Sheep can be produced under many production systems in New Mexico. Here are some things to consider when designing a sheep production system:
Available forage. Plan to make maximum use of seasonal forage because feed costs often amount to 50 to 60 percent of the total cost of producing lamb and wool.
Feed consumption is the greatest during late gestation and lactation; producers may be able to reduce feed costs by grazing ewes on pasture at these times. Available labor. When sheep are added to other farming enterprises, it may be advisable, from a managerial standpoint, to lamb when labor is not needed for other activities.
Lamb prices. Lamb prices normally fluctuate during the year, and it may be more profitable to produce lambs for the expected high market. Typically, that is during the late spring and early summer.
Size of flock. Small flocks, from 10 to 50 ewes, often are not profitable because they tend to be poorly managed. The primary reason is that mechanization is not feasible, so return per hour of labor is not maximized.
Small farm flocks generally are used simply to control weeds on irrigation ditches or maintained as a hobby.
Purebred Sheep Production
Purebred sheep supply genetics for the development of commercial sheep production systems. In general, depending on the breed and availability, it is more expensive to start a purebred sheep business than a commercial one. Purebred sheep are often more expensive to produce, and more expense is involved in advertising and marketing. Ordinarily, purebred sheep are fed at a higher nutrition level than are commercial flocks. A well-fed purebred flock is more productive and more attractive to prospective buyers than are sheep maintained on lower nutrition levels.
To grow to maximum size, ewe and ram lambs must be born early. On most purebred sheep operations, breeding occurs in July and August. This usually results in a suboptimal lamb crop percentage because most ewes are more fertile during September and October.
A purebred sheep operation produces stud rams, commercial rams, and replacement ewes, usually for a price above their commercial value. Managing such an operation requires a thorough understanding of genetics, nutrition, reproduction, and health.
Commercial Sheep Production
Many management alternatives are available to the commercial sheep producer. One major distinction among these alternative production systems is the season in which lambing occurs.
Fall lamb production. For fall lambing, an abundant supply of fall and winter forage, small-grain pasture, alfalfa stubble, or other crop residue is necessary.
For ewes to lamb in October and November, breed them in May and June. The ewe flock must be of those breeds that tend to breed out of season. The fine-wools, Dorset, and crossbred ewes that are at least 50 percent fine-wool are best suited for fall lamb production.
Even so, the lamb crop percentage from May and June breeding is likely to be low. Ewes may need hormone therapy to induce estrus and ovulation (see section on reproduction, page 11). Furthermore, farm labor often is busy elsewhere during fall lambing when the ewes need attention. Occasionally, fall-born lambs are weak and small because of heat stress during the summer gestation period.
Winter lambing. One advantage of winter lambing is that labor requirements of other agricultural enterprises are generally low at this time, so more attention can be diverted toward the ewes. This program is best for the producer who has an abundance of homegrown forages.
Under this production system, slaughter lambs of market weight and condition are ready to be sold during May and June, when lamb prices are normally high.
For winter lambing, breed the ewes in late July, August, and early September. Since this is somewhat earlier than normal, it may be necessary to flush the ewes to increase ovulation rate. After the ewes are bred, graze them on good pasture that will satisfy their nutritional requirements until about four to six weeks before lambing. Prior to lambing, supplement the ewes with high-quality hay and possibly with grain to meet their nutritional needs. Lambs born in the winter should be creep-fed as soon as possible with grains and highquality legume hay.
If feed and pasture are available, lambs can be weaned at about 60 days. It is generally more economical to feed lambs directly than to feed nursing ewes. Many producers keep the lambs in a drylot and put the ewes back on pasture. This helps to prevent internal parasite problems in the lambs.