“Increasing intestinal lysine availability during transition improved several markers of uterine health”Phil Cardoso, associate professor of animal science at the University of Illinois at Urbana-Champaign, found the team.
Published in a research journal Journal of Dairy Science..
Feeding rumen-protected methionine as a non-essential amino acid source has been shown to improve reproductive performance in lactating cows, but the effects of rumen-protected lysine (RPL) feeding during the peripartum period on reproductive performance have not been well studied. .
The authors said they sought to determine the effects of RPL feeding prenatally, postpartum, or both on follicular dynamics, uterine health, and endometrial mRNA gene expression.
Uterine infection is common in the postpartum period and can have a detrimental effect on ovarian and uterine function, the authors note.
Improving immune function and reducing the risk of inflammatory diseases of the reproductive system may lead to better reproductive outcomes, they said.
“Uterine infections can also be detrimental to ovarian regeneration because inflammation can affect the growth and function of the first dominant follicle (DF) through the neuroendocrine mechanisms of inhibiting hypothalamic GnRH release and pituitary LH secretion. .
“Furthermore, there is evidence of localized inflammatory mediators directly acting on the ovary by suppressing estradiol secretion and reducing follicular growth rate, resulting from bacterial contamination of the uterus after parturition. .
“Furthermore, chronic inflammation may result in disruption of uterine repair processes in the early postpartum period, potentially altering uterine functional capacity and future reproductive performance..
“Therefore, ovarian regeneration may benefit from modulation of the uterine immune response through nutritional strategies.”.
However, the effects of RPL feeding on reproductive tract physiology and immune response are still lacking, the paper reads.
The team added a rumen-protected lysine product at a rate of 0.54% to the total mixed ration (TMR) for 28 days before calving. After birth, lysine supplementation was added at 0.4% for 28 days.
Cows received lysine supplementation before or after calving, or both, while a control group did not consume any supplemental lysine at any time period.
“We found that genes associated with the production of inflammatory proteins in the uterus were reduced by rumen-protected lysine, particularly in cows consuming the amino acid before and after calving. And genes involved in keeping the uterus clean were more active. Overall, our results show that these cows have less inflammation, which means they can use less energy to defend against infection.”Cardoso commented. “It’s just more efficient.”.
In addition to characterizing gene expression in the uterus, the team looked for evidence of metritis, a uterine infection that affects 30% of US dairy cows after calving. Although the general inflammatory state of the uterus improved with lysine supplementation, the researchers found no statistical difference in metritis between cows consuming and not consuming lysine.
“Metritis is a clinical manifestation of inflammation of the uterus. For this to manifest, a greater challenge than the environment is required. Perhaps our farm does not show real stress in this regard. We also found a difference in the subclinical form. subclinical endometritis. The number of inflammatory cells (PMN) in the uterus calculated, cows receiving rumen-protected lysine had lower cell counts, indicating less inflammation.said the expert.
It has no effect on ovulation .
The authors said they also tracked the first postpartum follicular growth cycle in the ovaries. Lysine did not affect the time to first ovulation (average of 18 days in milk for all groups) and follicle diameter at ovulation.
Cardoso, who conducts research and provides outreach programs in dairy nutrition and reproduction, said he was neither surprised nor disappointed that lysine did not affect ovulation. He added that the health of the uterus immediately after calving is more important than producers think.
“When farmers are asked how they rate reproductive progress and productivity, the answer is always pregnancy. Usually, farmers breed cows about 60-70 days after calving, but if they fail, it’s because of things like metritis or subclinical endometritis. This study shows that rumen-protected lysine can set your cow up for success right after parturition so she can have a favorable pregnancy later.”.
Cardoso’s findings related to lysine with a previous study evaluating rumen-protected methionine, another limiting amino acid, in lactating cows. It showed genes affected by methionine related to inflammation and estrogen production and increased embryo survival.