When I first started researching balanced homemade diets for dogs, I heard so much about how wonderful raw milk (namely raw goat milk) is for animals, from practically everyone! No matter where I turned, it seemed like every corner of the raw feeding internet thought raw goats milk was the best thing since sliced bread...and I honestly did not think anything of it.
I used to pick up cartons of Answer's Fermented Raw Goat Milk from the frozen section of the pet store because I figured that's what every pet parent would do, but man oh man, those cartons of raw goat milk are not cheap & the cost was starting to add up! Based on everything I was reading from other raw feeding accounts, raw milk was supposed to be an excellent source of probiotics, aid in digestion, and raw goats milk, specifically, was basically one of "the best" things to supplement in your pet's diet (especially for puppies & kittens).
Initially, the thought of handling unpasteurised milk products and feeding it to my dogs was a bit unsettling because I was unsure of the bacteria load and I had no idea if it would be okay to feed to my dogs (I didn't want to feed them something that could potentially make them ill). I later had less reservations once switching Nolo (my oldest dog) from balanced home-cooked food to balanced raw food. I figured, if his body is designed to handle a raw diet, then the raw milk should be okay, so long as I am not feeding unpasteurised milk products that have gone bad. At this point, I had also figured out what my new daily routine would look like- cleaning, disinfecting and sanitising my meal prep area/living space now that I had a raw fed dog; so I was confident in my ability to contain messes, raw meat/raw milk etc and effectively clean said spaces.
As I got further into my raw feeding journey, I found myself looking into making kefir/fermenting products at home. Because I do not have access to affordable (unfermented) raw cows milk or raw goats milks locally, I started making kefir and kefir cheese for my dogs using regular, whole, pasteurised milk and that got me thinking...what are the ACTUAL benefits to feeding a dog or cat raw milk compared to whole pasteurised milk/milk products (fermented or not)? We also hear so much about how amazing raw goats milk is, but is it REALLY worth all the hype? I wanted answers, so I went digging and what I found as been shared below! :)
Consumption of raw or heated milk from different species: An evaluation of the nutritional and potential health benefits - W.L. Claeys (2014)
ABSTRACT
“Based on literature data, the composition of milk from different ruminants (cow, sheep, goat, buffalo, camel, llama, yak and deer) and equidae (horse and donkey) and of human milk were compared to examine possible nutritional differences. Additionally, the alleged health benefits attributed to some of these milks and the effect of heating are discussed. Very generally, ruminant milk has a lower lactose content, but a higher protein (and casein), fat (with a higher share of saturated and mono-unsaturated fatty acids and a higher cholesterol level), vitamin (except for vitamin C) and mineral content compared to horse or donkey milk. Milk composition may however vary largely, not only between ruminants and non-ruminants, but also between different breeding variants of the same species and between individual animals. Consequently, a constant health promoting potential is, if present, difficult to guarantee. Moreover, differences in milk composition do not only concern the relative proportions of the milk components, but also occur at the molecular level (e.g. monomeric versus dimeric proteins, different amino acid sequence). Pasteurization is not expected to affect the nutritional (or presumed health) benefits significantly, regardless of differences observed in thermostability between components of considered types of milk. Even though the milk composition of some animal species resembles to a great extent the composition of human milk, it is recommended to give either human milk or formula milk to babies and infants. For people suffering from milk allergy, milk other than e.g. bovine milk may offer a solution, but this greatly depends from one person to another.”
