Methionine is a limiting amino acid in the diet of high producing dairy cows. The extent of limitation depends on the level of production, stage of lactation, lactation number, body weight and the available forages and feed ingredients.
Ration software models predict that for a dairy cow1 producing 7 pounds of milk components (3.8 lbs fat + 3.2 lbs protein) the requirement for metabolizable (absorbed) methionine is about 75 g/day 2. Commercial diets, balanced for methionine, typically supplement 8-10 grams of metabolizable methionine from a commercial rumen protected/stable product form to meet the total methionine requirement3.
MINTREX® is a bis-chelated trace mineral, with 2 molecules of methionine hydroxy analogue (HMTBA) protecting every molecule of mineral. This structure provides stability in the digestive tract, reducing mineral reactions with other diet components and allowing for optimized mineral absorption.
When the HMTBA separates from the metal, it contributes to the methionine requirement of the animal.
MINTREX® zinc, copper and manganese contain 80, 78 and 76% methionine activity (HMTBA) by weight respectively. Feeding 3g of MINTREX® Zn, 2g MINTREX® Mn and 1g MINTREX® Cu supplies 4.7g of pure HMTBa and 2.6g of metabolizable methionine4, which supplies up to 20% of the cow’s daily requirement for supplemental rumen bypass methionine.
As a result, the amount of supplemental rumen protected methionine can be reduced with the addition of MINTREX® to a diet, i.e. REDUCE AND REPLACE™. Table 1 illustrates this substitution using two common sources of supplemental methionine. To calculate, divide the metabolizable methionine from MINTREX® in the example above (2.6 g/d) by the metabolizable methionine value of each source.

As illustrated above, the savings5 from applying the REDUCE
AND REPLACE™ program can be significant. Furthermore, if MINTREX® is replacing
another trace mineral source in the diet then there will be an additional cost
reduction due to removal the other trace mineral source. MINTREX®
delivers both optimum trace mineral bioavailability and excellent methionine
value in dairy rations.
References
1. Tucker, H.A. and A. Provin. 2020. Benefit of zinc methionine hydroxy analogue chelate to increasing tissue enrichment with dietary antagonism in Holstein calves. J. Dairy Sci. 104
(Suppl. 1) W81.
2. Holstein cow, 710 kg, 2nd lactation, 100 days in milk, 45.4 kg milk, 3.8% fat, 3.2% true protein.
3. Nutritional Dynamic Systems (NDS), Reggio Emilia, Italy. Copyright 2021.
4. Metabolizable methionine values are from product data sheets of commercial products.
5. Prices are based on current commercial market price lists.