A wide variety of feedstuffs can meet the nutritional needs of ewes during their different production stages. There is no one perfect feeding program. The choice of feeding program will depend upon geographic region, when lambs are born, and the cost and availability of feedstuffs.
Life cycle feeding of ewes
Feeding the ewe so she is gaining weight about 2 weeks before breeding is called flushing. Flushing may increase lambing percentage by increasing the number of eggs that the ewes ovulate. Flushing works best on thin ewes. Ewes that are already in good body condition usually do not respond well to flushing.Flushing has more effect early in the breeding season. Flushing may also be beneficial late in the breeding season. Mature ewes respond better to flushing than yearlings. You can flush ewes by feeding them 0.5 to 1 lb. of grain per day or by moving them to a better pasture. If flushing is continued through the breeding season, it may enhance embryo survival during early pregnancy.
Ewes should not be bred on pastures that contain a high percentage of legumes. Clovers (especially red clover), alfalfa, and birdsfoot trefoil may delay estrus. Fescue grasses, as well as barley grain and oat grain also contain compounds with estrogenic activity. Estrogenic compounds are present in varying concentrations in most all legume plants during the entire growing season, though not when the plants are mature and dry.
Early/mid gestation is a critical period because placental development occurs from day 30 to day 90 of gestation. Placental size or weight affects nutrient transfer between the ewe and the her fetuses. Underdeveloped placentas result in lower birth weights regardless of late gestation nutrition. Twenty-one (21) days of severe underfeeding or 80 days of moderate underfeeding can affect placental development.
Knowing how much to feed ewes during late gestation can be difficult because it depends upon the number of fetuses the ewe is carrying. Underfeeding will result in the birth of small lambs. Small lambs are less resistant to cold stress and will have slower pre-weaning growth. Most of the ewe’s mammary development occurs during late gestation. Underfeeding will reduce the yield and quality of milk. Big lambs increase lambing problems and have a higher mortality rate.
The nutrients that are important during late gestation are energy, protein, calcium, selenium, and vitamin E. The amount of energy required depends upon the number of fetuses and cold stress. Winter lambing ewes usually cannot consume enough forage to meet their energy needs. More energy is required two weeks before lambing versus six weeks before lambing. Ewes carrying singles do not need to receive grain as early as those carrying multiple births.
Pregnancy toxemia or ketosis is the most common nutritional disorder that occurs during late gestation. It is caused by an inadequate intake of energy during late gestation, as fetuses make 70 percent of their growth. As the ewe breaks down her body fat to meet her increasing nutritional needs, toxic ketone bodies are produced.The ewes that are most prone to pregnancy toxemia are fat ewes, thin ewes, old ewes, timid ewes, and ewes carrying multiple births. Treatment is to increase the blood glucose level. In advanced cases, a caesarian section may be necessary.
Milk fever is different in sheep as compared to dairy cattle in that symptoms occur pre-lambing. Milk fever is low blood calcium. It is caused by either inadequate intake of calcium or the inability to mobilize calcium reserves. The clinical symptoms are very similar to pregnancy toxemia. Differential diagnosis is based on the affected ewe’s response to calcium therapy.Vaginal prolapses tend to occur more frequently in fat ewes or ewe lambs carrying multiple fetuses. There is simply not enough room. Preventing ewes from becoming overfat and limiting intake are two ways to reduce vaginal prolapses.
Lactation places the greatest nutritional demand on ewes. How much you feed a ewe will depend upon how many lambs she is nursing, her size and condition, her age, and the time of the year the lambs are born. Ideally, ewes should be separated into production groups and fed according to the number of lambs they are nursing. A general rule of thumb for concentrate feeding of lactating ewes is 1 pound of grain for each lamb nursing the ewe.
Protein and energy are both critical nutrients for milk production. If either nutrient is fed below the requirement, milk yields and lamb gain will be reduced. After the first 60 days of lactation, you should reduce the amount of feed you are feeding because all it will accomplish is making the ewes fat.
Most ewes will lose weight during lactation. Weight loss during lactation affects protein requirements. The more weight ewes lose, the higher their protein requirement will be.
Lactating ewes require a lot of water if they are expected to milk well. It is estimated that lactating ewes require 100 percent more water than non-lactating ewes. Ewes should have a free-choice supply of fresh, clean water at all times. Heated water bowls should be used during the winter to encourage water consumption. Water bowls should be checked and cleaned on a daily basis.
Weaning often takes place at a time when ewes are still producing a lot of milk. In this is the case, grain should be reduced 1 to 2 weeks prior to weaning. For the last week or so prior to weaning, no grain should be fed to the ewes. For the last several days before weaning, ewes should be fed a low quality grass hay or straw. After the lambs have been weaned, the ewes should be maintained in dry lot and fed low quality grass hay or straw until their udders start to dry up and recede.It is not necessary to remove water from ewes at weaning. It can also be dangerous during hot weather. Do not turn ewes onto pasture immediately after weaning. Spring grass is high in protein, water, and other nutrients which promote milk production.
The overriding concern at weaning time for ewes is to prevent mastitis. Ewes need to be watched closely during the weaning period for mastitis. Ewes with spoiled udders have decreased or no future production value.
The maintenance period is usually the longest period in the ewe’s production year. Maintenance means the ewe only needs to maintain her body weight or have slow growth to recover the weight (condition) she lost during lactation. A wide variety of low-cost feed stuffs can meet the maintenance requirements of ewes. Pasture or grass hay is all most sheep need to maintain themselves. Pet sheep should always be fed at a maintenance level.