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Feeding Large & Extra Large Breed Puppies
Energy, Fat & Protein
Vitamin D is composed of a group of sterol compounds that regulate calcium and phosphorus metabolism in the body. There are two pro-vitamin forms of this vitamin.
- Vitamin D2 (ergocalciferol)
- D2 is formed when the compound ergosterol is exposed to ultraviolet radiation (UV Rays). D2 is found in many plants and the conversion is only possible in harvested or “injured” plants, not living plant tissue.
- D2 is only of significance to ruminant & non ruminant herbivores eating sun-dried or irradiated plant materials. D2 is used less efficiently than D3 by dogs.
- Vitamin D3 (cholecalciferol)
- D3 is of great nutritional importance to dogs, and they are dependent on getting it via dietary sourcing because they have limited ability to convert 7-dehydrocholesterol in the skin to cholecalciferol.
Vitamin D’s functions are intricately involved with normal calcium and phosphorus homeostasis in the body. At the site of the intestine, vitamin D stimulates the synthesis of calcium-binding protein, which is needed for efficient absorption of dietary calcium & phosphorus. Vitamin D affects normal bone growth & calcification by acting with Parathyroid Hormone (PHT) to mobilize calcium from bone and by causing an increase in phosphate reabsorption in the kidneys. <—- What does all that mean?! It means vitamin D’s actions in the intestines, bones, and kidneys creates an increase in plasma calcium and phosphorus, to the level needed for normal mineralization of bone.
Dietary sources of vitamin D3 for dogs are relatively low. Moderate amounts can be found in foods such as mackerel, salmon, whole egg, turkey liver, beef liver, beef kidney, domesticated duck meat, and turkey heart. Fish liver oils and cod liver oil are two concentrated food sources of vitamin D. Cod liver oil should be used with caution and careful attention paid to the amount given.
Critical Recap: Vitamin D3 plays an important role in regulating calcium and phosphorus metabolism. A deficiency in vitamin D3 can impact bone mineralization and cause skeletal issues.
Effects of Complex Carbohydrates on Growth
Starch is not needed to balance a puppy’s diet nor is it recommended as a main component of a puppy’s diet. Complex carbohydrates are starches or fibers, which are digested more slowly than simple carbohydrates. Starch requires additional breakdown by enzymes that are produced by the pancreas and intestinal wall. When starch isn’t prepared properly or it is fed in excess, it can rob the puppy of essential nutrients and starch can also create systemic yeast infections. Sometimes people reach for starch to fill calories with but we do not want to do that in growth and so leaving starch out of a growing puppy’s diet is best.
Fiber and Growth
It is important to provide fiber in moderation but fiber sources shouldn’t be looked to for balancing a diet. Dietary fiber reduces energy intake by way of dilution. Feed fiber that is in the form of low glycemic vegetables or high fiber, lower sugar fruits. Fiber is best fed to growing puppies after a meal, not before. Fiber is discussed more in depth in other puppy guides here on the website.