CONCLUSION
“Health beneficial effects are mostly attributed to the consumption of raw milk. Since raw milk entails a realistic health risk for the consumer due to a possible contamination with human pathogens originating from animals (even clinically healthy animals) or from environmental contamination during milk collection or storage, it is recommended to heat milk before consumption (Claeys et al., 2013; O’Mahony et al., 2009; Robinson et al., 2013; Verraes et al., in press). Information on the effect of a heat treatment on the milk components from animal species other than cows is scarce. Despite the fact that milk composition and thermal stability of certain milk components may differ between species, the main conclusions that were drawn in a former study in which the effect of a heat treatment on the risks and benefits of the consumption of raw bovine milk were discussed (Claeys et al., 2013), can be extrapolated to milk from other species. As such, it can be assumed that the nutritional benefits associated with the consumption of raw milk, including its contribution to the uptake of calcium, phosphor, proteins and essential amino acids (especially lysine), and a number of vitamins, are generally maintained after pasteurization or UHT treatment. The other nutrients in milk that may (partially or fully) or may not be destroyed by heating, contribute less to the daily nutritional needs. The main negative effect of biochemical nature of a heat treatment is the modified organoleptic profile of milk, although this is more a matter of individual perception. (Heat-related changes of technological significance, e.g. with respect to emulgating and water binding properties of proteins, are not addressed.). Other arguments against heating milk, including a less good digestibility of milk, an increased susceptibility for allergies and a counteracting of health beneficial properties, can be largely refuted or strongly nuanced. For a founded evaluation of putative therapeutic or health beneficial effects attributed to the consumption of raw milk from certain species and of the impact of a heat treatment on these effects, a confirmation of these effects is needed by sufficiently large, epidemiological studies. Moreover, the milk components responsible for these effects need to be identified and the interaction of these components with other milk components has to be accounted for.”
DISCUSSION
This article serves to compile research which relates to the comparison between milks of different species as well as the effect of heat treatment on their nutritional values.
With over 100 cited works, the authors come to a rather direct conclusion that heat treatment in the process of pasteurisation does not have a significant effect on the milk’s nutritional benefits, digestibility, or allergy resistance. This is an important point to be made since the touted benefits of raw goats milk are also present in heat processed milk, which eliminates virtually all pathogenic bacteria from the product and prevents communication of deadly diseases to humans/animals ingesting the milk.
According to the article, “the presence of food borne pathogens has been demonstrated in many surveys and food borne infections have been repeatedly reported for Campylobacter, Salmonella spp. and human pathogenic verocytotoxin-producing Escherichia coli after raw milk consumption.”
While dogs and other animals may be less susceptible to infection from these types of deadly bacteria than humans are, they are still exposed to a great risk of infection that could lead to hospitalisation.
When it comes to comparing milk compositions, the trend seen across research on the topic is that goat milk is lower in lactose, while higher in saturated fats and casein proteins compared to cow milk (see Table 1 above).
It is noted across many of these studies that the fat composition of goat milk samples varies greatly on several factors including breed, stage of lactation, and quality/quantity of feed.
Overall protein fractions across different milk types can be seen in Table 2 above. Notably, goat milk had lower concentrations of Lactoferrin, Lysozyme, and Immunoglobulin proteins compared to cow milk.
These proteins are important for immune system function and help newborn animals fight off infections while they feed on their mother’s milk. While these proteins also help boost immune systems of non-newborns, they are not a necessity. It is also seen that Immunoglobulin (Ig) activity reduces with pasteurisation since proteins generally have lower thermal stability compared to other organic macromolecules:
“During high temperature/short time (HTST) pasteurization (72C/15s) only 10 to 30% of bovine milk Ig activity is lost, whereas ultrahigh temperature (UHT) treatment (138C/4s) destroys the majority of the specific immune activity of milk. It is however, difficult to determine Ig heat losses accurately or to compare the heat induced Ig losses between different species since chemical composition, pH and other milk factors affect Ig levels during thermal treatment. In general, studies suggest that the antigen binding region of the Ig molecule is more thermolabile than the other molecule regions, and that IgG is the most and IgM the least thermostable.”
