B13

Manager's Guide for Breeding Fibre Goats

PART 2: Pregnant and Lactating Does.

• Bruce McGregor, Goat Specialist Agriculture Victoria, Attwood, 3049, VIC.

Summary

The paper recommends the following "best bet" management practices to maximise reproductive performance of pregnant does and survival of kids.

1. Stocking rate. The dry sheep equivalent of breeding does is approximately 1.5 DSE plus 1.4 DSE per doe if kids are kept past weaning. Goats should not be grazed at greater than 7.5/ha. Ideally, does should be body condition score 3 at kidding.
2. If does are body condition score 1 or 2 then provide energy supplements to pregnant and lactating does. Feeding should start 4 weeks before kidding and build up to 250g/day/goat.
3. In southern Victoria and in mountain districts iodine drenches should be given to does 4 weeks before kidding.
4. Other management needs such as vaccinating, drenching and shelter also require careful attention.

If these practices are followed better kid survival and growth will be achieved with enhanced financial returns to producers.

Introduction

Improvements in the reproductive performance of breeding does will not only improve the profitability of growers, and improve the ability to select better quality goats but will provide a better flow of stock to prospective new growers. Financial returns are maximised if the proportion of finer fibre (from young goats) in the clip is increased.

Obtaining maximum reproductive performance from breeding does is dependent on good management throughout the year.

This article discusses good management practices for pregnant does and does in early lactation. (The emphasis of this article is placed on maximum performance per doe as, generally speaking, does are in limited supply and recommendations are provided as a "best bet" strategy.)

Nutritional Management

Keeping pregnant does on the right nutritional plane is the most important aspect of doe management. The main nutritional factors affecting pregnant does are stocking rate, energy deficiency and iodine deficiency.

Stocking rate

Many people have claimed that stocking rates of goats are 25% greater than sheep - i.e. if you could run 10 sheep/ha (4/ac) then you could run 12.5 goats/ha (5/ac). This advice is WRONG on pasturelands and in the wheat/sheep belt of Australia. Research at Werribee has shown that goats run at 25% above the recommended stocking rate for sheep were stunted, very vulnerable to cold stress and subjected to severe internal parasite attack during spring and were in poor body condition (score 1 to 2).

Running goats at a high stocking rate is certainly not the correct environment in which to breed kids. At high stocking rates not only would the potential kidding performance be reduced as does would be lighter (up to 9kg lighter at mating in February) but during winter when the foetus should be developing rapidly the does are usually under nutritional conditions which prevent any Iiveweight gain. Young kids would also acquire heavy internal parasite burdens. Goats run at below the recommended stocking rate for sheep have been up to 10kg heavier, not subject to severe internal parasite attack, in good body condition (score 2 to 4) and far less vulnerable to cold stress. It is therefore recommended that goats should not be grazed at intensities greater than 7.5/ha (3/acre) and any remaining grazing capacity be utilised by sheep or cattle.

In addition, people claiming that farmers could run more goats than sheep have overlooked 4 important aspects:

1. Recommended stocking rates are based on dry sheep - i.e. non reproducing wethers or dry ewes. One dry sheep equivalent (DSE) is the feed required to maintain a 45kg Merino wether for one year. If one runs breeding merino ewes then the stocking capacity in terms of numbers of sheep declines by about 30% i.e. 1 breeding Merino ewe = 1 .3DSE. As breeding crossbred ewes are bigger sheep and more fertile than Merinos, their DSE = 2.1 (with most lambs sold at weaning). See White and Bowman (1981) for more details.
2. A grazing property has a limited grazing capacity. This capacity depends on pasture type, soil fertility and rainfall. If a 200 ha property has a grazing capacity of 10 DSE/ha, then the total carrying capacity is 200x10=2000 DSE.
3. Mature does weigh up to 60kg. The mean liveweight of 3000 does weighed in recent experiments was 45kg. There is no way that their requirements can be less than Merino ewes.
4. Well managed does rear more offspring (100 to 120%) than Merino ewes (80%).

