1. Common salt (sodium chloride) is one of the essential nutrients in the rations of sheep and lambs, and the proper provision of it makes for a more profitable and satisfactory sheep husbandry.
2. Free-choice salt feeding with our present knowledge appears to be the most satisfactory method of allowance under Corn-belt conditions to secure near-optimum nutritional results.
3. When salt is arbitrarily allowed, mixed with the feeds, experimental results indicate that with our present understanding of the factors controlling salt needs, it is very difficult to approximate the correct quantitative allowance.
4. Researches with wintering ewes indicate that salting the feed may be easily overdone, or underdone. An absence of salt from the feeds allowed ewes resulted in lesser gains, less efficient use of feeds, an impaired lamb crop and a decreased wool yield. The ewes not fed salt developed a marked craving for it.
5. The records kept on 1,306 winter-fed lambs show an average daily salt consumption of 0.011 pound per lamb, the range by lots being from 0.001 to 0.019 pound. It is estimated that lambs fed at Ames secure about one-half of their total sodium (pure common salt contains 39.34 percent of the "mineral" sodium) and three-fourths of their chlorine (salt contains 60.66 percent of chlorine) from the salt box (salt self-fed). Ames campus water supplies but very little of the total salt constituents, but the feed provides practically all the sodium and chlorine not supplied in the salt box.
6. The character and composition of the rations fed affect in large measure the salt consumption and r equirements of fattening lambs. Feeding beet molasses markedly decreased salt consumption, whereas alfalfa hay had the opposite effect.
7. Fattening lambs consume much more salt per unit weight than steers fed under similar conditions, and whereas the daily salt consumption of lambs increases during the feeding period, that of the steers decreases. Lambs in the finishing lots consume more roughage in proportion to concentrates than do steers; this ratio of roughage to concentrates is the more marked as the period of feeding progresses. The greater the proportion of roughage, the larger apparently is the salt consumption.
8. The salt required for a hundred pounds gain on 1,306 fattening lambs averaged 3.78 pounds, the range being from 0.21 to 11.18 pounds. A typical representative of an average lamb, gaining 30 pounds in our experiments, would therefore require a little over one and a tenth pounds of salt during the winter feeding period.
9. The observations and data as available and interpreted indicate that the free-choice feeding of salt of high grade, block or flake, is good practice in the fattening of lambs.
Evvard, John M.; Brown, L. C.; Culbertson, C. C.; and Hammond, W. E.
"The salt consumption of sheep: Fattening lambs,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 7
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol7/iss94/1