Suplementação de vacas leiteiras com metionina rúmen-protegida

Abstract

Methionine is an essential amino acid for milk production in dairy cows, playing an important role in the metabolism and health of these animals. However, its degradation in the rumen can compromise the efficiency of supplementation, limiting its utilization. To overcome this issue, rumen-protected formulations have been developed and are available in several countries, ensuring that methionine reaches the small intestine intact, where it is absorbed, incorporated into the bloodstream, and utilized by the body. In Brazil, the high cost of these supplements still limits their adoption in much of the dairy production systems. In this context, national products are beginning to be developed, but they require scientific validation regarding the efficacy of ruminal protection, absorption, and positive impacts on animal performance. This study aims to review the importance of methionine in dairy cow nutrition and present the results of a study that evaluated the effects of rumen-protected methionine supplementation. For the study, 20 Holstein cows were selected based on similar criteria and divided into two groups: Treatment (TRAT), supplemented with 30 g/day of commercial protected methionine, and Control (CON), with no supplementation. Both groups were fed the same diet and milked twice a day. Weekly, on days 0, 7, 14, 21, and 28, blood samples were collected to analyze plasma methionine levels, along with body weight measurements and milk production. The results showed that plasma methionine levels did not differ between groups (p>0.05). However, the TRAT group showed higher milk production compared to the control (p<0.01) and greater body weight gain (p<0.01). Although plasma methionine levels did not differ between groups, the observed benefits in productive performance allow us to conclude that rumen-protected methionine was effective in its function, contributing to increased milk production and weight gain in mid-lactation dairy cows. It is important to consolidate these findings to expand the use of this technology in Brazil.