Evaluating a Non-antibiotic Treatment of Mastitis in Organic Dairy Cows

View the project final report

Commodities

• Animals: bovine
• Animal Products: dairy

Practices

• Animal Production: animal protection and health
• Production Systems: organic agriculture

Mastitis is an inflammation of the mammary gland typically caused by bacterial infection and is a significant animal health and economic issue for the dairy industry. It is estimated to cost the US dairy industry over $2 billion per year in reduced milk production, discarded milk, early cow culling, veterinary services, and treatment costs (Hogeveen et al., 2011). In addition to the economic impacts, mastitis causes pain and suffering in affected cows, leading to suboptimum animal welfare (Peterson-Wolfe et al., 2018), all of which contribute to reduced sustainability in the dairy farms.

Traditionally, antibiotic therapy has been the primary treatment for mastitis. However, there are concerns about the overuse of antibiotics contributing to antibiotic resistance in bacteria. The development of antibiotic-resistant bacteria is a threat to both animal and human health. In addition, USDA organic-certified dairy producers face further challenges treating mastitis because of the restricted use of antibiotics in these operations (Reugg, 2009). There is a need for effective alternative therapies to treat mastitis in dairy cows while reducing reliance on antibiotics.

The proposed solution is to evaluate the efficacy and cost-effectiveness of using AHV compounds as an alternative to antibiotics for treating mastitis in dairy cattle. This will be accomplished through a controlled field trial at a commercial USDA certified organic dairy farm, comparing udder health, milk quality, dairy cow performance, and economics between an AHV treatment group and non-treated control group.

This study evaluated the impact of plant-derived bolus supplementation in organic dairy cows with subclinical mastitis. The bolus supplementation demonstrated its effectiveness in reducing somatic cell counts, particularly in late lactation cows and in cows infected with contagious pathogens. Additionally, supplementation increased milk yield and water intake in cows infected with contagious pathogens. These findings suggest that the plant-based antibiofilm bolus has the potential to support cows with subclinical mastitis in organic dairy farms.

The objective of this study was to evaluate the efficacy of a plant derived rumen bolus supplement for the treatment of subclinical mastitis in dairy cows managed under certified organic management conditions. This study included naturally occurring cases of subclinical mastitis, defined as somatic cell count (SCC) >200,000 cells/mL, in 218 quarters from

218 multiparous lactating Holstein cows in a commercial organic dairy farm in central Texas were enrolled in the study. One affected quarter per cow was sampled and included in the analysis. Cows were assigned randomly to treatment (TRT; n = 104) and control (CON; n = 114) groups. The TRT group received plant-derived commercial bolus supplementation regimen (AHV Rapid^® and AHV Extend^®; AHV, CA, USA) orally, while CON cows were subject to the regular farm health protocol. Quarter-level milk samples were collected on day 0 (before-treatment) and day 30 (after-treatment) for SCC and bacterial culture. Cow level daily milk yield (kg/d), daily rumination time (min/d), and daily water intake (L/d) were evaluated from 7 days before to 30 days after treatment using Afimilk® and Smaxtec® systems available at the farm. Statistical analyses were performed in SAS using PROC MIXED for continuous outcome variables and PROC GLIMMIX for the binary outcome variable (the bacteriological cure). Our results indicate that TRT had significantly lower linear scores of SCC (LSSCC) than the CON group at 30 d after treatment (5.8 ± 0.17 vs 6.8 ± 0.16), particularly in late lactation cows (6.4 ± 0.27 vs. 7.3 ± 0.21) and in cows infected with contagious pathogens (5.7 ± 0.19 vs 6.9 ± 0.18). Bacterial growth (logcfu) was not statistically different between groups at 30 d after-treatment. Treatment cows infected with contagious pathogens had significantly greater daily milk yield and water intake compared to CON (21.5 ± 0.55 vs. 20.0 ± 0.52 kg/d, and 94.6 ± 1.06 vs. 91.1 ± 0.97 L/d, respectively). We conclude that plant-derived bolus supplementation has the potential to improve udder health in cows with subclinical mastitis in organic dairy farms, particularly against contagious pathogens.

The expected key project outcomes are:
- Determination of AHV regimen efficacy based on somatic cell count reduction, bacterial inhibition, and clinical mastitis rate compared to non-treated cows
- Economic analysis indicating potential or lack of return on investment for AHV therapy under real-world conditions
- Documentation of impacts on milk production, cow health, and retention to provide a comprehensive assessment of AHV therapy
- Identification of any practical limitations or areas needing refinement for on-farm AHV use
- Scientifically-validated evidence to support or reject further research and adoption of AHV compounds as a non-antibiotic mastitis treatment