Sheep do not require specific feedstuffs. They require energy, protein, vitamins, minerals, fiber, and water.
Energy
Energy makes up the largest portion of the diet and is usually the most limiting nutrient in sheep diets. Carbohydrates, fat, and excess protein in the diet all contribute towards fulfilling the energy requirements of sheep. Carbohydrates are the major sources of energy. Concentrates (grain) contain starch, which is a rich source of energy. Forages contain fiber or cellulose, which is not as rich in energy as starch. The major sources of energy in a sheep’s diet are pasture and browse, hay, silage, and grains.
Meeting energy requirements without over or underfeeding animals is one of the producer’s biggest challenges. Energy deficiency is the most common nutritional deficiency in sheep. An energy deficiency will manifest itself in many ways. In growing animals, an early sign of energy deficiency is reduced growth, then weight loss, and ultimately death. In reproducing females, early signs of an energy deficiency are reduced conception rates, fewer multiple births, and reduced milk production.
With restricted energy consumption, wool growth slows, fiber diameter is reduced, and weak spots (breaks) develop in the wool fiber. An energy deficiency reduces the function of the immune system. Undernourished sheep are more susceptible to diseases, especially gastro-intestinal worms.
On the other hand, excess energy consumption can cause many problems in sheep. Extra energy is stored as fat (adipose tissue). Gross excesses in adipose tissue impair reproductive function in rams and ewes. During late gestation, fat ewes are more prone to ketosis (pregnancy toxemia).
Energy is quantified in the ration in many ways. The simplest measure is TDN or total digestible nutrients. Metabolizable energy (ME) and net energy (NE) values are more accurate measures of energy in a sheep’s diet. TDN is usually used to formulate rations for breeding animals, while the net energy system is usually used to calculate diets for growing lambs.
Protein
Protein is usually the most expensive part of the diet. Since the rumen manufactures protein from amino acids, the quantity of protein is more important than the quality of protein in a sheep’s diet. Protein requirements are highest for young, growing lambs who are building muscle and lactating ewes who are producing milk proteins.
The most common protein supplement for sheep is soybean meal. Other less common sources include sunflower meal, cottonseed meal, whole cottonseed, whole soybeans, peanut meal, canola meal, fish meal, and alfalfa pellets. It is illegal to feed meat and bone meal from other ruminants. Legume hays, when they are harvested in the early to mid-bloom stage are intermediate sources of protein.
Though levels vary, grains are usually low in protein. Urea is the most inexpensive source of protein or dietary nitrogen. Urea is converted to protein in the rumen. It has an equivalent crude protein value of 280 percent. It needs to be carefully incorporated into sheep rations and should not be included in creep rations.
Protein blocks are the most expensive way to provide supplemental protein to pastured animals, but they save labor. The hardness of the block regulates intake by the sheep.
Excess protein is an expensive and inefficient source of energy.
Minerals
Sixteen (16) minerals have been classified as nutritionally essential in sheep diets. Macro-minerals are required in large amounts. They include sodium (Na), chloride (Cl), calcium (Ca), phosphorus (P), magnesium (Mg), Potassium (K), and Sulfur (S). Microminerals are required in small amounts. They include iodine (I), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), molybdenum (Mo), cobalt (Co), selenium (Se), and fluoride (Fl), are required in small amounts.
Salt
Salt (sodium [Na] and chloride [Cl]) has an important regulatory function in the body. Inadequate salt intake can decrease feed and water intake, milk production, and growth of lambs. Animals desiring salt may chew on wood and/or lick dirt. They are more likely to consume poisonous plants. When adding salt to mixed rations, it is customary to add 0.5 percent to the complete diet or 1% percent to the concentrate portion. Salt is sometimes used to limit the intake of free choice mineral mixes.
Calcium and phosphorus
Calcium (Ca) and phosphorus (P) are interrelated in the development and maintenance of the skeleton. Deficiencies may result in rickets. An imbalance of Ca and P in the diet can cause urinary calculi in male sheep. The calcium in most forages is usually adequate to meet the needs of sheep. Deficiencies of calcium most often result when high-grain diets are fed. The ratio of calcium to phosphorus in the sheep’s diet should be at least 2:1.
