Water in Animal Feeds (AP232) - PDF

AP232-Feeds and Feeding Water Topic # 2 Belal S. Obeidat, Ph.D.  Water 2  Most vital nutrient ingested  May lose 100% of body fat, 50% of body protein and still live  Lose 10% of body water, dehydration occur...

AP232-Feeds and Feeding Water Topic # 2 Belal S. Obeidat, Ph.D.  Water 2  Most vital nutrient ingested  May lose 100% of body fat, 50% of body protein and still live  Lose 10% of body water, dehydration occurs, potentially resulting in death  Water requirements are often not listed, but it is assumed that animals have free access to good quality water for optimum performance  Water 3  Consequences of water restriction  If water is restricted by 50% of ad libitum  Reduce: Intake by 25% Weight gain by 50% Efficiency by 30%  Water 4  Typically consume 2-4 times more water by weight than dry feed intake  Functions of water  Solvent for many biological systems  Transport of digesta and nutrients  Excretion of waste  Lubrication, shaping, and cushioning  Substrate for chemical reactions  Water 5  Sources  Drinking water: Most common source  Free water: Moisture content of feeds  Not chemically bound  As-is or as-fed feed intake vs. dry matter intake  As-is or as-fed nutrient composition vs. nutrient composition expressed on a dry matter basis  Metabolic water  Chemically bound and released through metabolic processes occurring at the cell level  As-fed vs. Dry Matter 6  As-fed implies that “free” water is present  Dry Matter implies that “free” water has been removed through a mathematical calculation or removed through a drying process  As-fed Intake vs. Dry Matter Intake 7 As-fed intake X % DM of feed = Dry matter intake 12 kg as-fed intake X 80% DM = 9.6 kg DM intake Dry matter intake = As-fed intake %DM of feed 9.6 kg Dry matter intake = 12 kg as-fed intake 80% DM  Nutrient Composition (As-fed) vs. Nutrient Composition (Dry Matter) 8 Nutrient Composition (DM) X % DM of feed = Nutrient Composition (As-fed) 12% Crude Protein (DM) X 80% DM = 9.6% Crude Protein (As-fed) Nutrient Composition (As-fed) = Nutrient Composition (DM) % DM of feed 9.6% CP (As-fed)_ = 12% CP (DM) 80% DM  Fresh vs Dry – Dilution Effect 9 Water Carbohydrates Lipid Protein Ash Fresh Basis (%) Turnips 91.0 7.0 0.2 1.1 0.7 Grass (young) 80.0 13.7 0.8 3.5 2.0 Barley Grain 14.0 73.0 1.5 9.3 2.2 Muscle 72.0 0.6 4.4 21.5 1.5 Egg 66.7 0.8 10.0 11.8 10.7 Dry Matter Basis (%) Turnips 0 77.8 2.2 12.2 7.8 Grass (young) 0 68.5 4.0 17.5 10.0 Barley Grain 0 84.9 1.7 10.8 2.6 Muscle 0 2.1 15.7 76.8 5.4 Egg 0 2.4 30.0 35.5 32.1  Nutrients – Dry matter 10  Moisture content of feeds  Dry the sample in 100oC oven for 24 h  Common to find organic and inorganic compounds together  Ex: organic compounds contain mineral elements as structural components  Proteins  Sulphur  Lipids and carbohydrates  Phosphorus  Plants vs Animals 11 Carbohydrates Lipid Protein  Plant cell walls = CHO DM Basis (%)  Animal cell walls = protein and lipid Turnips 77.8 2.2 12.2 Grass (young) 68.5 4.0 17.5  Plants store energy as CHO Barley Grain 84.9 1.7 10.8 Muscle 2.1 15.7 76.8  Animals store energy as fat Egg 2.4 30.0 35.5  Water – Normal Losses 12 Body water can be lost in a number of ways: – Urine, feces, lungs, skin surface, and milk. Some animals conserve body water with kidneys that produce concentrated urine; other species produce very dilute urine, increasing water loss. Water losses increase when animals increase feed consumption or are fed diets higher in protein, various mineral salts, or high in fiber. – When water consumption is reduced, feed consumption and performance will be reduced.  Water – Requirements 13  Water consumption: Animal Liters/day  Beef cattle 20-70  Dairy cattle 40-110  Sheep and goats 5 - 15  Horses 30 - 45  Pigs 10 - 20  Chickens 0.2 – 0.5  Water – Requirements 14  Factors that affect water consumption:  Heat stress Water loss through perspiration or panting  Dry matter consumption Increased DM consumption increases water drinking  Diet type High moisture feeds lowering drinking High salt feeds increase drinking  Water – Requirements 15  Factors that affect water consumption:  Animal species  Amount of water lost in feces  Cattle feces wetter than sheep feces Type of urinary system  Mammals – urine (95% water)  Avian – uric acid (semi-solid)  Animal function  Lactating vs dry cows  Milk = 85 to 90% water  Water – Deficiencies 16  Reduce feed intake  Weight loss due to dehydration  Higher excretion of nitrogen and electrolytes  Na and K  Water – Digestion and Absorption 17  Water does not need to be digested  Absorbed from most sections of the GIT  Factors that affect water absorption  Animal species  Diet