"Warning - Feeding these dog foods to your dog could be hazardous to his health"...when I saw this statement on a piece of my mail today, I had an internal dialogue.
Maybe that statement should have been on all the fudge, bottles of wine, gravy and mashed potatoes, cookies, pumpkin pie, and margaritas that I consumed in excess over the past two weeks? I laughed and pondered the thought for a moment then giggled and said...nope, wouldn't have helped one tiny bit. I would have enjoyed all those things in excess regardless of any silly warning statement provided. Why? Because I LOVE and ENJOY those foods (and drinks). Key words there: ENJOY & LOVE...and consumed in the last 2 weeks, not ALL THE TIME.
So here it goes, I'm sure many of you will be shocked and dismayed to find out that on occasion, I commit the most horrible of dog-mom sins...I let my dogs indulge on crap food or treats. I even indulge Mr. Keegan in a few M&M's every now and then. They are to him what margaritas are to me...God's gift to the taste buds. I've always said the best thing about having a Ph.D in nutrition is the ability to justify eating ANYTHING!
What I've never been able to justify is how did it come to be that we decided there were "certain" ways we should feed our dogs and certain foods that we should or shouldn't feed our dogs? My favorites are the statements like "you can't feed raw and kibble at the same time" and "dogs are carnivores and should only have meat" and "by-products are crap", "you should never give your dogs bones" and "you can't feed raw eggs to dogs" and "raw is the only way to go if you want a healthy dog" of course the list goes on and on.
When did we figure there was a "right" and "wrong" way to feed an animal that evolved with us? This is where I struggle. We know that the "right" way for a human to eat is to eat a variety of foods including proteins, fruits and vegetables, whole grains and limit processing as much as possible. Does it not make sense that dogs should eat that way as well? The only difference I see is that the dog is anatomically a carnivore and has a very short digestive tract compared to ours. Dogs do need more animal protein but shouldn't be fed ONLY meat. An "only meat" diet may be the natural history for the African Hunting Dog but certainly not that of the dog.
When we consume a healthy and varied diet the majority of time, guess what happens when we over indulge during the holidays? NOTHING...isn't it beautiful? I just love that! Truly nothing. The more balanced our guts are, the greater the ability to re-balance when we decide to pig out on cookies and candy. I have watched the same thing with my dogs. My dogs have an extremely varied diet from day to day. They are fed raw, kibble, cooked meat, dehydrated, canned, commercial raw frozen, and sometimes I even mix them all up at once. I also have chickens and the dogs do eat raw eggs (and cooked eggs) regularly.
Are there products out there that our dogs should not be fed as a regular and major component of their diets? Of course. I can't imagine what my health would be like if I ate pumpkin pie and drank margaritas every day. Nor could I imagine what my gut would be like if I only ate grilled chicken and rice every day. It certainly wouldn't be strong enough to allow me the enjoyment of indulging during the holidays without some pain and discomfort involved. Both scenarios are dangerous for the human and canine gut alike.
I challenge you to consider the natural history of the animal you are feeding and think about what actually does make sense for you and for your pet. Just because your training partner feeds raw, doesn't mean that your choice to feed kibble is wrong. Both of you can have healthy animals if you provide them the right balance and variety to support an optimal environment in the gut.
Optimized Animal Nutrition
Monday, December 30, 2013
Monday, July 15, 2013
Choline
My new obsession is dietary choline. Choline is classified with other vitamins; however, doesn't quite act like other vitamins and can really cause problems in formulations due to stability (or lack thereof). It is currently giving me gray hairs in supplements for large felids and Fishing cats.
I find choline so intriguing because it is extremely complicated. Not only do mammals synthesize it, but it interacts with several other nutrients such as B12, folate and methionine. In other words, their status will impact the status of choline and vice versa. Choline is synthesized from the two amino acids serine and methionine through a reaction dependent on S-adenosylmethionine (SAMe). The later may be a compound you have seen on supplements, particularly for joint health.
