Lamb Nutrition and Feeding
Original Author:
Dan Morrical, Sheep Extension Specialist
Iowa State University, Department of Animal Science
337 Kildee Hall, Ames, IA 50011
Phone: 515-294-0847, Email: morrical@iastate.edu
With Modifications and Additions By:
David L. Thomas, Sheep Extension Specialist
University of Wisconsin-Madison, Department of Animal Sciences
1675 Observatory Dr., Madison, WI 53706
Phone: 608-263-4306, Email: dlthomas@facstaff.wisc.edu
In most cases, farm flock operations in the Midwestern U.S. feed lambs from birth to market. A
primary objective of such operations has been to maximize rate of gain to get lambs to market as
early as possible in order to capture a high early lamb market. This objective of maximum gain
may no longer be the most desirable since the lamb market of late does not seem to be following
historical trends of peak prices around Easter and high prices in May and June followed by
falling prices through the remainder of the year. One must evaluate the most desirable marketing
date and lambing season to determine the best method of feeding the lamb crop. However,
additional benefits of rapid lamb gains are improved feed efficiency and lower fixed costs.
Creep Feeding
Creep feeding lambs is a very common practice that improves weaning weights 10 to 20%.
Additionally, it allows for a smoother transition on to full feed during the post-weaning period.
Young lambs prefer feeds with relatively small particle size. As they get older, they prefer
coarser diets and whole grains.
Young lambs find soybean to be very palatable, and some producers use straight soybean meal
(SBM) for their creep starter. Still other producers top dress SBM on the creep feed to get lambs
started. Other feeds high on the palatability scale for young lambs include corn, alfalfa hay, and
molasses. Table 1 contains some example creep rations using the previously mentioned feeds.
Lambs will begin to nibble on creep feed at 7 to 10 days of age. Consumption will be very low
and keeping the creep feed fresh is a primary objective. Location of the creep can help or hinder
lambs getting started. The creep should be easily accessible, close to the ewe flock and out of
the traffic flow, but very near it. Creep areas need to be well lit, clean, and dry - in other words
one of the most comfortable locations in the barn. Creep areas serve another important function
in that they provide a sanctuary for lambs to get away from the ewe flock. As lambs grow, creep
gates need to be adjusted to allow lamb access yet continue to prevent ewe access. This is no
easy task. Feeders used in the creep area need to be designed such that lambs cannot stand in the
feeders to reduce exposure to coccidia.
As lambs approach weaning age, a management decision must be made on whether to switch
lambs to the post-weaning ration before or after weaning. Weaning age directly influences this
decision. With lambs weaned at greater than 60 days of age, the switch can be made preweaning. However, with lambs weaned at younger ages, the change needs to occur after
weaning. An additional factor to consider is the cost of the creep ration compared to the
grower/finisher ration.
Growing and Finishing Diets
Many producers feed lambs the same diet from weaning to market. This is generally done for
convenience, and lambs will grow well if fed the growing diet throughout. However, grower
diets should have 16 to 18% protein (as a % of dry matter) (Table 1), and lambs over 70 to 85
pounds do not need this much protein (Table 2). Therefore, switching to a finishing diet (Table
1) that is lower in protein when lambs are approximately 85 pounds can reduce feed costs.
Complete mixed diets can be formulated from several ingredients (Table 1) or purchased from
commercial feed companies. Feeding whole shelled corn in combination with a high protein
pellet that also contains minerals and vitamins is generally more cost effective than feeding a
complete mixed diet. Many commercial feed companies sell a protein pellet of approximately
34% protein, and rations utilizing such pellets are presented in Table 1. Iowa State University
has developed a 42% protein pellet (Table 3), and its use in rations is presented in Table 1. It is
important that the corn in these corn/high protein pellet diets is not processed. Hay is generally
not fed with these diets, and the whole shelled corn provides the “scratch” factor necessary for
proper rumen function.
Feed management is very important on these high concentrate growing and finishing rations.
