Effect of supplementation of protected methionine, lysine and choline on performance of lactating cows -A review

As production of milk by dairy cow increases, research has focused on increasing the supply of amino acids to high producing dairy cows. Methionine and Lysine often are implicated as limiting amino acids for milk production. Choline is also an essential component of phospholipids which is important for proper membrane function and in the structure of lipoproteins, improves milk fat, overall production and reduces the risk of ketosis and reproductive disorders. Unfortunately, if unprotected crystalline amino acids are fed to cows, ruminal bacteria degrade it resulting in little increase in passage of these respective amino acids to small intestine. However, there is difference of opinion among researchers regarding the effect of protected methionine, lysine and choline on dry matter intake, digestibility, milk yield, its composition and blood profile of lactating dairy cows. Therefore present review discusses the effect of these protected amino acid supplementations on dry matter intake, digestibility, milk yield, milk composition and blood profile of lactating cows.