- - AGRICULTURE CORE CURRICULUM - - (CLF3000) Advanced Core Cluster: ANIMAL SCIENCE (CLF3150) Unit Title: NUTRITION AND FEEDS ____________________________________________________________________________ (CLF3151) Topic: FEED IDENTIFICATION Time: Year(s) & NUTRIENT EVALUATION 2 hours 3 / 4 ____________________________________________________________________________ Topic Objectives: Upon completion of this lesson, the student will be able to: Learning Outcome #: (B-1) - Identify three common roughages and four common concentrates available in your local area and discuss which feeds have the highest content (percentage) of nitrogen, energy, protein, calcium, and phosphorus. Special Materials and Equipment: Samples of the roughages and concentrates from your local area. References: Fridline, Clarance R. (1979). LIVESTOCK NUTRITION AND FEEDING. Maynard, Leonard A. (1979). ANIMAL NUTRITION (7th ed.). Evaluation: Quiz by instructor and completion of Supplemental Worksheet #1. TOPIC PRESENTATION: FEED IDENTIFICATION & NUTRIENT EVALUATION REVIEW: Basic Core, Animal Science, CLF261, "Nutrient Needs". A. Feed Classification 1. Feeds can be classified as roughages, concentrates or supplements. a. Roughages are feeds that are high in cellulose or fiber and relatively low in digestible nutrients. b. Concentrates are feeds that are low in fiber and relatively high in digestible nutrients. c. Supplements are "extras" like a salt or mineral block that supply some necessary nutrient. d. Feed additives are compounds added to feed to preserve it or to alter animal metabolism. They may or may not always supply a nutrient. Examples are: (see also rumensin in CLF3152) 1) monensin 2) bicarbonate e. Average values for feeds (% protein and TDN) can vary based on a plant's maturity, the weather, soil variety and processing. Concentrates vary in protein and energy, but not to the same degree as roughages do. B. Common Roughages 1. Legume hays: a. are made from alfalfa, clover, soybeans or birdsfoot trefoil. The major legume hay in California is alfalfa. b. use nitrogen from the air to produce "fixed" nitrogen for their own use. Legume hays supply more protein than hays from grasses such as oat hay and sudan hay. c. supply more calcium and phosphorus than grasses and have slightly less or about the same amount of energy as oat hay. 2. A typical oat hay: a. contains about 9 percent protein as compared to alfalfa at 17 percent. b. has less calcium and phosphorus than alfalfa. 3. A typical corn silage: a. contains about 8 percent protein. b. contains less calcium and phosphorus than oat hay. c. contains about 70 percent Total Digestible Nutrients (TDN is a measure of energy). Whereas, alfalfa and oat hay have from 56 - 60 percent TDN, therefore corn silage is higher in energy than either, depending on quality. C. Common Concentrates 1. Corn: a. is very low in protein, (10 percent). b. is very palatable to livestock and contains about 88 percent TDN, which makes it a very good source of energy (because it is highly digestibile).. c. is very low in calcium. 2. Cottonseed: a. contains about 25 percent protein when fed whole and about 43 percent protein when fed as cottonseed meal. b. contains 98 percent TDN as whole cottonseeds, but only 77 percent TDN as cottonseed meal. c. is usually quite expensive and therefore not economical to feed as an energy source. d. causes health problems if fed in excessive amounts to swine. e. is a source of phosphorus. 3. Barley: a. may be substituted for corn. b. has a nutrient content that is similar to corn, with 13 percent protein and 83 percent TDN. 4. Oats: a. contain about 13 percent protein and 76 percent TDN which makes them lower in energy than corn and barley. b. are very low in calcium. 5. Sorghum (milo): a. is similar in feeding value to that of corn, if properly processed. b. contains about 77 percent TDN and 7 percent protein, which is rather low. c. is very low in calcium. D. Supplements 1. Minerals: a. Salt is needed by all animals and may be supplied in various forms such as loose salt, a mineral-salt block, or a granule mixture mixed into the ration. b. Trace minerals such as copper, iodine, iron, manganese, selenium, and zinc may be supplied using salt blocks or mineral premixes in the feed. c. Calcium and phosphorus ratios are very important and must be fed in a correct ratio or deficiency diseases may result. The following are sources of calcium and phosphorus: 1) dicalcium phosphate, 2) bone meal (both calcium and phosphorus), 3) ground limestone (calcium only), and 4) sodium monophosphate (phosphorus only). d. Minerals do not contain energy or protein, but some minerals do supply nitrogen (which can be used by gut flora to produce proteins). 2. Vitamins: a. May be supplied completely by ingredients in the ration or they may be added to a ration deficient in specific vitamins. b. Vitamin A and D are the most important to ruminants. c. May be supplied by adding the following to the ration: 1) dehydrated alfalfa meal (vitamin A), 2) irradiated yeast (vitamin D), or 3) commercial vitamin preparations from feed suppliers. 3. Protein: a. May be classified as a supplement when added to a ration in small amounts and is also sometimes classified as a concentrate. b. Some examples of feeds classified as protein supplements: 1) Meat and bone meal which: a) contains 49.5 percent crude protein; b) contains about 60 percent TDN, however, this supplement is fed in small amounts because it is not palatable to ruminants and is expensive; and c) also supplies large amounts of calcium and phosphorus (twice as much calcium as phosphorus). 2) Fish meal which: a) includes a variety of types which all contain a very high amount of protein (60 percent or more CP); b) is high in TDN (63 percent), however, this supplement is not very palatable and may leave a residue in the milk; and c) contains large amounts of both calcium and phosphorus. 3) Soybean meal: a) is the mainstay of protein supplements in the United States livestock industry; b) contains from 39 to 47 percent CP depending on how it is processed; c) contains from 75 - 80 percent TDN; d) is very palatable to livestock; and e) supplies both calcium and phosphorus. 4) Cottonseed meal (previously discussed as a concentrate): a) is more economical in California for ruminants than soybean meal because of its abundance (grown locally). b) is less economical in the upper midwest, because soybean meal is more abundant and is therefore relatively inexpensive. c) Regardless of region, cottonseed meal is needed by non- ruminants in its "de-gossypolized" form, otherwise use soybean meal depending on its availability and cost. 5) Dried skim milk: a) contains about 33 percent CP. b) has about 80 percent TDN. c) has high levels of both calcium and phosphorus. c. Amino Acids have been used as supplements in swine rations, especially the following: 1) Lysine, 2) Methionine, 3) Cystine, and 4) Tryptophan. __________________________________________________________ ACTIVITY: 1. Bring in feed samples from your area and have students learn to identify them. 2. Use Supplemental Worksheet #1 to reinforce feed composition understanding. __________________________________________________________ SUPPLEMENTAL WORKSHEET #1 FEED IDENTIFICATION NAME_____________________ DATE_____________________ PER._____________________ Choose 10 feeds and complete the following chart using your notes as a reference. Under the word "Type", indicate whether your feed is classified as a Concentrate(C), Roughage(R), or Supplement(S). A feed sample may be of more than one type. ============================================================================ Feed name Type Energy level Protein Calcium Phosphorus (high/low) (high/low) (high/low) (high/low) ============================================================================ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ | | | | | | | | | | _____________|________|______________|____________|___________|_____________ 5/2/90sg #%&C