Animals must never be without feed if on self-feeders or never be without feed for a long period
of time (several hours) if hand fed. Lambs fed a high concentrate diet after being without feed
2
for a several hour period will overeat and consume a very large quantity of grain in a short period
of time. This can result in a rapid drop in rumen pH (acidosis), founder, and death.
Self Feeding Versus Hand Feeding
There are advantages and disadvantages to both systems. The biggest disadvantage of selffeeding is that monitoring lamb health is more difficult. This is because all lambs are not
actively eating at the same time and requires the shepherd to move through the pen(s) observing
lambs for signs of illness. However, hand feeding requires more bunk space. Unless the ewe
flock is dry-lotted, feeders previously used to feed ewes during pregnancy and lactation can be
used by hand-fed lambs. Hand-fed lambs require 9 to 15 inches of bunk space per head. The
higher space requirements are for heavy lambs (>120 pounds) or lambs in full fleece. Hand
feeding does require more labor and should be done in two equal feedings each day. Ideally,
feeding times should be similar from day to day as lambs become accustomed to a specific
feeding schedule. An additional advantage of hand feeding is the incorporation of hay into the
ration. At times hay can be a very economical ingredient to include in the ration at 10 to 20
percent of the total ration.
Cost Control Measures
Generally when discussing feed cost of gain, one first considers the cost of the ration as the
biggest factor. Ration costs are currently very low and furthermore should stay low in future due
to incredibly high inventories of grains. Even today with our cheap grain prices, there may be
some byproduct feeds that can cheapen the ration even further. An example might be dry corn
gluten feed. It is important to shop around for under-utilized (cheap) feed resources in the area.
Protein requirements (Table 2) of native farm flock lambs are high because they are generally
sired by Suffolk or Hampshire rams and have greater average daily gains than white-faced lambs
common in the West. Higher protein levels will increase the cost of the diets. As lambs reach
heavier weights, their protein requirements decrease (Table 2) so frequently adjusting protein
content downward throughout the feeding period can reduce feed costs. An additional means of
reducing protein costs is to investigate cooperative purchasing of commercially available protein
supplements or ordering a custom protein supplement. In most cases, a minimum of three tons is
required for custom orders.
3
The custom protein supplement formulation used at the Iowa State University McNay Research
Farm along with feeding directions is presented in Table 3. Incorporating alfalfa hay into the
finishing ration may also provide a cheaper protein source. Feeding rations with more than 10%
hay will result in slower growth rates and poorer feed conversions. This may result in a higher
feed cost of gain even though the ration cost per ton is lower.
Other means of reducing lamb feeding costs is timely marketing of finished lambs. It takes more
feed to produce a pound of fat than it does to produce a pound of lean. As lambs reach market
weight they become much less efficient and feed cost of gain increases dramatically. Ewe and
wether lambs should be marketed at 65 to 75% of their potential mature weight in order to
produce a market lamb with desirable feed efficiency and fat cover (Yield Grade 2 or 3 carcass).
Another way to improve growth efficiency is to use large-framed, heavy-weight terminal sires
because their offspring have better feed efficiency to the same weight than small- or mediumframed lambs. Table 4 presents market weights at which ewe and wether lambs produced from
parents of different sizes are expected to produce Yield Grade 2 carcasses (.16 to .25 inches of
fat over the loin at the 12th-13th rib). The target weights in Table 4 should be increased by 10 to
20 pounds if the goal is Yield Grade 3 carcasses (.26 to .35 inches of fat over the loin at the 12th13th rib).
Lamb death loss during the feeding period also impacts feed cost of gain. Preventative health
programs addressing health problems that have occurred in the past is money well spent. The
last area that is not often discussed relative to controlling feed cost of gain is to minimize waste.
With appropriately constructed feeders, this should not be a problem. Feed spoilage due to poor
storage or sloppy transport from storage to feeders can increase cost of gain 2, 5 or even 10
percent.
