Feeding Practices in Sheep

Succulent pasture furnishes adequate energy, protein, vitamins, and minerals for ewes and lambs; no added grain is necessary. When pasture is not being used (confinement rearing), ewes should be fed one of the rations outlined for pregnant ewes in Rations for Pregnant Ewes up to 6 Weeks Before Lambing, and 1–1.5 lb (450–675 g) of one of the grain mixtures in Grain Mixture for Pregnant Ewes. Ewes should have access to a mixture of trace mineralized salt and dicalcium phosphate. Ewes with twin or triplet lambs should be separated from those with single lambs and fed more concentrates (grain) and/or better-quality forages. Ewes nursing twin lambs produce 20%–40% more milk than those with singles. Under confinement rearing or accelerated lambing, lambs may be weaned at 2 months of age. The ewe’s milk production declines rapidly after this period, and creep feed is more efficiently converted into weight gains when fed to lambs than to the ewe.

Orphaned lambs, extras, triplets, or those from poor-milking ewes can be raised on milk replacers to improve productivity. Such lambs should receive 10%–20% of their body weight in colostrum divided into multiple feedings within 18–24 hours of birth. If ewe colostrum is unavailable, a frozen, pooled supply from several cows can be used. Milk replacers designed specifically for lambs are available and contain ~30% fat, 25% protein, and a high level of antibiotic. Under certain conditions, it may be advisable to inject orphaned lambs with vitamins A, D, and E and selenium. In hand rearing systems, ewe milk replacers are preferable; however, good quality replacers designed for calves may be fed to lambs. When mixing milk replacers, care should be taken to ensure that the powder and water are properly mixed into a suspension. Feeding small quantities throughout numerous feedings helps reduce the incidence of bloat and/or diarrhea. Milk replacers should be fed at 10%–20% of the lamb’s body weight, divided into 4–6 feedings/day during the first week of life. The number of feedings can be reduced over time to twice a day by 3–4 weeks of age.

Multiple-nipple pails or containers can be used. Cold milk replacer can be used by older lambs who nurse more often. By 9–10 days of age, lambs should be given water in addition to the milk if a creep ration is offered. They can be weaned abruptly at 4–5 weeks of age if consumption of creep feed and water intake is at a reasonable level.

Lambs should be preconditioned before they leave the producer’s property. This includes starting on feed, vaccinating, worming, and under some conditions, shearing. If this is not done, the lambs should be rested for several days and fed dry, average-quality hay after arrival at the feedlot. See table Recommended Formulas for Finishing Lambs ^a for some recommended formulas for finishing lambs.

There is no best method or diet for finishing lambs. They may be finished on good to excellent quality forage (alfalfa, wheat) with no supplemental grain. They may be started on pasture or crop residue and moved to grain feeding systems as the forage is used up. When fed in a dry lot, they are usually allowed free access to feedstuffs. These diets may be pelleted, ground and mixed, a mixture of ground forage (alfalfa) pellets and grain, and/or high-concentrate type. Self-feeding usually results in maximal feed intake and gain, with reduced labor costs. Hand-feeding can be mechanized with an auger system or self-unloading wagon. It involves feeding at regular intervals so that the lambs consume all the feed before more feed is offered. Feed consumption and gain can be controlled. When used, corn silage should be hand-fed to minimize spoilage.

Producers who feed lambs year-round, or feed heavy lambs, usually prefer to place the lambs on full feed as soon as possible (10–14 days). Lambs can be started safely on self-fed, ground, or pelleted diets containing 60%–70% hay. Within 2 weeks, the hay can be reduced to 30%–40% when the ration is not pelleted. Other roughages such as cottonseed hulls or silage can be used in a similar manner.

Corn, sorghum, or alfalfa silage can replace about half the hay with hand-feeding, but finish and yield will be decreased to some extent. See table Pattern for Range Supplements for Sheep for rations that can be used in self-feeding. Corn, barley, milo, wheat, or a mixture of these are used; 0.5% salt and 0.5% bone meal or equivalent should be added to the grain. Pelleting of rations for finishing lambs is beneficial when low-grade roughages or high-roughage rations are used. Caution should be used when feeding large amounts of wheat; lambs not adapted to it are more apt to develop acute indigestion than if fed grains such as corn, sorghum, or barley.

Mineral supplements, including salt, should be offered separately whether or not they are included in the grain mixture.

Deficiencies most apt to be seen among range forages are associated with dietary protein, energy, salt, and phosphorus. These are more prevalent as the forages approach maturity or are dormant. Such diet-related problems may appear singly but are more common in combination. Range sheep often travel long distances and are exposed to cold weather, resulting in higher energy requirements. Protein supplements (soybean or cottonseed meal, alfalfa pellets, etc) increase digestibility and use of poor-quality forages. When possible, the inclusion of a phosphorus supplement (eg, dicalcium phosphate, monocalcium phosphate, defluorinated rock phosphate) to a salt or trace mineral salt mixture may greatly improve productivity.

Most ranges used for winter grazing are considered adequate in carotene, because many species of browse furnish as much carotene as sun-cured alfalfa hay. However, when sheep are required to graze dry grass ranges for >6 months without intermittent periods of 'green' forages, vitamin A supplements are recommended. The addition of 45–50 IU of vitamin A/kg/day improves productivity in cases of extended consumption (>2 months) of dry or weathered forages.

On the range, portable mineral boxes are convenient for sheep. One of these mineral mixtures should be fed free choice. A salt and dicalcium phosphate or phosphorus supplement (defluorinated rock phosphate) can be used if there are no iodine or trace-mineral deficiencies. Iodized salt is substituted for regular salt when an iodine deficiency exists, and trace mineralized salt is substituted if deficiencies of trace minerals are present.

Under winter range conditions, the amount of phosphorus supplement that should be added to range pellets varies with the type of range forage available, the rate of feeding, and the ingredients used in the pellets. It is suggested that 36%, 24%, and 12% protein pellets contain 1.5%, 1%, and 0.5% phosphorus, respectively. When feeding supplemental protein, 36% protein pellets should be fed at the rate of 0.25 lb (115 g) per head daily, the 24% protein pellets at 0.33–0.5 lb (150–225 g), and the 12% protein pellets at 0.2–0.5 lb (90–225 g), together with alfalfa or clover hay. Care should be taken when adding supplemental phosphorus and magnesium to the diet of rams or whethers, because this is associated with urolithiasis.