Sheep Pocket Guide (continued)

AS-989, May 1996

Nutrition (continued)

Feeding Tips Flushing the Ewe Feeding Alternatives for Ewes Creep Feeding Lamb Feeding Urinary Calculi Nutrition and Health Water Ration Nutrient Requirements

Minerals Signs of Mineral Deficiency Signs of Vitamin Deficiency Urea Feedstuff Values Weights of Grains Pasture Management Stocking Rates Buying Hay

Ration Nutrient Requirements

Requirements and Toxic Levels of Minerals for Sheep

Like other nutrients (protein, energy, vitamins, and water), minerals have to be supplied within certain limits to serve their purpose. Sheep, like all other livestock, have their own specific requirements and toxic levels. The following is a list of requirements and toxic levels of different minerals for sheep. These figures are based on the sheep's total diet.

MINERAL 	REQUIREMENT  	TOXIC LEVEL
------------------------------------------------
Calcium		0.20-0.82 %	     -
Phosphorus	0.16-0.38 %	     -
Magnesium	0.12-0.18 %	     -
Potassium	0.50-0.80 %	     -
Sulfur		0.14-0.26 %	     - 
Sodium		0.09-0.18 %	     - 
Iodine		0.10-0.80 ppm	   50 ppm  
Iron		  30-50 ppm	  500 ppm
Copper		   7-11 ppm	   25 ppm
Molybdenum	   0.50 ppm	   10 ppm
Cobalt		0.10-0.20 ppm	   10 ppm
Manganese	  20-40 ppm	 1000 ppm
Zinc		  20-33 ppm	  750 ppm
Selenium	0.10-0.20 ppm	    2 ppm
Fluorine     	    -	       60-150 ppm
------------------------------------------------

Within the ranges of values above, the requirements are higher for young growing animals and lactating ewes as compared to fattening lambs and dry ewes. Requirements for pregnant ewes in their last six to eight weeks of gestation fall in the middle of the ranges.

Additional Comments:

• The salt requirement for sheep on complete mixed rations is met when salt is about 0.5 percent of the total diet. Ewes provided salt in the loose form generally consume 0.25 to 0.40 ounces per head per day. Normally, toxic levels of salt are not a problem if clean, soft water is provided at all times. However, be aware that a problem could arise with water that is high in salt content. Sheep can tolerate water containing 1.0 to 1.3 percent salt over a relatively long period of time but cannot tolerate water containing 1.5 to 2.0 percent salt.
• Sheep have a high requirement for sulfur due to their wool growth.
• Of all livestock, sheep are the least tolerant to excess copper. However, higher molybdenum levels (3-5ppm) can increase their copper tolerance.
• Do not use swine mineral for sheep, in part because of the excess copper.

Signs of Mineral Deficiency

Salt      - decreased feed consumption and water intake.
Calcium   - abnormal bone development, tetany, urinary calculi.
Phosphorus- abnormal bone development (rickets), slow growth,
	    depraved appetite, unthrifty appearance, listlessness.
Magnesium - tetany, frothing at mouth, profuse salivation.
Potassium - decreased feed intake, reduced gains, listlessness,
	    stiffness.
Sulfur    - loss of appetite, reduced gains, reduced wool growth,
	    shedding wool.
Cobalt    - lack of appetite, severe emaciation, decreased estrous
	    activity.
Copper    - "swayback" in lambs, "steely or "stringy" wool in adults.
Iodine    - thyroid enlargement (big neck), lambs born without wool.
Iron      - poor growth, lethargy, anemia, increased respiration rate.
Manganese - impaired growth, skeletal abnormalities, incoordination
	    of baby lambs.
Selenium  - "white muscle disease", unthriftiness, early embryonic
	    death.
Zinc      - decreased appetite, retarded growth, "parakeratosis",
	    reduced reproductive ability. 

Signs of Vitamin Deficiency

Vitamin A - growth retardation, retained placenta, bone malformation,
	    degeneration of the reproductive organs, night blindness.
Vitamin D - rickets in young lambs, osteomalacia in adult sheep.
Vitamin E - "white muscle disease", stiffness, arched back.
Vitamin B1- polioencephalomala (Thiamine) 

Urea

General Recommendations for the Use of Urea in Sheep Rations

• Urea can be used as about 1 percent of the total ration or 3 percent of the concentrate portion of the ration, but should not make up more than 1/3 of the total nitrogen in a ration. Urea can be added to silage at the rate of 1 percent at time of ensiling.
• Urea should be not used in rations for very young lambs or creep rations. The rumen of young lambs is not functioning completely and cannot utilize urea. Deaths may result if used.
• Urea should not be used in range sheep rations or in lamb rations when lambs are on limited feed. Urea is broken down to ammonia rapidly and absorbed and excreted in the urine, resulting in incomplete utilization.
• Urea should be introduced into the diet gradually to allow for adaptation by the rumen microorganisms. Full adaptation takes two to three weeks.
• Urea works best in rations containing high levels of readily available carbohydrates (grains).
• Care should be taken to be sure the urea is thoroughly mixed in the diet and to use formulations that prevent separation of ingredients. Also, the urea-containing diet should be fed regularly. Sudden high intakes (by a very hungry animal, or from urea settled to the bottom of the feed bunk) can cause toxicity and death.

Taken from The Sheepmen's Production Handbook (SID, Inc.), Revised 1986

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AS-989, May 1996