There continues to be significant interest in researching the benefits of feeding rumen-protected methionine and methionine analogues, with nearly 60 new methionine-related abstracts presented during the 2019 annual meeting of the American Dairy Science Assn., according to an announcement from Adisseo.
“Now that methionine is recognized as an essential nutrient with wide-ranging roles in dairy nutrition, its impact on production, health and reproductive performance continues to be more fully explored,” said Brian Sloan, global ruminant business director at Adisseo. “For dairy farmers, supplemental methionine offers gains in the production of milk, milkfat and milk protein. It also offers longer-term gains in terms of health and reproductive performance.”
According to Adisseo, notable recent findings included research from Cornell University that explored the effect of calf starters with either supplemental rumen-protected methionine or methionine analogues on calf growth and efficiency from 14 to 91 days of age. Contrasts among the methionine supplements indicated that the methionine analogue HMTBi, the isopropyl ester of the hydroxy analogue of methionine, improved feed intake and bodyweight gain postweaning, with a tendency for a greater final bodyweight.
Other research from Dr. Mike Van Amburgh's research group at Cornell investigated the optimal quantity to feed of an ideal profile of the 10 essential amino acids relative to metabolizable energy to maximize milk performance and feed efficiency, Adisseo said. Results confirmed the hypothesis that, on a methionine and lysine basis, at least 1.14 and 3.03 g/Mcal of metabolizable energy, respectively, are minimally necessary.
Research at the University of Illinois evaluated the effects of feeding rumen-protected methionine to 32 multiparous cows subjected to heat stress, Adisseo noted, adding that the researchers concluded that heat stress negatively affected physiological and production parameters. The rumen-protected methionine supported milk, milk protein and milkfat production.
Research at The Ohio State University investigated the effects of methionine sources on rumen fermentation and biohydrogenation of linoleic acid in vitro, as these affect milkfat depression, according to Adisseo. The researchers concluded that linoleic acid at 3% of substrate dry matter depressed feed digestibility and altered acetate and propionate production. However, methionine and the analogue of methionine, 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), alleviated the negative effect of linoleic acid on fiber digestibility, and HMTBa produced more acetate and less propionate than linoleic acid, which did not occur for methionine, Adisseo said.
The changes in the biohydrogenation of linoleic acid by methionine and HMTBa did alter the biohydrogenation pathways that relate to milkfat depression.
Research from INRA in France investigated the effect of methionine, lysine and histidine supplementation at both a low and high net energy supply in dairy cows. The research showed that increasing the net energy supply increased milk protein yield and also increased milkfat yield, Adisseo noted. Better balancing amino acids increased the milk protein yield through a tendency to increase milk yield at both the high and low energy levels. This led to an overall increase in metabolizable protein efficiency.
Research conducted at the University of New Hampshire explored the feasibility of evaluating the methionine bioavailability of rumen-protected technologies using the plasma amino acid dose-response technique without using ruminally cannulated animals, Adisseo said. The researchers found that this could be done when using a reference rumen-protected amino acid supplement with a known bioavailability. According to the results, the bioavailability of the test product used was 20.8% relative to the reference rumen-protected methionine, Adisseo explained. The use of ruminally cannulated cows was shown to not be needed.