By Dr Clive Dalton
- Goats don’t have a split upper lip like sheep so don’t graze as close to the ground.
- They are classical browsers and are used successfully by farmers to graze out weeds and avoid chemical sprays. Offering goats a wide choice of feed can cause problems as they may for example take a liking to feeds of low nutritional value when you want them to put on weight.
- They are effective ruminants relying completely on pasture by about 15 weeks of age when feral goats synchronise their grazing behaviour with their dam.
- Goats seem to be less concerned about eating prickly plants suggesting their lips are different to sheep.
- They eat a lot of roughage that includes weeds, woody shrubs, leaves and bark. They are well known for ring barking trees.
- They eat plants from tip down to base which explains why they are so good at killing gorse and thistles and stopping them seeding.
- Goats will stand on their hind legs to reach up high to browse and will use their front legs to hold branches down. They'll even climb trees to get at leaves. This has a major reason why they have been involved in turning farmland into deserts aided by humans.
- They do not relish clover so goat pastures end up being very clover dominant.
- The key principle of nutrition is that feed intake by the animal must meet its nutritional needs in terms of energy, protein, minerals and trace elements and vitamins.
- Water is important and although it’s not classed as a nutrient, it’s essential for body function. Water must come from a clean source and not from stagnant dams, swamps or dirty troughs.
- The animal’s feeding needs are divided into “Maintenance”, and “Production. Maintenance feed keeps body systems functioning when the animal is standing still in a warm temperature.
- Nutrients for Production are needed over and above Maintenance and are used for movement, grazing, bodyweight, fibre growth and reproduction. More nutrients are also needed if the animal is stressed by cold or disease.
- Goats have a greater level of voluntary feed intake that sheep relative to their metabolic body weight so when fed hay, goats ate more than sheep.
- As ruminants, goats can digest cellulose in plants more efficiently than by any other ruminant. Lignin is plant cellulose that normally cannot be digested.
- As well as feed intake, the digestibility of what they eat is important. Lush pasture is highly digestible but has low Dry Matter, and feeds high in plant fibre have low digestibility and high bulk. All these components have to be taken into account when working out feeding levels.
- In calculating feed requirements, an Angora or feral goat is taken as 0.7 stock units. A stock unit is the feed needed to maintain a 50kg ewe with a single lamb for a year.
- A goat equivalent is another measure used and is a 40kg goat. One goat equivalent equals 0.25 stock units. Note that these values are very crude measures but have been used for years to describe “carrying capacity” of farms.
- Kids are less efficient than calves or lambs when fed milk diets. Kids fed at the same concentration, goat milk, cow milk or milk replacer resulted in similar growth rates.
- Minerals, trace elements and vitamins are important but a balanced diet based on pasture should meet these needs.
- However as New Zealand soils are “recent’ in geological terms, mineral deficiencies such as copper, selenium and Iodine can occur. There are also situations where there can be too much, so for peace of mind consult your veterinarian to have blood and liver tests done on animals at critical times of year such as in mind pregnancy, as their body stores may need to be built up over time like charging a battery.
- With any ruminant, changes in diet should be made gradually to allow the rumen micro-organisms to adapt to any changes. Allow from 4-7 days for complete diet changes, and when starting off on concentrates, feed very small quantities(e.g. <40g/head/day).>
A goat doesn’t eat knowing its nutritional needs. Seeking out fibrous plants or salt may prove this statement wrong, but generally they are mainly interested in feeds that are palatable and to continue eating until they are satiated.
At certain times such as when they are suckling kids we want them to eat as much high quality digestible feed as possible and in winter when pregnant we provide feed for maintenance only so they may be hungry for parts of the day and be looking for a chance to escape to get more feed
Factors affecting feed intake are:
- Type and quality of feed. They will eat more high quality than low quality feed.
- Amount of feed on offer. If you see goats lying contented and cudding after grazing and clearly full, if you open the gate they will generally run to the new feed and start grazing again. Give them more and they will usually eat more.
- Frequency of feeding: If you offer feed many times a day in small amounts goats will eat more than if they are fed in fewer larger feeds. They also waste less when fed more frequently.
