Research Review: 2024 ADSA meeting

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

The 2024 American Dairy Science Association (ADSA) Annual Meeting was held June 16-19, 2024 in West Palm Beach, Fla. In addition to the two Agrarian Solutions® posters on DTX™ research, one mycotoxin-related abstract supported Kihal et al. (2022) and a separate poster indicated the impact of mycotoxins on ruminal microflora.

Oyebade et al (2024) fed a TMR contaminated with DON (4.32 ppm) and ZEA (575 ppb) for 21 d to nine heifers and then added AB20® (HSCAS) at 0.5% of the diet for 5 d. Urine samples were assayed on d 0 (pre-feeding of AB20) and then 5 d later for DON and its derivative (DOM-1), as well as ZEA and its derivatives alpha-ZOL and beta-ZOL. All heifers tested positive for DON and DOM-1 on d 0 and 5; further, urinary DON concentration increased (P=0.008) from 72.5 to 461 ng/mg creatinine, and DOM-1 increased (P=0.005) 242.4 to 1,982 ng/mg creatinine from d 0 to d 5. On d 0, alpha-ZOL and beta-ZOL were not detected in the urine, but eight of the heifers were positive for ZEA. On d 5, only one heifer tested positive for ZEA, two heifers tested positive for alpha-ZOL and beta-ZOL. The beta-ZOL is a toxic metabolite that harms cellular gene expression. The authors concluded that AB20 could inhibit ZEA absorption but had no effect on DON absorption. These results support the reporting of Kihal et al. (2022) that HSCAS had binding capacities of 11% for DON and 52% for ZEA.

Praisler et al. (2024) evaluated the effect of AF (600ppb) and ZEA (1,000 ppb) on protozoa volume in ruminal fluid during in vitro fermentation. While mycotoxins did not affect (P>0.10) the number of live protozoa after 6 hr of fermentation, the Isotrichidae protozoa volume decreased (P<0.01) by 14% and did not affect (P>0.10) entodiniomorphids. The authors concluded that mycotoxins could have a negative impact on certain protozoa with consequences on whole ruminal fermentation, especially fiber utilization. The long-term consequences of mycotoxins at more realistic levels on ruminal protozoa health merits further research.

Two posters presented by Roth et al. (2024a and 2024b) attracted great attention and conversation about DTX as a novel probiotic for mycotoxin protection. Researchers and nutritionists are looking for mycotoxin protection alternatives to binders, and the presented research supported DTX’s abilities to improve milk production and reproduction under the study conditions.