The goat population is increasing worldwide and is gaining popularity in Europe due to its lean meat, the annual congress of the Ruminant Veterinary Association of South Africa (Ruvasa) was recently told. Ariena Shepherd, a KwaZulu-Natal veterinarian specialising in the treatment of goats and sheep, spoke about goat management and highlighted a few critical things farmers need to get right.
Regarding goat slaughter weight, the average remains relatively low, says Ariena. Milk production has significantly improved over the past 20 years, with some animals producing 15-18 litres daily.
Goat milk is also becoming more popular. Reasons include the fact that it can be immediately frozen without pasteurisation and it is a good option for children with lactose intolerance.
Goats vs. sheep
Goats have 60 chromosomes (the same as cattle) while sheep have only 54. Despite this, crossbreeding between sheep and goats is possible, and the hybrid offspring can be fertile.
There are approximately 300 goat breeds, including meat, milk, Angora and cashmere goats. The Boer goat bred in South Africa is the only one raised exclusively for meat, and there are more Boer goats elsewhere in the world than in Southern Africa.
The top breeds in South Africa include the Boer, Kalahari Red, Savanna, Angora and Indigenous Veld goats.
Anatomy and behaviour
The pelvis of a goat is smaller than that of a sheep. Ariena says few people can insert their hand into a goat’s pelvis like they can with a sheep. “The uterus is delicate – you can easily tear it. It’s not like a sheep or a cow that has a muscular uterus. Work very carefully with a goat. When you pass through the cervix, the uterus is located entirely downward. Don’t push your hand straight through the cervix into the uterus because it can easily damage.”
Due to the smaller pelvis, kids are much smaller than lambs. While lambs weigh 4-5kg, kids weigh 1.5-2kg.
Does leave their kids during the day, which is normal behaviour. Lambs, by contrast, stay with their mothers often up to a year.
Kids start being left alone after three days, and their mother only comes back to check on them. Kids prefer to lie together in groups and won’t roam around with their mother.
A goat’s tail points upwards, while a sheep’s hangs down. Therefore, a goat should not be sat down on its hindquarters, as its tail could break.
Goats like to clamber on bushes and shrubs. This is why they thrive in areas with poor grazing conditions. If kept in a confined spaces, their behaviour should be considered. Feed troughs should be placed against the side of the pen or a wall to prevent them from climbing in.
Unlike in cattle and sheep, goats’ body condition is not determined on their back but at the front, because their fat is distributed on their chest and abdomen.
Therefore, it must be established how much of the brisket bone and muscles can be felt to determine if the goat is in good or poor condition.
The hornless (polled) trait is an autosomal dominant gene in goats. The intermediate gene is linked to the polled gene. If a polled ram and a polled doe are bred together, it is highly likely that the offspring will be infertile.
“My advice is that the ram should always have horns,” says Ariena.
Some breed societies in European countries require that goats must be polled to be registered, and this is a contentious issue.
Some characteristics of goats without horns include split scrotums, or a goat that looks like a doe but urinates like a ram.
Reproduction
The oestrous cycle of goats is longer than in sheep and lasts 19 to 21 days. Goats are very light-sensitive for mating, especially European breeds. Dairy goats do not breed well during long summer days or cold winter days. They prefer changes in daylight length.
Semen survives for only 24 hours in the female reproductive system. This is very short compared to cattle and sheep, and is something to be kept in mind when artificially inseminating. The maintenance of pregnancy depends solely on progesterone secreted by the corpus luteum.
Pregnant does should not be unnecessarily stressed. Any disturbance, such as transportation, feeding and handling, can lead to abortion or pregnancy toxaemia. If the dead foetus remains in the uterus, the corpus luteum will continue to function. Therefore, a goat should be physically aborted in such a case.
Light can be used to manipulate goats for mating. If goats are placed in a shed and the lights are adjusted to manipulate day length, goats can be brought into heat.
Goats are sensitive to nutrition and will come into heat quickly with flush (stimulative) feeding. When combined with light manipulation, you can expect good results.
Goats do not respond well to hormones. Natural manipulation works better.
The ram effect has a positive impact on goats. When rams are removed from the does for 20 to 25 days and they are not seen, smelt or heard, the does can probably be synchronised after three days when the rams are reintroduced.
When testing rams for fertility, there is a significant variation between seasons and testes and scrotum circumference, unlike in cattle and sheep.
“So, don’t think you have infertile goats if you test them in June and find that the testes are only 28cm. Give them a bit of food, manipulate them with light, and after two months the circumference will be much better.”
Sexual maturity is highly breed-dependent. Goats won’t necessarily become sexually mature faster if they are fed. The sperm cycle of 47 days is similar to that of sheep.
Pregnancy
Because the uterus is positioned downward, the unborn kid lies very low, and this should be kept in mind when handling the pregnant doe.
During late pregnancy, rumen space, similar to sheep, becomes a significant issue. The average goat weighs 60kg, and can compress the rumen severely. Feeding should be adjusted accordingly.
