ASCI 220 Midterm 2

What do we measure when we are using a new diet

Blood work, Body Mass, Food Intake(input), Digestion, Excretions(output), Length of time it take food to pass through GI tract

Digesta Passage: marker, transit time and mean retention time

Marker: not normally secreted, digested, or absorbed by the gut, not toxic

Transit Time(TT1): Time from marker administrations to first appearance in feces

Mean retention time (Rgit): average time the markers takes to be excreted after administration

Digestibility

Proportion of nutrients in a feed or diet that are observed from the GI tract, difference between the amount consumed and excreted.

Apparent digestibility (aDig), % calculation and ideal Digestibility (in vivo/in animal)

Intake(kg DM/day) - fecal or ileal outputs (kg DM/day) /intake x 100 = % aDig

Partial Tract Digestibility

Proportion of nutrients in feed or diet that are absorbed from the GI tract start at SI and end at anus

In situ Digestibility

Cannulated cow has a bag in rumen and measure the in situ digestibility in specific location (rumen)

In vitro Digestibility: process, species tested on

Study digestion in the lab. Tiller and Terry tested ruminant and keep the rumen fluid in body temp of cow, and shake it. Bodies and Fernandez’s created a 3 stage closed batch (stomach, SI, Hindgut) to emulated swine digestion. Lockhart tested it on horses. Animal donated fecal matter to get microbes. Easier to manage 10 tubes in a shaking water bath than 10 horses.

Nutrient Compsition of Food

• Dry matter and water

• Inorganic

  • Non vs Essential Minerals (Macro vs Micro)

    • Macro: Ca, P, K, Mg, Na, Cl, S

    • Micro: Cu, Co, Fe, I, Mn, Mo, Se, Zn

• Organic

  • Carbonaceous

    • Carbs:

      • structural (Cellulose, Hemi-cellulose)

      • Non structural (Sugars, Starches)

    • Lipids

      • Simple (fatty acid) vs compound (sterols)

    • Vitamins

      • Fat soluble (A,E)

      • Water soluble (Thiamine, Riboflavin, Ascorbic Acid)

  • Nitrogenous

    • Protein vs non protein

      • Essential (lysine, arginine) semi (glycine, cystine) and non essential (alanine, proline) amino acids

Biological Dose Response Graph (x/y axis) and areas

Biological function (%) y over Concentration of nutrient in diet, areas: death → deficient → optimum → toxic → death

Proximate Analysis Process

Air dry sample -dry at 105C for 24 hours→ moisture free sample → crude protein → fat free residue → crude fiber + ash

Measure to Manage definition

Use data to confirm beliefs about management practices and strategies.

Water functions, percentage make up, if animals does have water?

Component of metabolism, solvent, transport medium, diluent, hydrolysis and oxidation. Regulation of body temp, lubrication, cushion, structural. 60% of animal body weight, if animals doesn’t have water it won’t eat

What parts of the body have more water? How do we find out how much of the body is water if they are living?

Blood, kidney, heart, lungs, spleen, brain, intestine, skin, muscle liver. Bioelectrical impedenle analysis: electrodes all of body send small electrical signals that detect resistance and electricity

Water Sources

Preformed water: in the food itself

Free water: water not in food, in a body of water (bowl)

Metabolic: water generated through chemical reactions in body

Metabolic Water: definition, breakdown of what nutrient produces the most water?

A byproduct of metabolizing energy-yielding nutrients from foods into carbon dioxide and energy, does not include water in foodstuff. Breakdown lipids produces more water per gram than carbs and proteins. Ex; hibernating bears build up fat as water storage.

Losses of water

Urine, fecal, perspiration, insensible (lactation) parturition

Water requirement factors

Dictated by need to balance intake and loss, influenced by: food composition, intake , metabolism, activity/production, environment. Ex: more sodium intake needs to drink more water and pass through urine

Relationship between dry matter intake (kg) and water intake (L)?

Very consistent across species, 2-3 times their dry matter intake

Water Dehydration vs Intoxication, hyponatremia?

Dehydration: water leaves in trace duller fluid into extracellular fluid via osmosis

Intoxication: water moves to intercellular fluid from extracellular fluid via osmosis and dilutes ions in intracellular fluid that are needed for processes such as sodium potassium pump, cells swell

Hyponatremia: low sodium levels in blood, cells swell

Three classes of nutrients that provide energy

Carbohydrates, Lipids and Protein

Short term vs long term sources of energy. Where does the energy come from?

Short: glycogen, Long term: adipose tissue (fat). The energy is in the bonds

How many more energy per gram in lipids compared to carbs and proteins

Lipids have 2.25 times more energy per gram than carbs and proteins

What do we use to measure how much energy in food in US? EU? Definition?

Calorie: the amount of energy (heat) required to raise 1 gram of water from 14.5 to 15.5 C

Joule: A unit of work or energy equal to the work done by force of one newton acting though a distance of one meter

Calories vs calories

Calories (kilocalorie) is 1,000 calories