Research & Publications

 In doing research to write this article the difficulty has been to sift out the truth from the myths. There will be a list of references for whoever desires to read each of the studies in depth. I will try to give their objectives of their studies and their conclusions. There is big conflict between the organizations that have “skin in the game” and something to gain or to lose. There is, to me, overwhelming evidence of health issues, whether good or bad found in these studies. So, I will start off by giving an explanation of what A1 and A2 milk is and how they test for it. I will also share animal studies and human studies and even cattle studies. As this is a relative new discovery as related to history, there is a lot that still needs to be studied, trialed and either proven or disproven. 

  Every mammal produces milk that is made up of fats, carbohydrates, proteins, vitamins, minerals and water. As producers we know how important it is to have our livestock well nourished with healthy nutrient rich grass and forbs, with vitamins, minerals and good clean water available as their bodies, like ours, require this for maintenance and to have a body condition that is able to reproduce, be healthy and stay healthy. 

 When our calves nurse it is important that they get the required fats, carbohydrates, proteins, vitamins, minerals and water, or they can be stunted in their development and susceptible to poor health. All of us know how important and vital the colostrum is in the first few hours of the calf’s life is, but do we consider the importance of the milk it receives after the colostrum period. 

We all have cows, that compared to herd mates, raise superior calves. I believe that as we study this that it will be revealed that this beta casein known as A1 or A2 will be found to be poly-genetic. 

 In all the mammals that have been tested, all came back as A2A2, except for the bovine which can be A2A2, A1A2, or A1A1. There is no positive knowledge as when this mutation occurred, but native cattle from Asia and India are A2A2, while many cattle from northern Europe have A1. There are many guesses out there as to why and when this mutation occurred, from the sun being shaded for a period of time by volcanic ash or smoke, to man trying to breed up to heavy milk production, with leaner animals and less fat, and many others. 

According to UC Davis Veterinary Genetics Laboratory, “The solids found in cow’s milk are composed of fat, protein, lactose and minerals. ß-casein is one of six milk proteins and is produced by the CSN2 gene. Fifteen genetic variants of CSN2 are known, which cause changes of certain amino acids in the beta-casein protein and alter its properties. Based on the amino acid in position 67, these variants can be classified into 2 groups - A1 and A2. The levels of bioactive peptide ß-casomorphin 7 (BCM7) produced from the metabolism of ß casein is several-fold higher for variants in the A1 group than in the A2 group. Higher levels of BCM7 have been associated with negative health effects in humans.” 

 From the International Journal of Molecular Sciences, Review “Does a Little Difference Make a Big Difference? Bovine Beta Casein A1 and A2 Variants and Human Health-An Update”; “For over 20 years, bovine ß-casein has been a subject of increasing scientific interest because its genetic A1 variant during gastrointestinal digestion releases opioid-like peptide ß-casomorphin-7 (BCM-7). 

  Since BCM-7 is involved in the dysregulation of many physiological processes, there is a growing discussion of whether the consumption of the ß-casein A1 variant has an influence on human health. 

 As we know in our Piedmontese they have to have the two alleles with C313Y to be two copy and registered. There is a big difference between a one copy and a two copy in terms of muscle growth. And another big difference between a one copy and a zero copy in muscle growth and tenderness. 

 In the following tests, trials and studies there should be enough evidence to make us consider further study on our own for the health, development and growth of our cattle and to bring to market the best product that we can. 

 A study by the Korean Society of Cancer Prevention posted online June 30, 2024, “The Effect of A2 Milk on Gastrointestinal Symptoms in Comparison to A1/A2 Milk: A Single-center, Randomized, Double-blind, Cross-over Study”. “The aim of this study was to evaluate the differences in GI discomfort after ingestion of A2 milk and A1/A2 milk. A randomized, double-blind, cross-over human trial was performed with 40 subjects who experienced GI discomfort following milk consumption. 

 For each intervention period, either A2 milk first (A2→A1/A2) or A1/A2 milk was first consumed for 2 weeks (A1/A2→A2) following a 2-week washout period. There were no significant adverse reactions during the trial. 

 A2 milk alleviated digestive discomfort in Koreans following A2 milk consumption (ClinicalTrials.gov NCT06252636 and CRIS KCT0009301). 

