Managing feeding correctly throughout the year is the foundation for keeping a healthy, productive flock. Poor nutrition is one of the most common and important reasons why some flocks contain too many thin sheep, leading to increased losses and compromised production. Remember that a full fleece may conceal the fact that sheep are much thinner than anticipated, so regular ‘hands on’ condition scoring is crucial to avoid nasty surprises.
Although a number of important chronic diseases cause abnormal thinness (see Chapter 6), the first and most important factor to consider if this is a problem is, are the animals being given enough food for their stage of production? For adult sheep, body condition does not remain the same throughout the year – during periods of plenty or when production demands are low, sheep gain body condition and can then utilize stored fat during periods when demands are high. This produces a well recognized cycle of what should be controlled weight gain and weight loss.
Target condition scores are as follows:
- tupping time – lowland ewes 3–3.5, hill ewes 2–2.5
- early pregnancy – maintain condition
- mid-pregnancy – gradual loss of up to half a condition score is acceptable, providing not too lean at tupping
- lambing time – lowland ewes 3, hill ewes 2–2.5
- lactation – loss of up to one condition score
- after weaning – recovery of body condition.
Fig. 178 It is possible to tell by looking that the coloured sheep on the left is very thin. The coloured sheep on the right may be too thin but needs handling in order to be sure. It is impossible to tell the body condition of the sheep in the centre because of the heavy fleece it is carrying.
Sheep are grazers, so the most important part of the diet is forage – grass through most of the year, and hay, haylage or silage during the winter months. Forage can be supplemented with various types of concentrate when demands are higher than what the forage can supply (during cold winters and most often in late pregnancy), but grass of the correct length and well made hay, haylage or silage is usually the cheapest and best food for any sheep through much of the year. Rams may need extra concentrates in the weeks prior to tupping time – see Chapter 8.
Assessing the Adequacy of the Feed
This book cannot go into great detail on feeding sheep, but what follows highlights the most important aspects. The three most important factors to consider when assessing adequacy of food supply are as follows:
- Quality – does the available food contain the necessary nutrients, particularly energy, for the stage of the production cycle?
- Quantity – is there a sufficient quantity of nutritious food for the number of animals needing it?
- Accessibility – can all the animals get their fair share of the food?
When sheep are relying on grazed grass the most important factor to consider is whether it is of the correct length. Sheep do best when grass is 2–6cm long; above this length the grass becomes too mature and is wasted. Restricting the sheep to an appropriate area to maintain this length may be necessary, but adjustments will need to be made particularly during periods of hot, dry weather and cold winter weather when grass growth slows or even stops.
Fig. 179 There is a common misconception that sheep at grass do not need a water supply. Animals grazing wet or lush grass may drink little extra water, but it should always be available. Ewes suckling lambs drink considerable amounts of water.
Fig. 180 Fields without streams running through them should have accessible water troughs installed. These should be checked for leaks and cleaned out regularly. This one is partly filled with large stones so lambs can get out if they jump into it whilst playing.
Fig. 181 Sheep need to have shade available during hot weather.
Fig. 182 This grass appears to be well managed, and growing at about the optimum length.
Fig. 183 Hill sheep grazing extensively keep the areas of palatable grass short while other areas covered with plants such as bracken are not generally grazed at all.
Fig. 184 Aftermath which grows after taking a hay or silage crop provides excellent grazing for getting ewes into the correct condition for tupping time.
Fig. 185 This grass is already too long for sheep and will probably end up becoming too mature; it will be wasted if it is not adequately grazed or conserved.
Fig. 186 The grass on these fields is very short and could limit the animals’ production.
Fig. 187 This field has fairly recently been spread with manure. Grazing a field like this can lead to disease problems if the manure is fresh. A high infection rate with toxoplasmosis has been found in flocks where the manure was contaminated with cat faeces. It is particularly dangerous to graze animals on fields spread with chicken manure, which can harbour the bacteria that cause botulism.
Fig. 188 Sudden or prolonged snowfalls can precipitate pregnancy toxaemia and hypocalcaemia in heavily pregnant sheep if extra food is not provided.
Fig. 189 If concentrates are fed it is often easier and better to feed cobs on the ground than to use troughs. If trough space is limited the weaker sheep get pushed out.
Fig. 190 A quad bike and ‘snacker’ allows sheep to be easily fed cobs on the ground.
If the area has been undergrazed, grazing with cattle, for which the optimum grazing length is longer, will improve the sward for sheep. Alternatively, topping the overgrown area will encourage new grass growth. When the grass supply is insufficient, supplementation will be necessary by providing extra forage, and concentrates or feed buckets if necessary in the field, or for extensively kept sheep, providing extra food at accessible points, or by housing and feeding indoors.
Fig. 191 Sheep can waste a lot of hay if it is fed loose on the field. Fortunately the ground is dry here but a lot will be wasted if the weather is wet.
Fig. 192 Floor-feeding cobs on the field in a different place each day allows all sheep to eat a fair share and avoids the ground becoming too muddy.
Fig. 193 Feeding roots is a common way of supplementing feed in some areas. They are very palatable, but the sheep need good incisor teeth to be able to eat them.
Fig. 194 This big bale of hay has quite a lot of spoilage on this end. The sheep will not eat this part of the bale.