A deficiency of choline will result in fatty liver and renal hemorrhage, along with potential cognitive loss or deficiencies in learning. Additionally, choline deficiency also has been documented to promote spontaneous development of cancer of the liver. In other words, a deficiency of choline is an ugly thing but it's a difficult one to asses because folate, B12, and methionine status also should be considered. Another compound called betaine and dietary methionine can actually replace some dietary choline in the diet. That said, a combination of high dietary methionine along with deficient choline likely results in elevated concentrations of plasma homocysteine, that in humans is a risk factor for vascular diseases. To say the least, choline is a complicated and fascinating nutrient.
Unprocessed and whole foods contain some choline. This is certainly one of those compounds that makes me happy I feed raw and makes me appreciate differences among species. When it comes to total choline concentrations, the best sources include beef liver (418 mg/100 g), lecithin (300 mg/100 g), chicken liver (290 mg/100 g) and eggs (251 mg/100 g). When it comes to muscle meats only, pork is the protein with the highest concentrations (>100 mg/100 g) compared with other proteins (Zeisel et al., Journal of Nutrition, 2003). The requirements for dogs and cats are set at approximately 1,700 and 2,500 mg per Kg of diet on a dry matter basis, or more simply...approximately 15 - 20 mg per pound of body weight for dogs and 20 - 30 mg per pound of body weight for cats. A typical egg is going to contain about 174 mg of choline (assuming it is 60 grams). Since my 35 Lb border collie eats 2 eggs daily, well over half of his choline requirement is coming from eggs. It is unlikely that raw diets including eggs and liver in the formulation will be deficient in choline.
There is indication in literature that perhaps choline requirements increase during exercise. Of course this hasn't been studied as it relates to agility dogs. Additionally, choline concentrations aren't documented in relation to raw meats typically fed to pets and carnivores. I've been on the fence about studying concentrations of choline in various meats and ingredients we typically use for carnivores, but it looks like we may head down that road. Somehow I always find questions that need answered regarding our sport dogs and raw diets...not to mention the exotic carnivores I continue to work with.
 |
| Fishing Cat (Photo by Cheryl Morris) |
I find choline so intriguing because it is extremely complicated. Not only do mammals synthesize it, but it interacts with several other nutrients such as B12, folate and methionine. In other words, their status will impact the status of choline and vice versa. Choline is synthesized from the two amino acids serine and methionine through a reaction dependent on S-adenosylmethionine (SAMe). The later may be a compound you have seen on supplements, particularly for joint health.
A deficiency of choline will result in fatty liver and renal hemorrhage, along with potential cognitive loss or deficiencies in learning. Additionally, choline deficiency also has been documented to promote spontaneous development of cancer of the liver. In other words, a deficiency of choline is an ugly thing but it's a difficult one to asses because folate, B12, and methionine status also should be considered. Another compound called betaine and dietary methionine can actually replace some dietary choline in the diet. That said, a combination of high dietary methionine along with deficient choline likely results in elevated concentrations of plasma homocysteine, that in humans is a risk factor for vascular diseases. To say the least, choline is a complicated and fascinating nutrient.
Unprocessed and whole foods contain some choline. This is certainly one of those compounds that makes me happy I feed raw and makes me appreciate differences among species. When it comes to total choline concentrations, the best sources include beef liver (418 mg/100 g), lecithin (300 mg/100 g), chicken liver (290 mg/100 g) and eggs (251 mg/100 g). When it comes to muscle meats only, pork is the protein with the highest concentrations (>100 mg/100 g) compared with other proteins (Zeisel et al., Journal of Nutrition, 2003). The requirements for dogs and cats are set at approximately 1,700 and 2,500 mg per Kg of diet on a dry matter basis, or more simply...approximately 15 - 20 mg per pound of body weight for dogs and 20 - 30 mg per pound of body weight for cats. A typical egg is going to contain about 174 mg of choline (assuming it is 60 grams). Since my 35 Lb border collie eats 2 eggs daily, well over half of his choline requirement is coming from eggs. It is unlikely that raw diets including eggs and liver in the formulation will be deficient in choline.