Goats are very susceptible to acidosis, which is nearly irreversible, and they die quickly or may abort in large numbers.
Pregnant goats must be fed with great care, and dietary changes should occur gradually. The protein and energy ratio must be 100% correct.
Goats should preferably be fed standing up during pregnancy.
Abortion diseases
It is important to know that most diseases that cause abortions in goats are zoonotic. Never pick up a foetus with your bare hands.
“Get plastic bags with cable ties, along with a box of disposable gloves, and keep it behind the seat of your truck. Put the foetus in it and tie it closed,” says Ariena
Causes of abortion diseases can include Brucella melitensis, Chlamydophila abortus, Coxiella burnetii, Toxoplasma gondii, Campylobacter and Listeria.
Milk production
Milk production is complex as the process is apocrine, unlike cattle milk production where the process is merocrine. This means the somatic cell count is usually significantly higher.
Goats have a type of cavity at the bottom of their udder where milk collects. About 40% of the milk is held there. This means that when the goat returns to her kid after a day, there is reserved milk for the kid. Goat kids suckle milk only two or three times a day, compared to lambs that suckle continuously throughout the day. Goats sometimes can’t be fully milked because only the lower part of the udder is milked.
Somatic cell counts differ significantly from cattle and should be interpreted carefully. They can vary significantly in a single day, from season to season, and also depending on the stage of lactation.
Internal Parasites
The same internal parasites that affect sheep also impact goats. However, goats’ eye colour is much paler than sheep. When using the FAMACHA system, it should be interpreted accordingly. You will almost never get a healthy red (1), and when the colour goes beyond 3 you are already in trouble.
Levamisole must be used at 1.5 times the sheep dosage to be effective. Wirevax (reg. no. G4200, Act 36 of 1947) is also very effective.
Genetic selection for resistance to internal parasites is just as effective as in sheep. However, it appears that goats have no natural resistance to flukes.
Coccidiosis and Cryptosporidium
Management is the solution to these diseases. If animals walk through the feed troughs or stand in them, problems with cryptosporidium and coccidiosis can arise. Treat does and not lambs.
For vaccination, Scourguard (reg. no. 3841) can be used, with 2ml administered two to three weeks apart in the first year. Thereafter, a booster dose of 1ml is given.
Try to get sick goats into the sunlight as soon as possible, as sunlight kills coccidia.
External parasites
Heartwater is a tick-borne disease that causes significant problems in goats. Ticks can also crawl into the horn base and cause pituitary abscesses. They can also get into the ears.
If a goat walks in circles or presses its head against objects, examine the animal for ticks in the ears and the base of the horn.
Because young goats like to lie around, they can get severe flea infestations and even die from them. Goats can be treated with Frontline (reg. no. G2999). The pen should also be cleaned to help break the fleas’ life cycle. Treatments for mites include pyrethroids, fipronil and macrocyclic lactones. Be careful with doses and weigh the goats beforehand. Do not use an average dose, as goat sizes vary significantly.
If you treat each goat according to a weight of 10kg and one goat weighs only 8kg, administering 25% more than the required dose can result in the animal dying.
Minerals
Goats often have a deficiency in iodine, leading to enlarged thyroids. Zinc is very important, especially for goat hair producers. Goats can easily develop a phosphate deficiency because phosphates are not recycled as they are in sheep.
Goats require significantly more copper than sheep. They perform well on cattle lick blocks, as those have more copper. However, too much copper can impair zinc absorption.
As in sheep, selenium can be an issue, as can cobalt. Ariena says insufficient cobalt levels are similar to symptoms of parasite infestation, and often autopsies and faecal don’t show the presence of coccidiosis. The cause is then probably a mineral deficiency.
Goats require far more salt than other animals because they lose a lot of salt by recycling their saliva.
Vitamins
If goats are fed too many carbohydrates, they develop a deficiency in vitamin B1, leading to polioencephalomalacia (PEM).
Symptoms include shaking and walking in circles. Treatment involves a vitamin B1 injection of 20mg/kg, administered five times every three hours. Feed containing sulfate, such as alfalfa and molasses, leads to acidosis.
Goats also suffer from white muscle disease, similar to sheep, due to a deficiency in selenium and vitamin E.
Common diseases
Goats are much more susceptible to kidney disease and should be vaccinated every six months.
They are prone to abscesses, viral infections of the mouth, like orf disease, and bacterial skin infections due to their habit of climbing and crawling. Goats are very sensitive to anaesthetics. Angora goats easily contract swelling disease, but it is not contagious. This might be due to increased permeability in blood vessels, leading to more release of fluids.
Floppy-kid syndrome can be a problem in goats aged one to three weeks. This is due to lactic acidosis, but the cause of the acidosis remains unknown. Urea exacerbates the problem.
Such animals need bicarbonate of soda and fluids, and this mixture can be administered intravenously or orally. Antibiotics should be administered afterwards, as goat kids are prone to pneumonia. Feeding them can be difficult, as they struggle to swallow. When these measure are combined with high-energy feed, kids can recover quickly.