Genetic improvement,
production performance will occur in meat goat herds (purebred and commercial)
only if the breeding stock used are genetically superior, on the average, to
the goats in the breeding herd of the previous year or previous
generation. Improved production should mean improved profits. The
function of performance records is to assist breeders in evaluating the
differences between goats and thus to increase the possibility of selecting
genetically superior animals. This applies not only to your herd but
also in the purchase of replacement stock.
Individual
performance records themselves have a limited value, but when all animals in a
herd group are recorded the comparison of those herd records becomes a very
valuable production tool. The more information a producer keeps the
better. But only if it kept on the entire population and only if it is
kept current. I would caution a breeder who had not kept performance
records in the past to decide to record with a multitude of factors; the task
may soon become overwhelming and be discontinued. Keep it simple and
keep it up.
An animal's
performance is determined by its genetic composition (one half of which was
inherited from the sire and half from the dam) and the environment (nutrition,
health, climate, management, etc.) The primary purpose of measuring and
recording performance on animals is to aid the breeder in determining which
animals are genetically superior. The differences between two goats in the
same group may all be due to genetics differences or none of it. Certain
traits have higher heritability estimates than other. Weight gain,
maternal abilities and feed efficiency have significant genetic
heritability. Reproductive traits are extremely important to
production but have low heritability factors. Carcass traits are highly
heritable but difficult to measure on live animals.
Given the
significance of weight on performance, this is an excellent place to start
your record keeping. Weigh the kids at birth, at weaning, two months
post weaning and / or six months and at eight to ten months. Weights
after one year of age have limited value as most animals which are raised for
consumption will have been slaughtered younger.
High or low birth
weights have genetic significance and also are an indication of the nutrition
the doe received prior to partition. They should also give you an idea
on whether or not you should be looking for an additional kid. When
birthing weights with different sires in the same group of does in the same
birthing season very sufficiently you can assume a higher level of genetic habitability
from a particular sire. Weaning weights give a measure of the kids
performance genetically and also indicate the maternal abilities of the
doe. This will be further confirmed when you weigh the kids two months
post weaning or at six months. If you calculate the average daily gain
from birth to weaning and then from weaning to six months you will determine
genetically superior animals, both does and kids. The does for maternal
abilities and the kids genetic value. You will need to compare kids of
the same litter size to reach valid conclusions; does producing triplets
cannot be compared to does producing singles.
To calculate
average daily gain, subtract current weight from current weigh and divide by
the number of days between weights. With boers you are looking for a
daily average gain of 250 gms. or .5 lbs. Higher or lower values are an
indication of nutrition available and genetic performance, both factors which
you as a produce can have an impact on.
