Selecting the types and amounts of feeds to give goats during a drought involves six steps:
1. Determining total energy and protein requirements of each class of goat;
2. Determining the energy and protein content of available and suitable feeds;
3. Calculating which of the available and suitable fodders is cheapest;
4. Calculating the amount and cost of the selected feed;
5. Assessing the proportion of feed requirements that can be met from pasture and /or crop residues;
6. Monitoring the individual mobs and adjusting their ration up or down.
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
Live weight kg Energy requirement MJ ME per dayA Crude proteinrequirement g per day
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:
• Up to day 66 of pregnancy, maintenance;
• From day 66 of pregnancy, maintenance plus 10%;
• From day 90 of pregnancy, maintenance plus 40%;
• From day 110 of pregnancy, 2.0 times maintenance;
• From day 140 of pregnancy and during lactation, 2.5 times maintenance.
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:
1. Rain, more than 5 mm;
2. Temperature, less than 10 degC minimum in wet conditions, less than 3 degC minimum in dry conditions;
3. Wind, stronger than 10 knots.
The implications for drought fed goats are:
• maintaining live weight increases susceptibility to cold stress compared with when goats are fed to grow;
• shearing increases cold stress for 6 weeks;
• adult goats have higher critical temperatures compared with adult Australian sheep at the same live weight;
• when wet and windy conditions are forecast producers need to increase energy provision prior to the arrival of the weather. Given the increasing reliability of weather forecasts, it should be possible to increase energy provision 3 to 4 day prior to arrival of bad weather;
• susceptible goats should be moved to suitable shelter;
• feeds suitable for rapid introduction need to be kept.
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%.
A special containment area should be provided for goats that are shy feeders and for goats in backward condition. In other words, separate the goats that are in the poorest condition from the main mobs. These goats need to be fed more hay and to be fed so they can gain some live weight.