Common Nutritional Disorders and Diseases
White Muscle Disease
Selenium and vitamin E are two nutrients that must be incorporated into creep rations. White
muscle or stiff lamb disease is the common name referring to deficiencies of either/or both
selenium and vitamin E. Soils throughout much of the Midwest and, therefore, feedstuffs grown
in the Midwest tend to be deficient in selenium. All lamb rations should be fortified with at least
4
.18 grams of selenium and 15,000 international units (IU) of vitamin E per ton of complete feed.
One quickly realizes that .18 grams is a very small (.000397 lb.) amount to incorporate into a ton
of feed. Therefore, accurate scales and thorough mixing are critical since 2 parts per million
(ppm) can be toxic (.0044 pounds).
Commercial mineral mixes specifically formulated for sheep almost always contain added
selenium, and mineral/vitamin premixes used in the formulation of lamb diets and commercial
complete mixed lamb feeds almost always have added selenium and vitamin E. However, feed
labels should always be checked to make sure that selenium and vitamin E, and the minerals and
vitamins discussed later, are present in the desired quantity.
Creep consumption by young lambs may not provide adequate selenium or vitamin E intake
relative to their requirements. Many sheep operations routinely administer injectable selenium
and vitamin E to lambs as additional insurance in combating a deficiency. Two important points
are critical to remember, one being that vitamin E stores in the body are very low and secondly,
serum vitamin E levels drop very rapidly to pre-injection levels (5 to 8 days). Lastly, very little
vitamin E crosses the placenta so colostrum or an injection are the lamb’s only means of getting
vitamin E.
Copper Toxicity
Sheep are very efficient at storing ingested copper. Excess copper is stored in the liver. When a
copper-loaded liver dumps its copper into the blood stream, the copper causes destruction of the
red blood cells and death quickly follows. Copper is an essential mineral and all feeds contain
some copper. Cooper also is a contaminate in sources of other minerals, so mineral mixes with
no major copper supplement will still have trace amounts of copper. It is important, however,
that copper not be added to mineral mixes or feeds for sheep. Copper is a common additive to
swine and poultry feeds and mineral so diets formulated for these species should not be fed to
sheep, and contamination of sheep diets with poultry and swine diets in commercial mills must
be avoided.
Common feedstuffs for sheep (e.g., corn, soybean meal, hay) do not contain toxic levels of
copper. However, even “normal” levels of copper can cause copper toxicity if the level of
molybdenum in the diet is very low. If lambs have died from copper toxicity and copper levels
5
in the feed and mineral are normal, feedstuffs should be analyzed for molybdenum level. Some
byproduct feeds also may contain high levels of copper (> 30 ppm) and if used, should not
constitute a high proportion of the diet.
Urinary Calculi (UC)
As previously stated, maximum gain is generally the objective when feeding lambs. This
requires the feeding of high concentrate diets that result in a poor calcium to phosphorous ratio
(less calcium than phosphorous). This is due to grain being very low (< .05%) in calcium. All
high grain rations should be fortified with calcium by adding 1 to 3% limestone to the ration.
Additional methods of preventing UC include adding 10 pounds of salt and 6 to10 pounds of
ammonium chloride or sulfate per ton of ration. Clean, fresh water sources reduce UC through
increased water intake and urine output that serves to flush the urinary tract. An additional
benefit with increased water intake is a corresponding increase in intake and performance.
During cold weather it is critical to provide a warmed water source to encourage consumption.
Polioencephalomacia (PEM)
Polioencephalomacia is a thiamine (vitamin B1) deficiency that usually occurs following a
digestive disorder. Symptoms of PEM are neurological with staggers, blindness, and
convulsions being the most common. Lambs will eventually go down flat on their side, paddle,
and arch their head over their back. Examples of situations that might create PEM include poor
communications that results in a double feeding, lambs being without feed for several hours and
then gorging on feed when fed, or lambs escaping from their feeding pen and having free access
to stored feed.
The best indicator of PEM is the response to thiamine injections. One should see rapid
responses. However, if digestive upsets created the problem, supplemental thiamine injections
may need to be continued for several days until the digestive health of the animal has returned to
normal, and it is eating aggressively.
