2015 Annual Report for GNE15-101
Research and educational approaches to guide dairy farmer decisions about kelp meal supplementation in the Northeast
Summary
The purpose of this project is to evaluate the effect of kelp meal supplementation on ruminal microbiota, iodine metabolism, diet digestibility, performance (e.g., milk yield and components), and markers of animal health (e.g., serum cortisol) in lactating dairy cows. The study was conducted at the University of New Hampshire Fairchild Dairy Teaching and Research Center from June to November, 2015. Five ruminally-cannulated lactating Jerseys cows were randomly assigned to one of 5 dietary treatments: 0 oz of kelp meal (negative control), 2, 4, or 6 oz of kelp meal, or 300 mg of monensin (positive control) in a 5 x 5 Latin square design. Treatments were administered daily, placed directly in the rumen. Cows were fed a total mixed ration (TMR) with a 65:35 forage to concentrate ratio. Each experimental period lasted 28 days with 21 days for diet adaptation and 7 days for data and sample collection. Feeds, refusals, ruminal fluid, milk, blood, urine, and feces were collected. Preliminary results showed no effect of incremental amounts of kelp meal on animal performance and milk components, but monensin significantly increased the concentrations of milk fat and milk protein. Cows fed monesin also showed higher plasma glucose concentration than cows fed kelp meal.
Objectives/Performance Targets
The original objectives in the plan of work remain the same.
Objective 1: Identify and quantify ruminal microorganisms in response to incremental amounts of kelp meal fed to lactating dairy cows. This objective has been partially completed. Ruminal samples collected are being analyzed for microbial quantification.
Objective 2: Develop a Kelp Feeding Guide to educate dairy farmers about kelp meal supplementation. This guide will include the following general topics, 1) Feeding practices 2) Milk quality (e.g., fat, protein, milk urea nitrogen, fatty acids, somatic cells count); 3) Animal production (e.g., milk yield, dry matter intake, nutrient digestibility); 4) Economics (e.g., income over feed costs); 5) Animal health (e.g., immune response); and 6) Public health (e.g., milk iodine concentration).
Accomplishments/Milestones
Objective 1:
The experiment was completed on November, 2015. Five ruminally-cannulated lactating Jerseys cows were randomly assigned to one of 5 dietary treatments: 0 oz of kelp meal (negative control), 2, 4, or 6 oz of kelp meal, or 300 mg of monensin (positive control) in a 5 x 5 Latin square design. Laboratory and statistical analyses are being conducted (See Tables 1 and 2, Preliminary results). Samples of feeds, refusals, and feces were processed and chemically analyzed for dry matter, crude protein, neutral detergent fiber, acid detergent fiber, lignin, macrominerals, and microminerals. Milk samples were analyzed for components [i.e., fat, protein, lactose, somatic cells count (SCC), milk urea nitrogen (MUN), and total solids]. Plasma and serum were analyzed for insulin, nonesterified fatty acids (NEFA), thyroid hormones (T3, T4), cortisol, glucose, plasma urea nitrogen, aspartate amino-transferase, albumin, and beta-hydroxybutyric acid (BHBA). Averages for performance and milk component variables across the 5 treatments were (Table 1): dry matter intake (19.7 kg/d), milk yield (20.4 kg/d), milk fat (4.7 %), milk protein (3.6 %), milk lactose (4.7 %), and MUN (10.4 mg/dL). Treatments (least square means comparison) did not impact dry matter intake, and yields of milk and milk components. On the other hand, concentrations of milk fat, milk protein, and MUN (11.2 mg/dL) were greatest in cows fed monensin (Table 1). Health markers analyzed (e.g., NEFA, BHBA, cortisol) were not affected by treatments (Table 2). Cows fed monensin had higher plasma glucose concentration (57.6 mg/dL) than cows fed kelp meal. Laboratory analysis for nutrient digestibility, creatinine, allantoin, uric acid, and urea nitrogen excretion are ongoing. Samples of ruminal fluid and serum were sent to commercial laboratories for volatile fatty acid and iodine analysis. Further statistical analysis will be performed and quadratic and linear effects will be tested in a mixed model to evaluate the effects of kelp meal on different variables.
Objective 2:
Literature search in database (e.g. AGRICOLA, Scopus, Web of Science, and Google Scholar) has started to obtain initial research data (related to the objective 2) on kelp meal supplementation. Due to their leadership in animal science Journal of Animal Science and Journal of Dairy Science are being specifically searched.
Impacts and Contributions/Outcomes
Previous research in our laboratory (Antaya et al., 2015) showed no effect of incremental amounts of kelp meal on milk yield and milk components in lactating Jersey cows during the winter season. Despite this lack of effect on milk yield and milk components, kelp meal reduced the concentrations of plasma NEFA and serum cortisol (Antaya et al., 2015). Kelp meal contains microminerals such as Cu, Zn, and Fe which are known to participate in animal’s antioxidant responses (Allen et al., 2001), and may help explain the positive impacts of kelp meal on animal health. We will use our results and literature data to generate the Kelp Meal Feeding Guide, thus helping organic dairy farmers in the Northeast to make informed decisions about kelp feeding practices. As a result, we expect that farmers will capitalize on our project insights to improve farm profitability by fine-tuning kelp meal supplementation in their family dairy enterprises. Our research will also affect farm practices through education of dairy farmers in local meetings, conferences, popular-press articles, and educational materials posted on UNH Cooperative Extension websites. Scientific publications will be also available. We will present project results on the 2016 Animal Science Joint Annual Meeting in Salt Lake City, UT.
References:
Allen, G., K. R. Pond, K. E. Saker, J. P. Fontenot, C. P. Bagley, R. L. Ivy, R. R. Evans, R. E. Schmidt, J. H. Fike, X. Zhang, J. Y. Ayad, C. P. Brown, M. F. Miller, J. L. Montgomery, J. Mahan, D. B. Wester, and C. Melton. 2001a. Tasco: Influence of a brown seaweed on antioxidants in forages and livestock-A review. J. Anim. Sci. 79: E21-E31.
Antaya, N. T., K. J. Soder, J. Kraft, N. L. Whitehouse, N. E. Guindon, P. S. Erickson, A. B. Conroy, and A. F. Brito. 2015. Incremental amounts of Ascophyllum nodosum meal do not improve animal performance but increase milk iodine output in early lactation dairy cows fed high-forage diets. J. Dairy Sci. 98:1991-2004.