There is indication in literature that perhaps choline requirements increase during exercise. Of course this hasn't been studied as it relates to agility dogs. Additionally, choline concentrations aren't documented in relation to raw meats typically fed to pets and carnivores. I've been on the fence about studying concentrations of choline in various meats and ingredients we typically use for carnivores, but it looks like we may head down that road. Somehow I always find questions that need answered regarding our sport dogs and raw diets...not to mention the exotic carnivores I continue to work with.
Friday, June 21, 2013
Carbohydrates 2: Dietary Fibers
Dietary fibers in my opinion are the most important carbohydrates to consider in diet formulations for animals, particularly for our pets.
Fiber often gets labeled as "filler" although some people refer to all carbohydrates in pet foods as fillers and that's just silly (especially to those of you reading this blog). Now, if you are feeding a food like Ol Roy (don't tell me if you are!), yes, you are feeding way too carbohydrate and your dog (or cat) will have the fecal output to show for it.
First off, dietary fiber is not a single or simple group of compounds. In fact, they are extremely complex and diverse carbohydrates with diverse physical and chemical properties. Structurally, some fibers are soluble and some are insoluble. Some are viscous and have very high water holding capacity, while others are non-viscous. Some are fermentable in the bowel and others are not. Lastly, they can be combinations of the above. So, you can have soluble - viscous - fermentable fibers for example (those are my favorites), or you can have something like psyllium (Metamucil), which is actually a very soluble-viscous-non fermentable fiber.
The frustrating issue for me is that the label and analytics involved, don't necessarily tell you about those properties. If you look on a label of food (for you) at the grocery store, you will see that perhaps it breaks down the fiber into Soluble and Insoluble, but often gives you the Total Dietary Fiber (TDF) amount. On an herbivore diet such as for cows or horses, the label will likely (hopefully) include ADF (acid-detergent fiber) and NDF (neutral-detergent fiber). The values of TDF, ADF and NDF and obtained through totally different analyses in a lab. On our petfoods, we will see a value called "Crude Fiber" which also is a totally different analysis for fiber. Unfortunately, crude fiber is a completely worthless value to use. The assay destroys all of the soluble fibers and many insoluble fibers and only recovers portions of cellulose, hemicellulose and lignin (totally insoluble, non viscous, non fermentable). Therefore, a petfood might have a crude fiber value of 2.5% on the label but in reality, may have TDF values closer to 10% or even 20% depending on the ingredients used.
Ideally, I want fibers on the ingredient list that will provide some soluble characteristics. Soluble - viscous - fermentable fibers can alter gastric emptying and transit time (this can be good and bad), aid in management of pH along the G.I tract, provide volatile fatty acids for energy to the cells lining the gut, and aid in the management of blood lipids and glucose. These fibers can be very good in appropriate concentrations. In addition, many of these fibers provide prebiotic properties and help maintain optimal microflora populations that provide a strong basis for overall health and immunity.
Many folks like to use canned pumpkin in diets. Canned pumpkin contains about 30% TDF. That fiber is about 20% soluble and 80% insoluble; therefore, it does provide a nice blend. Due to the high TDF concentration and the blend of soluble to insoluble, pumpkin is an ingredient that I can use effectively across a huge range of species including dogs and cats, bears, elephants and primates.
My dog's raw diet does contain grain (and quite often pumpkin). I use oats and barley predominately at 10% of the the diet (as-fed). Oats and barley contain 30 and 12% TDF, respectively. Corn and wheat actually contain about 19 and 17% TDF while rice contains less than 2% (white rice). Barley has the highest percentage of soluble fiber, consisting of 30% of the total TDF. This gives barely some very viscous qualities or thickening properties. Oats on the other hand only have about 10% of the TDF as soluble; therefore, combined, I get a very nice blend of fiber qualities in my diet. Corn, wheat and rice contain 18, 14, and 20% of the TDF as soluble. Rice has such a low TDF value overall, I tend to not use it much, especially because it also has a very high glycemic index. Corn and wheat are definitely options for those animals that tolerate them. I will use fresh corn in my diet because an additional 15 - 20% (as fed) will consist of fresh fruits, greens and vegetables. If you are wondering, the breakdown looks like this:
55 - 60% muscle meat
10 - 15% organ meat (mostly liver and heart)
15 - 20% Greens, vegetables, fruit (seasonal)
10% grain
I supplement with eggshells for calcium and feed raw meaty bones 2-3 times week.
