Balancing Rations

1. Balancing Rations Animal Science II Unit 8

2. Objectives • Classify feeds as roughages and concentrates • Describe the six functions of a good ration • Explain the characteristics of a good ration • Balance livestock rations using commonly accepted practices

3. Classification of Feeds

4. Roughages • Contain more than 18% crude fiber when dry • Includes: hay, silage, pasture, fodder • 2 general class: legume roughage and non-legume roughage

5. Legume Roughages • Can take nitrogen from the air • Able to due so because they have nodules on their roots that contain bacteria • These bacteria fix the nitrogen from the air in soil and make it available for the plant to use • Do so by combining the free nitrogen with other elements to form nitrogen compounds • All the clovers, alfalfa, soybeans, trefoil, lespedeza, peas and beans • Usually higher in protein than nonlegume roughages

6. Nonlegume Roughages • Cannot use nitrogen from the air • Lower in protein • Many common livestock feeds are nonlegume • Corn silage, sorghum silage, fodders, bluegrass, timothy, redtop, bromegrass, orchardgrass, fescue, costal Bermuda grass, common Bermuda grass, prairie grass (Western wheatgrass, Kentucky bluegrass, etc)

7. Concentrates • Less than 18% crude fiber when dry • Two classes • Protein supplements • Energy feeds

8. Protein Supplements • 20% or more protein • Divided into 2 groups based on their source

9. Animal proteins Come from animals or animal by-products Common: tankage, meat scraps, meat and bonemeal, fish meal, dried milk (whole & skimmed), blood meal, feather meal Most contain more than 47% crude protein More balanced essential amino acids Variable quality compared to vegetable proteins Vegetable Proteins Come from plants Common: soybean oil meal, cottonseed meal, linseed oil meal, peanut oil meal, corn gluten feed, brewers dried grains, distillers dried grains Most contain less than 47% crude protein Soybean oil meal is used most Can supply necessary amino acids for swine and poultry Only protein source that can be used for ruminants Protein Supplements

10. Made by commercial feed companies Mixes of animal and plant protein feeds Usually made for 1 class of animal Often mix of minerals, vitamins, antibiotics Feed tag needs to be read and feeding directions followed Commercial Protein Supplements

11. Energy Feeds • Feeds with less than 20% crude protein • Most grains • Oats, corn, sorghum, barley, rye, wheat, ground ear corn, wheat bran, wheat middling's, dried citrus pulp, dried beet pulp, dried whey • Corn is the most widely used • Followed by sorghum grain, oats, barley

12. Ration Characteristics

13. Ration Characteristics • Animals need proper nutrition to efficiently produce meat, milk, eggs, wool, work, etc • A ration is the amount of feed given to an animal to meet its needs during a twenty-four hour period • A balanced ration is one that has all the nutrients the animal needs in the right proportions and amounts • Diet refers to the ration without reference to a specific time period

14. Palatability • Ration must taste good • Mold, insect and weather damage all lower palatability

15. Feed & Economics • Feed accounts for approximately 75% of the total cost of raising livestock • Therefore it is necessary to develop rations that are as economical as possible

16. Poisonous Plants • Should not be included in the diet • Sometimes grow in hay fields or pastures • See Table 8-1 p.165

17. Balancing for Species and Age • Ruminants use more roughage than nonruminants • Younger animals cannot use as much roughage either • Also need to consider the purpose for which the animal is being fed • For example fattening animals generally should be fed less roughage than breeding animals

18. Micronutrients and Feed Additives • Used in small quantities • Care needs to be taken to thoroughly mix these for uniform distribution • Excessive amounts of micronutrients can be harmful

19. Functions of the Ration

20. Functions of Rations • Must be considered when determining nutrient requirements • Functions include • Maintenance • Growth • Fattening • Production • Work

21. Maintenance • Primary use of nutrients is to maintain life • Animals must have energy for the functioning of the heart, breathing and other vital body processes or the basal metabolism • Energy is also needed to maintain body temperature • The ration must also provide protein, vitamins and minerals, fatty acids to replace those that are naturally lost • About ½ of the ration fed is needed for maintenance • An animal on full feed will use about 1/3 of the ration for maintenance

22. Growth • Nutrients can only be used for growth after maintenance requirements are met • Animals mature by growing • Larger species mature slower • Growth rate of large animals is faster than that of smaller animals

23. Fattening • Nutrients that are not used for maintenance or growth may be used for fattening • Fat is stored into the tissues of the body • Fat within the muscle is called marbling • Marbling makes meat juicy and good tasting • The object of fattening is to obtain the right amount of fat in the muscle without getting too much fat • Feeds that are high in carbohydrates and fats are used for fattening

