FIG. 201.—General view of Sheep Acres, a 100-acre tract devoted to sheep experiments at the animal-husbandry experiment farm, Beltsville, Md.
Advantages of Forage-Crop Pastures
SHEEP Acres Test Pastures at Beltsville
Sheep Acres is the name used to designate a portion of the animal husbandry experiment farm at Beltsville, Md., which has been set aside for the.study of sheep production under intensive conditions typical of the South Atlantic region of the United States. This tract, consisting of approximately 100 acres of tillable land, has been improved with a well-planned system of pasture rotation and modern sheep equipment. (Fig. 201.) Although there had been some sheep at the Beltsville farm since 1911, the work as now outlined was begun in the fall of 1915, when 53 purebred Southdown ewe lambs, bred at the United States Morgan Horse Farm, Middlebury, Vt., were shipped to Beltsville.
One of the main lines of work conducted at Sheep Acres is the
development of a practical system of forage-crop pastures whereby
sheep can be pastured longer and moved from field to field more often
than when kept by the usual permanent-pasture method. This makes
it possible to keep the farm flock on less cured feed, which is rather expensive-in this region. In addition, sheep can be kept in larger
numbers on a given area, because the danger of serious infestation
and loss from internal parasites—one of the principal drawbacks to
the sheep industry along the eastern seaboard—is greatly reduced. The results of this work are discussed in Farmers’ Bulletin 1181,
“Raising Sheep on Temporary Pastures.”
[This also suggests improvements based on something that sounds a lot like what's called regenerative grazing today. -ASC]
Another problem of general interest which is being studied at the farm is the effect of different degrees of nourishment of the ewes at breeding time on the percentage of twins in the lamb crop. Results covering 10 years’ work show an advantage of 16 lambs per 100 ewes in favor of the highly nourished ewes compared with those kept on short feed during breeding season. Work on this experiment is reported in Department Bulletin 996, “Flushing and Other Means of Increasing Lamb Yields.”
The study of various phases of growth in lambs is another problem being investigated at Sheep Acres. Weekly weighings are made on all lambs until 1 year of age and all mature stock is weighed at intervals of two weeks. Studies are made on the growth of lambs as related to birth weight, gain of dam during gestation, weight and age of dam, and size of sire. Further data are also obtained from periodical measurements on representative lambs of each of the breeds. These data consist in measurements of width and depth of chest, length from shoulder to hip, circumference of the middle of the body, and length from nose to the end of the tail dock.
Type fixing in purebred sheep is carried on at this station by selective breeding. The matings are made as a result of information obtained from the bureau’s scoring system, which consists of five numerica] scores on the mutton conformation and five scores on the wool of each individual sheep. Corrections are attempted in the matings by use of rams which show by their offspring that they are especially excellent in their ability to transmit characteristics in which a ewe shows, by her offspring, that she is lacking. Controlled breeding is practiced and by using a rather large number of tested sires much has been accomplished in the elimination of undesirable characteristics in the progeny.
The flocks at Beltsville, December 1, 1926, consisted of 48 Southdown, 30 Shropshire, 27 Hampshire, and 30 Corriedale ewes of breeding age, 12 stud rams, 30 ram lambs, and 40 ewe lambs of the various breeds. These flocks are maintained on a basis of one-quarter replacement each year by the addition of ewe lambs produced at the farm.
Room is made for the ewe lambs by the selection of ewes of various ages for disposal each year. None of the best ewe lambs are ever sold. By this process it has been possible to set the type and fix the characteristics of each of these flocks far beyond what the average sheep breeder can do if he depends on apparent individual excellence of the breeding stock rather than on a careful study of the strong points and weaknesses in breeding ability of individual sheep as shown by their offspring.