Week: 3 Energy Budgets Dr. Ir. Happy Nursyam, MS

Energy Budgets IF I = E Growth = 0 I < E Growth = Intake ( I = Income) Macronutrients Carbohydrates Fats/Oils Proteins Micronutrients Vitamins Essential Fatty Acids Amino Acids Sugars Energy Use (E = Expenditure) Respiration Osmoregulation Movement Feeding Digestion Reproduction IF I = E Growth = 0 I < E Growth = I > E Growth = +

A Transition Zone - Energetics Hormonal Control Ingestion Storage Lipid Carbohydrate Mobilization Lipid Carbohydrate Protein Adsorption Renal Stomach Intestinal Excretion Growth Reproduction

Bioenergetics Models Basic Bioenergetics Equation Consumption = Growth – Respiration – Waste or C = G – R – W Expanded Equation Consumption = Growth – Standard Metabolism – Activity – Digestion – Feces – Urine Or C = G – RS – RA – RD – F – U Winberg Equation G – 2 RS Consumption = ------------------------- 1 – (RD + F = U) Production Based Model Production (Over Specified Interval) = Growth (Over Interval) X Mean Biomass (Over Interval Or P = G . B)

Bioenergetics (Continued)

Energetics – A Question of Temperature First Order Kinetic Equations for Enzyme Action

Second Order Kinetic Equations

Energetics (Continued) Proteins and Amino Acids Fish have higher protein requirements than terrestrial vertebrates (20 – 55% vs. 12 – 25%) Carnivores – High up to 60% of diet Low cost associated with homeothermy in cold temperature Ease of excretion Herbivores Can digestion protein But depending on experimental conditions growth vs. % protein in diet will vary Limiting factor is essential amino acids

Energetics – Some Considerations Use of Fish Protein vs. Plant Protein Fish meal is becoming and issue Salmon offal often contains pathogens requiring pasteurization Examples Salmon use Salmon Tilapia use poultry waste Growth is Protein Based

Constraints on Growth Food Quality Food Quantity Digestible vs. Indigestible Ratio Availability of Digestible Micro Macro Nutrient Ratio Prey (sasaran) Shifting Ontogenetic Shifts Food Quantity Prey Availability Herbivore Compensation Microbial Digestion to Produce VFAs

Protein Based Energy Assimilation Nature of Food Invertebrates Algae Increasing Protein Macrophytes Detritus Increasing Energy Assimilation