No doubt, fibers have personality!!! I love them!
Fiber often gets labeled as "filler" although some people refer to all carbohydrates in pet foods as fillers and that's just silly (especially to those of you reading this blog). Now, if you are feeding a food like Ol Roy (don't tell me if you are!), yes, you are feeding way too carbohydrate and your dog (or cat) will have the fecal output to show for it.
First off, dietary fiber is not a single or simple group of compounds. In fact, they are extremely complex and diverse carbohydrates with diverse physical and chemical properties. Structurally, some fibers are soluble and some are insoluble. Some are viscous and have very high water holding capacity, while others are non-viscous. Some are fermentable in the bowel and others are not. Lastly, they can be combinations of the above. So, you can have soluble - viscous - fermentable fibers for example (those are my favorites), or you can have something like psyllium (Metamucil), which is actually a very soluble-viscous-non fermentable fiber.
The frustrating issue for me is that the label and analytics involved, don't necessarily tell you about those properties. If you look on a label of food (for you) at the grocery store, you will see that perhaps it breaks down the fiber into Soluble and Insoluble, but often gives you the Total Dietary Fiber (TDF) amount. On an herbivore diet such as for cows or horses, the label will likely (hopefully) include ADF (acid-detergent fiber) and NDF (neutral-detergent fiber). The values of TDF, ADF and NDF and obtained through totally different analyses in a lab. On our petfoods, we will see a value called "Crude Fiber" which also is a totally different analysis for fiber. Unfortunately, crude fiber is a completely worthless value to use. The assay destroys all of the soluble fibers and many insoluble fibers and only recovers portions of cellulose, hemicellulose and lignin (totally insoluble, non viscous, non fermentable). Therefore, a petfood might have a crude fiber value of 2.5% on the label but in reality, may have TDF values closer to 10% or even 20% depending on the ingredients used.
 |
| "Shadow" |
Ideally, I want fibers on the ingredient list that will provide some soluble characteristics. Soluble - viscous - fermentable fibers can alter gastric emptying and transit time (this can be good and bad), aid in management of pH along the G.I tract, provide volatile fatty acids for energy to the cells lining the gut, and aid in the management of blood lipids and glucose. These fibers can be very good in appropriate concentrations. In addition, many of these fibers provide prebiotic properties and help maintain optimal microflora populations that provide a strong basis for overall health and immunity.
Many folks like to use canned pumpkin in diets. Canned pumpkin contains about 30% TDF. That fiber is about 20% soluble and 80% insoluble; therefore, it does provide a nice blend. Due to the high TDF concentration and the blend of soluble to insoluble, pumpkin is an ingredient that I can use effectively across a huge range of species including dogs and cats, bears, elephants and primates.
My dog's raw diet does contain grain (and quite often pumpkin). I use oats and barley predominately at 10% of the the diet (as-fed). Oats and barley contain 30 and 12% TDF, respectively. Corn and wheat actually contain about 19 and 17% TDF while rice contains less than 2% (white rice). Barley has the highest percentage of soluble fiber, consisting of 30% of the total TDF. This gives barely some very viscous qualities or thickening properties. Oats on the other hand only have about 10% of the TDF as soluble; therefore, combined, I get a very nice blend of fiber qualities in my diet. Corn, wheat and rice contain 18, 14, and 20% of the TDF as soluble. Rice has such a low TDF value overall, I tend to not use it much, especially because it also has a very high glycemic index. Corn and wheat are definitely options for those animals that tolerate them. I will use fresh corn in my diet because an additional 15 - 20% (as fed) will consist of fresh fruits, greens and vegetables. If you are wondering, the breakdown looks like this:
55 - 60% muscle meat
10 - 15% organ meat (mostly liver and heart)
15 - 20% Greens, vegetables, fruit (seasonal)
10% grain
I supplement with eggshells for calcium and feed raw meaty bones 2-3 times week.
No doubt, fibers have personality!!! I love them!
Tuesday, June 4, 2013
Carbohydrates 1 = Sugars and Starches
Next to "grains", sugars and starches are likely the biggest culprits of "anti-carb" propaganda in relation to petfoods.
