moderate heritability traits.
Doelings being considered as herd replacements should score higher than their dams in the important production traits. Does which consistently raise growthy, muscular kids with good temperament and teat placement are often the best candidates to produce nice herd replacements.
Other desireable traits include strong legs and feet, parasite resistance, disease resistance, good teeth, and hooves which don't require freqent trimming. Most of these have a high genetic influence and can be used by breeders as selection criteria as well.
Most breeders like to point out how many ennoblements are in the pedigrees of their Boers, and to some extent, being related to many ennobled goats can be a good predictor of breed character and future productivity. However, having ennobled ancestors does not guarantee that a Boer's kids will look like those ancestors!
It seems that many judges seem to like Boers which are long-bodied with long necks, which can run contrary to the genetics controlling other important factors, such as strong backs, breeding ability, etc. Consider that the bulk of the meat in a goat is in the hind quarters, followed by the shoulder, the neck, and the loin. There is no advantage to having a long rib cage and loin, but a lot of advantage to having heavily-muscled thighs, shoulders, and necks. We need to remind ourselves sometimes that we are breeding meat goats, and not giraffes! See the photo below.
Another Dapple (our Kaboom)
Below: a chocolate kid
Spotted Boer (our Annie)
An example of a Boer doe showing extreme length of body & neck
Another paint pattern