PROBLEM OR OPPORTUNITY DESCRIPTION
Kelp meal is known to contain a wide spectrum of nutritional compounds, including minerals (particularly iodine), polyunsaturated fatty acids, bioactive peptides, and vitamins (1, 2). Kelp meal is also rich in antioxidants with potential animal health benefits and phlorotannins with antimicrobial properties (1, 3, 4).
Our 2013 survey (Northeast-SARE award# G12-049) revealed that 59% of organic dairies in the Northeast feed kelp meal seasonally or year-round (245 total survey respondents). Specifically, our survey showed that 131 or 92% farmers (142 respondents) feed kelp meal to their milking cows, while 116 or 82% (142 respondents) feed it to dry cows and heifers, and 84 or 60% (140 respondents) to calves. Farmers feed kelp meal because (i) it improves body condition and overall animal appearance, (ii) it decreases milk somatic cells count (SCC) and the incidence of pinkeye and reproductive problems, and (iii) it helps to control nuisance flies. Although these anecdotal claims seem to justify the use of kelp meal, there is limited scientific evidence to support its remarkable popularity among Northeastern organic dairies.
Excess iodine intake among children is a growing public health concern (5). We demonstrated that milk iodine increased linearly with feeding incremental amounts (0, 2, 4, or 6 oz/day) of kelp meal to organic dairy cows (2). American children 1 to 3 year-old should consume 2 cups of low-fat or fat-free milk daily as part of a healthy diet (6). This recommendation would result in excess iodine intake of 85, 342, and 448 micrograms daily if drinking milk from cows fed 2, 4, or 6 oz/day of kelp meal, respectively (2), as the tolerable upper intake limit for iodine consumption by 1 to 3 year-old children is 200 micrograms/day (7). Chronic consumption of excess iodine increases the risk of thyroiditis, hyperthyroidism, hypothyroidism, and goiter (B). However, a systematic evaluation of the content of iodine in organic retail milk has not been conducted to date in the US. Also lacking is a comprehensive evaluation of the effects of kelp meal on farm profitability, and markers of milk quality and udder health such as sec through on-farm research and analysis of DHI records. Producing and marketing fresh, high quality milk to improve consumer health are core values of organic dairy agriculture. This project builds on our
previous research to help organic dairies maintain consumer trust by unraveling challenges and opportunities of kelp meal supplementation in the Northeast.
This project will engage Northeastern organic dairy farmers in a research and educational program focused 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 US. Our educational and research components will address the top concerns about kelp meal use including its cost effectiveness and impact on milk SCC, its capacity to increase milk iodine content to levels potentially toxic to humans (2, 5, 8), and the amount of kelp to be fed. We observed no differences in the yields of milk and milk components in organic dairy cows fed incremental amounts of kelp meal (0, 2, 4, or 6 oz) during the winter or 4 oz of kelp during the summer (2, 9). These valuable insights will be integrated in our educational approach.
Kelp meal has been shown to improve health of large and small ruminants (1, 2). However, kelp meal is an expensive mineral-based supplement and most research to date showed no consistent improvements in production with feeding kelp (1, 2, 9). Thus, farmers need research-based information to make educated decisions about the tradeoffs between potential benefits in animal health and no consistent effect on milk production when feeding kelp. Our unpublished results showed that kelp meal reduced milk sec during the grazing season suggesting that kelp may have helped cows to cope better with heat stress and fly pressure resulting in improved milk quality and udder health. However, these results need to be validated with larger number of animals. To solve this limitation, we are proposing to recruit 6 organic dairy farmers who will feed kelp meal to approximately 350 milking cows (700 total) during 2 grazing seasons. On-farm trials wnt be enhanced by assessment of DHI records from 40 participant dairies, thus providing farmers with the information they need to make profitable 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, video, and publications make our research and educational program effective and integrated.
Sixty organic dairy farmers managing 3,500 cows with milk iodine of 1,370 micrograms/L and annual kelp meal costs of $8,891/farm ($0.07/oz of kelp × 58 cows/farm × 365 days) reduce milk iodine to 800 micrograms/L and annual kelp costs to $4,446/farm after fine-tuning kelp supplementation from 6 to 3 oz/cow/day.