Vitamins
Sheep require vitamins A, D, and E. Vitamin A is absent in plant material, but is synthesized from beta-carotene. Vitamin D is required to prevent rickets in young animals and osteomalacia in older animals. B-vitamins are not required in the diets of ruminants because they are synthesized in the rumen. Vitamin K is essential for blood clotting. Dietary supplementation is usually not necessary.
Learn more about minerals and vitamins required by sheep =>
Fiber
Fiber adds bulk to the diet and keeps the sheep’s rumen functioning properly by increases rumination and salivation. Most ruminant nutritionists agree that sheep should always have roughage in their diets, at least one pound per head per day. Sheep that do not consume adequate forage may chew on wood or wool.
Water
Water participates in nearly all body functions and is the most important “nutrient,” though oftentimes the most neglected aspect of feeding sheep. A sheep will consume anywhere from½ to 4 gallons of water per day, depending upon its physiological state and the environmental conditions.Voluntary water intake is usually 2 or 3 times dry matter intake and increases with high-protein and high-salt diets. Decreased water intake may reduce milk production in ewes and growth rates of lambs. Animals than consume adequate water have fewer digestive upsets and a lower incidence of urinary calculi.
Nutrient requirements
Sheep and lambs should be fed according to their nutrient requirements. Nutrient requirements vary by the age and size (weight) of the sheep and their stage and level of production.
Maintenance
A sheep’s nutrient requirements for maintenance are the amount of nutrients it must consume daily to neither gain nor lose body weight. A sheep that is not pregnant or nursing lambs does not have very high nutritional requirements.
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
2.3
|
1.7
|
1.26
|
0.22
|
0.0051
|
0.0051
|
|
150
|
2.6
|
1.7
|
1.45
|
0.25
|
0.0057
|
0.0053
|
|
175
|
2.9
|
1.7
|
1.62
|
0.28
|
0.0064
|
0.0059
|
|
200
|
3.2
|
1.6
|
1.79
|
0.31
|
0.0070
|
0.0066
|
|
225
|
3.5
|
1.6
|
1.96
|
0.33
|
0.0077
|
0.0070
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
Breeding
A ewe’s nutritional requirements do not change during breeding, unless you wish to “flush” her. Flushing is getting ewes to improve their body condition prior to breeding. It is accomplished by providing supplemental feed (usually grain) to ewes prior to and during the early part of the breeding season. Moving sheep to a better quality pasture will also accomplish the same thing. Flushing increases ovulation rate and subsequent lambing rate; although, it is generally not profitable to flush ewes that are already in good body condition or to flush ewes when ovulation rates are already naturally high.
Early to mid-gestation
A ewe’s nutritional requirements during early and mid-gestation are only slightly above maintenance. While lower quality feedstuffs can be fed during this period, inadequate nutrition can have an effect on embryo implantation.
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
2.7
|
2.7
|
1.47
|
0.25
|
0.0066
|
0.0055
|
|
150
|
3.1
|
2.6
|
1.68
|
0.28
|
0.077
|
0.0062
|
|
175
|
3.4
|
2.5
|
1.89
|
0.32
|
0.0086
|
0.0070
|
|
200
|
3.8
|
2.5
|
2.09
|
0.35
|
0.0095
|
0.0077
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
Late gestation
A ewe’s nutritional requirements increase substantially during late gestation, especially if the ewe is carrying multiple fetuses. This is because approximately 70 percent of fetal growth occurs during the last 4 to 6 weeks of pregnancy. Adequate nutrition is also necessary to increase ewe condition to assure adequate milk production.
While ewes and lambs can survive at lower feeding levels, inadequate nutrition can result in pregnancy disease, lighter lambs at birth, increased postnatal losses, and lessening of mothering ability and milk production. A ewe’s requirements for calcium also increase during late gestation.
