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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Research Project #434046

Research Project: Unraveling Challenges and Opportunities of Kelp Meal Supplementation in Northeastern Organic Dairies

Location: Pasture Systems & Watershed Management Research

Project Number: 8070-21000-009-07-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Mar 1, 2018
End Date: Oct 31, 2019

This project will engage northeastern organic dairy farmers in a research and educational program centered on fine-tuning kelp meal supplementation for improving farm profitability and animal health, while comprehensively assessing the concentration of iodine in organic retail milk for the first time in the Northeast. Our educational and research components will address the top concerns about kelp meal use including its cost-effectiveness and impact on milk somatic cell count, its capacity to increase milk iodine to potentially toxic levels to humans, and the amount of kelp to be fed. In preliminary work, we observed no differences in the yields of milk and milk components in organic cows fed incremental amounts of kelp meal (0, 2, 4, or 6 oz) during the winter or 4 oz of kelp during the summer. These valuable insights will be integrated in our educational approach. Kelp meal has been shown to improve health of large and small ruminants. However, kelp meal is an expensive mineral-based supplement and most research to date showed no consistent improvements in production with feeding kelp. Thus, farmers need research-based information to help them make educated decisions about the tradeoffs between benefits in animal health and no effect on animal production. Our unpublished results showed that kelp meal reduced milk somatic cell count during the grazing season, suggesting that kelp may have helped cows cope better with heat stress and fly pressure resulting in improved milk quality and likely udder health. However, these results need to be validated with a larger number of animals. To solve this limitation, we are proposing to recruit 6 organic dairy farmers who will feed kelp meal to approximately 348 milking cows during 2 grazing seasons. On-farm trials will be enhanced by assessment of Dairy Herd Improvement (DHI) records of 40 participant dairies, thus providing farmers with the information they need to make cost-effectiveness decisions about kelp meal. Our laboratory was recently awarded a Northeast-SARE grant (#G15-040) to investigate the effects of kelp meal on rumen microbial communities, while educating farmers about kelp supplementation by developing the Kelp Meal Feeding Guide. This guide will be integrated in our current research and educational program to streamline federal resources. We are confident that our University and on-farm feeding trials coupled with workshops, field days, project Facebook page, short video-clips, and publications make our research and educational products effective and integrated.

We hypothesize that the antimicrobial and antioxidant properties of kelp meal could improve animal health. We also hypothesize that iodine present in kelp meal is highly bioavailable resulting in milk iodine concentrations potentially toxic to children. These hypotheses will be tested by 2 mechanisms: Mechanism 1: Improve animal health and farm profitability by fine-tuning kelp meal supplementation. The University study will be conducted during the winter (year 1) at the University of New Hampshire-Organic Dairy Research Farm (UNH-ODRF) with cows receiving either soybean meal or canola meal as the sole protein supplements with or without kelp meal. The second set of studies will be conducted during the summer (years 1 and 2) in 6 commercial organic dairies with cows split into 2 treatments: 1) control (0 oz kelp meal) or 2) 4 oz kelp meal. Twenty milking Jersey dairy cows housed at the UNH-ODRF will be used in a factorial replicated 4 × 4 Latin square design (4 treatments, 4 periods) with 14 days for diet adaptation and 7 days for data and sample collection or 84 days total (4, 21-day periods). Approximately 696 milking dairy cows (n = 348/year) from 6 organic farms will be used with half assigned to the control treatment, and the second half to 4 oz kelp meal in a completely randomized block design over 2 grazing seasons assuming a herd size of 58 cows/farm. For the UNH-ODRF study, individual intake and milk production will be measured daily throughout the trial. Feeds and total mixed ration (TMR) will be collected in each period and analyzed for nutrient content. Individual milk, blood, urine, and fecal samples will be collected for 3 consecutive days in each period and analyzed for iodine. Milk will also be analyzed for somatic cell count, protein, fat, and urea nitrogen. For the on-farm studies, pasture and grain will be collected 3 times during the grazing season, pooled by treatment, and analyzed as reported for the UNH-ODRF trial. Milk samples will be collected and analyzed similar to the UNH study. Mechanism 2: Measure milk iodine concentration through an industry-scale survey of retail samples of organic milk in the Northeast. Whole fluid organically-labeled milk samples will be purchased 3 times/yr in the first year from stores across the 11 northeastern states and analyzed for iodine content. This project is guided by farmers’ insights about kelp meal supplementation in response to our 2013 survey. Farmers will continue their contribution by conducting on-farm research and participating in outreach activities. Educational approach We will invite approximately 227 organic dairy farmers who participated in our 2013 survey and deliver advertisements to about 1,000 farmers in the Northeast through dairy meetings. Recruitment materials will include background information about the project and an opportunity to sign up as a participant by conducting on-farm research or providing access to DHI records. This project combines a comprehensive educational and research program to fine-tune kelp meal supplementation for improving farm profitability and animal health, while surveying the iodine content of organic retail milk.