- Liveweight. Maintenance feeding needs is related to liveweight so bigger heavier animals will eat more than smaller animals.
- Stage of lactation: A milking animal milking has a high appetite to cope with the nutrient drain from its body.
- Pregnancy: In the last 2-3 weeks of pregnancy rapid foetal growth causes an increase in nutrient needs, but it’s at this time that appetite often drops. This is partly because the rumen is affected by the enlarged uterus and contents but there are also hormonal reasons involved in this appetite drop.
- Activity: It’s a rule of thumb that you should add 25% more to feed allowances for animals that have to graze actively.
Key times for good nutrition
- It’s important to have does in good condition when the bucks are joined with them. It’s been a traditional practice with sheep to “flush” them for about three weeks before joining, and this practice has been applied to goats to ensure good fertility and twinning.
- It’s always difficult (if not impossible) in dry summers leading into autumn to build up quality green feed for mating, so a far better practice is to make sure your goats never get into a skinny state as good body weight is critical in stimulating cycling (as well as declining day length) to start cycling and stimulating good ovulation rates.
- Where good pasture feed is not available, then good quality silage or balage can be used and if finances allow, concentrate feeds at around 50g/goat/day.
- Concentrates should only be needed if goats were in low body condition. Hay has too low a feeding value for this and weeds won’t meet their needs either.
- Coming up to mating, goats should be in as good condition as possible. It’s hard to Condition Score goats compared to sheep, as goats don’t lay down fat as easily as sheep.
- This is especially the case with milking goats that always look thin. But skinny goats are very obvious, and healthy well fed goats should have some fat cover on them.
Liveweight has a very important impact on fertility as the following table for Angora goats shows;
- Good feeding should continue for at least 4-6 weeks after the bucks go out hoping that few animals return to oestrus.
- This is a very critical period for the implantation of the embryo and the establishment of the placenta which has been shown in sheep to be very important in embryo survival later in pregnancy and birth weight and hence survival.
- There’s no reason to assume that goats will be any different. Whether your feeding regime is working is best judged by liveweight and BCS.
Pre- and post-kidding
- These are very important times. In the last 2-3 weeks of gestation the foetus grows rapidly so needs extra nutrients to ensure it has a good birth weight which is critical in survival, but this coincides with a drop in appetite by the dam.
- Then after kidding there is a massive surge of nutrients into milk and this cannot be met from the doe’s feed intake. The doe is described as being in “negative nutritional balance” for at least the first six weeks after birth and it’s a time when feeding concentrates is most cost effective.
- Her needs are often described as 2.5 times Maintenance.
- You cannot overfeed milking does, and do everything possible to get them to eat more and keep on eating such as offering new grazing twice a day.
- Goats cannot be made to eat soiled pasture to graze it out like you can with sheep and cattle.
- Aim to feed pasture of 2500kg DM/ha (700mm high) made up of 70% green content. Don’t make them graze below 500-600mm high so they are getting the most palatable and digestible parts.
- Nibbling weeds won’t do any harm as long as it’s only the very tips which have good feeding value in spring.
- If does were not shorn before kidding, this massive nutritional stress on their system will cause thinning of the fibre, weakness and break.
- Good feeding for at least the first 2-3 days after shearing is a good insurance against any losses due to stress if the weather is cold and wet.
Growing kids – weaners & yearlings
- There is plenty or research is all ruminants to show that feeding and hence growth in early life (pre and post weaning) will affect subsequent weight and production during the rest of the animal’s life. So it’s vital to keep young goats growing well.
- When using milk replacers, it’s never wise to use a cheap product. Feed the best quality product you can find and follow the instructions on the bag to the letter.
- There are plenty of figures for the feed needs of growing milking goats and an example is the table below showing the maximum Dry Matter intakes needed at different weights.
- This is a critical time as from this time, young animals are “on their own” with no more milk supplementation so they should be eating well.
- Kids can be weaned from 5 weeks old but normally weaning is around 2 months of age. Weaning weight should be based on weight and not age.
- A guide is for weaning weight to be at least 3.5 times birth weight and eating concentrates (around 40g/head/day).
- Young goats after weaning need around 1kg of DM/day (pasture plus concentrates) to keep them growing to reach a good weight for mating.