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
3.4
|
2.7
|
1.89
|
0.39
|
0.0119
|
0.0070
|
|
150
|
3.9
|
2.6
|
2.14
|
0.41
|
0.0136
|
0.0079
|
|
175
|
4.4
|
2.5
|
2.38
|
0.43
|
0.0152
|
0.0090
|
|
200
|
4.9
|
2.5
|
2.68
|
0.46
|
0.0169
|
0.0099
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
3.6
|
2.9
|
2.14
|
0.48
|
0.0143
|
0.0086
|
|
150
|
4.2
|
2.8
|
2.47
|
0.51
|
0.0165
|
0.0097
|
|
175
|
4.7
|
2.7
|
2.77
|
0.53
|
0.0185
|
0.0110
|
|
200
|
5.2
|
2.6
|
3.08
|
0.56
|
0.0205
|
0.0121
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
3.7
|
3.0
|
2.40
|
0.57
|
0.0169
|
0.0101
|
|
150
|
4.3
|
2.9
|
2.77
|
0.60
|
0.0194
|
0.0117
|
|
175
|
4.8
|
2.7
|
3.13
|
0.63
|
0.0218
|
0.0130
|
|
200
|
5.3
|
2.7
|
3.50
|
0.66
|
0.0240
|
0.0145
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
Lactation
A ewe’s nutritional requirements are highest during lactation, especially if the ewe is nursing multiple births. Ewes with twins produce 20 to 40 percent more milk than those nursing twins.
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
4.7
|
3.8
|
2.38
|
0.66
|
0.0178
|
0.0134
|
|
150
|
5.3
|
3.5
|
2.75
|
0.71
|
0.0205
|
0.0152
|
|
175
|
6.0
|
3.4
|
3.07
|
0.78
|
0.0231
|
0.0172
|
|
200
|
6.6
|
3.3
|
3.41
|
0.86
|
0.0255
|
0.0189
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
5.3
|
3.2
|
3.18
|
0.86
|
0.0211
|
0.0156
|
|
150
|
6.1
|
4.1
|
3.77
|
1.00
|
0.0242
|
0.0178
|
|
175
|
6.9
|
3.9
|
4.31
|
1.13
|
0.0271
|
0.0200
|
|
200
|
7.6
|
3.8
|
4.86
|
1.27
|
0.0301
|
0.0222
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
125
|
5.6
|
4.5
|
3.41
|
0.91
|
0.0229
|
0.0167
|
|
150
|
6.5
|
4.3
|
4.19
|
1.11
|
0.0262
|
0.0191
|
|
175
|
7.4
|
4.2
|
4.93
|
1.31
|
0.0293
|
0.0216
|
|
200
|
8.1
|
4.1
|
5.71
|
1.51
|
0.0323
|
0.0238
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
Ewe lambs
Nutrient requirements are higher for replacement ewes and ram lambs than they are for physiologically mature animals. This is because lambs and yearlings are still growing in addition to other production functions. It is especially important that the nutritional requirements of ewe lambs be met.
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
66
|
2.6
|
3.9
|
1.70
|
0.41
|
0.0141
|
0.0057
|
|
88
|
3.1
|
3.5
|
2.00
|
0.39
|
0.0130
|
0.0057
|
|
110
|
3.3
|
3.0
|
1.90
|
0.30
|
0.0106
|
0.0053
|
|
132
|
3.3
|
2.5
|
1.90
|
0.30
|
0.0099
|
0.0055
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
88
|
3.1
|
3.5
|
1.80
|
0.34
|
0.0121
|
0.0066
|
|
110
|
3.3
|
3.0
|
1.90
|
0.35
|
0.0115
|
0.0068
|
|
132
|
3.5
|
2.7
|
2.00
|
0.35
|
0.0121
|
0.0075
|
|
154
|
3.7
|
2.4
|
2.20
|
0.36
|
0.0121
|
0.0082
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
88
|
3.3
|
3.8
|
2.10
|
0.41
|
0.0141
|
0.0068
|
|
110
|
3.5
|
3.2
|
2.20
|
0.42
|
0.0139
|
0.0075
|
|
132
|
3.7
|
2.8
|
2.40
|
0.42
|
0.0146
|
0.0084
|
|
154
|
4.0
|
2.6
|
2.50
|
0.43
|
0.0150
|
0.0093
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
88
|
3.3
|
3.8
|
2.20
|
0.44
|
0.0163
|
0.0077
|
|
110
|
3.5
|
3.2
|
2.30
|
0.45
|
0.0172
|
0.0086
|
|
132
|
3.7
|
2.8
|
2.50
|
0.46
|
0.0179
|
0.0095
|
|
154
|
4.0
|
2.6
|
2.60
|
0.46
|
0.0181
|
0.0104
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
88
|
3.7
|
4.2
|
2.50
|
0.56
|
0.0132
|
0.0095
|
|
110
|
4.6
|
4.2
|
3.10
|
0.62
|
0.0143
|
0.0104
|
|
132
|
5.1
|
3.9
|
3.40
|
0.65
|
0.0150
|
0.0112
|
|
154
|
5.5
|
3.6
|
3.60
|
0.68
|
0.0157
|
0.0123