Mechanism 1: Improve animal health and farm profitability by fine-tuning kelp meal supplementation.
Mechanism 2: Measure milk iodine concentration through an industry-scale survey of organic retail milk in the Northeast.
We hypothesize that the antimicrobial and antioxidant properties of kelp improve animal health, and that kelp’s iodine is promptly transferred to milk 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.
Mechanism 2: Measure milk iodine concentration through an industry-scale survey of retail samples of organic milk in the Northeast.
Mechanism 1 (Fine-tuning kelp meal supplementation – University Research): A 84-day long feeding trial was conducted at the University of New Hampshire-Organic Dairy Research Farm (UNH-ODRF) from February to May, 2017. Twenty milking cows received diets containing soybean meal or canola meal as the sole protein sources supplemented or not with kelp meal in a factorial replicated 4 x 4 Latin square design (4 treatments and 4 periods) with 14 days for diet adaptation and 7 days for data and sample collection. Dietary treatments were fed as total mixed rations and consisted (dry matter basis) of 55% grass-legume mix baleage, 2.5% liquid molasses, 2% roasted soybean meal, 2% mineral-vitamin premix, and one of the following energy-protein mix: (1) 28.5% ground corn, 10% soybean meal, and 0 oz kelp meal, (2) 28.5% ground corn, 10% soybean meal, and 3 oz kelp meal, (3) 26% ground corn, 12.5% canola meal, and 0 oz kelp meal, and (4) 26% ground corn, 12.5% canola meal, and 3 oz kelp meal. In the 2 diets without kelp meal, ethylenediamine dihydoiodide (EDDI) was fed to keep diets with similar concentrations of iodine. Our rationale is that canola meal contains goitrogenic compounds that reduce the transfer of iodine into milk, whereas soybean meal is deprived of such metabolites. If kelp meal is economical to feed or positively impacts animal health, canola meal may allow farmers to continue feed kelp without producing milk with excess iodine.
Individual intake and milk production were measured daily throughout the trial. Milk samples were collected analyzed for fat, protein, lactose, urea nitrogen (MUN), and somatic cells count. Feeds and TMR were collected in each period and analyzed for dry matter, crude protein, neutral and acid detergent fiber, ash, and minerals. Blood samples were collected and analyzed for thyroid hormones and cortisol.
Mechanism 1 (Fine-tuning kelp meal supplementation – On-farm Research): Approximately 700 milking dairy cows (n = 350/year) from 6 organic farms will be used with half assigned to the control treatment (0 oz kelp), and the second half to 3 oz kelp in a completely randomized block design over 2 grazing seasons assuming a herd size of 58 cows/farm. Farm-specific mineral-vitamin premix will be formulated to meet animal requirements, thus minimizing the risk of confounding effects with feeding control vs. kelp-supplemented diets. The rationale for feeding 3 oz kelp meal is to meet industry recommendations (i.e., 2 to 4 oz/cow/day). Feeds including pasture and milk samples will be collected in June, July, and August of each year and analyzed as reported for the UNH-ODRF trial.
Mechanism 2 (Milk iodine industry-scale survey): Conventional and organic milk were purchased (May-June and September 2017) from grocery stores across the Northeast to determine iodine concentration. In the first set of trips, which were conducted during May-June 2017 to capture the onset of the grazing season, 12 states (i.e., NY, PA, MA, NJ, MD, CT, NH, ME, RI, VT, DE) and DC, 22 cities, and 79 grocery stores were visited with 288 different brands of conventional and organic milk purchased. The second set of trips was done in September 2017 to asses changes in milk iodine concentration during the grazing season; 6 New England states (i.e., MA, CT, NH, ME, RI, VT), 10 cities, and 26 grocery stores were visited with 64 different brands of organic milk bought. To complete this survey, a third set of trips will take place this winter-spring (March 2018) following the schedule done for the May-June 2017 trips for purchasing of conventional and organic milk across the Northeast to capture differences in iodine concentration during different seasons.
