1. Nutrients in ruminant nutrition

2. 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.

3. 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.

4. 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 silage @ 65 % water =13 lb of water consumed.

5. 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.

6. 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.

7. 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

8. 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

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

10. 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

11. Average daily intake, cattle BW, kg L / day • Calf 51 5-6 • Calf 93 9-10 • Cattle (yearling) 350 23-30 • Beef cattle 450-600 30-40 • Dairy cow 545-730 38-100 • Cattle on pasture 545-730 20-40

12. Average daily intake, sheep BW, kg L / day • Lamb 9 1.5-2.5 • Lamb 23 2-3.5 • Sheep on pasture 60-90 4-8 • Sheep (feedlot) 60-90 5-10