Methionine Enhances Embryo Survival
Research at the University of Illinois (U of I) has shown that adding methionine to the diets of Holstein cows could enhance a pre-implantation embryo’s chance for survival.
“We know that the lack of methionine limits cows in producing protein in the milk,” says U of I animal scientist Phil Cardoso. “Now we’re beginning to understand that it affects more than just the milk protein. We want to learn more about the biological effect it has on the cow and, in this case, on the embryo.”
Because cows cannot produce methionine, it needs to come from the diet. “But anything I feed to a cow is first going to come in contact with, and be digested by, the bacteria in the rumen,” Cardoso explains. “If I give crystal methionine to a ruminant animal, it gets used up by the bacteria. So we supplement the diet with rumen-protected methionine (RPM), and 85% of that is absorbed in the duodenum and goes into the blood stream. Fifteen percent still gets used by the bacteria, but now the cow has methionine.”
In the study, researchers began supplementing the diets of one group of cows 21 days before they gave birth and continued the supplement through 72 days after birth. The control group did not receive methionine.
Cow were bred beginning 60 days after calving, and embryos were harvested seven days after insemination. The team at Illinois then sent some of the embryos to their colleagues at the University of Florida. Their analysis showed that the pre-implantation embryos from cows that were fed methionine had more lipid droplets inside the embryo. Lipids are molecules that contain hydrocarbons and make up the building blocks of the structure and function of living cells.
“We think the methionine is allowing the embryo to have more lipids, which can be used as energy to help them survive more stress,” Cardoso says. “A study done at the University of Wisconsin showed that cows, treated or untreated, became pregnant at the same rate, but in the cows treated with methionine, embryonic death was much lower. In untreated cows, embryonic death was around 19%, but in treated cows, it dropped to around 6%.”
Cardoso says the research also showed that the embryos of the treated cows were larger, which could also be a result of lipids used as energy.
Note: This story appears in the May 2017 issue of Dairy Herd Management.
