Using chitosan microparticles to treat metritis in lactating dairy cows

Abstract

The main objective of this study was to evaluate the efficacy of intrauterine administration of chitosan microparticles (CM) in curing metritis in dairy cows. A secondary objective was to evaluate the effects of metritis treatments on milk yield, survival, and reproductive performance. Cows with a fetid, watery, red-brownish vaginal discharge were diagnosed with metritis. Holstein cows (n = 826) with metritis from 3 dairies located in northern Florida were blocked by parity (primiparous or multiparous) and, within each block, randomly assigned to one of 3 treatments: CM (n = 276) = intrauterine infusion of 24 g of CM dissolved in 40 mL of sterile distilled water at the time of metritis diagnosis (d 0), 2 (d 2), and 4 (d 4) d later; ceftiofur (CEF; n = 275) = subcutaneous injection of 6.6 mg/ kg ceftiofur crystalline-free acid in the base of the ear at d 0 and d 3; Control (CON; n = 275) = no treatment applied at metritis diagnosis. All groups could receive escape therapy if condition worsened. Cure was considered when vaginal discharge became mucoid and not fetid. A group of nonmetritic (NMET; n = 2,436) cows was used for comparison. Data were analyzed by generalized linear mixed and Cox's proportional hazard models. Cows in CM and CON had lesser risk of metritis cure on d 12 than cows in CEF (58.6 ± 5.0 vs. 61.9 ± 4.9% vs. 77.9 ± 3.9, respectively). The proportion of cows culled within 60 days in milk (DIM) was greater for cows in CM than for cows in CEF and CON (21.5 ± 2.7 vs. 9.7 ± 1.9 vs. 11.3 ± 2.0%, respectively). Treatment did not affect rectal temperature or plasma nonesterified fatty acids, β-hydroxybutyrate, and haptoglobin concentrations. Milk yield in the first 60 DIM differed for all treatments, and it was lowest for CM (35.8 ± 0.3 kg/d), followed by CON (36.8 ± 0.3 kg/d) and CEF (37.9 ± 0.3 kg/d). The hazard of pregnancy up to 300 DIM was lesser for CM than CEF (hazard ratio = 0.62; 95% CI: 0.50-0.76), for CM than CON (hazard ratio = 0.77; 95% CI: 0.62-0.95) and for CON than CEF (hazard ratio = 0.80; 95% CI: 0.65-0.99). Culling was greater, and milk yield and fertility were lesser for CEF than NMET. In summary, CM did not improve the cure of metritis, and was detrimental to milk yield, survival, and fertility compared with CON. In contrast, CEF increased the cure of metritis, milk yield, and fertility compared with CM and CON. Finally, the negative effects of metritis on milk yield culling and fertility could not be completely reversed by CEF.

Effect of Chitosan Microparticles on the Uterine Microbiome of Dairy Cows with Metritis

“…Because chitosan is safe in humans, we expected that it would be safe in animals. Nonetheless, in our larger study, we observed that chitosan microparticle treatment resulted in increased culling from the herd (i.e., loss through sale or death) in the first 60 days postpartum (16). When we looked at the reasons for culling, chitosan microparticle treatment resulted in a greater proportion of cows being culled because of pelvic inflammation and peritonitis.…”

Microflora in the Reproductive Tract of Cattle: A Review

“…Meta-analysis studies have also depicted that commonly used ceftiofur antibiotics have a beneficial effect in the treatment of bovine metritis [115]. Similarly, Oliveira and colleagues [116] recently showed that treating cows for metritis with ceftiofur increased cure rates but did not decrease culling in the first 60 d postpartum, but instead, it increased milk yield and fertility up to 300 d postpartum.…”

“…On the other hand, there have also been reports of varying degrees of effectiveness of alternative drugs or agents for the prevention and treatment of metritis. These include probiotics usage [124], bacteriophages [79], non-steroidal anti-inflammatory drugs [125], botanical essential oils [126], Sheng Hua Tang [127], and chitosan microparticles (CMs) [116,128,129]. For example, it has been demonstrated that the intrauterine administration of CMs can be a viable alternative to traditional antibiotics for the prevention of metritis [128] as well as their effectiveness against the treatment of bacterial infections in animals [130].…”

Recent advances and future directions for uterine diseases diagnosis, pathogenesis, and management in dairy cows

“…But differences in the rate of metritis were not present at day 4 (11.5% vs. 17.3%), 10 (61.5% vs. 73.1%), and 14 postpartum (63.5% vs. 73.1%). A recent study enrolling 826 cows with metritis from three dairies located in northern Florida investigated the effects of intrauterine infusion of 24 g of CM administered at metritis diagnosis, and day two and four after diagnosis in comparison with ceftiofur crystalline-free acid and control untreated with cows with metritis (Oliveira et al, 2020). Surprisingly, treatment with CM not only failed to improve the cure for metritis, but it also impaired milk yield, survival, and fertility when compared control untreated with cows with metritis (Oliveira et al, 2020).…”

“…Therefore, the promising prospects of CM are not an option to consider for the treatment of metritis. The authors speculated that the negative impacts of CM might be at least in part due to uterine related inflammatory conditions, such as metritis, pelvic inflammation, peritonitis, and mass in the pelvis (Oliveira et al, 2020).…”