An introduction to feeding small ruminants
Feed is the single largest cost associated with raising small ruminants, typically accounting for 60% or more of total production costs. It goes without saying that nutrition exerts a very large influence on flock reproduction, milk production, and lamb and kid growth.
Late-gestation and lactation are the most critical periods for ewe and doe nutrition, with lactation placing the highest nutritional demands on ewes/does. Nutrition level largely determines growth rate in lambs and kids. Lambs and kids with higher growth potential have higher nutritional needs, especially with regards to protein. Animals receiving inadequate diets are more prone to disease and will fail to reach their genetic potential.
Small ruminants require energy, protein, vitamins, minerals, fiber, and water. Energy (calories) is usually the most limiting nutrient, whereas protein is the most expensive. Deficiencies, excesses, and imbalances of vitamins and minerals can limit animal performance and lead to various health problems. Fiber (bulk) is necessary to maintain a healthy rumen environment and prevent digestive upsets. Water is the cheapest feed ingredient, yet often the most neglected.
Many factors affect the nutritional requirements of small ruminants: maintenance, growth, pregnancy, lactation, fiber production, activity, and environment. As a general rule of thumb, sheep and goats will consume 2 to 4 percent of their body weight on a dry matter basis in feed. The exact percentage varies according to the size (weight) of the animal, with smaller animals needing a higher intake (percentage-wise) to maintain their weight.
Maintenance requirements increase as the level of the animals' activity increases. For example, a sheep or goat that has to travel a farther distance for feed and water will have a higher maintenance requirements than animals in a feed lot. Environmental conditions also affect maintenance requirements. In cold and severe weather, sheep and goats require more feed to maintain body heat. The added stresses of pregnancy, lactation, and growth further increase nutrient requirements.
The following chart gives the nutritional requirements for various classes of sheep and goats:
| Sheep | Percent
Protein (CP) |
Percent
Energy (TDN) |
| Maintenance (154 lb. mature ewe) | 9.6 |
57.6 |
| Late Gestation 180-225% lamb crop expected |
11.2 |
66.7 |
| Lactation Nursing Twins |
14.8 |
64.5 |
| Early Weaned Lambs
(66 lbs.) Moderate growth High Growth |
14.5 |
75.8 |
| Lamb Finishing 88 lbs., 4-7 mos of age |
11.7 |
77.1 |
| Yearlings (110 lbs.) | 9.1 |
57.6 |
| Source: Sixth Revised Edition, National Research Council, 1985. | ||
| Goats | Percent
Protein (CP) |
Percent
Energy (TDN) |
| Bucks | 11 |
60 |
| Dry Doe | 10 |
55 |
| Late Gestation | 11 |
60 |
| Lactation Avg. Milk High Milk |
11 14 |
60 65 |
| Weanling | 14 |
68 |
| Yearlings | 12 |
65 |
The next chart gives typical "book values" or "ballpark" figures for the nutritional content of various feedstuffs commonly fed to sheep and goats.
| Feed Stuff | Percent
Protein (CP) |
Percent
Energy (TDN) |
| Mature Pasture | 8 |
50 |
| Clover Pasture | 25 |
69 |
| Orchardgrass Pasture | 18 |
65 |
| Browse (Honeysuckle) | 16 |
72 |
| Soybean Meal | 44 |
88 |
| Complete Pellets | 12 |
78 |
| Barley Grain | 13.5 |
84 |
| Corn Grain | 10 |
89 |
| Poor Hay | 8 |
50 |
| Grass Hay | 12 |
58 |
| Mixed Hay | 15 |
50 |
| Legume Hay | 18 |
62 |
A sheep or goat's nutritional requirements can be met by feeding a variety of feed stuffs. Feed ingredients can substitute for one another so long as the animals’ nutritional requirements are being met. Small ruminant feeding programs should take into account animal requirements, feed availability, and costs of nutrients.
Pasture, forbs, and
browse
Pasture, forbs, and browse are usually the primary and most economical source
of nutrients for sheep and goats, and in some cases, pasture is all small ruminants
need to meet their nutritional requirements. Pasture tends to be high in energy
and protein when it is in a vegetative state. However, it can have a high moisture
content, and sometimes it may be difficult for high-producing animals to eat
enough grass to meet their nutrient requirements.
As pasture plants mature,
palatability and digestibility decline, thus it is important to rotate pastures
to keep plants in a vegetative state. During the early part of the grazing season,
browse (woody plants, vines and brush) and forbs (weeds) tend to be higher in
protein and energy than ordinary pasture. Sheep are excellent weed eaters. Goats
are natural browsers and have the unique ability to select plants when they
are at their most nutritious state. Sheep and goats that browse have fewer problems
with internal parasites.
Hay
Hay is the primary source of nutrients for small ruminants during the winter
or non-grazing season. Hay varies tremendously in quality, and the only way
to know the nutritional content is to have the hay analyzed by a forage testing
laboratory. Hay tends to be a moderate source of protein and energy for sheep
and goats. Legume hays --alfalfa, clover, lespedeza -- tend to be higher in
protein, vitamins and minerals, especially calcium, than grass hays. The energy,
as well as protein content of hay depends upon the maturity of the forage when
it was harvested for forage. Proper curing and storage is also necessary to
maintain nutritional quality of hay.
