CLF269 - - AGRICULTURE CORE CURRICULUM - - (CLF200) Core Area: ANIMAL SCIENCE (CLF260) Unit Title: NUTRITION AND FEEDS ______________________________________________________________________________ (CLF269) Topic: LIVESTOCK RATIONS time taught in year 2 hours 1 ______________________________________________________________________________ Topic objectives: Upon completion of this lesson the student will: Learning outcome # (E-3) - Be able to describe a simple feeding regime for market swine, lambs and beef. (E-3,9) - Develop an understanding of how to balance a ration. (E-3,9) - Be able to distinguish between a balanced ration and an economically balanced ration for livestock. (E-3,9) - Develop the ability to compute a least-cost ration for their project. Special Materials and Equipment: A sample of premixed feed. Evaluation: Testing and Supplemental Worksheets #1-4 REFERENCES: Blakely and Bade, THE SCIENCE OF ANIMAL HUSBANDRY, 4th edition. Bundy and Diggins, LIVESTOCK AND POULTRY PRODUCTION, 2nd edition, pg. 266-267, 330-331, 503. Cullison and Lowery, FEEDS AND FEEDING, 4th edition, pg. 502-601, 503-601. Ensminger, ANIMAL SCIENCE, 5th edition, pg. 147-150, 519-524, 687-692, 884- 892. Morrison, FEEDS AND FEEDING, 9th edition, pg. 136-143, 15, 621-622. TOPIC PRESENTATION: LIVESTOCK RATIONS TEACHERS: You will not have time to teach student both methods of ration balancing demonstrated herein if you want to complete this lesson in two hours. _______________________________________________________________ ACTIVITY: As a review and to emphasize the need for balanced rations which vary with the use of the animal, have the students complete the attached Supplemental Worksheet #1 (Livestock Nutrient Needs)in groups. Then have them summarize this activity on the board and discuss the results. _______________________________________________________________ PART A: Balancing a Ration for Livestock. 1. A ration is: a. the feed allowed for a given animal during a 24 hour period, whether it is fed at one time or in portions at different times during the day. 2. A balanced ration is: a. generally contains more than one feed, so proper quantities of essential nutrients will be provided; and b. is one which furnishes the required nutrient in such proportion and amount that the animal is properly nourished for the 24 hour period. 3. There are three methods for balancing rations: a. the square method (used for calculation of protein only) (sometimes used since protein is often a limiting factor in a ration); b. the feeding standard (used for any and all animal requirements); and c. computer formulated rations. 4. Feeding standards are found in: a. tables stating the amounts of nutrients which should be provided in rations for specific animals of various ages and classes in order to secure the best results (found by themselves and/or in nutrition and animal science texts). You should use the feeds that you have available; "importing" feeds from elsewhere often is too expensive to be practical. 5. The Square Method (use Supplemental Worksheet #2: Pearson Square): a. Step 1: 1) Determine (using the appropriate table) the percent protein needed. 2) Decide what protein supplement and which grain(s) you will use in the ration. b. Step 2: 1) Construct a square in the middle of your paper. 2) Put the desired crude protein percentage of the animal's feed in the middle of the square. 3) Put the crude protein percentages of the feed on the left hand side of the square. a) Supplement (may be roughage) in lower corner b) Grains (or average of grains) in upper corner 4) Subtract diagonally and place the differences at the right hand corners. a) Upper right gives parts of supplements b) Lower right gives parts of grain. 5) Add the values on the right side of the square and place that sum below each of the numbers in the right corners; this represents (in fraction form) the portions of each feed needed to mix the ration balanced for protein. ___________________________________________________________ ACTIVITY: Have the students perform this on their own after demon- strating it on the board. Provide them a sheet of paper with a square and diagonal arrows from corner to corner drawn on it, or use Supplemental Worksheet #2. Have them check their work by determining the pounds of protein provided each by the supplement and the grain, then sum the two and divide it by the total pounds for the ration. The answer, converted to percentage, should equal the number in the middle of the square. Then ask them to calculate the amount of grain and supplement needed for one ton of the ration. ___________________________________________________________ 6. Feeding Standards Method (the following is an exercise using Supplemental Worksheet #3) a. Step 1: 1) Determine the type and class of animal being fed. 2) Decide which feeds you will use, depending on availability and cost. b. Step 2: 1) Provide Supplementary Worksheet #3: Livestock Rations to all students c. Step 3: 1) Look up the composition of the feeds you have selected, including digestible protein, T.D.N. and calcium. 2) Look up the requirements of total protein, T.D.N., calcium and total pounds required/day for your animal. 3) Place these in their respective boxes. d. Step 4: 1) Estimate the amount of each ingredient to feed your animal (remenber the total for the ingredients cannot be larger than the REQUIREMENT). 