Thus to ensure good growth and survival of kids, the stocking rate of does would be lower than the stocking rate of Merino ewes. it is recommended that the DSE of breeding does is 1.5 DSE plus 1.4 DSE per doe if kids are kept until 18 months of age (mating age).

Stocking rates are a general guide, dependent on rainfall, fertiliser practices etc., so if you are unsure about stocking rates in your district, discuss this with your local Department Advisory Officer.

During the year, short periods of less than optimal nutrition are not serious (except around kidding time) as goats can successfully utilise some of their reserve supplies of energy and protein. Goats will mobilise their reserves during pregnancy, lactation and late summer and loose weight. Ideally, pregnant does should have a body condition score of 3 or better at kidding.

The clear message is that breeding does should not be overstocked if maximum breeding performance per doe is to be obtained. If does are overstocked then supplementary feeding will be required in most years, but internal parasite problems will still occur. Supplementary feed is expensive in time and in money terms.

Energy deficiency

While lowering the stocking rate will provide more feed per goat and enable the goats to reach heavier Iiveweights, I wish to discuss specifically the last 30 days before kidding and the first 60 days after kidding. Optimising fleece quality is also discussed.

Pre-kiddlng

From mating until about 50 days before kidding, the developing foetus grows slowly. During the last 45 to 50 days the foetus grows rapidly and over 90% of its growth occurs during this time. Does must gain in liveweight during the last 2 months of pregnancy as a single foetus plus foetal fluids, placenta etc. weigh

about 5-6kg and twins plus fluids etc. weigh about 8-9kg. Severe nutritional stress just prior to, or during this period, will result in abortions or, more frequently in Australia, birth of weak kids which die soon after birth.

During this period, which usually coincides with late winter, feed supply from the pasture is usually low and cold stress is common, leading to nutrient requirements of does increasing 50% over that of the non-pregnant state and of that during early pregnancy. Does in condition score 3 with good pasture will be able to supply sufficient nutrients to the developing foetus. However, does with poor pasture supply or in condition score 1 or 2 it is recommended that whole barley or sweet lupins grain be supplied from 4 weeks before kidding. The grain must be introduced gradually to the diet over a period of 10 to 14 days. The amount fed should reach 250g per day per doe.

Feeding moderately digestible roughages such as hay or oats is also generally of limited value as they have either the same of lower nutritive value as the pasture (why waste time and money feeding them when grazing is cheaper and as good?). In addition, hay and oats are very bulky feeds. During late pregnancy rumen capacity is reduced and supplying bulky feeds is not a way of maximising energy intake. During droughts, or when pregnant goats are fed indoors, ideally good hay (25-30% of ration) should be fed. If hay has to be fed ensure it is highly digestible. When buying hay ask for a feed evaluation test for digestibility.

Economics of feeding different grains

Feeds such as wheat, maize, millet or oats can be used but the purchase price should be related to the energy content of the grain. Table 1 compares the energy content of grains on a price basis. Supplements of wheat and maize can be used successfully if introduced slowly and or mixed with other feeds. I have fed whole wheat to goats as complete diets for up to 10 months, but many goats do not like consuming whole wheat diets. There is no magic in using maize or corn, the Texans use it because it is the cheapest form of energy as no wheat is grown for 100’s of miles (See McGregor 1987). In Australia, maize is often a very expensive form of energy. Crushed limestone at 1 1/2% by weight should be added to grain if fed for periods longer than 2 months.

TABLE 1.

With goats grazing growing pasture it is unnecessary to specifically provide protein as the pasture should supply sufficient. Sweet lupins are recommended only on the basis of being highly digestible (good energy supply) and are readily eaten by goats. Rapidly growing goats fed lupins also require 1.5% crushed limestone.

There is no advantage in supplying processed grain to goats - in fact there may be disadvantages. Processed grain is much more expensive than whole grain. Goats are not horses; goats ruminate, horses do not ruminate. Thus goats chew up most of the whole grain they eat. The amount of whole grain which passes out undigested is very small, about 2% of the amount fed, and certainty less than the higher price charged for processed grain. Another disadvantage of feeding processed grain is that it could lead to severe rumen disorders if not carefully controlled.

