In 1978, Point Reyes National Seashore (PRNS) reintroduced Tule elk, which is the only National Park unit where Tule elk can be found. The State of California provided the initial elk Tomales Point in PRNS. State wildlife biologists were members of the team that managed the re-introduction and subsequent monitoring. Tomales Point is a fenced area; however, one goal of the 1998 Tule Elk Management Plan was to establish a free-ranging Tule elk herd to the seashore. That plan stated the forage is unaffected by the number of elk occupying the range and elk do not have a strictly negative effect on vegetation. However, in 1999, PRNS moved a free-range herd of 28 elk from Tomales Point to the wilderness area near Limantour Beach. Within weeks, a few elk unexpectedly migrated to ranches in the designated pastoral zone. Currently, Drakes Beach (D Ranch) herd includes approximately 150 Tule elk. Designated pastoral zone, where livestock and dairy producer operations may be permitted, are charged an annual lease based on the lands’ carrying capacity. In 2004, beef and dairy producers began to express concerns about the impacts elk were having on forage, organic certifications, and overall economic viability. In 2014, PRNS initiated the Ranch Comprehensive Management Plan to assess growing concerns of beef and dairy producers related to the free-ranging elk impacts to the pastoral zone. PRNS staff have not implemented any of their 1998 control methods, and are currently only hazing elk away from permitted operations. The efficacy of hazing elk away from the pastoral zone is in question; and PRNS has stated an inability to do more control due to recent litigation. Efforts should focus on non-lethal effective elk management options, such as contraception, which abide by current litigation constraints while mitigating producer burden and concern. The objective of this paper is to develop a case for potential multi-species management (i.e., elk plus cattle) at PRNS while protecting its historical, biodiversity, and economic value.

In 2019, California accounted for approximately 40% of organic products in the US, and dairy products and milk were the top organic commodity in the state. The objective of this study was to describe organic dairy cattle farmers' management practices and perceptions of diseases in California. A survey inquiring about farm history and demographics, animal diseases, parasite problems, housing and pasture management, and organic education, was mailed to 160 organic dairy farms, of which 36 (22.5%) responded. Among respondents, the majority (83.9%) were located in Northern California; median farm size was 310 cows, and the dominant breed was Holstein (60.0%). Respondents were more likely to report mastitis in cows (45.2%), pinkeye in heifers (31.3%), and digestive problems in calves (47.0%), as issues affecting their stock "often" or "almost always" in the last 12 months. Although most farmers vaccinated their cattle against Bovine Viral Diarrhea (86.1%) and Escherichia coli mastitis (80.6%), they still described that these diseases frequently impacted their animals. Over half of the farmers did not perceive gastrointestinal parasites or biting flies to be a problem and did not observe signs of lice and mites. According to the results, the management of disease in all age classes is a concern; options and efficacies of alternative therapeutic methods, as well as preventive measures for organic dairies need to be further explored.

Background

This study describes the occurrence of antimicrobial resistance (AMR) in commensal Escherichia coli and Enterococcus/Streptococcus spp. (ES) isolated from fecal samples of dairy cows and assesses the variation of AMR profiles across regions and seasons following the implementation of the Food and Agricultural Code (FAC) Sections 14400-14408 (formerly known as Senate Bill, SB 27) in California (CA).

Methods

The study was conducted on ten dairies distributed across CA's three milk sheds: Northern California (NCA), Northern San Joaquin Valley (NSJV), and the Greater Southern California (GSCA). On each study dairy, individual fecal samples were collected from two cohorts of lactating dairy cows during the fall/winter 2018 and spring/summer 2019 seasons. Each cohort comprised of 12 cows per dairy. The fecal samples were collected at enrollment before calving (close-up stage) and then monthly thereafter for four consecutive time points up to 120 days in milk. A total of 2,171 E. coli and 2,158 ES isolates were tested for antimicrobial susceptibility using the broth microdilution method against a select panel of antimicrobials.

Results

The E. coli isolates showed high resistance to florfenicol (83.31% ± 0.80) and sulphadimethoxine (32.45%), while resistance to ampicillin (1.10% ± 0.21), ceftiofur (1.93% ± 0.29), danofloxacin (4.01% ± 0.42), enrofloxacin (3.31% ± 0.38), gentamicin (0.32% ± 0.12) and neomycin (1.61% ± 0.27) had low resistance proportions. The ES isolates were highly resistant to tildipirosin (50.18% ± 1.10), tilmicosin (48% ± 1.10), tiamulin (42%) and florfenicol (46% ± 1.10), but were minimally resistant to ampicillin (0.23%) and penicillin (0.20%). Multidrug resistance (MDR) (resistance to at least 1 drug in ≥3 antimicrobial classes) was observed in 14.14% of E. coli isolates and 39% of ES isolates. Escherichia coli isolates recovered during winter showed higher MDR prevalence compared to summer isolates (20.33% vs. 8.04%). A higher prevalence of MDR was observed in NSJV (17.29%) and GSCA (15.34%) compared with NCA (10.10%).

Conclusions

Our findings showed high rates of AMR to several drugs that are not labeled for use in lactating dairy cattle 20 months of age or older. Conversely, very low resistance was observed for drugs labeled for use in adult dairy cows, such as cephalosporins and penicillin. Overall, our findings identified important differences in AMR by antimicrobial class, region and season.