The greatest constraint for utilizing the reproduction potential of sheep is inadequate nutrition during late gestation and early lactation. These highly productive stages require an increase in the level of energy over maintenance of up to 175 percent for ewes suckling twins during early lactation. Higher levels of protein are also required.

Difficulties in keeping multiple birth lambs alive often reflect inadequate nutrition during late gestation and/or early lactation. The greatest opportunity for increased flock productivity is directly related to the number of lambs marketed per ewe per year. Nutrition during the last 4 to 6 weeks of pregnancy is critical, especially for ewes with multiple fetuses. Approximately two-thirds of the fetal development occurs during this period. Higher quality feedstuffs become important at this state of production. The highest nutritional requirement for productive flocks is during the first 3 to 5 weeks of lactation. The quality or concentration of energy and protein is important so that intake will not become a limiting factor for milk production. Milk production is directly affected by the number of suckling lambs. Twin-rearing ewes may produce 25 percent more milk than ewes nursing singles. Therefore, the nutritional requirements of lactating ewes are dependent upon their level of milk production. Protein nutrition is especially important for high milk production.

The importance of body energy reserve (fat) condition is important for optimum performance. Grouping ewes on the basis of body condition (thin, average, fat) 4 to 6 weeks prior to lambing is a practical way to more efficiently feed ewes during late gestation.

Ewes suckling multiple lambs have higher milk yields and improved lamb survivability if they are at average or higher body condition during lactation. Production grouping should be done after lambing based on rearing group (single vs. multiple), age of ewe, and lambing date as a practical management practice for providing proper nutrition to the lactating ewe. This practice can result in significant feed cost savings.

Most ewes can raise multiple lambs naturally and efficiently if adequate economical diets are available. High levels of milk production sufficient for triplet rearing can be obtained from older ewes with adequate body energy reserve (fat) provided they receive adequate high energy diets supplemented with high quality protein.

One should realize that lamb starvation and some other causes of perinatal mortality are closely associated with improper ewe nutrition during late gestation and early lactation.

1993