Post Kidding

The greatest nutrient demand comes in the first six weeks of lactation when the energy requirements of does are increased to 2 1/2 times over the non-pregnant state. During this time a lactating doe has to produce 2 to 3 litres of milk a day. Milk production is greatly affected by nutrition, before and after kidding. The amount of feeding at kidding affects the milk production of the whole lactation, not just the first few weeks. After kidding the milk production will increase for about 4 to 6 weeks until peak is reached. Milk production will then slowly decline. The higher the peak the slower and longer the decline. Good nutrition at this time is critical for many reasons.

1. Good nutrition will ensure rapid growth of kids. Kids potentially grow fastest on their mothers. Rapid kid growth is important to ensure greater resistance to cold stress, diseases and survival over summer. Bigger kids too do better after weaning, and faster growing kids reach meat market weights sooner.
2. Does will rapidly lose liveweight and condition if not well fed. Some liveweight (2 to 3 kg) loss is usual during the first few weeks of lactation, however, excessive loss (10 to 12kg) will severely affect mating liveweights for next year and so reduce next years kidding performance. Does which are poorly fed will milk poorly and lose a lot of weight.
3. Good nutrition will ensure good fleece development and maximise fleece growth rate of kids.
4. Twin kids will grow much slower than single reared kids. Ideally, twin rearing does and their kids should be separated and given higher levels of feeding until weaning weights are reached. This practice will be of greater importance in years of poor pasture growth.

Optimising fleece quality

Nutritional practices undertaken in mid pregnancy and during lactation have both short term and long term effects on the quality and production of mohair grown by kids. These effects have been closely examined in a very detailed long term experiment.

Nutrition in mid pregnancy, which enabled liveweight gain of does from about 7 to 15 weeks after mating combined with excellent nutrition in lactation resulted in:

• Mohair growth at the highest level with
• Mohair fibre diameter at the lowest level and
• The incidence of medulated fibres at the lowest level.

The benefits from this nutritional practice were more significant at the second and third shearing as the goats had developed better skin mohair growing follicle populations.

Nutrition during mid pregnancy which resulted in does losing liveweight combined with low nutrition during lactation resulted in:

• Mohair growth at the lowest level
• Mohair fibre diameter at the highest level and
• The highest incidence of medullated fibres.

The potential economic benefits of good over poor nutrition were estimated at a 10 to 20% increase in kid fibre value and a 10% increase in doe fibre value. There were also other economic benefits depending on farm and enterprise management.

Overall

If plenty of pasture is available (>7cm high) and does are in condition score 3 then no supplementary feed should be necessary.

If does are in condition score 1 or 2 then 250g per day of grain would be required. Larger amounts of supplement will be required if pasture supply is limited (<2cm). There is little advantage to be gained in feeding more than 400g per day if lactating goats are grazing pasture. Feeding of grain can be reduced from 4 weeks after kidding and discontinued after 6 weeks if spring pasture is available.

Goats grow best on spring pasture so don't feed expensive grain supplements unless needed. Supplementary feeding at times other than kidding are usually wasted. If you are going to feed supplements you will obtain greatest benefits if you feed them at kidding time. The cost of these recommendations for does in condition score 1 or 2 per doe = 70 days x 200g/head/day (average allowing for slow increase and decrease) = 14kg barley valued at 18 cents per kg = $2.50 per doe. No supplementary feed should be required for does in good condition on good pasture.

Iodine deficiency

Goats seem to have a higher requirement for iodine and are the most susceptible of all livestock to iodine deficiency. It has become widely recognised that low or marginal iodine nutrition of goats is a significant problem in areas of high rainfall in southern Victoria and mountain districts of the Great Dividing Range in New South Wales.

Kids whose mothers provided them with insufficient iodine develop goitre, are weak at birth, may not stand up and may die soon after. In extreme cases, kids might be born with physical deformities, such as protruding jaws or lack of hair. If the thyroid gland can be felt in the from of the neck as two lumps larger than the top of a little finger, then the kid can be considered to have goitre. Mortality of kids in affected flocks is often high.

