NUTRIENTS IN RUMINANT NUTRITION

Nutrients  Nutrition is the series of processes by which an animal takes in and assimilates feed components for promoting growth, milk, or fiber production and replacing worn or injured tissues.

Water  71 % of the fat-free animal body.  Free access to good-quality water.  Acts as a solvent as most of our enzymes are water soluble and need water to get dispersed.  Blood is composed mostly of water.  Involved with the transport of waste products in the urine.

Water Sources  Drinking water: free choice  Water also from feeds: this water is not chemically bond to feed.  Dry feedstuffs have 9 % to 13 % free water.  Silage has 65 % to 75 % free water, 20 lb of corn 65 % water =13 lb of water consumed.

Water Sources  Metabolic water: water that is chemically bound to the feed and is released when the feed is broken down into nutrients.  Generally oxidative reactions.

Water Losses  Through urine, feces, lungs, skin, milk.  Kidney uses lots of water (concentration-dilution).  High protein diet increases water losses; high urea. increases urinary excretions.  High in mineral salts increases urine.  High fiber diets increase urine.  Increase in food consumption increases urine.

Water Losses  Water loss in feces varies;  Sheep dry feces  Cattle wet feces  Fecal water content reflects feed water content.  Evaporative water losses varies with heat, humidity and wind  Lactation: 100 lb milk has 87 lb of water

Water Quality  Affects water and feed consumption  < 2,500 mg/l total dissolved solids (TDS)  Depending on solids could tolerate 15,000 mg/l  Toxicity may show up before palatability reduces intake: nitrates, fluorine, other heavy metals

Water Quality  100 to 200 ppm nitrates toxic  1 g/l sulfate may causes diarrhea  Palatability: problems from microorganisms, algae, protozoa, hydrocarbons, pesticides, chemicals

Water Quality  Common minerals in water: chloride, sodium, calcium, magnesium, sulfates, bicarbonate  Mineral present depend on soil type and water source.  1% salt max for cattle and sheep  Water as a source of minerals, yes ?  30% of NaCl; 15% Ca; 7% Mg; 32% Su

Average daily intake, cattle  Calf  Calf  Cattle (yearling)  Beef cattle  Dairy cow  Cattle on pasture BW, kgL / day

Average daily intake, sheep  Lamb  Lamb  Sheep on pasture  Sheep (feedlot) BW, kgL / day