Agriculture Reference
In-Depth Information
litters will tend to grow slower than kids born as single
offspring. Heavier birth weights will result in heavier kid
goats even if the rate of growth is the same as for kid goats
with lighter birth weights. Male kids will have heavier
weight deposition than female kids. Age of the doe will
infl uence growth. Kid goats from yearling does are
expected to grow more slowly than those from older does
that have more highly developed and more productive
mammary systems.
Slow pre-weaning growth may be due to parasitism,
worms or coccidia, insuffi cient milk supply, poor quality
milk replacer for bottle-fed kid goats, or a bacterial or viral
disease. It may be expected that after the fi rst 3 or 4 days
following birth, kid goats will consume 1-2 quarts (1-2
liters) of milk daily. Improved nutrition of lactating does
can increase milk yield and thus increase weight gains in
the kid goats. Growth is higher with ad libitum intake
rather than limited amounts of milk.
of age and should weigh a minimum of 30 pounds (14 kg)
when weaned at this age. Kid goats receiving adequate
nutrition will often have weight increases of 10-15 pounds
(5-7 kg) per month for the fi rst 3 months of age. During
the pre-weaning period, goats can grow up to 0.5 pound
(227 g) per day from grass with some supplementation.
Average feed conversion effi ciency can be from 0.1-0.125
pounds or kg of gain per pound or kg of feed for goats
(Van Niekerk and Casey, 1988).
Comparison of Pre - Weaning Growth Rates
A standard method of comparison of pre-weaning growth
rate is to compare the weight at 90 days of age. This weight
can be determined by adding the birth weight to the average
daily gain over the period of growth of 90 days. This
allows direct comparison of growth between kid goats
weaned at 6 weeks of age (42 days) and those 10 weeks
old (70 days). Adjustments must be made to correct for the
development that occurs at different ages of pre-weaning
growth. Correction factors are based upon litter size, age
of doe, and sex of the kid goat.
After the average daily gain (ADG) is determined,
the 90-day weaning weight is calculated as the ADG
Supplementation during Pre - Weaning Growth
Supplemental nutrients may compensate for a lack of
nutrients by the doe or provide additional nutritional value
through concentrates or grazing high quality forage. The
addition of nutrient value when the doe is providing suf-
fi cient milk is known as creep feeding or, in the case of
forage, creep grazing. Sometimes creep grazing, which is
access to high quality pasture by kid goats and prevention
of access by the does, is used to provide the kid goat with
added nutrition.
Creep feeding or creep grazing usually increases growth
rate pre-weaning and often improves weight gain immedi-
ately after weaning because the goat has been prepared to
consume nutrients from sources other than milk and so is
more prepared for the shock or stress caused by weaning.
Spanish, Boer × Angora, and Boer × Spanish kid goats
were fed milk replacer twice daily until weaning at 8
weeks of age and had ad libitum access to commercial goat
starter (20% CP) beginning at 3 weeks of age. The results
indicated that Boer crossbred kid goats gained more body
weight (0.17 pounds, 74 g) than Spanish kid goats (0.13
pounds, 60 g) from weeks 3-8 (Luo et al., 2000). Pre-
weaning growth will improve by offering creep feed that
is high in crude protein (14-18%) and energy and by pro-
viding access to high quality hay or pasture.
The ability of the kid goat to digest roughage or grain
feeds is determined by development of the rumen. Kids
that receive lower amounts of milk may have rumens that
develop at an earlier age to allow them to eat on their own
and compensate for a lack of milk. It is usually considered
that kid goats should be weaned from milk by 10-12 weeks
9 0
plus the birth weight. When birth weight is not available,
ADG cannot be determined over the entire pre-weaning
growth period. In the absence of birth weight records, the
previous equations can be replaced by 90-day weaning
weight = (weaning weight/weaning age)
×
90. Adjustments
are made to 90-day weights because litter size and age of
doe can affect weaning weight. On average, weaning
weights decrease as litter size increases, and young does
wean lighter kids than mature does. Multiplying the 90-day
weight by the appropriate correction values (Table 13.1)
will result in the adjusted 90-day weight.
Recent data showed that buck kid goats had heavier
birth weights at 7.3 pounds (3.3 kg) than doe kid goats at
6.7 pounds (3.0 kg) while single, twin, and triplet kid goats
had birth weights of 7.9 pounds (3.6 kg), 7.1 pounds
(3.2 kg), and 6 pounds (2.7 kg), respectively. Buck kid
goats gained weight faster than doe kid goats (0.4 pounds
or 183 g) compared with (0.34 pounds or 154 g)). Pre-
weaning ADG is higher for Boer
×
Kiko
crosses (0.40 pounds/day or 180 g/d)) and lower for
Spanish
×
Kiko, and Kiko
×
Boer (0.34
pounds or 155 g/day) crosses. Buck kid goats were heavier
at weaning than doe kid goats (35 pounds or 16.1 kg com-
pared with 30 pounds or 13.6 kg). Single, twin, and triplet
kid goats had weaning weights of 39 pounds (17.7 kg), 33
pounds (15.0 kg), and 26 pounds (11.9 kg), respectively
(Browning, 2007 ).
×
Spanish, Kiko
×
Spanish, and Boer
×