24. Production • Cows, swine, horse, sheep, goats all produce milk to feed their young • Dairy goats and cows produce milk for human use as well • Chickens produce eggs • Sheep and goats produce mohair • All this production requires nutrients. The nutrients depend on the kind of production

25. Reproduction • Requires proper nutrition • Animals may become sterile • Extremely important for pregnant animals • Most of the fetus’s growth takes place during the last third of the pregnancy • Additional amounts of nutrients are needed during pregnancy

26. Work • Horses-riding, driving • Energy needed for work comes from carbohydrates, fats, extra protein • Other needs of the body are met before nutrients are available for work • Animal will use fat stored in the body for work if the ration does not supply enough • Extra salt is also needed due to animals sweating

27. Balancing Rations

28. General Principals • Must meet the nutritional needs • Nutrient allowance should be met as close as possible • Not more than 3% below the requirement

29. Dry Matter • Must have a certain amount in the ration • If not the animal will be hungry • The digestive system will not function properly • Also an upper limit that varies with the animal being fed and its size • Total dry matter in the ration of a full fed animal should not be more than 3% above its need

30. Protein • Measured by the total protein (TP) need of the animal • Digestible protein may also be used to balance the ration • Essential amino acids must be included when balancing a ration for nonruminants • Acceptable to allow 5-10% more protein in the ration than the animal needs

31. Energy • Four methods of measurement • Digestible Energy (DE) • Total Digestible Energy (TDE) • Metabolizable Energy (ME) • Net Energy (NE) • Gross energy of feed is measured in a lab using a bomb calorimeter • The feed is burned completely and the total amount of heat released from the burning is the gross energy

32. Digestible Energy • The gross energy of the feed minus the energy remaining in the feces of the animal after the feed is digested

33. Metabolizable Energy • For Ruminants • The gross energy in the feed minus the energy found in the feces, gaseous products of digestion and urine • For Non Ruminants • The gross energy in the feed minus the energy found in the feces and urine

34. Net Energy • Metabolizable energy minus the heat increment • Energy used for • Maintenance only NEm • Amount of energy used to keep the animal’s energy in equilibrium-there is no net gain or loss of energy in the animal’s body tissues • Maintenance plus production NEm+p • Production only NEp • Amount of energy need above the amount used for maintenance that is used for work, tissue growth, fat production, fetus growth, or milk, egg, or wool production and so on

35. Total Digestible Nutrients (TDN) • Total of the digestible protein, digestible nitrogen-free extract, digestible crude fiber and 2.25 X’s the digestible fat • Gives a measure of the total energy value of the feed when it is fed • Varies with the class of animal to which it is fed • Should not be more than about 5% more than what the animal needs

36. Balancing Calcium and Phosphorus • Important in balancing rations • Should be between a 1:1 and 2:1 ratio • The ratio is more important than the total amount being fed • Total Ca and P are often more than needed when other requirements are met • Other mineral needs are usually not considered and can be met with trace-mineralized salt

37. Vitamins • Vitamin A is taken into account when balancing the ration • Other vitamin needs are added with out calculating the vitamin content of the feed • Vitamin A will often be more than needed but is not harmful • Vitamin deficiencies can occur in cattle and sheep during pregnancy if low quality legume hay is fed • Vitamin supplements should always be added to pregnancy rations

38. Getting the Most Bang for Your Buck • Some feeds are cheaper sources of nutrients than others • Energy feeds should be compared based on the price per pound of energy (TDN, DE, ME or NE) • Protein feeds should be compared in terms of price per pound of total protein or digestible protein • The least expensive source of nutrients should be used as much as possible

39. Relationship Between 100% Dry Matter Basis and As-Fed Basis • All feed contains some moisture and the amount varies with the feed, form of feed, stage of growth at harvest, length of time in storage, storage conditions • The appendix in the back of the book shows the average percent dry matter in the feeds listed

40. 100% Dry Matter Basis • Data presented is calculated on the basis that all moisture has been removed

41. As-Fed Basis • Data is calculated on the basis of the average amount of moisture found in the feed as it is used on the farm

42. Rules of Thumb for Balancing Rations

43. Beef • See p. 172-73 in text

44. Swine • See p. 173 in text

45. Sheep • See p. 173 in text

46. Goats • See p. 173 in text

47. Horses • See p. 173-74 & Table 8-2

48. Poultry • See p. 174 in text

49. Steps in Balancing a Ration

50. Step 1 • Identify the kind, age, weight and function of the animal(s) for which the ration is being formulated. • In our text suggested rations and feeding programs are found in the units on the specific species; these may be used for formulating rations.