  A study from Spain titled “A2 Milk: New Perspectives for Food Technology and Human Health”, from MDPI has much health information regarding the health problems that can be associated with BCM-7 from A1 milk. Their aim for the review was to provide an update on the effects on human health of A2 milk, as well as its different technological properties to produce dairy products. 

 The various health problems they discuss that is related to A1 milk is autism, allergies and intolerance, cardiovascular health, type 1 diabetes Mellitus, neurological disorders, and effects on intestinal microbiota. 

 Under the heading of Physical and Technological Properties of A2 Milk: “it was revealed that due to their composition, A2 milk has a higher percentage of total proteins and fat than A1 milk [12].” And “With respect to fat % in A2 milk, some authors found higher rates of fat in A2 animals than in A1 genotype cows when produced by the same dairy cow breed and in the same ambient [11,24].” 

 “When dairy products are consumed, digestive enzymes in the human intestine act on ß-casein A1, thereby releasing the bioactive opioid peptide ß-casomorphin 7 (BCM-7), which is primarily responsible for triggering the allergic process and is associated with a delayed milk gastrointestinal transit time [5,54]. 

  The opposite is true for ß-casein A2, which only under specific in vitro conditions with pH and enzymatic conditions not found in the human intestine can release small amounts of BCM-7 [54]. 

  In fact, the BCM-7 concentration in the gut was found to be four times higher when produced from milk obtained from homozygous A1 cattle than from A2/A2 cattle [55]. Moreover, BCM-7 may be detected in the blood after the digestion of A1 milk but not after the consumption of A2 milk [13].” 

 And “Thus, after the intake of milk or dairy foods containing ß-casein A1, the produced BCM-7 binds with μ-opioid receptors, which are responsible for pain or thirst, in the walls of the gastrointestinal tract and nervous system of consumers. In contrast, A2 milk consumption has been shown to increase the natural production of glutathione, which shows antioxidant activity and, consequently, health benefits. Due to its opioid-like activity, BCM-7 was proposed as a risk factor for adverse gastrointestinal symptoms perceived by consumers as milk intolerance, as well as for certain diseases [17], whereas A2 milk is considered safe.” 

 And “With respect to neurological disorders, BCM-7 in the urine of autistic children who consumed A1 milk was found to be 10-fold higher than in children who consumed A2 milk, indicating a potential benefit of A2 milk consumption for this group [76].” 

 Under the heading “Effects on Neurological Disorders” Opioid receptors are widely distributed throughout the brain and are also found in the spinal cord and peripheral sensory nerves and are involved in several different functions, including appetite, depression, feeding behavior, respiratory behavior, and euphoria [88]. The μ receptor to which BCMs preferentially bind shows high levels of expression in areas of the brain and spinal cord with an important role in pain and analgesia, gastrointestinal functions, or even mood and thermoregulation [88]. 

 I would encourage those who are interested to look up this paper as it is full of information in regards to health associated with the A2 vs. A1 ß-caseins. 

  The conclusion of this study suggests that ß-casein A2 supplementation was associated with improvements in physical growth and related biomarkers in stunted children. Additionally, ß-casein A2 milk may produce fewer BCM-7 metabolites compared to ß-casein A1 milk, which has been hypothesized to be associated with certain adverse health outcomes. 

 (The following study was performed by Classic Livestock Management Services located in Maryborough, Queensland Australia. Their website is Classiclivestock.com.au

They also have a book titled, “Vision Tender, The Keys to Livestock Mastery. The foundation traits and pathways that maximize quality and production” by Gerald Wyatt.)

There has been a long held belief amongst some cattle producers that there is a relationship between meat and milk quality. However, there is little in the way of evidence to support this view. This has prompted the company, Classic Livestock Management Services to explore ways of finding sound evidence that would support this view.

 CLMS has developed a system of identifying meat quality through the assessment of a number of traits that animals have. Each identified trait is scored by a trained evaluator with a score of 5 being the lowest for quality, consistency, balance and functionality and a score of 1 being the best. They have conducted taste tests and a Warner Bratzler Shear Force test to verify their system in terms of identifying meat quality consistently in cattle that score highly on their grading system. 

  With the identification of the A2 beta casein protein gene in New Zealand in 2003, it became possible to identify higher quality milk using DNA testing of hair from cattle.  