Probiotics in Goat Milk Products: Delivery Capacity and Ability to Improve Sensory Attributes- C.S. Ranadheera (2019)
ABSTRACT
“Dairy foods, particularly those of bovine origin, are the predominant vehicles for delivery of probiotic bacteria. Caprine (goat) milk also possesses potential for successful delivery of probiotics, and despite its less appealing flavor in some products, the use of goat milk as a probiotic carrier has rapidly increased over the last decade. This review reports on the diversity, applicability, and potential of using probiotics to enhance the sensory properties of goat milk and goat milk-based products. A brief conceptual introduction to probiotic microorganisms is followed by an account of the unique physicochemical, nutritive, and beneficial aspects of goat milk, emphasizing its advantages as a probiotic carrier. The sensory properties of probiotic-enriched goat milk products are also discussed. The maintenance of probiotic viability and desirable physicochemical characteristics in goat milk products over shelf life is possible. However, the unpleasant sensory features of some goat milk products remain a major disadvantage that hinder its wider utilization. Nevertheless, certain measures such as fortification with selected probiotic strains, inclusion of fruit pulps and popular flavor compounds, and production of commonly consumed tailor-made goat milk-based products have potential to overcome this limitation. In particular, certain probiotic bacteria release volatile compounds as a result of their metabolism, which are known to play a major role in the aroma profile and sensory aspects of the final products.”
CONCLUSION
“The diversity of available goat milk products containing probiotics is considerably less than that of bovine milk probiotic foods, suggesting that the potential market for dairy industries is currently under-exploited. One avenue particularly worthy of further development is the use of fresh goat milk and goat milk products as sources of potential probiotic microorganisms for isolation and use in enhancing the sensory properties of other goat milk products. Certain probiotic cultures produce volatile organic compounds that contribute significantly to the production of aroma in the product, resulting in a final product with the characteristic unpleasant odors of certain goat products minimized and with aromas and flavors more typical of wider consumer expectations enhanced. The large natural biodiversity of probiotics therefore offers an array of potential for improving the flavor of goat milk based products. Hence there is considerable scope for further targeted research to identify alternative probiotics beyond the more traditionally utilized species, with properties specifically suited to tailoring the sensory characteristics of a wider range of products. Most importantly, current evidence suggests that along with selection of probiotic cultures, the suitability of each ingredient for probiotic viability, processing procedures, complementary strategies to mask characteristic undesirable flavors, and the employment of suitable storage conditions, will all undoubtedly be critical for improving the sensory quality of probiotic-enriched goat milk products.”
DISCUSSION
This second study investigated the differences between (primarily) cow and goat milk with regards to their compositions, characteristics, and health benefits across different types of dairy products.
When considering differences in protein composition, this study corroborates the conclusions made in the previous article in our discussion and explains how this impacts the properties of goat versus cow milk.
Overall, both types of milk provide the same total protein content for nutritional purposes:
“Although the protein constitution of goat milk is generally comparable to the profile of bovine milk (Verruck et al., 2017), some unique differences exist in the composition of the proteins and their components. In general, goat milk has higher quantities of β-casein, lower quantities of αs-casein, and nearly identical quantities of κ-caseins. In contrast to bovine milk, β-casein is the chief protein in goat milk (Clark & Garcia, 2017; Slacanac et al., 2010). Goat milk presents a slightly inferior level of casein concentration compared to bovine milk, with very little to no αs1 casein (Hodgkinson et al., 2018). Since the level of αs1 casein impacts the coagulation ability of milk, this deficiency is one of the features contributing to the poor coagulating properties of goat milk, compromised cheese production, and weak yogurt structure (Hodgkinson et al., 2018).”
Goat milk does surpass cow milk in terms of fat content, however.
The study reported that goat milk has a greater concentration of monounsaturated fatty acids, as well as conjugated linoleic acid, than cow milk. These “acids” are parts of more complex fat molecules that have specific organic structures which are generally linked to various health benefits in humans- and presumably other mammals.
Another important topic in this article is how goat and cow milk can be used as probiotic carriers.
In the process of making fermented milk products, milk is first pasteurised in order to have potentially dangerous bacteria removed from the equation and then known strains of probiotic bacteria (bacteria that do not cause disease) are added to the sample of milk. Then starts the fermentation process- which allows the probiotic bacteria to create beneficial nutrients that are otherwise not found in the milk.
