Effects of an intrauterine carbon matrix with high adsorption capacity, administered to postpartum dairy cows, on antibiotic use and fertility in a commercial farm. Auswirkungen einer intrauterinen Kohlenstoffmatrix mit hoher Adsorptionskapazität auf den Antibiotikaeinsatz und die Fruchtbarkeit bei postpartalen Milchkühen in einem kommerziellen Betrieb

Dairy cows are susceptible to postpartum metritis. As antibiotic use in food-producing animals must be reduced to limit resistance, alternative treatments are needed. Ultrapure carbon sorbent matrix proved to retain bacteria and toxins in media and in women with uterine infections. This study evaluated the effect of a carbon matrix administered in postpartum dairy cows on: (i) antibiotic use due to uterine infection and (ii) fertility. A total of 120 Holstein-Friesian cows were included and randomly assigned to carbon (Carb, N = 50) or control (Ctrl, N = 70) group. Treatment consisted of the insertion, 24-48 h after calving, through the cervix and under aseptic condition, of two cellulose boluses each containing 19.8±0.2 g of microporous Carb spheres (300 m2/g of adsorbing surface, 0.5-1.0 mm diameter). One case of puerperal metritis was observed in Ctrl group. Treatment did not significantly affect the risk of receiving antibiotic due to metritis diagnosis, nor fertility, in primiparous cows. In multiparous cows, increased odds of receiving antibiotic in Carb (OR = 5.50, p = 0.05) was observed, while open days were reduced (157.78 ±12.51 in Ctrl vs. 117.92±11.83 in Carb, p < 0.05). The general linear model excluded the effect of the interaction between treatment and antibiotic on fertility (p = 0.316). Although not optimal, these results suggested that intrauterine microporous matrices may help restore the uterine environment after calving and improve clearance, probably due to initial stimulation of inflammatory response; future studies should aim to mitigate exudate characteristics, which probably influenced the veterinarian decision to administer antibiotic treatment.