With this in mind, CLMS took hair samples of cattle that were graded for meat quality and sent to laboratories registered to carry out the appropriate A2 tests in New Zealand and Melbourne, Australia, for testing to see if there was a correlation between meat quality and A2 milk.

Their Hypothesis: Cattle that score highly on the CLMS grading system for meat quality will produce high quality milk.

  The other animal that tested as A2 graded 4 on the CLMS system but as noted had a variation in bone shape between each side jawbone and so could have been considered as borderline also.

So in this part of the trial there was a direct correlation between A2 milk and tender meat in 27 out of the 29 samples. In both the other cases, the samples could be considered to be on the borderline and therefore inconclusive.

 In the second part of the trial, the cattle were all Bos indicus or Bos indicus cross. Forty samples predominately of the better quality cattle had hair samples taken and sent away for DNA testing. Thirty five head that graded as score 3 on the CLMS grading system DNA tested as carrying the A2 milk genes. Three head graded as 4 on the CLMS system and DNA tested as being A1 quality milk and 2 that graded as 3 for tenderness on the CLMS system came back as A1/A2 for milk quality. Again, this shows a direct correlation for 38 out of the 40 head tested and an inconclusive result for the other two. 

  The third part of the trial was conducted on the cows at the Fairbrae Jersey stud herd at Kyogle. As the cows were being milked they were graded for meat tenderness using the CLMS grading system. On completion, the CLMS scores were compared with the stud’s herd records and the above results were obtained. These results show that 27 cows scored 2 or 3 on the CLMS grading system and were also A2 for milk quality. A further 23 scored 4 or 5 using the CLMS grading system and were A1 for milk quality. The remaining sample scored 4 for tenderness but was A2 for milk quality. This was the only variation in the 51 head tested. 

 Overall, the results show a direct correlation between meat tenderness and A2 high quality milk for 115 out of the 120 samples tested.

Of the others, 4 of the 5 could be considered as inconclusive with only one being different.

This leads to the conclusion that with over a 95% correlation there is a strong relationship between meat tenderness and milk quality.

 Pharo Cattle Company (PCC) puts out an update on their website and in 2024 started a 4 part series regarding A2 ß-casein. They posted that the A2 contributes to the nutritional value of the milk.

Their theory is that an A2/A2 cow can raise a bigger calf on less milk than an A1/A2 or A1/A1 cow.

Their claim to fame is producing moderate-sized, low input PCC cows that can raise big calves without being heavy milkers.

 They believe the A2 ß-casein is another edge that we can take it or leave it. They posted this saying they had reason to believe that a high percentage of their cattle are A2/A2. They said they tested all of their PCC AI sires (76) and they had 86% that were A2/A2. They wonder, if A1 causes so many immune diseases, what does it do to calves? Having 86% of AI sires, they believe is a significant finding and proves to them that their AI sires are putting calves on the ground with another competitive advantage. To further test their theory, PCC had all the bulls being developed for their 3 fall bull sales tested. They tested 474 bulls and had 82% that were A2/A2. They believe these bulls will sire replacement females that will make more money. 

 They state that the A2 ß-casein increases the nutritional value and the digestibility of the milk. Steve Campbell estimates that 50% of beef cattle are A2/A2. PCC scores every bull for 10 different traits and a score of 5 is the best with 3 being average and of the bulls they tested they had 442 Angus and Red Angus that they theorized the 5-star bulls should have a higher percentage of A2/A2 than their 4-star and 3-star bulls. They found out that 86% of the 5-star bulls were A2/A2, 82% of the 4-star were A2/A2, and 80% of the 3-star were A2/A2. They now believe that A2/A2 is correlated with calf health and quality. They also believe that for those that sell Grass-fed beef, that there will soon be a premium market for A2 beef, just as there is for A2 milk. 

They say if an A2 calf is healthier, why wouldn’t the meat be healthier? “Anecdotal observations make a pretty clear case!”

So after my research and study regarding A1 and A2 milk, I believe it does matter in human health and in the animals that were in the studies. Inflammation and insulin resistance are two of the main causes of ill health. If we can stop these two antagonist before they can start, I believe we will have stopped many associated diseases and problems. I for one am going to be keeping an eye on my cattle’s ß-casein, as I believe it has a poly-genetic effect on them and their offspring.