Developmental Stages of Lambs Dr. Dan Morrical Iowa State University

Development Stages of Lamb Digestive System Birth - 3 weeks pre-ruminant 3-8 weeks - psuedo ruminant 8 weeks & on - ruminant

Birth: Solely dependent on milk Composition of ewes milk: 18.2% dry matter 5-7% fat 24.7% crude protein 26.4% lactose 7.5 mg/lb Vit E 11 IU /lb Vit E

Milk Yield and Composition Impact Lamb Performance •Higher milk fat leads to increase energy intake •ISU creep trials: 16, 21 & 26% CP No variation in performance •Megalac increases milk fat

Creep Diets Palatable -Corn -Soybean meal -Molasses Roughage is of minimal value Lambs get adequate roughage intake from ewe diets

Creep Diets •Easily digestible •15-20% crude protein •Added fat

Creep Ration Corn 1470 SBM 49% 370 Molasses 100 Limestone 40 TM salt 10 Ammonium sulfate 10 CTC 50 grams Selenium .2 grams Vitamin A 1,000,000 IU Vitamin D 100,000 IU Vitamin E 35,000 IU Zinc 136 grams Crude protein 16.7% TDN 83.4% Calcium .84% Phosphorous .38%

Ration Physical Characterics Very young lambs Meal form 3-8 weeks Medium grind 8-12 weeks Coarse grind >12 weeks Whole grains

Nutrient Requirements Factors : Sex Lean Growth Potential Weight

Composition of Gain Rams Lambs Superior Wethers Intermediate Ewe Lambs Poorest

Mature Size Lambs are market ready at 65% of average mature weight of ewes of parent breeds. 220 lb. sire + 180 lb. dam = 400 ÷ 2 = 200. 200 x .65% = 130.

% Protein Concentration of Lamb Rations ADG Lamb Wt. .50 .60 .70 .80 40 15.9 17.0 18.6 20.4 55 13.4 14.7 15.8 16.9 70 12.8 13.9 14.7 15.5 85 12.0 12.7 13.4 14.3 100 11.4 11.9 12.6 13.3 115 10.8 11.4 11.9 12.5

Protein Quantity and Quality Very young lambs - solely dependent on feed protein for quality and quantity Ruminant -Protein quality depends on Feed origin Bacterial origin

Ruminant - Protein Quantity •Intake •Microbial yield -impacted by energy intake -rumen ammonia level -liquid dilution rate

Rumen Bacteria Cellulolytic - Fiber digesters Amylolytic - Starch digesters Proteolytic - Bacterial protein digesters

Lamb Intake Controlled by: Low concentrate diets -- fill Energy Low concentrate diets -- fill High concentrate diets -- energy

Specific Nutrients Vit E. 30,000 IU/ton Se .3 ppm Ca .48 P .24 Salt .5-1.0%

What Type of Ration 1. Targeted marketing date. 2. Relative costs of nutrients. 3. Compositional goal. 4. Facility size. 5. Feed processing equipment & storage. 6. Feeding system.

Simplest System Whole corn: Pelleted Protein Supplement. Advantages: -Superior feed efficiency -Self fed -Low processing costs -Low cost diet -Acidosis risk

Simplest System...continued Disadvantages: -Sorting -Slower gains -Quality of protein supplement -Cash expense for protein

High Hay Rations Advantages: -Minimal cash outlay -Value added to hay crop -Improved composition Disadvantages: -Lower ADG -More facilities, bunks and pens -Hay waste

Weaned Lamb Performance on Grass Factors - Forage Species Grass vs. legumes -Age of lamb -Health of lambs -Condition of lambs

Lamb Gains on Straight Grass .20 - .25 pounds per day .35 - .50 w/pound supplementation Conversion 1:10 t0 1:5

Escape Protein for Pasture Lambs Sources: •Blood Meal •Fish Meal •Corn Gluten Meal

Nursing Lamb Performance on Grass Milk Production is Key 1. Rotational grazing a. high quality and quantity of forage b. reduced competition between ewe & offspring 2. Creep Feeding a. improved growth b. allows coccidia control c. increases cost of production