Coccidiosis
Most commercially available lamb feeds contain Bovatec (Roche), an ionophore that improves
feed efficiency (3 to 5%) and controls coccidiosis. The Roche technical manual indicates that
lambs should consume 15 to 80 mg of Bovatec per day. Consumption of approximately one
6
pound of creep ration is necessary in order to get this amount of Bovatec. In very young lambs,
this level of intake is impossible due to their low bodyweight. In most situations, prevention of
coccidiosis in very young lambs requires strict sanitation and management along with a much
more aggressive strategy to increase Bovatec intake. One must note that FDA allows the
maximum level of Bovatec incorporation into the feed at 30 grams per ton.
Enterotoxemia (Overeating)
Overeating (OE) is one of the most common causes of death in feedlot lambs. Management
inputs to minimize OE include gradual ration changes, vaccination programs, and feeding 20
grams per ton of oxytetracyline (OTC) or chloratetracycline (CTC). Neither antibiotic is cleared
to be fed with Bovatec. Lambs being fed on self-feeders must always have feed available once
they are adapted to self-feeders. Flocks using hand feeding should monitor daily consumption
and adjust feed offered so that lambs are just slightly hungry. In farm flock operations, annual
boosters to ewes during late gestation along with lamb vaccinations at 3 and 6 weeks of age
provides the best possible protection through weaning. Careful administration of the vaccine
(clostridium perfringens type C & D toxoid) along with appropriate handling and storage of the
vaccine increases the efficacy of the vaccine products.
Conclusion
The objective of lamb feeding programs is to provide low cost diets that are balanced and result
in rapid and efficient gains and healthy animals. Frequently adjusting the protein concentration
in the ration will reduce cost. Many other factors impact the feed cost of gain and lamb health,
and all areas must be addressed in today’s market to insure profitable lamb feeding.
7
Table 1. Creep, growing, and finishing rations.
Ingredient
Corn, lb.
Oats, lb.
SBM (49%), lb.
ISU Lampro 42, lb.
Comm. Protein 34, lb.
Corn Gluten Feed, lb.
Alfalfa Hay EB, lb.
Molasses, lb.
Limestone, lb.
Ammonium chloride,
lb.
Trace mineral, lb.
Selenium (grams)
Vit. A, 1,000,000 IU
Vit. D, 100,000 IU
Vit. E
IU
Antibiotic or Bovatec,
respectively (grams)
Calculated Nutrient
Content (Dry Matter
Basis)
Crude Protein, %
Total Dig. Nutrients,
%
Calcium, %
Phosphorous, %
Creep Feeds
1470
1015
Grower Rations
1240
1500
1375
1435
400
370
425
1170
Finisher
1235
1000
360
270
1750
1675
1535
1170
300
600
450
415
500
160
250
625
325
600
700
300
200
100
100
100
60
60
60
60
60
60
40
40
40
35
35
25
50
25
50
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
.2
.2
.2
.2
.2
.2
.2
.2
.2
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
35,000
35,000
35,000
20,000
20,000
20,000
20,000
20,000
20,000
50 or 30
50 or 30
50 or 30
50 or 30
50 or 30
50 or 30
50 or 30
50 or 30
50 or 30
16.7
18.4
21.0
18.1
17.9
18.0
18.0
18.0
18.1
13.4
13.4
13.4
13.3
83.4
81.0
82.7
83.7
80.6
83.4
81.9
79.9
80.8
85.3
83.6
81.5
80.9
.84
.84
.86
1.11
1.14
.74
.74
.75
1.02
.57
.61
.66
.99
.38
.40
.43
.39
.43
.41
.41
.39
.57
.37
.39
.35
.56
8
Table 2. Suggested protein levels for lamb rations as affected by lamb daily gain and weight.
