water and energy in feedstuffs

what is the most essential nutrient?

water

functions of water

1. transport nutrients, waste, hormones

2. lubrication and cushioning of joints, organs

3. temperature regulation

4. chemcial reactions

water requirement is influenced by:

age/size, physiology, environment, production, species

water requirement goes ___ as the animal size gets ________

up; bigger

water sources

1. drinking water (70-90%)

2. metabolic water (released; 0-10%)

3. feed moisture (10-30%; higher in animals eating silage or fresh grass)

water losses

feces, urine, perspiration (species-dependent), respiration

The quality in the drinking water can ………

limit intake more than the quantity

things to water for in drinking water:

1. contaminants (bacteria, blue-green algae, toxins)

2. high total dissolved solids (dirty)

3. sulfates, nitrates, iron (low water level can lead to high mineral)

water presence in feedstuffs:

most ‘dry’ feedstuff are about 10% water; some feedstuffs contain more like 65-70%

must account for ammount of moisture in ‘wet’ feedstuffs because…….

animals are driven to have a consistent dry matter intake (not full until they have eaten enugh dry matter); nutrient levels in feedstuffs are reported on a dry matter basis

an animal’s feed intake can be impacted by:

amount a human feeds it (limit-fed)

gastrointestinal capacity (fed ad libitum or at ones will)

the 1st limiting factor in diets is usually ________

energy (second most important nutrient)

energy

every metabolic process requires it

energy needs

animals must meet before they can fully use any other nutrient

when chemical bonds break ____________

energy is released

energy is measured by

bomb colorimetry

calorie

the quantity of energy required to raises 1 g of H₂O by 1^oC

1000 calories

1 kcal (kilocalories)

1000 kcal

1 Mcal (megacalorie)

proteins provide how much energy

5.7 kcal/g

proteins form bonds between:

N, C, O, H

lipids provide how much energy

9.4 kcal/g

lipids form bonds between:

lots between C, O, H

carbohydrates provide how much energy

4.1 kcal/g

carbohydrates form bonds between:

few bonds between C, O, H

plants use photosynthesis to create

stored energy

feedstuffs are a source of

potential energy

different ________ have different amounts of ________ energy

feedstuffs; potential

digestion releases……

stored energy

energy is used by the _______ or stored in _______

animal; animal tissues

different feedstuffs have different amounts of

potential energy

almost all feedstuffs have some combination of

proteins, lipids, carbohydrates

combination and density of elements and bonds changes…..

potential energy

feedstuffs - variation

used as energy source in diets because they have greater enrgy density and digestibility

feedstuffs are usually selected based on……..

relative energy value

feedstuffs - grains

relatively inexpensive source of easily digestible calories; measured by bushel basket

value of grains is based on ______, which is indicative of its ___________

weight, energy density

corn bushel weight

56 lb/bu

sorgum bushel weight (milo)

56 lb/bu

wheat bushel weight

60 lb/bu

bushel weight

60 lb/bu

barley bushel weight

48 lb/bu

oats bushel weight

32 lb/bu

corn

benchmark energy source in U.S.

high relative energy value

4th highest kcal/kg

sorghum (milo)

more drought-tolerant than corn

slightly lower energy value than corn

lowest kcal/kg

wheat

higher energy, sometimes unsafe for fermenters

more expensive, competes with human food

highest kcal/kg

barley

hull lowers energy density

common in lamb diets if available

3rd highest kcal/kg

oats

hull lowers energy density

high pre-cal starch digestibility→great for horses

2nd highest kcal/kg

feedstuffs co-products

bakery by-product meal

citrus pulp

dried whey

grain co-products

grain co-products

dried distillers grains - ethonol co-product made from corn, milo

corn gluten feed or meal - co-product from corn starch or high fructose syrup production

wheat middlings - co-product form wheat flour production

alfalfa

high quality legume

rarely grazed

brome

moderate quality grass, used for hay and grazing

common in Kansas

fescue

moderate quality grass, used for hay and grazing

hardy but may have endophyte issues, problems in cattle

prairie

mix of warm season native grases (bluestem, switchgrass)

lower quality, often used for maintanence rations

silages

fermented grain stalks (corn, sorghum)

high energy and good preservation

animal fat

saturated

beef tallow, choice white grease (pork), yellow grease (chicken)

vegtable oil

unsaturated

corn oil, soy oil

AV blend

25% tallow, choice white grease, yellow grease, corn oil