Balancing a Ration: it’s NOT magic!!!

1. Balancing a Ration:it’s NOT magic!!!

2. Definition of terms • Ration • An amount of feed consumed in 24 hours • Balanced ration • A mixture of feedstuffs that provides the proper amounts and proportions of all the required nutrients (and nourish the animal for 24 hours)

3. Prerequisites for Diet Balancing • What kind of information do you need before you can balance a diet?

4. Feed Intake—Rule of Thumb Animal Daily DM intake (% BW) Poultry 5–6 Pigs 4–5 Sheep 3–4 Cattle 2–3 Horses 1.5–2.5

5. Feed Intake - Rule of Thumb • Animals eat to satisfy their energy requirement • High-energy diets • Low-energy diets • Feed intake is limited by gut fill • Physical limitations

6. Selecting Feeds • Availability • Grown and harvested on site • Can be fed out or sold • Ensiled feeds almost always fed out – difficult to sell • Inventory drives feeding rate • Purchased feeds • Bag or bulk • Cost per pound • Cost per unit energy • Cost per unit protein • Limitations – palatability, storage, handling

7. Selecting Feeds I • Determine inventory for feeds you MUST feed • Ex. 3000 bales of alfalfa hay at ~80 lbs/bale to feed 150 head from November through May • 80 lbs x 3000 bales = 240,000 lbs. hay • (240,000 / 210 days) = 1,143 lbs/day • 1143 / 150 head = 7.6 lbs./head/day

8. Selecting Feeds II • Calculate feeding values for available feeds • Ex. barley at 88% dry matter, 8.8% digestible protein, and 0.78 Mcal/lb NEm at $130/ton (as fed) • 2000 x 0.88 =1760 lbs dry matter per ton of as fed barley • ENERGY VALUE - $130/(1760 * 0.78) = $.095/Mcal (DM basis) • PROTEIN VALUE- $130/(1760 * .088) = $.84/lb digestible protein (DM basis)

9. Selecting Feeds III • Rank feeds available based on costs per unit of nutrient • Consider limitations of feeds for the class of animal you are feeding • Carnivores – digestibility of grains vs. meat proteins • Ruminants – rate of rumen degradability, compatibility with other feeds in terms of making microbial proteins (nutrient synchrony) • All animals – palatability, digestibility

10. Selecting Feeds IV • Consider issues with transportation, handling and storage • Factors include bulk, water content, corrosiveness, bunklife at feeding • Wet distillers, liquid whey, etc. are expensive to transport (high water content) and challenging to store and handle • Whole cottonseeds are difficult to auger

11. Balancing the Ration – Computer Programs • Allow operator to “plug in” actual chemically analyzed values for feedstuffs • Allow operator to set pre-determined feeding rates (7.6 pounds of hay per head per day) • Allow operator to set limits on feeding rates for certain feeds (limit of 15% fat in a horse ration, for example) • Allow operator to include other factors that modify nutrient requirements (temperature, wind speed, compromised hair coats)

12. Assessing the Ration • Are the values reasonable? • Dry matter provided daily • If it greatly exceeds “rule of thumb” values, then re-assess your inputs! • Individual components provided daily • Especially unpalatable or potentially toxic feeds (urea) • Does it match the digestive system of the animal you are feeding?

13. Creating an “As-fed” Ration • Convert dry matter values back to as-fed to determine feeding rates per 100 pounds (provides percentage basis) for each feed • Calculate total feed to be mixed at each feeding • Calculate amount of each feed to be included in each “batch” of feed

14. Assessing Ration Performance • Growth • Performance • Milk, eggs, racing performance • Changes in body condition • Reproductive performance • Health • Disease, acidosis, lameness