I have not seen any discussion on this thread regarding what makes up the protein and that is something you really need to look into when making a buying decision on dog food. Most of these big time dog food companies are simply a means to dump waste products and very profitably.
These companies have over the years developed very clever marketing schemes to entice you to buy it and they give huge volume discounts to trainers so trainers will promote their products.
I use VICTOR Select Hi Pro Plus 30/20 for my working 3 year old and another VICTOR product Victor Select Performance for my 11 year old lab 33/16.
The reason why I chose to go to this dog food is that they are very transparent with the products analysis, something the others are not. I also like the fact that they put Selenium into the food because it is known to help reduce cancer and provides other benefits as well. See link on ehow: http://www.ehow.com/facts_5630732_benef ... dogs_.html
For example, the 30/20 product displays the actual amount of meat used as a protein source; 83% from meat, poultry & fish sources, 7% from plant and 10% from grains. No Corn or Corn Gluten meal is used.
It is a known fact from nutrition experts that MEAT is the primary means by which canines metabolize the food into the amino acids necessary for life. Not CORN! If you look at the Biological Value of CORN, compared with Meat or Eggs you will see its way down the scale.
Protein is used by the canine to repair and mend muscles, tendons, ligaments etc primarily as well as for energy though FAT is the primary means from which canines get energy, not carbohydrates.
CCL injuries are the most often and painfully debilitating injuries our dogs suffer. The #'s of dogs with CCL injuries has risen year after year as has the incidence of cancer.
Ask any vet in SD, ND, MN when they have the highest number of CCL's to repair and they will tell you its during Pheasant season. Now part of that is due to hunters not conditioning the dogs but when you ad poor quality dog food into the equation and feed it year after year that dog is going to be predisposed to a lot more ailments than one fed a good quality food.
So, yes buy the 30/20 but careful what you buy and demand that the dog food company tell you what the % of Meat is in the dog food.
Another good dog food recommended to me by a top field trial pro is Dr. Tims, again this product line uses high %'s of Meat protein in the lines of Momentum and Pursuit. It was founded by a Vet that participates in Iditerod trials and the formula worked on with a Canine Nutritionist.