Enhancing reproductive success of mycotoxin-challenged cows

Larry Roth, Ph.D., PAS - Vice President of Nutrition, Agrarian Solutions and Caroline Knoblock, MSc, - Director of Nutrition

Enhancing reproductive success may be one of the most crucial factors for improving dairy profitability. A recent third-party study with over 920 cows, proved supplementing DTX™ Concentrate to early-lactation Holstein cows challenged by mycotoxins improved the first-service pregnancy/service by 28.6% for artificial insemination (A.I.) and 15.6% for embryo transfer (ET) services at first pregnancy check (28-34 d post-service). Why did DTX Concentrate supplementation improve reproductive success?

The mycotoxin TMR contamination levels (approximately 1.56 ppm DON and 147 ppb ZEA) experienced by cows in this study were not excessive. Even moderate levels of mycotoxins disrupt the intestinal lining, causing reduced nutrient absorption and increased nutrient demand from the subsequent immune response. Improving nutrient absorption and efficiency enables the cow to use nutrients for productive purposes that can result in reproductive success.

Researchers have repeatedly demonstrated that achieving less severe negative energy balance post-fresh significantly enhances reproductive success. Further, glucose is a key carbon source for rapidly developing cells, such as follicles, and a glucose shortage due to nutrient re-partitioning and deprivation due to mycotoxin exposure would also negatively impact first service conception rate. In addition, glucose and other nutrients are necessary for the rapidly developing egg after conception to avoid early-pregnancy loss.

The enhanced pregnancy success per service observed in cows supplemented with DTX in the recent study could be attributed to heightened mycotoxin defense, which facilitated better nutrient absorption, efficient nutrient allocation, and increased availability of glucose for the rapid development of follicles. Consequently, leading to a higher number of cows conceiving and maintaining pregnancy.

The cow prioritizes nutrient allocation to maintenance, growth (depending upon age), milk production, and lastly reproduction. Nutrient shortages and re-partitioning due to mycotoxin exposure, even at medium risk levels, could have profound negative reproductive effects due to the cow’s hierarchy of nutrient utilization.