2) Put the number of pounds in its boxes on the chart. 3) (This is the trial and error part of the problem. Remember that a protein supplement should never be more than 1/3 of the total ration.) e. Step 5: 1) Multiply the pounds of individual feed times the percentages of feed values for each of the categories including "Dig. Protein," "TDN" and "Calcium." f. Step 6: 1) Add the results and observe if the totals are even or above the animal's requirements. 2) Adjust the individual pounds of feed and remultiply and get as close as possible to the requirements of the animal. g. Have them calculate the cost to feed the animal on the ration for 120 days. ___________________________________________________ ACTIVITY: Take a sample of a ration and hand out a small amount to each student. Have them separate the grains and determine the amount of each grain in the mixture. ___________________________________________________ PART B: Computing least-cost balanced rations. 1. Substitution of feeds: a. Make up a new balanced ration using substitute feeds such as soybean meal for cottonseed meal, or almond hulls for corn. b. Compare the cost of the new ration with the old one. c. Determine if the substitution pays or not. (NOTE: The balance of Part B is for teacher reference or for ENRICHMENT of the nutrition unit as the instructor deems appropriate.) 2. Rules of thumb: a. Silage can be substituted for hay at a rate of 3 pounds of silage for 1 pound of hay. b. Start cattle on new feed with 2 lb/head the first day, increase the ration 1/2 - 1 lb daily until they reach approximately half the volume of feed, and then increase the ration by 1 pound every third day until full feed is obtained. This will reduce the risk of gastric distress c. Lambs started on grain: Feed 1/4 lb. per head per day. Gradually increase it until they are eating free choice. The amount of feed will vary greatly depending on the breed of sheep. d. Other feeds which can be substituted for alfalfa: 1) clover, 2) lespedeza, 3) timothy hay, and 4) prairie hay. e. Feeds which can be substituted for corn in rations: 1) Barley, 2) Milo, 3) Sorghum, 4) Oats, 5) Rye, and 6) Wheat. f. Protein supplements: 1) linseed meal, soybean meal, and cottonseed meal (may be used almost interchangeably depending on which is more economical); 2) tankage and meat scraps; 3) soybeans; and 4) wheat bran 3. Guides for concentrates and roughages: a. Swine: 1) Fattening pigs in drylot: 5-15% legume hay in ration. 2) Pregnant sows in drylot: 10-15% legume hay in ration. 3) Pregnant sow: 1-1.5 lb. of concentrate per 100 lbs. body weight. 4) Pregnant gilts: 1.5-2.0 lbs. of concentrates per 100 lb. body weight. 5) Fattening swine will consume 5 lb. of feed (mostly concentrates) per 100 lb. of body weight. b. Beef cattle: 1) Fattening cattle: 2.1 lbs. or more of concentrates and dry roughages daily per 100 lbs. of body weight. The allowance on concentrates ranges from less than 1 lb. to 1.7 lbs. or more daily per 100 lbs. of live weight. Full feed: Cattle will consume 1 3/4 - 2 1/2 lbs. of concentrates and 3/4 - 2 lbs. of hay per 100 pounds of live weight daily. 2) Breeding cows: If roughage is low in protein, 1 lb. per head daily of protein supplement should be fed along with a small amount of grain. c. Dairy cattle: 1) Dairy cows in milk: 2.0 lbs. of dry roughage daily per 100 lbs. of live weight. For concentrates use the tables in the Feeds reference book. 2) Dairy heifers: Up to 6 months - 2 to 3 lbs. of concentrates per head day on good roughage. 4 to 5 lbs. on poor roughage. Over a year old: 2 - 4 lbs. of concentrates on fair roughage. d. Sheep: 1) Breeding ewes: good roughage up to 4-6 weeks before lambing. During 4-6 weeks, .5 to .75 lbs. of concentrates per head per day. 2) Nursing ewes: Ewes not on pasture need 1 lb. or more per head per day of concentrates in addition to good roughage. 3) Fattening lambs: 70 lbs, 1.5 lbs. of roughage per head per day and all the grain they will eat. 2.5 lbs. or more of hay per head per day when grain is restricted. Full feed: lambs will consume about 2 lbs. of grain and about 2 lbs. of roughage per head per day. 4. Compute the cost of a ration: a. Figure the cost of feed to price per pound. 1) Take a ton price and divide by 2000 to get the price per lb. b. Then multiply this amount by the lbs. of feed used per day in the ration. c. Add together the figures for all the feeds used and divide by the numbers of animals fed to get the cost of feed per animal per day. 5. Sudden feed changes: a. Digestive disturbances will result and animals will go off feed; in certain instances, they may even die. 6. Least-cost balanced ration vs. balanced ration: a. A ration will not be economical unless the animals like it, it keeps them in good health, and they grow, fatten, or produce well on it. b. A balanced ration is not necessarily the most economical ration to feed the livestock. c. Least cost balanced rations should include the following factors: 1) Use the feeds you have available at the lowest cost. 2) Meet the minimum requirements from the feeding chart(s). 