Drought Feeding of Goats
Drought is a feature of the Australian farming landscape. This article is based on a recent review of available information on the drought feeding of Australian goats. The full review is available here as a PDF. This article summarises the main nutritional issues that goat producers need to manage during drought.
Objectives and key steps
The objectives of feeding goats during droughts are:
Most goat producers aim to keep their breeding flock substantially intact so they can recover their stock numbers as rapidly as possible when the drought breaks. Culling reduces the costs of feeding and avoids expensive purchases of replacement stock when the drought ends.
Critical live weights
Drought feeding should be started well before the goats reach their critical live weight. The concept of critical live weight indicates the minimum live weight that will enable an animal to survive. Further weight loss may endanger the survival of the goats by leaving them too weak to walk, graze or safely obtain drinking water. The critical live weight is also used when determining feeding level and for long term budgeting and purchasing of feed (Table 1).
Table 1. Guideline to critical live weights (kg) for goats. These live weights are off pasture with an allowance for fleece growth equal to half of a shearing interval
As each flock of goats is different, you need to determine your own critical live weight. One method is to use a weight 30 % less than the recent peak live weight plus 1 kg for each year of age plus estimated fleece weight.
Critical body condition scores
Stocking rate and drought
The severity of seasonal and long-term drought is indicated by the quantities of fodder it is necessary to feed to keep goats above critical live weight. Drought feeding is associated with stocking rate. Increasing stocking rate increases the severity and onset of drought.
The drought feeding requirements of goats depend upon their grazing management. In some grazing situations there may be more herbage available in goat grazed pastures than in sheep grazed pasture. This will allow goats to graze for a longer period before they reach a critical live weight. Goats can be out competed when grazed with sheep on pastures at high stocking rates. In these circumstances the goats may reach their critical live weight earlier than the sheep and will need more drought feeding.
Managing goats in a drought
Adult goats above the critical live weight can be allowed to lose some weight and condition at the start of a drought without drastically altering their chances of survival. Start the introduction to drought feeding when the goats are 3 kg above the critical live weight.
Control gorging and shy feeders
Frequency and methods of feeding
It is especially important to avoid sudden changes in the ration. If it is necessary to use a different grain, arrange the supplies early and mix the old grain with the new, gradually increasing the concentration over at least a week. Feeding processed grain to goats can increase the incidence of grain poisoning and so reduce appetite.
Selecting the types and amounts of feeds to give goats during a drought involves six steps:
Energy is a major nutrient requirement and normally the first limitation during drought. Energy requirements for maintaining live weight and for growth are given in Table 2. Energy is provided in units of metabolisable energy (ME). For growth, determine the maintenance requirement and then add the requirements for growth.
These guidelines should be used as a starting point, as every drought situation is different. The guidelines need to be modified based on regular monitoring of the live weight and body condition score of goats.
The energy requirement of working bucks is 15% greater than the maintenance requirement listed in Table 2.
Table 2. Guide to the daily nutrient requirements for maintenance of goats during a drought under stable dry conditions with minimal activity. If some grazing is provided then requirements increase by 25%. Under cold, wet and windy conditions energy provision should be doubled
A Mega joules of metabolisable energy (ME)
BFor maximum performance of kids the ration should contain at least 10 MJ ME/kg and 16% crude protein.
Energy requirement for breeding does
The suggested energy provision for feeding pregnant and lactating does during drought is:
Remember to increase the ration only at the suggested rate.
Cold stress increases energy requirements
The impact of cold stress on the energy requirements of goats is large. Under cold, wet and windy conditions the energy requirement of goats will be two or more times maintenance requirements.
A goat will increase its heat production if the air temperature falls below the critical temperature. The maximum attainable heat production of a goat cannot be maintained for more than a few hours (about 4) before death. Relative to sheep, goats appear to be more vulnerable to continuous rain at low wind speed and to intense storms.
Goats less than 30 kg live weight and with a body condition score less than 3 are particularly vulnerable to death from cold stress.
Goat producers are advised to listen daily to weather bureau forecasts. If any two of the following weather conditions arise, goat producers should take precautionary action to reduce the risks of goat deaths:
The implications for drought fed goats are:
Protein requirements are listed in Table 2. Generally most hays, grains and purchased commercial pellets have adequate crude protein for adult non-lactating goats. It is common that dry grazed pasture, some browse plants, poorer grass hays, straw and oaten grain in southern Victoria are below 7% crude protein. As a consequence animals fed these feeds will lose weight and may drop below their critical live weight. This situation is particularly dangerous for weaners and stock below 20 kg.
Urea can be used to supplement poor-quality dry pasture, and low protein hay and grain in order to speed up the rate of digestion, increase food intake and stop animals losing weight. Urea is sprayed on to roughage or grain or fed in licks or with molasses. Precautions must be taken to prevent urea poisoning.
Feeding weaned kids
In severe drought conditions it is suggested that kids could be weaned at about 10 to 13 kg. At this age, the kids need very careful management and highly digestible rations. It is suggested that early-weaned kids should be fed ad libitum rations of about 10 MJ ME/kg DM and 16% crude protein. The idea of early weaning is to reduce the energy used to produce milk. This approach has not been clearly documented for goats but has worked for lambs in drought.