Iodine deficiency is only a problem in new-born kids. Adult goats can tolerate the seasonal decline in iodine supply by using reserves stored in the thyroid gland. This reserve is not available to the developing foetus.

Research has shown that the intake of iodine from pasture is lowest during the winter months, particularly in years of high rainfall. This was when iodine requirements of breeding flocks were highest. Iodine levels are low in lush pasture. Kids born during late winter and spring (July to October) under conditions of high rainfall receive low levels of iodine from the doe.

Drenching is the best way to ensure that individual does receive adequate iodine. Does should be drenched once (or in wet years twice) before they give birth, first at eight weeks before and again (if needed) four weeks later. The iodine drench could be given with anthelmintics (worm drenches) but NOT with drenches based on levamisole.

The drench is made up by dissolving 28 g. of potassium iodide in one litre of water. Each doe should then be given 10 ml (280 mg) of the drench. It is important to mix the drench just before use otherwise the iodine goes "off". Old mixtures should be thrown away after use.

lodised salt licks and certain proprietary feed supplements, including fresh seaweed meal, are no substitute for iodine drenching. Some goats always miss out on getting enough iodine from the licks, or the feed. Drenching is the cheapest, and best way of supplementing iodine.

Goat breeders who had weak or deformed kids should contact animal health staff at the nearest office of the Department, or a private veterinarian.

GENERAL HUSBANDRY

The major points of general goat husbandry for pregnant does relate to preventative health practices.

Vaccinate all does and kids

All does should be given their booster vaccinations to control clostridial diseases of Tetanus and Pulpy Kidney one month before kidding. The dose required is 2 ml of PK-Tet. By giving the booster dose at this time, kids will receive a good passive protection to these diseases by way of antigens in the first milk (colostrum) from the doe.

These two diseases (Tetanus and Pulpy Kidney) are very deadly diseases when they strike. The small expense in purchasing the vaccine and the extra time involved in vaccination is small insurance indeed when viewed in the light of all the other work done on stock. (Kids should also receive vaccinations at 4 to 6 weeks of age and again 4 weeks later.)

Minimise internal parasites in does

Does should be "worm tested" about four weeks prior to kidding. This involves taking faecal samples and examining them for internal parasite eggs. There is a natural build up of internal parasites in pregnant does and parasite egg output also increases. If needed, does should be drenched as this will help to reduce parasite build up later in spring.

Footpare all does if required

In many districts Angora goats need to be footpared to reduce the length of the horn on the hooves and prevent foot problems such as scald and abscess. The best time to do this is in May when the horn is soft from the wet ground. Paring in May/June will enable the goats to walk easily during the wet months and prevent any unnecessary compaction of soil in the hooves. If paring is left too late, then pregnant goats will be unnecessarily stressed. Indeed paring mid winter is a cold, and muddy job best avoided by better planning.

Provide shelter

Kid survival will be enhanced by the provision of good shelter. In very cold, wet and windy conditions many lambs and kids die. Shelter can be provided in many forms. Obviously sheds and a lean-to will be of great benefit. Paddocks with overgrown phalaris and reeds are very useful. Experiments using electric fences to prevent animals grazing strips of phalaris have shown great benefits in lamb survival. The phalaris grows into large tussocks which provide excellent shelter. Good plantations are beneficial but many old plantations are useless in windy weather as they have been grazed out and are "hollow" at ground level. Hilly undulating country where animals can find protected areas should be saved for kidding.

Other husbandry practices

Good predator control (foxes and wild dogs) needs to be practised as kids are very vulnerable during their first week. Shearing should be completed before kidding.

Lice are often noticed early in winter. Lice are an unnecessary nuisance to pregnant does and kids, and may reduce fleece production by up to 10%. Lice can be eliminated and the best way to control lice is dipping in spring or summer. If lice are not controlled it is often because the underside of the neck is not properly treated (wetted). It is best to avoid dipping in late pregnancy.

CONCLUSIONS

Suggested Work Schedule for management of pregnant does is given below:

TABLE 2.

© 2000 B. A. McGregor