During dry periods, hand-feeding of stock is aimed at either increasing production or preventing deaths caused by starvation. An understanding of the principles of hand-feeding is necessary to obtain the most efficient utilisation of dry pastures. Indiscriminate feeding of supplements often occurs, and reserves can be wasted during the early stages of supplementary feeding.
Hand-feeding can occur under a number of different circumstances. Small amounts of high-protein supplements can be fed, or urea blocks or mixtures can be provided, to increase the utilisation of low-protein pastures. However, if the quantity of pasture becomes restricted, the feeding of an energy supplement becomes necessary. Further restriction in the amount of pasture to bare conditions leads to the total hand-feeding of survival rations.
The role of hand-feeding during these different stages is outlined below.
During dry summers which follow abundant spring growth, there are commonly present ample dry residues. Burr, "green pick" or fallen grain in stubble paddocks will often give sufficient supplement to improve the utilisation of the dry fibrous material.
Recent field trials, which were designed to study the usefulness of urea supplements under these pasture conditions, indicated that hand-feeding of any supplement is not necessary for dry sheep under these conditions for a number of weeks. Unsupplemented sheep grazing in trials lost little body weight during the first eight to ten weeks.
The protein content of the dry residues in many of the trials was between 2 and 4 per cent. The daily intake of this type of roughage by unsupplemented sheep in pen trials is usually no greater than 1 lb. per sheep. Assuming an energy value of 20 food units per 100 lb. for this material, the dry residues would provide normally only about 1½ food units per week.
As the body weight of the sheep in the field trials was between 90-110 lb., and little weight loss occurred, the amount of additional energy obtained, either directly from burr, "green pick" or fallen grain, or by a stimulated intake of dry material, was at least 2½ food units per week.
While such calculations are based on some assumptions, these observations indicate how dry material can be utilised for a period without the need for hand-feeding.
Eventually, either the amount of burr or dry residues will become limited. If an area contains only a small quantity of burr, it is necessary to move immediately into Stage 2. If there are still ample dry residues without burr, consideration can be given to feeding high-protein supplements.
Supplements of high protein content stimulate the intake of low protein residues; 3 oz. of linseed meal daily increases the intake of roughage containing 2-4 per cent protein by up to 40 per cent. However, supplements of cereal grains often depress the intake of low-protein pastures. It would appear that the lower protein content of cereal grains (9-11 per cent) is not sufficient to increase the animal's appetite for low-protein pasture. Supplements of cereal grain result in what is referred to as replacement or alternative feeding.
High-protein supplements include linseed meal, good quality lucerne or clover hay, and manufactured nuts or pellets containing above 15 per cent protein. The feeding of supplements containing urea could also be considered during this period. Urea feeding will be mentioned briefly below.
If the dry conditions continue, the amount of dry material will often become limited and sheep will lose weight, as insufficient energy can be harvested.
A considerable amount of fodder can be saved by allowing sheep to fall to poor store condition before feeding survival rations. Often sheep will be in store condition at the end of Stage 1, but the inadequacy of the pasture to provide necessary energy forces farmers to alter the type of supplement from one high in protein to one which provides energy at the lowest cost.
Results of drought feeding trials indicate that the energy supplied by the loss of 1 lb. body weight is equivalent to the energy supplied by three food units. Allowing sheep to fall from 90 lb. to 75 lb. before totally hand-feeding would result in a saving of 45 food units, which is equivalent to 60 lb. of wheat. At present prices this would mean a saving of 15/- a sheep
The saving may not be so high as it may be necessary to feed small amounts of energy supplements to accustom sheep to hand-feeding, or to avoid imposing stress too rapidly.
During this stage total hand-feeding is required. The information given in recently published articles on drought feeding should be considered.
At present prices wheat is the most economical drought fodder to buy. The cost of landing wheat on to a property is about 15/- a bushel. This is equal to 25/- per 100 lb. As wheat contains 72 food units per 100 lb. the price per food unit would be 4-1/6d. The cost per week for a survival ration of four food units of wheat would be 1/5d.
Alternatively, the price of landing oats would be at least 10/- a bushel, or 25/- per 100 lb. As oats contain 60 food units per 100 lb., the price per food unit would be 5d, and the cost of the weekly ration would be 1/8d.
Many types of blocks containing urea are marketed in N.S.W. These types can be broadly classified into three groups.
Type 1. Blocks containing no more than 3 per cent urea, a high content of sodium chloride and mineral salts, and very little energy. This was the only type of block containing urea which was marketed in N.S.W. before July, 1963. Little information is available on the usefulness of this type of block.
Type 2. Blocks containing 3-10 per cent urea, a high amount of energy supplied by grain products or molasses products (15-60 per cent) and a low content of sodium chloride and other mineral salts.
Type 3. Blocks containing 15-35 per cent urea, a small amount of grain products or molasses (5-10 per cent), a high amount of sodium chloride (greater than 50 per cent) and mineral salts.
There are also a number of other mixtures containing urea which can be prepared on a property. One of these mixtures contains 40 lb. molasses, 10 lb. bran or oats, 10 lb. superphosphate, 10 lb. finely ground limestone, 15 lb. urea, 1 tablespoon cobalt sulphate. The urea is dissolved in 11 gallons of hot water, the cobalt added, and the solution mixed thoroughly with the other ingredients.
It is important to note that only 5 lb. of urea is used in the mixture during the first week of feeding. During the second week, 10 lb. of urea is used. By the third week 15 lb. of urea can be safely included in the mixture.
When bran is used, the final product is a "dry porridge", while a more liquid product is obtained when oats are substituted for bran.
Trials feeding urea blocks and mixtures have recently been conducted in pens at Temora Agricultural Research Station, and a number of trials with grazing sheep have been conducted on private properties.
The progress results of these trials can be briefly summarised as follows:
1. The intake of straw chaff (2.1 per cent crude protein) was increased by more than 150 per cent when penned sheep were allowed free access to Type 2 blocks, and wool production was significantly increased. However, consumption of this block was high, and it was observed that water intake was greatly increased.
2. The intake of the same roughage was increased by about 20 per cent when Type 3 block was fed. More sheep survived in the group given this block, than in the unsupplemented block.
3. When roughage of higher protein content (5.1 per cent crude protein) was fed, both types of blocks had significantly less effect upon roughage intake.
4. When given unrestricted access to Type 2 blocks, ewes in the last six weeks of pregnancy gained the same amount of weight at less cost than similar ewes supplemented daily with 1 lb. oats.
5. Consumption of Type 2 and Type 3 blocks, and the urea mixtures, was low under paddock conditions which provided sufficient nutrients to maintain animals at a relatively constant body weight.
6. When animals commenced to lose body weight and paddock conditions deteriorated, consumption of urea blocks or mixtures increased and the rate of body weight loss was reduced.
While it has been shown that urea supplements are nutritionally worth while, the economics will have to be assessed by each farmer under his local conditions.
The results of future trials should permit a more accurate assessment of the economics of urea supplementation.