Dry matter
Daily gain, lb./day
Lamb wt., lb. intake, lb./day
.5
.6
.7
.8
40
55
70
85
100
> 115
2.4
2.9
3.1
3.4
3.6
3.8
15.9
13.4
12.8
12.0
11.4
10.8
17.0
14.7
13.9
12.7
11.9
11.4
18.6
15.8
14.7
13.4
12.6
11.9
20.4
16.9
15.5
14.3
13.3
12.5
Table 3. Protein supplement (ISU LamPro 42)a formulation fed at Iowa State University McNay
Research Farm.
Ingredients
Amount per ton
Soybean meal, 49%
Blood meal
Limestone
Molasses
Ammonium sulfate
Trace mineral saltb
Selenium premixc
Zincc
Chloratetracycline or Bovatec
Vitamin A, IU
Vitamin D
Vitamin E
1340 lb.
200 lb.
220 lb.
100 lb.
70 lb.
70 lb.
1.3 grams
300 grams
200 grams
7 million
800,000
150,000
Nutrient density, as fed
Crude protein
NEm (mcal/lb.)
NEg (mcal/lb.)
Calcium
Phosphorous
Selenium (ppm)
a
Supplement is to be fed with whole shelled corn.
Should not contain added copper.
c
Reduce this amount equal to that supplied by trace mineral salt.
b
The supplement shown above, when fed with corn in the following ratios,
provides the nutrient levels listed (dry matter basis)
Corna:supplement ratio Crude protein, % Calcium: phosphorous ratio
4 :1
6 :1
8 :1
10 :1
16.2
14.0
12.8
12.0
2.35 :1
1.74 :1
1.38 :1
1.15 :1
a
Corn is assumed to have 8.5% crude protein on a dry matter basis.
Please be advised that these are very high energy rations.
9
42.4%
.69
.46
3.88%
.54%
1.27
Table 4. Target slaughter weightsa to produce YG2 carcasses from ewe and wether lambs produced from sire
and dam breeds of varying mature weights.
Ewe breed
mature wt., lb.
250
240
230
Sire breed mature wt., lb. (Wt. of ewes of the breed)
220 210 200 190 180 170 160 150 140
130
120
250
240
230
220
210
200
190
180
170
160
150
140
130
120
163
159
156
153
150
146
143
140
137
133
130
127
124
120
159
156
153
150
146
143
140
137
133
130
127
124
120
117
156
153
150
146
143
140
137
133
130
127
124
120
117
114
153
150
146
143
140
137
133
130
127
124
120
117
114
111
124
120
117
114
111
107
104
101
98
94
91
88
85
81
120
117
114
111
107
104
101
98
94
91
88
85
81
78
150
146
143
140
137
133
130
127
124
120
117
114
111
107
146
143
140
137
133
130
127
124
120
117
114
111
107
104
143
140
137
133
130
127
124
120
117
114
111
107
104
101
140
137
133
130
127
124
120
117
114
111
107
104
101
98
137
133
130
127
124
120
117
114
111
107
104
101
98
94
133
130
127
124
120
117
114
111
107
104
101
98
94
91
130
127
124
120
117
114
111
107
104
101
98
94
91
88
127
124
120
117
114
111
107
104
101
98
94
91
88
85
a
Target slaughter weight =((sire breed mature wt. + ewe breed mature wt.)/2) x .65.
Shaded areas indicate desired live weights for market lambs in most commercial markets.
Estimates of average mature ewe weights for some U.S. breeds:
230 - Suffolk; 210 - Hampshire; 200 - Columbia; 180 - Dorset, Lincoln, Oxford, Shropshire;
170 - Border Leicester, Corriedale, Dorper, East Friesian, Montadale, Romney, Targhee;
160 - North Country Cheviot, Polypay, Rambouillet, Texel; 150 - Coopworth, Romanov, Southdown, Tunis;
140 - Cheviot, Clun Forest, Finnsheep, Katahdin, Merino, Perendale, St. Croix;
130 - Cheviot, Scottish Blackface; 120 - Barbados, Karakul; 110 - Jacob; 90 - Shetland.
10