Sugars are typically referred to as mono and di-saccharides and common examples include glucose, galactose, fructose, sucrose (table sugar), lactose (milk sugar), and maltose. They are typically included in foods to increase palatability, change viscous properties, alter texture, and/or provide color (browning reactions). Honey is an ingredient in many of my recipes, specifically because of its balanced concentration of gluocse and fructose. It provides a sweet taste that many dogs appreciate (or at least my Keegan thinks it's awesome). Interestingly, I often hear performance dog handlers indicate that honey makes their dogs sluggish. I do believe this is similar to some of the dogs that collapse during exercise (specific genetic diseases excluded). Fructose metabolism is a bit more complicated than glucose metabolism. It will either get used for energy or converted directly to fat (this is why high fructose corn syrup is so "fattening" for us humans if we don't use it for energy). Therefore, in our performance dogs, if they have a high glucose demand that gluconeogenesis is not maintaining, then yes, honey may not be the best option and more rapidly available carbohydrate sources are optimal.
Starches are interesting ingredients as well. Starch in its basic definition is just a lot of glucose molecules joined together in one of two patterns, linear (amylose) or branched (amylopectin). Amylopectin is more rapidly digested and thus, higher concentrations result in higher glycemic index. Food sources vary in the ratio of these two forms; therefore, one type of grain or carb does not equal another...hence all the confusion. For example, low amylose and high amylopectin in rice, make it rapidly digested but also give it a very high glycemic index. It is often used as the "go to" for many diets because of its high digestibility. I tend to not use it so much because of its very high glycemic index. Instead I use primarily barley and oats in my formulations, or when I'm looking at petfoods. I like the fact that both have nice amylose to amylopectin ratios and they each have additional cooling (barley) or heating (oats) properties (a topic for later discussion), and viscous fibrous properties (...more on that later as well).
I would really love to see some studies related to glycemic index of grain-free petfoods. Most of these are made with potato starch, because a good deal of starch is needed for the extrusion process in order to hold the kibble together. I'd like to see this because I suspect that many of the grain-free foods made with potato, will actually cause a higher glycemic index (this may be a good thing for those of you with dogs that are prone to collapse at trials or during intense exercise but may be a concern for overweight cats prone to diabetes). Interestingly, some groups in Canada are studying the increased use of peas and pea starch in petfoods. Like barley and oats, peas have some really awesome fiber characteristics as well and the resulting glycemic index is much lower than rice or potato. I love peas (for me and the dogs!)
My dogs are fed extremely varied diets included raw, home-cooked (quite literally the only thing I cook), kibble, canned, dehyrated and combinations of all of the above. I am fortunate they don't have issues with grains or carbs; therefore, I can and do provide varied sources. In my raw and cooked diets, 30% of the diet is a carbohydrate mix that includes fruits, vegetables, greens, and grains (barley, oats) in equal proportions by weight. I do not include potatoes in my blend but will on occasion include corn (especially in the summer when I can buy it fresh). I bet you wondered if I'd say the "c" word. Absolutely, I will use corn in moderation just like the rest of my carb sources. I try to add at least 3-5 different fruits and vegetables in every batch (typically 2 weeks worth of food). I do buy what is seasonal (I am an Animal Scientist after all, and "least cost formulations" are important to me).
If any of my dogs seemed to have issues at trials or during exercise with hypoglycemia or collapse, I would actually utilize some of the higher protein and fat (maintaining a 2:1 protein to fat ratio) diets that have rice or potato listed in the top 5 ingredients (many many options). I would use these throughout trial weekends, along with my raw diet and if the dogs were agreeable, I'd use them as treats (perhaps make meatballs with ground up kibble and raw meat...a little honey added if Keegan were the chef) throughout trial weekends. This might take some trial and error to see what worked best but that would be my plan A (I don't come up with Plan B until I need it)!
Cheers!!!