3) Use the proper proportions of concentrates and roughages in your ration. _______________________________________________________ ACTIVITY: Ask the students to call or look up in a newspaper the prices of the feeds that they used in Part A. Then ask if a cheaper feed could have been used. _______________________________________________________ ______________________________________________________ ACTIVITY: Have the students answer the questions on Supplemental Worksheet #4. ______________________________________________________ SUPPLEMENTAL WORKSHEETS ATTACHED Supplemental Worksheet #1: Livestock Rations Date__________________ Name________________________________ Class__________________ Nutrient Needs of Animals: Rate the needs of the following using the terms "low," "medium" and "high." | | | Animal | Energy (TDN) | Protein | Vitamins and Minerals | | | ______________________________________________________________________________ 1. "Lazy" Adult | | | Horse | | | | | | | | | ______________________________________________________________________________ 2. "Lazy" Adult | | | Cow | | | | | | | | | ______________________________________________________________________________ 3. Race Horse | | | | | | | | | | | | ______________________________________________________________________________ 4. Yearling | | | Beef Steer | | | | | | | | | ______________________________________________________________________________ 5. Heavily | | | Lactating Cow | | | | | | | | | ______________________________________________________________________________ 6. Weiner Pig | | | | | | | | | | | | ______________________________________________________________________________ 7. Pregnant Ewe | | | | | | | | | | | | ______________________________________________________________________________ Supplemental Worksheet #2: Pearson Square Date__________________ Name________________________________ Class__________________ Complete the following square using requirements taken from tables or provided by your teacher, and then fill in the blanks on items 1-4. (CP = crude protein) ________ ______________________________________ ________ | * * | | * * | (CP in grain) | * * | (Fraction of whole | * * | that is grain) | * 20% * | | * ___________ * | | * (CP desired) * | | * * | | * * | | * * | | * * | ________ |_____________________________________| ________ (CP in protein (Fraction of whole supplement) that is supplement) 1. Percentage grain: _____________ divided by _____________ = _____ % grain numerator denominator 2. Percentage supplement: _________ divided by _________ = _____ % supplement numerator denominator 3. Check your work: ______ % grain + ______ % supplement = 100% 4. (Fill in) _________ lbs. of grain and _________ lbs. of supplement are needed to mix one ton of this feed. Supplemental Worksheet #3: Livestock Rations Date__________________ Name________________________________ Class__________________ Animal______________ Weight______ Type of Activity_______________ Summary of Dietary Needs: List the types of feed (two to four) and the percentage, in that feed, of the listed nutrient found in each box; then insert the information taken from the nutrient requirement tables in the reference book provided by the instructor. Ingredient | Amount Fed/Day | Dig. Prot | TDN | Calcium | Pounds) | (%) | (%) | (%) _________________________________________________________________________ | | | | | XXXXXXXXXXXXXXX | | | _________________________________________________________________________ | | | | | XXXXXXXXXXXXXXX | | | _________________________________________________________________________ | | | | | XXXXXXXXXXXXXXX | | | _________________________________________________________________________ | | | | | XXXXXXXXXXXXXXX | | | _________________________________________________________________________ REQUIREMENT | | | | | _________lbs./day | | | _________________________________________________________________________ RATION CALCULATION: Estimate the amount of each ingredient using the information from the above chart. (Hint start by estimating the total weight of each of the feeds needed to reach the REQUIREMENT/day, then first calculate the protein, from there, work backwards to TDN and calcium. Keep juggling the quatities until it begins to balance and meet the REQUIREMENT listed at the bottom.) Ingredients | Amount Fed/Day | Dig. Prot | TDN | Calcium | Pounds) | (%) | (%) | (%) _________________________________________________________________________ | | | | | | | | _________________________________________________________________________ | | | | | | | | _________________________________________________________________________ | | | | | | | | _________________________________________________________________________ | | | | | | | | _________________________________________________________________________ REQUIREMENT | | | | | _________lbs./day | | | _________________________________________________________________________ Supplemental Worksheet #4: Livestock Rations Date__________________ Name________________________________ Class__________________ 1. What is a ration? 2. What is a balanced ration? 3. What are the methods of balancing a ration? 4. What is meant by feeding standard? 5. What feeds should you use to balance a ration? 6. What information do you need before you balance a ration? 7. How do you balance a ration (use both methods)? 8. What are some "rulse of thumb" used in substituting one feed for another in a ration? 9. What are some guidelines in swine, beef, dairy and sheep rations related to the proportions and amounts of concentrates and roughages used? 10. How do you compute the cost of a ration? 11. Discuss the difference between a balanced ration and a least cost ration.