Economic and livestock health impacts of birds on dairies: Evidence from a survey of Washington dairy operators

The survey described in this research paper aimed to investigate the economic and health impacts of birds on dairies. Birds are common pests on dairies, consuming and contaminating feed intended for cattle. As a result, dairy operators experience increased feed costs and increased pathogen and disease risk. We surveyed dairy operators attending the 2017 Washington Dairy Conference to examine the impact of birds on dairies in Washington State. Dairy operators reported feed losses valued at $55 per cow resulting in annual losses totaling$5.5 million in the Western region of the state and $9.2 million in the Eastern region of the state. Shooting was the most commonly used bird management method and European starlings (Sternus vulgaris) were the most frequently implicated species statewide. Bird abundance greater than 10,000 birds per day was associated with larger herd size and with self-reported presence of Johne’s disease and Salmonella

Bovine-avian interactions on dairies wild bird influence on pathogen prevalence, cow nutrition, and cow behavior

Wild birds cause significant damages to dairy farms through the transmission of bacteria to cattle, as well as the consumption of cattle feed. It is also possible that wild birds affect the feeding behaviors of dairy cattle. The objectives of this study were to: 1) determine the prevalence of bacteria in wild bird fecal matter; 2) determine the quantity of bacteria in bird feces; 3) observe behavioral interactions between wild birds and dairy cattle; and 4) determine the nutrients lost due to bird consumption. Five farms were visited once in the winter of 2017-2018 to collect bird fecal samples, cattle feed samples, and to record interactions between birds and cattle. Bird fecal samples were collected at the feed bunks of 14 pens and 1 commodity shed, placed into screw-top test tubes, and were analyzed for E. coli, Campylobacter, and Salmonella. Differences in the presence of pathogens and the quantity of pathogens among locations were determined using a log linear model in SAS. Fresh and bird-depleted feed samples were collected by hand and analyzed for dry matter, total digestible nutrients (TDN), protein, crude fiber, ash, fat, and net energy. Linear regressions were conducted in order to determine the relationship between the feed components and bird density. Intra- and inter-specific aggressive and aversive behaviors, proportion of head-gates used, number of cows eating, and the number of birds at the feed bunk were recorded using on-farm cameras. Differences between locations were analyzed using PROC GENMOD in SAS. E. coli was isolated in 34/88 of bird fecal samples, C. jejuni was isolated in one sample, and Salmonella was not recovered in any of the samples. There was no difference in the presence of E. coli among locations (P = 0.14) nor were there differences in the quantity of E. coli among locations (P =0.12). There was no significant difference between bird density and changes in feed components. Finally, bird density differed among locations (P < 0.0001) and the proportion of head gates used differed among locations (P < 0.0001). Understanding where birds prefer to feed on dairies, may improve current bird deterrent strategies

Understanding and Preventing Bird Damage on Dairies

Wild birds cause significant damage to dairy farms through the consumption and spoilage of cattle feed. A survey of Washington State dairy farmers revealed approximately $14 million in bird damage losses for the Washington State dairy industry, annually. Furthermore, farms that reported the presence of more than 10,000 birds per day were more likely to report the presence of Salmonella spp. or Johne’s disease (caused by Mycobacterium avium subsp. paratuberculosis). Over the course of three years, we assessed the impact of bird populations on the presence of bacteria in bird feces and the nutritional composition of cattle feed. Five dairies were enrolled into the study and visited to collect bird fecal samples and cattle feed samples. Several pens were monitored on each dairy. Bird fecal samples were analyzed for three bacterial populations. Fresh and bird-depleted feed samples were analyzed for dry matter, total digestible nutrients, protein, crude fiber, ash, fat, and net energy. The prevalence of bacterial populations in bird fecal samples did not differ among farms, but Campylobacter jejuni, a bacterial strain known for causing abortions in cattle, was discovered in one location. The number of birds observed at the feed bunk and the percentage of nutritional loss in cattle feed differed among pens. Understanding where birds prefer to feed on dairies may improve the effectiveness of bird deterrent management techniques. A variety of bird deterrent methods are available for dairy farmers but, at best, the most commonly used methods were considered only “somewhat effective” by farmers. The use of more sustainable methods, such as attracting native birds of prey to dairies, may be beneficial to dairy cattle well-being as well as dairy farmer economic sustainability