Sugars are typically referred to as mono and di-saccharides and common examples include glucose, galactose, fructose, sucrose (table sugar), lactose (milk sugar), and maltose. They are typically included in foods to increase palatability, change viscous properties, alter texture, and/or provide color (browning reactions). Honey is an ingredient in many of my recipes, specifically because of its balanced concentration of gluocse and fructose. It provides a sweet taste that many dogs appreciate (or at least my Keegan thinks it's awesome). Interestingly, I often hear performance dog handlers indicate that honey makes their dogs sluggish. I do believe this is similar to some of the dogs that collapse during exercise (specific genetic diseases excluded). Fructose metabolism is a bit more complicated than glucose metabolism. It will either get used for energy or converted directly to fat (this is why high fructose corn syrup is so "fattening" for us humans if we don't use it for energy). Therefore, in our performance dogs, if they have a high glucose demand that gluconeogenesis is not maintaining, then yes, honey may not be the best option and more rapidly available carbohydrate sources are optimal.
 |
| Keegan (Photo by: Marsha Kingsley) |
I would really love to see some studies related to glycemic index of grain-free petfoods. Most of these are made with potato starch, because a good deal of starch is needed for the extrusion process in order to hold the kibble together. I'd like to see this because I suspect that many of the grain-free foods made with potato, will actually cause a higher glycemic index (this may be a good thing for those of you with dogs that are prone to collapse at trials or during intense exercise but may be a concern for overweight cats prone to diabetes). Interestingly, some groups in Canada are studying the increased use of peas and pea starch in petfoods. Like barley and oats, peas have some really awesome fiber characteristics as well and the resulting glycemic index is much lower than rice or potato. I love peas (for me and the dogs!)
My dogs are fed extremely varied diets included raw, home-cooked (quite literally the only thing I cook), kibble, canned, dehyrated and combinations of all of the above. I am fortunate they don't have issues with grains or carbs; therefore, I can and do provide varied sources. In my raw and cooked diets, 30% of the diet is a carbohydrate mix that includes fruits, vegetables, greens, and grains (barley, oats) in equal proportions by weight. I do not include potatoes in my blend but will on occasion include corn (especially in the summer when I can buy it fresh). I bet you wondered if I'd say the "c" word. Absolutely, I will use corn in moderation just like the rest of my carb sources. I try to add at least 3-5 different fruits and vegetables in every batch (typically 2 weeks worth of food). I do buy what is seasonal (I am an Animal Scientist after all, and "least cost formulations" are important to me).
If any of my dogs seemed to have issues at trials or during exercise with hypoglycemia or collapse, I would actually utilize some of the higher protein and fat (maintaining a 2:1 protein to fat ratio) diets that have rice or potato listed in the top 5 ingredients (many many options). I would use these throughout trial weekends, along with my raw diet and if the dogs were agreeable, I'd use them as treats (perhaps make meatballs with ground up kibble and raw meat...a little honey added if Keegan were the chef) throughout trial weekends. This might take some trial and error to see what worked best but that would be my plan A (I don't come up with Plan B until I need it)!
Cheers!!!
Sunday, May 26, 2013
Carbohydrates - totally misunderstood!
No other group of nutrients gets more grief than carbohydrates, especially in diets for carnivores. Much of the misunderstanding is simply in the fact that carbohydrate compounds are lumped into one huge category and we don't have a specific requirement for them. Indeed, when you look through the NRC for Dogs and Cats, there is no requirement for carbs like there is for fats and proteins. This leads people to believe that dogs and cats don't need them. I completely DISAGREE! In fact, I use carbohydrate blends all the time in raw formulations for carnivores and they are invaluable to me in most of my clinical formulations. Even our formulations for big cats at the zoo include some carbohydrate; however, we are very specific about the types and amounts.
Unfortunately, the term carbohydrate includes everything from sugars and starches to dietary fibers and prebiotics. Confusing? Absolutely. Even dietary fiber isn't analyzed the same. The fiber included on the label of a pet food is what we call "Crude Fiber" and it means absolutely not one thing to a dog or a cat. It's not even the value we see on human food products which is referred to as Total Fiber. Oh yes, they are totally different analyses and give you completely different results. There are even specific fiber assays that we use for herbivores that recover different fibrous compounds.