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
88
|
4.6
|
5.2
|
3.20
|
0.67
|
0.0185
|
0.0123
|
|
110
|
5.1
|
4.6
|
3.50
|
0.71
|
0.0192
|
0.0132
|
|
132
|
5.5
|
4.2
|
3.80
|
0.74
|
0.0198
|
0.0141
|
|
154
|
6.0
|
3.9
|
4.10
|
0.77
|
0.0205
|
0.0152
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
Ram lambs
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
88
|
4.0
|
4.5
|
2.50
|
0.54
|
0.0172
|
0.0082
|
|
132
|
5.3
|
4.0
|
3.40
|
0.58
|
0.0185
|
0.0093
|
|
176
|
6.2
|
3.5
|
3.90
|
0.59
|
0.0187
|
0.0101
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
Feeding lambs
There are many ways to manage and feed lambs for market. If maximum gains are the objective, concentrate feeding is usually necessary. Pasture-reared lambs will gain more if they are supplemented.
Nutrient requirements for lambs will vary by the age of lambs and their genetic potential for growth. Frame size is used as an indicator for growth potential.
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
44
|
2.2
|
5.0
|
1.80
|
0.37
|
0.0119
|
0.0055
|
|
66
|
2.9
|
4.4
|
2.20
|
0.42
|
0.0148
|
0.0071
|
|
88
|
3.3
|
3.7
|
2.60
|
0.44
|
0.0170
|
0.0086
|
|
110
|
3.3
|
3.0
|
2.60
|
0.40
|
0.0154
|
0.0084
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
44
|
2.6
|
5.9
|
2.00
|
0.45
|
0.0143
|
0.0064
|
|
66
|
3.1
|
4.7
|
2.40
|
0.48
|
0.0159
|
0.0075
|
|
88
|
3.3
|
3.7
|
2.50
|
0.51
|
0.0190
|
0.0095
|
|
110
|
3.7
|
3.4
|
2.80
|
0.53
|
0.0207
|
0.0106
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
|
BW
|
DMI, lbs.
|
DMI, %
|
TDN, lbs.
|
CP, lbs.
|
Ca, lbs.
|
P, lbs.
|
|
66
|
2.9
|
4.4
|
2.10
|
0.42
|
0.0146
|
0.0106
|
|
88
|
3.5
|
4.0
|
2.70
|
0.41
|
0.0146
|
0.0071
|
|
110
|
3.5
|
3.2
|
2.70
|
0.35
|
0.0123
|
0.066
|
| Source: Nutrient Requirements of Sheep, 6th revised Edition, 1985. | ||||||
Other factors
There are other factors which affect a sheep’s nutritional requirements: weather, shelter, activity, and body condition.
Critical temperature
Below the critical temperature, livestock must expend more energy to keep warm. A sheep’s critical temperature depends upon the length of its fleece. A freshly shorn sheep’s critical temperature is 50°F. For a sheep with a 2.5 inch fleece, the critical temperature is 28°F. There is a 1% increase in energy requirements for each 1°F below the critical temperature. High quality hay is a better feed source during cold weather because more body heat is produced when it is digested.
Activity
The farther a sheep has to travel for food and water, the greater her nutritional requirements will be. Thus, pen-fed sheep have lower nutritional requirements than grazing sheep.
New NRC requirements
Revised nutrient requirements for sheep (and other small ruminants) were published in 2007 by the National Academies of Science. The new requirements are much more detailed and complex than those published in 1985.
About the Author
Susan Schoenian is the Sheep & Goat Specialist at the University of Maryland’s Western Maryland Research & Education Center in Keedysville, Maryland. She has been with University of Maryland Extension since 1988. Susan began her extension career as an agricultural extension agent (“county agent”) in Wicomico County, Maryland. She also served as a Farm Management Specialist for Maryland’s nine Eastern Shore counties. In addition, she operates the following websites: Sheep 101, Sheep 201 and Maryland Small Ruminant Page, and Wormx.
