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Cato
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« on: May 03, 2009, 09:34:57 PM » |
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Bug: "Complete and Balanced Diet for All Life Stages" IS a work of fiction!  BTW - Does the new NRC have a new formula for calculating the Energy Density of pet food (or any food)? I have the old formula, but I am wondering if they now have adjusted for availability and digestibility of nutrients too? Sorry Bug , you can just tell me to get lost if its a hassle to find. I really really want that book. |
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bug
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« Reply #1 on: May 04, 2009, 12:35:53 PM » |
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What's the old formula? I can compare it to what the new edition says for you. It's no problem -- not a huge book to leaf through.
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Red and Bones, my baby boys, you'll always be in my heart. Mom will see you later. Look after each other, ok?
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Cato
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« Reply #2 on: May 04, 2009, 04:57:16 PM » |
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I typed all this up and then when I hit the "post" cookie, I got a disconnect  Let's see if this one will go through... ok. This is the formula I have for petfood: ( percentage in diet from guarnateed analysis) x ( Modified Atwater Factor) = kcal/100g food x 1000g/kg = Energy Density For example, calculating energy density from the "Guaranteed Analysis" of Woof-Woof Dog Kibble: Protein: 26% x 3.5 = 91 Fat: 15% x 8.5 = 127.5 Carb: 47% x 3.5 = 154.5 _____ Total: 382 kcal Total 382kCal x 1000g/kg = 3820 kcal/kg Energy Density or 3820 kcal/kg x 2.2lb = 1736.4 kcal/lb Energy Density Is the New NRC formula any different? *** For home-made cat food, I do use the Atwater Factor 4-9-4 ME (Protein-Fat_Carbohydrate) used for human food - becuase it is human grade ingredients  |
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« Last Edit: May 04, 2009, 05:02:16 PM by Cato »
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3catkidneyfailure
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« Reply #3 on: May 04, 2009, 06:29:24 PM » |
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Cato, where are you getting the carbohydrate figure from, since it's not on any pet food labels, for us novices?
Just the remainder after protein and fats are deducted? Or?
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bug
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« Reply #4 on: May 04, 2009, 07:15:30 PM » |
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Ah, yes. They do take the type of diet into account in calculating metabolizable energy. If it is a purified diet (>90% digestible), they recommend using the actual Atwater factors for PRO (4 kcal/g) and CHO (4 kcal/g), but modified for fat (8.5 kcal/g) because the digestibility of fats is lower in cats than dogs or humans.
I, like you, would have used unmodified Atwater for human food, but they recommend the 8.5 for fats.
Processed food - much more complex situations because of the variability in digestibility of the diets.
Anything else you need out of this book, let me know.
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« Last Edit: May 04, 2009, 07:20:51 PM by bug »
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Red and Bones, my baby boys, you'll always be in my heart. Mom will see you later. Look after each other, ok?
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Cato
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« Reply #5 on: May 04, 2009, 07:17:32 PM » |
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Cato, where are you getting the carbohydrate figure from, since it's not on any pet food labels, for us novices?
Just the remainder after protein and fats are deducted? Or?
Yes. So, for example, you have canned food. Guaranteed Analysis read: Protein 10% Ash: 2% Fiber: 1% (strictly seaking, fiber beloongs to carbohydrate group) Fat: 5% Water: 78% ----------- total 96% Calculating for Carb 100% - 96% ------- 4% Carbohydrate To calculate ME or Energy density, reduce to dry matter percentage by deducting moisture or water so... 100% - 78% ------- 22% Total Dry matter in food Calculating percentages: Protein: 10% -- 0.10 / .22 x 100% = 45.45% Fat: 5% ---- 0.05 / .22 x 100 = 22.72% Ash: 2% --- 0.02 / .22 x 100% = 9.09% Fiber: 1% --- 0.01 / .22 x 100% = 4.5% Carb 4% --- 0.05 / .22 x 100% = 18.18% |
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Cato
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« Reply #6 on: May 04, 2009, 07:19:09 PM » |
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Ah, yes. They do take the type of diet into account in calculating metabolizable energy. If it is a purified diet (>90% digestible), they recommend using the actual Atwater factors for PRO (4 kcal/g) and CHO (4 kcal/g), but modified for fat (8.5 kcal/g) because the digestibility of fats is lower in cats than dogs or humans.
I, like you, would have used unmodified Atwater for human food, but they recommend the 8.5 for fats.
Processed food - much more complex situations because of the variability in digestibility of the diets.
Anything else you need out of this book, let me know.
Ahhh! That's why I see "assuming 4kcal/g ME" in petood labels now! THANK YOU, Bug! |
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bug
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« Reply #7 on: May 04, 2009, 07:21:38 PM » |
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I'm going to start another thread under making your own pet food and maybe a moderator can move the posts that don't relate to testing there. I'll call it "Pet Food Nutritional Science."
Any questions that might be gleaned from this book will be entertained.
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Red and Bones, my baby boys, you'll always be in my heart. Mom will see you later. Look after each other, ok?
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Cato
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« Reply #8 on: May 04, 2009, 07:26:42 PM » |
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I'm going to start another thread under making your own pet food and maybe a moderator can move the posts that don't relate to testing there. I'll call it "Pet Food Nutritional Science."
Any questions that might be gleaned from this book will be entertained.
GOOD Idea! |
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bug
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« Reply #9 on: May 04, 2009, 07:26:54 PM » |
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Any questions that I can answer by looking information up in my trusted resources can be posted here.
I will entertain topics such as physiology, feeding behaviour, macro and micronutrients, physical activity, diet formulations, feed processing, nutrient composition of ingredients, other food constituents (holistic, etc.) and nutrient requirements.
Hopefully, Cato will also be on board as his Meowmie has done a crazy amount of research and can fill in the gaps answers from these topics may create.
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« Last Edit: May 05, 2009, 04:41:51 PM by bug »
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Red and Bones, my baby boys, you'll always be in my heart. Mom will see you later. Look after each other, ok?
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catbird
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« Reply #10 on: May 04, 2009, 07:36:16 PM » |
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I'm going to start another thread under making your own pet food and maybe a moderator can move the posts that don't relate to testing there. I'll call it "Pet Food Nutritional Science."
Any questions that might be gleaned from this book will be entertained.
OK, I moved the last page of posts from the testing thread to this thread, since they seemed to be the ones most directly related to this topic. If there are others further up the food testing thread that you want moved here, they will have to be cut out individually and moved. Please send me the reply numbers if so. |
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Read "The Omnivore's Dilemma" and you'll know where we are going and why we are in this handbasket.
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bug
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« Reply #11 on: May 04, 2009, 07:36:52 PM » |
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Thanks very much, moderator. Much appreciated! You got all of them.
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Red and Bones, my baby boys, you'll always be in my heart. Mom will see you later. Look after each other, ok?
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Cato
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« Reply #12 on: May 06, 2009, 11:08:51 AM » |
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Bug: If you have time, could you post the new NRC recommended daily allowances of nutrients for dogs and for cats?
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JustMe
Administrator
Hero Member
Posts: 7917
Elvis
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« Reply #13 on: May 06, 2009, 11:17:06 AM » |
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"One cat just leads to another." ~ Ernest Hemingway
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lesliek
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« Reply #14 on: May 06, 2009, 11:44:00 AM » |
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Good find,I've never seen that site before.
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"the world's most inept extortionist"
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