Containment areas are recommended during drought feeding to protect the environment and the sustainability of soils and to reduce energy expenditure by animals. Grazing goats with some hill climbing have an energy requirement of maintenance plus 25%.
Feeds and feed costs
The cost of a ration largely depends on the ME content and the total delivered cost. The energy values of feeds can vary from 20% up to 50% of the values given in feed tables. It is best to determine energy values by testing. FeedTest, Pastoral and Veterinary Institute, Hamilton,Victoria. Telephone 1300 655 474, Fax (03) 55 730 939 offer this service in Victoria.
To determine the cost of a ration requires four steps:
Before finalising plans to feed any feedstuff, by-product or unusual feedstuff to livestock, it is advisable to have a sample analysed. In most circumstances choose the drought feed that provides energy at the lowest cost. You must note the dry matter of by-products or unusual feeds as well, since moist feeds may appear inexpensive on an as fed basis but in fact be quite costly because of their low dry matter content.
Table 3. The cost of energy in different feeds over a range of purchase prices on an as fed basis
Example: The cost of feeding a 35 kg dry goat in a containment area/feedlot. A 35-kg goat requires 5.8 MJ ME per day for maintenance (Table 2). The cost is calculated by using Table 3.
The amount of feed required for 100 non breeding goats are provided in Table 3. For example, a full ration for 100 27 kg goats fed oats needs 340 kg of oats each week. If your goats are a different live weight, you can work out the requirements from these values.
Table 4. Estimated quantities of feed needed for the maintenance of 100 non breeding goats per week at selected critical live weights for goats in stable dry conditions with minimal activity. Values in kg of feed
NR: Weaned kids should not be provided with these rations
Other nutritional requirements
It will pay to buy or retain a small proportion of hay early in the drought so that you have some roughage in autumn when pasture or crop residue is scarce. Good hay is required as 30% of the ration during lactation (less if pasture is available), for shy feeders and if full cereal grain feeding is required.
Vitamins, A and E, are the only vitamins likely to be deficient as a direct result of drought feeding. Long term feeding of grain will induce deficiencies of these vitamins.
Goat farmers should ensure that adequate water and shade is provided to all goats grazing dry summer pastures and during drought feeding, especially young and light weight goats. Water intake of Angora goats grazing dry unshaded pastures has been measured as 50% greater than that of Merino sheep. There is some evidence that Boer goats consume less water than sheep.
If goats exhibit signs of being heat stressed, maintenance energy allowances should be increased by 7% during rapid shallow breathing and increased by 11 to 25% for deep open-mouthed panting.
Limited evidence suggests that goats have similar or slightly greater tolerances to salt in water compared with sheep. However, in drought the salt content of river and dam water can increase to high levels and should be monitored to ensure salinity remains at safe levels.
When budgeting on a water allowance you can plan for average daily consumption (4 l/head/day), however this can change dramatically with the weather. On very hot days, intake will be greatly increased so you need to be able to supply the maximum rate (up to 9 l/head/day). Allow enough trough space so that 10% can drink at any time, or 15 metres of trough edge for 500 goats.
Weeds and native vegetation
Buying in feed can introduce weed seeds to your property. Many pasture weed species in southern Australia and some native plant species have high nutritional values making the plants suitable as feed for goats. However the long term grazing of many native plants is likely to result in poor nutritional status endangering the welfare of the animals. For many plants, after the leaves have been eaten, the remaining plant stems have very low nutritive value.
Rapid introduction of feed
Research with goats fed whole grain wheat without an introduction period showed that slaked lime treated wheat diets reduced the incidence of grain poisoning compared to diets without slaked lime. These results suggest that treating wheat with 2% slaked lime (Limil) is a practical method for rapid introduction of goats to high-energy grains.
Ammonium chloride (0.5%) should be added to cereal grain to prevent formation of urinary calculi in wethers and bucks.
Monitoring goats during drought
The management of goats during a drought depends on knowing how the animals are faring. The only real way to know how they are going is to weigh and condition score them. Goats need to be inspected regularly. Fence lines need to be checked to release any goats caught in fences.
When the drought breaks
Goat welfare and disease
There is a national guide for acceptable goat farming practice that describes actions relevant during drought. This means that all parts of Australia are covered by this National Code of Practice. Some States have their own code of practice for goats. Producers should become familiar with these Codes. Animal welfare is an important issue at all times, but especially during drought.
as shearing or transport, may exacerbate
with goats in poor condition. The
main welfare issue
is assessment of drought affected
animals and in
deciding how much weight and body
condition an animal
should be allowed to lose.
Further readingAll the issues raised in this guide are discussed in full by: McGregor, B.A. (2005). Nutrition and management of goats in drought. RIRDC Research Report No 05/188. pp.90 + x. (RIRDC: Barton, ACT). http://www.rirdc.gov.au/reports/NAP/05-188.pdf
All Government Departments concerned with Agriculture have drought management information for grazing animals.
Simmonds, H., Holst, P., Bourke, C., 2000. The Palatability and Potential Toxicity of Australian Weeds to Goats. RIRDC: Canberra. 166 pp.
Financial support of the Rural Industries Research and Development Corporation is gratefully acknowledged.
Cartoons by Simon Meek, "Old Womens Creek" Garland NSW.
The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned.
The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.
© State of Victoria, Department of Primary Industries