The crude fiber assay only recovers a very small fraction of true fiber found in food as portions (not even all) of lignin, hemicellulose and cellulose (structural carbohydrates in plants). Those fabulous soluble dietary fibers that we are encouraged to consume and the wonderful long chain polysaccharides that act as prebiotics in the gut are destroyed in that assay; therefore, not included. So where do those get recovered in terms of pet food labeling? They don't. They wind up being lumped along with starch and sugar in the total carbohydrate calculation minus the Crude Fiber...or what we call Nitrogen Free Extract (NFE).
The calculation is based on subtracting out protein, fat, crude fiber and ash (total minerals) from the total dry matter in the diet and looks something like this: NFE = 100% - protein % - fat % - ash% (total minerals) - crude fiber %. In other words, we are accounting for the minerals, fat, protein and the tiny bit of fiber; however, EVERYTHING else gets lumped into the "NFE" package including vitamins, starch, long chain polysaccharides, all soluble dietary fibers, most insoluble dietary fibers, FOS & MOS (prebiotics), and sugars...yes, the good the bad and the ugly all get lumped together. I have come across many websites and blogs that refer to this NFE fraction as "carbohydrate" which is misleading.
It is frustrating to hear the misconceptions about carbohydrates because they have a purpose in pet foods. For example, if you enjoy the convenience of a kibble pet food, then you are enjoying the benefits of starch because it must be there in substantial concentrations to hold the kibble together (including those grain-free foods). Although there is no specific requirement for carbohydrates, they do provide benefit and provide nutrition. That said, some types of carbohydrates are frequently overused in pet foods and that poses issues and concerns.
Over the summer I'll be writing a series on carbohydrates to hopefully answer some of your questions about their advantages, disadvantages and functions in foods. Hopefully, we'll also get to some vitamin issues as well (the group of nutrients I love to hate!).
Unfortunately, the term carbohydrate includes everything from sugars and starches to dietary fibers and prebiotics. Confusing? Absolutely. Even dietary fiber isn't analyzed the same. The fiber included on the label of a pet food is what we call "Crude Fiber" and it means absolutely not one thing to a dog or a cat. It's not even the value we see on human food products which is referred to as Total Fiber. Oh yes, they are totally different analyses and give you completely different results. There are even specific fiber assays that we use for herbivores that recover different fibrous compounds.
The crude fiber assay only recovers a very small fraction of true fiber found in food as portions (not even all) of lignin, hemicellulose and cellulose (structural carbohydrates in plants). Those fabulous soluble dietary fibers that we are encouraged to consume and the wonderful long chain polysaccharides that act as prebiotics in the gut are destroyed in that assay; therefore, not included. So where do those get recovered in terms of pet food labeling? They don't. They wind up being lumped along with starch and sugar in the total carbohydrate calculation minus the Crude Fiber...or what we call Nitrogen Free Extract (NFE).
The calculation is based on subtracting out protein, fat, crude fiber and ash (total minerals) from the total dry matter in the diet and looks something like this: NFE = 100% - protein % - fat % - ash% (total minerals) - crude fiber %. In other words, we are accounting for the minerals, fat, protein and the tiny bit of fiber; however, EVERYTHING else gets lumped into the "NFE" package including vitamins, starch, long chain polysaccharides, all soluble dietary fibers, most insoluble dietary fibers, FOS & MOS (prebiotics), and sugars...yes, the good the bad and the ugly all get lumped together. I have come across many websites and blogs that refer to this NFE fraction as "carbohydrate" which is misleading.
It is frustrating to hear the misconceptions about carbohydrates because they have a purpose in pet foods. For example, if you enjoy the convenience of a kibble pet food, then you are enjoying the benefits of starch because it must be there in substantial concentrations to hold the kibble together (including those grain-free foods). Although there is no specific requirement for carbohydrates, they do provide benefit and provide nutrition. That said, some types of carbohydrates are frequently overused in pet foods and that poses issues and concerns.
Over the summer I'll be writing a series on carbohydrates to hopefully answer some of your questions about their advantages, disadvantages and functions in foods. Hopefully, we'll also get to some vitamin issues as well (the group of nutrients I love to hate!).
Subscribe to:
Posts (Atom)