Preliminary results of the feeding trial conducted at the UNH-ODRF are reported in Table 1 (see attachment; Table 1). Cows fed diets containing soybean meal and kelp meal produced more milk than those fed canola meal and EDDI. Dry matter intake was increased by 1.2 kg/d in cows fed canola meal compared with those fed soybean meal with no differences between both iodine sources (kelp meal vs. EDDI). Decreased concentrations of milk fat and milk protein in cows fed soybean meal vs. canola meal may be explained by a dilution effect caused by increased milk volume in the former vs. the latter treatment. In contrast, the concentration of MUN was greater with feeding soybean meal vs. canola meal likely because protein from soybean meal is more degraded in the rumen than that from canola meal.
Iodine analyses on milk, blood, urine, and feces will be done this spring and summer. Blood samples for determination of cortisol and thyroid hormones were analyzed, but calculations will be done soon. We are planning to start the on-farm research trials this coming summer. Iodine analyses in milk collected during our Northeast survey will be also analyzed this summer.
We will invite approximately 245 organic dairy farmers who participated in our 2013 survey, and deliver advertisements to about 1,000 farmers in the Northeast through dairy meetings [e.g., Vermont Organic Dairy Producers Conference, Northeast Organic Farming Association (NOFA)-NY Organic Dairy and Field Crop Conference, Northeast Organic Dairy Producers Alliance (NODPA) Annual Field Days and Conference], newsletters, email networks, and farmer-oriented publications and websites (e.g., NODPA News, Graze, On Pasture). Recruitment materials will include background information about the project and an opportunity to sign up as participant by conducting on-farm research or providing access to DHI records. We recently surveyed the Northeastern organic dairies and learned about kelp meal supplementation practices, knowledge level, and educational needs. These insights will be used in our educational program and recruitment approach.
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. The educational program will be based on our previous survey and will proceed through a multi-pronged approach that includes field days, direct-farmer-to-farmer learning, social-media technology transfer, workshops, and development of a decision aid tool (i.e., The Kelp Profitability Calculator). This tool will be based on income over feed costs and sensitivity analyses condensed into an Excel spreadsheet and posted on University and project Facebook webpages for farmer access. We will also recruit 6 farmers who will conduct on-farm feeding trials. University and on-farm research results including the effects of kelp meal supplementation on farm profitability (measured as income over feeds costs) and animal health (measured via reduced milk SCC or incidence of pinkeye and mastitis) will be shared and discussed with participants in workshops and field days. These project activities and knowledge transfer and exchange will help farmers make informed decisions about how to fine-tune kelp supplementation in their family dairies. We will also engage milk processors and the general public in our workshops to educate them about the relationship between kelp meal supplementation and milk iodine, while bring their perspectives to our integrated research and educational program.
1,000 Northeastern organic dairy farmers learn about kelp meal supplementation educational opportunities and receive an online survey to gauge their interest in participating in project activities. (September 2016)
200 farmers return the survey; 150 farmers agree to participate in our educational program; 6 farmers agree to conduct kelp meal feeding trials and become peer-leaders helping disseminate project results. (December 2016)
100 farmers attend 3, 2-hour workshops in New England and Pennsylvania that explain performance target, known benefits and challenges about kelp meal supplementation, ongoing kelp research, on-farm feeding trials, and The Kelp Profitability Calculator; 40 of these farmers agree to provide access to dairy herd improvement
(DHI) records. (January to March 2017)
80 farmers attend field days at University of New Hampshire (UNH) and lead dairies about fine-tuning kelp supplementation and its cost effectiveness. (June 2017)
On-farm feeding trials start in 6 lead dairies to investigate the effects of kelp meal on animal health, milk iodine, and farm profitability. (June to August 2017)
Farmers consult with project team via email, phone calls, and Facebook about the impact of kelp meal on milk quality, animal health, and feed costs. (Ongoing)
90 farmers attend field days at UNH and lead dairies to learn about the results of the kelp meal feeding trials. (June to September 2018)
65 farmers who attended field days at UNH and lead dairies and participated in project surveys and educational program submit kelp meal supplementation strategies for project team to review. (October 2018)
Project team produces a video-clip to educate farmers, milk processors, and the general public about the relationships among kelp meal supplementation, milk iodine, and human health; video is disseminated via project Facebook and UNH websites. (March 2019)
60 farmers fine-tune kelp meal supplementation to reduce feed costs, thus improving the economic sustainability of organic dairying in the region. (June to September 2019).