Silage
Silage made from forage or grain crops has been successfully fed to both sheep
and goats; however, special attention must be paid to quality, as moldy silage
can cause listeriosis or "circling disease" in small ruminants. As
with fresh forage, the high-producing animal often cannot consume enough high
moisture silage to meet its nutritional needs. Silage is typically fed on large
farms, due to the need for storage and automated feeding equipment.
Concentrates
It is oftentimes necessary to feed concentrates to provide the nutrients that
forage alone cannot provide. This is particularly true in the case of high-producing
animals. There are also times and situations where concentrates are a more economical
source of nutrients. Creep feeding and supplemental feeding of lambs and kids
has been shown to increase growth weight, but should only be done to the extent
that it increases profit.
There are two types of concentrate feeds: carbonaceous and proteinaceous. Carbonaceous concentrates or "energy" feeds tend to be low in protein (8-11%). They include the cereal grains --corn, barley, wheat, oats, milo, and rye. It is not necessary to process grains for sheep and goats unless the animals are less than six weeks of age and lack a functioning rumen.
One of the problems with feeding a lot
of cereal grains is that they are high in phosphorus content, but low in calcium.
Feeding a diet that is high in phosphorus and low in calcium can cause urinary
calculi (kidney stones) in wethers and intact males. Inadequate calcium can
lead to milk fever (hypocalcemia) in pregnant or
lactating ewes/does.
Proteinaceous concentrates or "protein supplements" contain high levels of protein (>15%) and may be of animal or plant origin. They include soybean meal, cottonseed meal, and fish meal. Ruminant-derived meat and bone meal cannot (by law) be fed to other ruminants, including as sheep and goats. Protein quantity is generally more important than protein quality (amino acid content) in ruminant livestock since the microorganisms in the rumen manufacture their own body protein.
Livestock do not store excess protein; it is burned as energy or eliminated (as nitrogen) by the kidneys. Since parasites often cause blood loss in small ruminants, higher levels of protein in the diet may enable the animal to mount a greater immune response to parasites.
By-products feeds, such as fat, soy hulls, wheat middlings, and broiler litter may contain high levels of various nutrients and can be incorporated into small ruminant diets if they are cost effective. Due to its copper content, it is not recommended that sheep be fed broiler litter for sustained periods of time.
Many feed companies offer
"complete" sheep and/or goat feeds -- pelleted or textured -- which
are balanced for the needs of the animals in a particular production class.
Pelleted rations have an advantage in that the animals cannot sort feed ingredients.
While complete sheep feeds have been available for many years, it has only been
in recent years, that meat goat rations have been introduced to the market place.
Complete feeds come in 50 or 100 lb. sacks and tend to be much more expensive
than home-made concentrate rations.
Vitamins and minerals
Many minerals are required by small ruminants. The most important are salt,
calcium, and phosphorus. The ratio of calcium to phosphorus should be kept around
2:1 to prevent urinary calculi. Vitamins are need in small amounts. Small ruminants
require vitamins A, D and E, whereas vitamin K and all the B vitamins are manufactured
in the rumen.
A free choice salt-vitamin-mineral premix should be made available
to small ruminants at all times, unless a premix has been incorporated into
the grain ration or TMR (total mixed ration). In the very least, ewes and does
should be fed pre-choice mineral during late gestation and lactation. Either
a loose mineral or mineral block may be offered. Force-feeding minerals and
vitamins is actually better than offering it free choice since animals will
not consume minerals according to their needs.
Mid-Atlantic soils are typically deficient in selenium, thus the premix should be fortified with selenium to prevent white muscle disease in lambs and kids and reproductive problems in females. Supplementing selenium via the feed or mineral is preferred to giving selenium injections.
Goats appear to have a much higher tolerance for copper in their diets as compared to sheep, thus it is recommended that feeds and/or premixes contain copper, unless the goats are co-mingled with sheep. Sheep should be fed mineral mixes that have been specifically formulated for sheep.
It is possible to get pelleted supplements that contain vitamins and minerals, as well as high levels of protein (34-40%). These supplements can easily be combined with whole grains or by-product feeds to create a balanced concentrate ration. Coccidiostats and antibiotics can also be added to the mineral mix or supplement. Bovatec® (lasalocid) is FDA- approved to coccidiosis in lambs. Rumensin® (monensin) is FDA approved for goats. Deccox® is approved as a coccidiostat for both species.
Water
Small ruminants should have ad libitum access to clean, fresh water at all times.
A mature animal will consume between ¾ to 1 ½ gallons of water
per day. Water requirements and intake increase greatly during late gestation
and during lactation. Water requirements increase substantially when environmental
temperatures rise above 70?F and decline with very cold environmental temperatures.
An animal’s nutrient requirements will increase if it has to consume cold water during cold weather. Rain, dew, and snowfall may dramatically decrease free water intake. Inadequate water intake can cause various health problems. In addition water and feed intake are positively correlated.
Copyright © 2003.
Resources and additional reading
Ration balancer and nutrient requirement calculator for goats
Montana State University's Sheep Ration Program
Sheep and meat goat rational evaluator (Excel spreadsheet)
Feeding sheep - Virginia Tech
The basics of feeding sheep - Purdue University
Nutrition of meat goats - NC State University
Feeding programs for meat goats - GoatWorld
Life cycle feeding of sheep and goats [PowerPoint presentation]
Nutrient requirements of sheep and goats [PowerPoint presentation]
Created or last updated
by Susan Schoenian on
23-Dec-2009
.
