|BIRTH WT. EPD: Birth weight EPD is expressed in pounds and is
an indicator of an individual's contribution to its progeny's weight at
birth and is a comparison to breed average. Birth weight seems to affect
calving ease of first calf heifers.
BIRTH WEIGHT: Birth weight
is moderate in heritability and excessive birth weight may increase
calving difficulty. Birth weight seems to have a positive relationship
to yearling growth and each breeder must determine how much birth weight
is acceptable. It seems birth weight will vary from year to year
depending on winter weather and feeding rations. Length of gestation can
also effect birth weight. The unborn calf is gaining about one pound per
day during the last days of gestation.
WEANING WEIGHT EPD: Weaning weight EPD is expressed in pounds
and is an estimate of the amount of increase or decrease in weaning
weight you would expect from the progeny of a bull compared to an
average bull of the breed for weaning weight. It is related to the
genetic growth that a bull will pass along to his offspring.
WEANING WEIGHTS: Actual weaning weight is taken at the time of
weaning. Adjusted 205 day weight is a calf's weaning weight adjusted to
a standard 205 days of age. Adjusting weaning weights allows for
comparison of one bull against another for weaning growth. These
comparisons are only against other animals in a contemporary group in
the same herd where all animals are handled the same. Since adjusted
weaning weights are moderately heritable, choosing bulls with high ADJ
WW can increase that trait in your herd.
YEARLING WEIGHT EPD: The yearling EPD is expressed in pounds
and is an estimate of the amount of increase or decrease in yearling
weight you can expect from the offspring of a bull compared to an
average bull of the breed for yearling weight.
ADJUSTED 365 DAY WEIGHT: Yearling weights are adjusted to 365
day weights to make an accurate comparison of bulls. This comparison is
also made against animals of a contemporary group. Since 365 day weight
is considered highly heritable, choosing for the 365 day weight will
increase growth. There is a direct correlation between birth weights and
increased yearling weights. Accepting a little more birth weight may be
necessary in increasing yearling weight.
MILK EPD: Milk EPD's are a prediction of milking ability of
the bull's daughters. Milk EPD's are not related to teat size or udder
shape of those females.
PELVIC AREA: Pelvic area is one of the factors which
determines calving ease. Pelvic area is attained by multiplying the
width times the depth of the pelvic opening. Pelvic area is highly
heritable and measuring the pelvic area in bulls should be a good
indicator of pelvic size that can be expected in a bull's daughters.
SCROTAL CIRCUMFERENCE: Scrotal circumference is directly
related to mobility and concentration of semen. Bulls with larger
testicle size are more likely to have higher pregnancy rates. Scrotal
circumference is also closely related to age at puberty in both bulls
and females. Maintaining early sexual maturity in larger, fast growing
cattle is among the most important performance traits and is essential