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ANSC 3375

Composition tables. A

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ANSC 3375

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    1. ANSC 3375 Laboratory 2 Composition and requirement tables

    2. Composition tables A warehouse of chemical composition of feedstuffs An average of many laboratory analyses that are compiled over time Even though the avg or mean CP for a feed may be 10%, it could range from 8 to 12% In practice, better to use values determined for your location, etc. if feasible

    3. Composition tables Available from a number of sources Popular, professional magazines (Beef, Feedstuffs) National Research Council specie nutrient requirements and feed composition

    4. Composition tables Feedstuff names note that the table we use has some unusual feeds Names also indicate the form of the feed reflects any processing Not all feeds listed will be relevant for a particular region

    5. Composition tables DM, % = 100 - the percentage of moisture or water normally found in the feed Determined by completely drying a sample and measuring the remaining weight moisture evaporated This influences as-fed nutrient concentrations In this table, all other compositional values are on a DM basis

    6. Composition tables Measures of energy content Total digestible nutrients (TDN) an early measure that describes the digestibility of the nutrients (carbohydrate, lipid, protein) as a % Similar to digestible energy (DE), but DE expressed as calories

    7. Composition tables Measures of energy content Net energy for maintenance (NEm) the energy value of a feed when used to support animal maintenance functions respiration, body temperature, locomotion Net energy for gain (NEg) energy value of a feed when used for productive purposes (e.g., weight gain) smaller than NEm whys that?

    8. Composition tables Measures of energy content Net energy for lactation (NEl) one NE used for dairy cows because the efficiency of using calories for maintenance and lactation are similar

    9. Composition tables Crude protein - % N x 6.25, includes N from true protein and NPN in the table, this reflects % CP on a DM basis Bypass, % - describes the proportion of CP that is not degraded in the rumen dependent on a number of factors, so it is not really a constant in practice currently, the term undegraded intake protein (UIP) is used more commonly

    10. Composition tables Interpreting the bypass value - describes the proportion of CP that is not degraded in the rumen alfalfa cubes contain 18% CP on average, and 30% of this CP is considered UIP Thus, 5.4% of alfalfa cube DM is UIP (18 x 0.3) and 12.6% of alf cube DM is DIP (degraded intake protein, 18 x 0.7)

    11. Composition tables Crude fiber the standard for feed labeling, but not as useful as other measures to describe fiber utilization Detergent fiber neutral detergent fiber (NDF) plant cell wall; hemicellulose, cellulose, lignin acid detergent fiber (ADF) cellulose and lignin effective NDF (eNDF) describes the ability of NDF to maintain optimum ruminal pH; incorporates particle size

    12. Composition tables EE, % - describes the crude fat fraction, often referred to as ether extract fats, oil, waxes, complex lipids Ash, % - the inorganic material (crude mineral fraction) after oxidizing or combusting the organic fraction a necessary step before assaying individual minerals ppm commonly used in the US, but = to mg/kg

    13. Requirement tables Pay close attention to units in columns and rows Feed intake or DM intake approximate amount of DM that an animal should consume each day Table 13-2, rows 6 and 7 ME intake, kcal/day kcal ME/kg of DM

    14. Requirement tables Pay close attention to units in columns and rows Table 14-1, columns 4 and 5 col 4 conc of protein in the diet with the assumed feed intake col 5 quantity of protein/day with the assumed feed intake (see footnote)

    15. Requirement tables Pay close attention to units in columns and rows Table 17-4 mature cow maintenance Mcal/day for the cow nutrients for milk production amount/kg of milk

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