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any abnormalities or problems are suspected, a semen evaluation should
be carried out. Many systemic debilitating diseases, arthritis, foot
rot, and scrotal infections can affect fertility of bucks.
9 The Pregnant Doe
Pregnancy diagnosis should be done to ensure pregnancy has occurred
and if not, the situation corrected before the end of the season.
Gestation in goats is 150 days. Pregnancy diagnosis continues to be a
problem in small ruminants. Nonreturn to estrus is the most commonly
used sign of pregnancy. This requires close observations and can be
adequate. If a buck is present, return to estrus determination is
simple.
10 Recto-abdominal palpation with the aid of a rectal probe can be done
with great caution and experience from 70 to 110 days but many
veterinarians find it too dangerous to recommend. After 110 days the
fetuses can be palpated through the abdominal wall. Ultra sound and
radiography pregnosticators are available but the initial expense is a
limiting factor.
11 Milk tests, e.g. available from DHIA labs, can be used at 21 to 23
days post-breeding to detect levels of the pregnancy hormone,
progesterone. Low levels indicate a non-pregnant status. However, goat
owners should keep in mind that an animal detected as pregnant may
later lose the fetus, because goats may be more susceptible to abortion
than cows, particularly during the periods of poor nutrition.
12 Contagious reproductive diseases are not a common problem in goats.
Brucellosis caused by B. melitensis is not found in the United States
although it is a problem in other parts of the world. Goats are
resistant to Brucella abortus, the brucellosis of cows and it is not a
problem. Enzootic abortion, a chlamydial infection, occurs in
California and causes abortions. Characteristically 80 percent of
abortions occur in first and second fresheners and 3 to 4 weeks before
normal kidding. Natural immunity develops and vaccination programs are
effective in problem areas. Whenever an abortion occurs, careful
examination of the aborted fetus(es) and placenta is essential by
submitting to a diagnostic pathology laboratory.
13 The Dry Doe
The pregnant doe should have a 60 day dry period prior to kidding
and should be gaining in condition for the last month before kidding
without fattening. Nutrition must be carefully managed to provide the
necessary nutrients balanced so that no metabolic disorders such as
ketosis and milk fever may occur. About four and two weeks prior to
kidding an intramuscular administration of a selenium treatment (Bo-Se)
at the rate of 1 ml per 40 lb of bodyweight is advisable in selenium
deficient areas such as the Northeast, Mid-Atlantic, Great Lakes, East
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Coast, Florida, and Northwest areas in the US.
14 The Kidding Doe (Parturition)
Attendance at kidding is life saving and cleanliness is very
important. The fetus acquires the capacity for extrauterine life only
shortly before term, and may die in utero if parturition is unduly
delayed. As kidding time approaches, the udder rapidly enlarges, the
pelvic ligaments relax around the tail head, and the vulva becomes
greatly enlarged. Eight to 12 hours before birth, the cervix begins to
dilate and the cervical mucus plug will be in evidence, as a tan,
sticky substance smeared about the hind parts of the doe. This first
stage of kidding lasts 1 to 6 hours. If progress stops, a vaginal exam
with clean, well lubricated hands is in order.
15 Normally the fetus enters the birth canal and the doe starts an
abdominal press. The chorioallantoic sac is ruptured and the unbroken
amniotic sac (water bag) is then forced through the vulva. Delivery of
the kids usually occurs in a short time once the water bag can be
viewed. Kids may be presented either with their front feet forward or
in posterior presentation where their rear feet are presented first.
The doe may rest between each kid for a short period of time. Most does
are best left alone during parturition. Interference with parturition
of does kidding for the first time may result in the doe rejecting the
kids. It is important that does lick the kids as soon as possible after
they are born as this indicates her acceptance of them. Dystocias
(difficult births) are rarely encountered.
16 If labor is prolonged for more than one hour with no progress, a
vaginal exam is again indicated. With multiple births, more than one
fetus may be lodged in the pelvis. Careful sorting is necesary before
delivery is possible. The goat's uterus is very fragile and prolonged
manipulation may result in uterine rupture. ''Ring womb'' occurs,
when, with prolonged labor, the cervix begins to contract, making
delivery impossible. Caesarean sections are done with overlarge
fetuses, monsters, ''Ring womb'' and other dystocia that might
threaten the doe's life.
17 After parturition, the doe should begin to lick the kids, and she
may eat part of the fetal membranes. There is no evidence for benefit or
harm from ingestion of the fetal membranes. Normal kids will start
trying to stand up immediately and should be on their feet and nursing
within a short period of time. It is important that kids nurse the doe
as soon as possible after birth in order to get the first milk or
colostrum. It may be necessary occasionally to help slow or weak kids to
nurse. Kids navels should be dipped in iodine solution. Retention of
the fetal membranes, a condition not uncommon in cows, seldom occurs in
goats. A retained placenta should be treated conservatively with the
exposed portions clipped off. The placenta is discharged naturally 3-5
days if not normally expelled within 6 hours after kidding. Systemic
antibiotics are indicated only if the doe shows signs of illness.
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18 Thorough disinfection of pens after each delivery and especially
after problems is important for successful reproductive management.
Tetanus toxoid and enterotoxemia C and D bacterin injections are
advised after each delivery as well as deworming. Colostrum feeding
should be continued to kids beyond the first hours after kidding for
three days. Excess colostrum can be frozen successfully for later use
in other kiddings. The fresh doe will normally discharge a deep red,
mucus-like material called lochia for 7 to 14 days postpartum. Abnormal
is a large amount of bright red blood, foulsmelling exudate, or pus.
19 The Intersex
The most important cause of infertility in dairy goats is the
occurrence of the hermaphroditism or intersex condition. Affected
animals are more frequently female genetically with a normal female
complement of chromosones (60,XX). They may have a normal size vulva
but an enlarged clitoris and a short or atretic vagina. A penile
clitoris or even an ova testis may occur in does that appear
phenotypically female otherwise. A shortened penis, hypospadias, or
hypoplastic testes may also occur.
20 Both hermaphroditism and congenital hypoplasia of the reproductive
tract are related to naturally hornless or polled goats and are more
likely to occur when both parents are polled. Breeding to horned bucks
will avoid the problem but breeding to horned does can reduce the [ Pobierz całość w formacie PDF ]