AN_SCI 3212 1st Edition Lecture 2 Outline of Last Lecture II. Life RequirementsA. Plants B. Animals/HumansIII. Why is it Important for YOU to Know Something About Nutrition?IV. What is a Nutrient?V. Categories of Nutrients in Foods/Feedstuffs That are Organic…VI. What do Animal Nutritionist Do?Outline of Current Lecture VII. Watera. Functionsb. Sourcesc. Absorption d. Managing Intakee. Quality FactorsCurrent LectureKey Points From Previous Lecture- Learning about nutrition is valuable- Nutrients are both elements and compounds- There are six major nutrient categories, of which four are organic (carbon based)- Feed/Food are usually complex mixtures- Nutrient content of feed/food vary- Nutrient requirements of animals vary- BEWARE of misinformation in the marketplaceWaterOften forgotten These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Four functions of water- As a solvent o All of life’s biochemical reactions occur in this medium; (imagine salt or sugar undissolved in your blood stream)- As a diluent o (Think of toxins & drugs, like alcohol & nicotine- As a transport medium o (Like a network of streams and rivers)- As a substrateo In hydrolysis reactions; S + H2O = P1 + P2 Lack of water can result in major loses of livestock- About 70-75% of animals is water- It is possible for animals to survive without a regular source of good quality drinking waterThree Sources of Water- “Drinking” water- Water within foodo (e.g. think of fruit bats that rarely have the need to drink plain water)- “Metabolic” watero 1 g of fat yields ~1 g metabolic water after the fat is oxidized to yield energy; 1 g of CHO & protein yields ~0.5 g of metabolic H2O- Electron transport chain produces “metabolic” watero Occurs in mitochondria in every nucleated cell in the body; O2 serves as the final electron (e- receiver; H2O is formed (i.e. the source of metabolic water)Absorption of water- Can occur throughout the GI tract- Lots of water is added to the foodstuffs in the early sections of the GI tract- Thus, most NET water absorption occurs in the large intestines (hid gut)- Water absorption occurs by passive diffusion3 Key factors that affect water requirements/intake- Water availability/quality- Dry matter intake- Water lossesManaging water resources- Too often in modern farms, meeting the water requirements of livestock is not given the practical management considerations it deserves to maximize animal performance- This is probably because IN THE MIDWEST water is often relatively inexpensive; because water sources are nearly always available. THUS it is ASSUMED that sufficient water is being supplied and consumed- However, this ASSUMPTION may not always be trueProperties of water that can affect intake & animal performance- Odor and taste- Physical properties (e.g. ice, snow, stream)- Chemical properties (e.g. pH under 5 or over 9 is unacceptable)- Presence of toxic compounds- Microbial contamination- Mineral/salt content (see later 2 slides)Water quality depends on water sourceNatural vs. producer Standing water vs. Flowing waterWater source (quality) impacts animal weight gain- Animals in the test all averaged 0.5 lbs per day or more gain as a result of drinking trough (clean) water vs. dugout/pond (muddy) waterFour common factors known to affect the suitability of water for livestock- Total dissolved solids (TDS)o TDS are defined as the sum of inorganic matter dissolved inwater (also are known as the salinity)o High TDS is BAD!o Livestock can tolerate higher TDS than humans- Sulfur & Sulfateo Sulfur present as hydrogen sulfide, imparting the rotten egg smell, is believed to affect water intake- Nitrateso Can pollute a water source via contamination of groundwater or runoff into surface water from urban or farm fertilizer useo Have been linked to reproductive problems in livestock- Irono Besides sulfate, iron in drinking water is probably the most frequent and important anti-quality consideration for livestocko The first concern is that high iron (>0.3 ppm) in water may reduce the palatability (acceptability) and therefore consumptiono High iron = a dark slime that will clog water lines and will have to flush with bleach to break