Walking along a dog food aisle, you’d easily be forgiven for feeling overwhelmed, swamped by the countless options and catchphrases being thrown at you. Grain-free, raw kibble, holistic, natural, extruded, cold pressed; but what do they all mean? Is it all a marketing grab? Today we’ll be focusing on Cold Pressed Dog Food, discussing what it is, how it's made and whether it's any better than extruded pet foods.
What is Cold Pressed Dog Food?
Cold Pressed refers to how the food has been processed and manufactured. Most dry dog food on the market is extruded. Extruded pet foods are created by mixing together all ingredients in one big container until a paste or dough type consistency is formed - this is then cooked under high pressure and temperature. Once cooked, the baked food must be cut into small pieces, which we see as kibble, and then dried to reduce the moisture content. This ensures the food doesn’t congeal in the bag and creates a biscuit crunchy texture: but, more importantly, by reducing moisture we inhibit bacterial growth, preserving the food for longer.
So how does cold pressed food differ? The maximum cooking temperature is lower for pressed food compared to extruded food, however the term cold pressed could be considered a little misleading. The food is still subject to heat, with certain ingredients like starches also requiring cooking (sometimes known as thermally treating) before cold pressing. With a slightly higher moisture content compared to extruded foods, and a manufacturing process that involves lower temperatures, the shelf life of cold pressed food is lower on average than other dry foods, with a higher chance of bacteria. But not all bacteria is bad bacteria, and it’s important to remember that temperatures high enough to kill bacteria will also negatively impact nutrient levels.
Cold Pressed dog food has a more pelleted appearance when compared to standard extruded kibble.
Though cold pressed is a relatively new concept to the pet food industry, on the whole, it’s a much older process - having been used to create agricultural animal feeds such as those for pigs, horses and others over the last 50 years. You might be wondering why it’s not used more commonly for dog food, with over 95% of dog food on the market being extruded. The truth unfortunately concerns efficiency. It’s much quicker to cook dog food at high temperatures with high pressure, meaning the manufacturer can produce more in less time. We have to ask ourselves, what is the impact of this on the nutritional value of the food?
Is Cold Pressed food better for my dog?
There are various claims for the benefits to Cold Pressed Dog Food; higher nutritional value, increased digestibility, decreased risk of bloat & better flavour and taste. Let’s analyse each of these claims.
Higher Nutritional Value
One of the main claims we tend to see regarding cold pressed dog food is that it has a higher nutritional value. Ultimately, unless a manufacturer was to publish a lab analysis of the food, we can’t conclusively state this as fact. Though one study comparing 21 extruded foods to 10 cold pressed foods noted higher amounts of Lysine (an essential amino acid) in the pressed foods. We also know from human cooking that roasting, baking and steaming preserves more nutrients than boiling - the latter being at much higher temperatures where vitamins and antioxidants especially undergo notable losses. This all suggests that, yes, cold pressed foods have on average more nutritional value than extruded foods.
Increased Digestibility
We don’t have many studies to prove this and those we do have provided mixed results. One study reported total-tract digestibility of crude protein was 78.4% vs 72.4% of pressed vs extruded diets. It was also noted in the same study that there was reduced fermentation in the hindgut leading to less bacterial protein excretion - in layman’s terms, the dogs had less gas!
Another study however showed mean crude digestibility of protein being 76.1% vs 79.6% for pressed vs extruded diets, demonstrating the opposite result of the prior study. This is likely due to the protein source being more heavily plant-based in the latter study; plant-based foods require cooking and pulverising for dogs to be able to digest with amylase.
In conclusion, it does appear that cold pressed dog food has higher digestibility, albeit not a significant increase.
Decreased Risk of Bloat
There are no studies to substantiate this claim, though it’s easy to see where it comes from. When looking at a comparison of the breakdown of extruded vs pressed food in a cup of water, extruded food swells and takes 5-6 hours to break down, whereas pressed food breaks down within an hour. However, this ignores that gastric volvulus (bloat) is caused by bacterial gas in the stomach, not food expansion - though it isn’t out of the realm of possibility that aged swollen food could produce bacterial gas.
Better Flavour & Taste
Anecdotally, we've seen fussy eaters tend to prefer cold pressed foods, and it’s not hard to understand when you open a bag of cold pressed food - the aroma is notably different to extruded foods.
Interestingly however, a two bowl taste preference test of 30 dogs demonstrated an intake of 34:66 of pressed to extruded foods suggesting dogs preferred the taste of extruded foods. It is important to consider that many poorer quality extruded foods have become so devoid of taste that taste enhancers have been sprayed over the foods, which may ultimately bear an impact on the study.
We suspect that flavour and taste is ultimately too subjective for us to say either way, here. But should you want to try cold pressed food for you dog and find yourself swamped with options, consult with our Head Nutritionist today to find the perfect food for your dog.
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