Fig. 195 Big bale silage can be very variable in quality. As soon as it is exposed to the air, secondary fermentation starts to take place, reducing quality and palatability. The bale should be eaten in a maximum of three days, preferably two, to avoid problems.
Fig. 196 Here a hay rack is being used which may reduce waste, but unless it has just been filled, a full rack may indicate that the hay is of poor quality and is unpalatable.
Fig. 197 Molasses blocks can be a practical, though expensive, way of supplying extra energy if forage quality is doubtful.
Fig. 198 If sheep are grazing roots, they should have access to a grass field as well. In this case the ground is quite dry, the gate at the far end of the field is open to the adjoining grass field, and big bale silage is available so the sheep are well fed and comfortable.
Fig. 199 Leafy forage brassica crops such as stubble turnips or forage rape are often grown to provide highly nutritious feed for fattening lambs in the autumn. A run back on to grass should be provided.
Feeding Housed Sheep
Housed sheep are entirely dependent on the shepherd for their food and water supply. Most commonly it is ewes that are housed for the last six to eight weeks of pregnancy. For early lambing flocks housing may extend into a considerable part of lactation, too – indeed, some lambs produced for the Easter market never go out. Also commonly housed are lambs that have not reached meat weight or finish by late autumn, so they may be fattened.
The same feeding considerations apply: quality, quantity and accessibility. Grouping ewes according to lambing date, scanning results and, most importantly, body condition enables food to be correctly allocated. Group sizes should not be too big – no more than forty or fifty to a pen, and they should all be able to access the forage and concentrates. If they cannot, the shy feeders and weaker animals will not receive an adequate amount and can quickly lose weight, becoming susceptible to pregnancy toxaemia.
Preferably, good forage should be available ad lib, with concentrates being floor fed if possible: this occupies the sheep for longer than trough feeding, ensures each gets its share, and virtually no food is wasted. Floor feeding is not appropriate for giving a home mix, however, so this will either have to be fed in troughs or in front of a barrier outside the pen. It is usual to begin feeding concentrates six to eight weeks before lambing is expected to start. These should be introduced into the diet carefully and the amount increased slowly so as not to upset rumen function.
Fig. 200 Housed sheep need a clean supply of water. Troughs and bowls can become contaminated so should be checked regularly.
Fig. 201 Large cattle-type water troughs can be a hazard in lambing pens as lambs may jump into them and drown.
Fig. 202 This homemade water trough has rather sharp edges where a hole has been cut from the barrel.
Fig. 203 While it is best to have an analysis of fodder quality, quite a lot of information can be gained by smelling it and looking at it, to see the colour and amount of leaf that is present. These indicate the stage at which the grass was cut and whether it was damaged by being out in wet weather before being harvested. The moisture content of silage is important, as sheep cannot eat sufficient very wet silage to provide their energy requirements.
Fig. 204 In this large shed the sheep have a plentiful supply of good hay. Unlike silage, the quality of hay does not deteriorate quickly when large amounts are put out.
Fig. 205 Overhanging roofs give the hay some protection from the weather.
Fig. 206 A rack where the sheep have good access to the hay it contains.
Fig. 207 In this situation a limited amount of hay is being fed so it is extremely important that all sheep can gain access to the rack at the same time. Some people think that limiting the amount of forage helps to reduce the occurrence of prolapse, but there is no real evidence for this – in fact, if the sheep have to push and shove to reach the hay this may precipitate prolapses.
Fig. 208 Here there is good access to silage, but care needs to be taken that it is all eaten within a maximum of two days. After this time any uneaten silage should be removed, as secondary fermentation reduces quality and also predisposes to the occurrence of listeriosis. This feed includes maize silage, which is not commonly fed to sheep.
Fig. 209 This round bale feeder is almost empty of silage and will need to be refilled. Care must be taken, as sheep, eager to get to the new bale, can get their heads trapped as the bale is dropped into the feeder.
Fig. 210 This round bale’s covering has been damaged and mould is growing on it. Either it should not be fed to sheep, or the spoilt part must be removed before feeding.
Fig. 211 Pens should be well bedded, but this is especially important if feed is being given on the floor.
Fig. 212 Although some information can be gained from the list of ingredients on feed labels, it does not tell you the energy content or protein quality. The quality of purchased concentrates is closely related to price, in that cheap generally means poor quality!
Fig. 213 Molasses blocks or liquid molasses, which sheep can lick from a ball feeder, are sometimes provided to boost energy intake but are expensive to buy.
Fig. 214 Good, clean straw can be used as the forage supply, but it must be provided ad lib so that sheep can sort through it to find the nutritious parts. It must be fed either in the pen or in walk through troughs, never from racks. The sheep will require extra concentrates, and may require extra calcium in the diet.
Fig. 215 This home-mixed concentrate appears to be of good quality, containing sugar-beet pellets, crushed barley and concentrate pellets, which probably contain a high protein source and a balance of minerals. It would not be suitable for floor feeding in the pen because of the high content of crushed grain, so would need to be fed outside a barrier or in troughs.
Fig. 216 A bucket or, as in this case, a coal scuttle, can be used to feed concentrates accurately providing the weight of nuts in a full container is known. These pellets could be successfully floor fed in the pen.