While many foods can contain probiotic bacteria without being fermented, the fermentation process ensures that the beneficial products made by bacteria like Lactobacillus strains are produced before digesting the bacteria. The digestion process, especially in dogs, can kill off a significant portion of the “good” bacteria in the milk product and thus reduce the final yield of probiotic products.
The primary type of probiotic bacteria used for fermentation of milk products is Lactic Acid Bacteria (LAB), which consumes carbohydrates from the food matrix (ie. milk) and produces lactic acid, as well as various alcohols, aldehydes, acids, esters and sulphur compounds that contribute to the flavour of the products (cheese, kefir, yogurts, etc).
Other probiotic strains which are normally found in mammalian digestive tracts, and therefore safe to consume, were isolated from fermented milk products for both goat and cow milk. Table 3 below compares the physicochemical benefits of these probiotic bacteria strains when incorporated into the fermentation process of either milk type:
Using several sources for the data on these comparisons, the table above indicates that goat milk is a more efficient source of antioxidant fermentation products when cultured with Bifidobacterium and Lactobacillus acidophilus strains, however had lower concentrations of Selenium (an antioxidant) when cultured with Pediococcus pentosaceus bacteria.
However, another study (Comparison of Antioxidant Activity of Cow and Goat Milk During Fermentation with Lactobacillus acidophilus LA-5, J.Álvarez-Rosales 2019) found evidence of the contrary. As seen in the table below, cow milk fermented with LAB strains displayed greater antioxidant performance than goat milk. (Radicals = oxidant)
Additional Reference
CONCLUDING THOUGHTS
When it comes to goat milk versus bovine, or cow milk, there are a few definitive differences. While overall totals of protein and fats are similar, we do see a difference in the types of proteins and fats that make up these totals. We also saw that goat milk has lower concentrations of lactose, as well as various probiotic characteristics- however, this varies greatly on the breed used, among other factors.
Also, these studies were all conducted with pasteurised milk samples (non-raw), so extrapolation to raw goat milk versus raw cow milk would make our conclusions even less reliable. And as your vet would tell you, these studies do state that no significant nutritional value is lost from the heat-treatment process, meanwhile doing so virtually removes any risk of harmful bacterial infection.
So is goat milk better than cow milk?
When looking at the literature on the topic, there certainly isn’t one type of milk that stands out in terms of nutritional value and/or health benefits. Some studies found goat milk to have certain probiotic qualities that compared favourably to cow milk, however, more recent studies contradicted those findings.
If anything, this means that introducing both cow and goat milk into one’s diet is preferable to choosing one over the other (if there are no present allergies/intolerances etc). If there are specific benefits to consuming goat milk that you cannot get from cow milk, and vice versa, then incorporating both into the diet will provide exposure to each type’s exclusive nutritional advantages.
Variety is always best.
Does this mean I should stop feeding raw goats milk & raw cows milk to my dogs/cats?
Not necessarily.
Would I go out of my way to purchase raw milk for my animals? Absolutely not.
Am I scared/terrified to ever feed them raw milk or raw cheese again? Also, no.
If you have access to raw milk/raw milk products and your animals tolerate them when consumed, AND you store them properly, not allowing for the rapid growth of harmful bacteria, then you should be okay. If this is not a risk you're willing to take, then the easiest solution would be to opt for pasteurised products.
Can I use raw goats milk or raw cows milk to wean kittens/puppies?
Raw milk does not provide all essential nutrients a puppy or kitten would need in order to support their growth and development. You should never use raw milk as a long term meal replacement for growing animals, unless that milk is coming straight from their mother's teat (sorry).
If you wish to introduce solid food to a young puppy or kitten, opting for a complete & balanced premade would be a better choice- look for a balanced puppy formula or one balanced for All Life Stages (balanced to AAFCO, FEDIAF, or even NRC feeding guidelines).
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Please consult physicians/veterinarians, and/or other trustworthy science-based sources for advice on human and animal dietary questions.
Hope this was helpful to some!
Follow me on instagram @nolorlin for more raw feeding content & recipes!
xoxo
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