Rer/mer energy requirments
definitions
• Resting Energy Requirements (RER) –
• This the energy level required by a living creature to maintain homeostasis whilst performing no physical exercise without losing weight.
• Maintenance Energy Requirements (MER) –
• is the energy requirement for a moderately active adult animal in a thermoneutral environment. Will give enough energy to maintain bodyweight and spontaneous exercise but no more.
Rer formula
Dogs and cats RER = 70 x Bodyweight (kg)⁰˙⁷⁵
weighing 2-30kg:
RER = 30 x bodyweight (kg) + 70
DOG Lifestage/Lifestyle Multiplication Factors
• Entire = 1.8 X RER
• Neutered = 1.6 x RER
• Sedentary = 1 X RER
• Light Exercise = 2 x RER
• Moderate Exercise = 3 X RER
• Obese prone = 1.4 X RER
• Senior = 1.4 X RER
• Housed in cold environment = 1.9 X RER
CAT Life stage /Lifestyle Multiplication Factors
• Entire = 1.4-1.6 X RER
• Neutered = 1.2-1.4 x RER
• Sedentary = 0.8-1 X RER
• Light Exercise = 2 x RER
• Moderate Exercise = 3 X RER
• Obese prone = 0.8-1 X RER
• Senior (>7-8 years) = 1.1-1.4 X RER
• Geriatric (>10-12 years) = 1.6 X RER
Horses Total Daily Ration
• Total feed capacity (kg) = (Bodyweight (kg)/100) x 2.5
• Energy Requirement for maintenance (MER)= 18 + (Bodyweight (kg)/10) MJ
Horse – work
• Light work (trotting) add 1-2 MJ of DE /50kg
• Medium work (some schooling) add 3-4 MJ /50kg
• Hard Work (Hunting 1-2 days) 5-6MJ/50kg
So for a 500kg horse in hunting season:
Total Feed capacity = (500/100) x 2.5 = 12.5kg of food
BASIC Energy Requirements = 18 + (500/10) = 68MJ of DE
+
Additional requirements = (500/50) x 5 = 50MJ
Total Energy Requirements = 68 + 50 = 118 MJ
118/ 9 = 13.1 kg hay This is above the total feed capacity so a proportion of the diet will be concentrates
Concentrates should never constitute > 50% of the ration
