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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #295517
Title: Kelp meal (Ascophyllum nodosum) did not improve milk yield or mitigate heat stress but increased milk iodine in mid lactation organic Jersey cows during the grazing season

Author
item BRITO, ANDRE - University Of New Hampshire
item Soder, Kathy
item WHITEHOUSE, NANCY - University Of New Hampshire
item GUINDON, N - University Of New Hampshire
item PERIERA, A.D. - University Of New Hampshire
item MUIR, C - University Of New Hampshire

Submitted to: Joint Abstracts of the American Dairy Science and Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 7/2/2013
Publication Date: 7/20/2013
Citation: Brito, A., Soder, K.J., Whitehouse, N., Guindon, N.E., Periera, A.B., Muir, C.C. 2013. Kelp meal (Ascophyllum nodosum) did not improve milk yield or mitigate heat stress but increased milk iodine in mid lactation organic Jersey cows during the grazing season. Joint Abstracts of the American Dairy Science and Society of Animal Science. 96(E-Suppl. 1):33.

Interpretive Summary:

Technical Abstract: Kelp meal (KM) made from dry and ground Ascophyllum nodosum, a brown algae, is often used as a mineral supplement on northeastern organic dairy farms. Twenty (12 primiparous and 8 multiparous) organic Jersey cows with an initial BW of 410 kg (SD ± 39) and DIM of 135 (SD ± 52) were blocked by milk yield and parity. Cows were randomly assigned to treatments (0 or 113 g KM as fed) to examine the effects of KM supplementation on milk yield, milk components, plasma metabolites, and indicators of heat stress. The study lasted from June to October 2012 with 4, 28- d periods with the last 7 d used for data and sample collection. Data were analyzed using the MIXED procedure of SAS with repeated measures over time. Cows had access to mixed mostly cool-season grass pasture for 16 h daily, which was managed using rotational strip grazing. Cows were supplemented a TMR made (DM basis) of 51% grass-legume baleage, 47% concentrate, and 2% liquid molasses fed via Calan doors. Kelp meal had no impact on milk yield, components or heat stress indicators. However, concentration of milk iodine was 77% higher in KM fed cows than those fed no KM, which is explained by the high concentration of iodine (i.e., 820 mg/kg DM basis) found in brown algae. No KM effects were seen for plasma cortisol, NEFA, and thyroxine (T4); a trend for lower plasma triiodothyronine (T3) was found in KM cows, likely as a result of higher iodine intake. Kelp meal did not improve milk yield or mitigate heat stress but increased milk iodine, which may be of concern to human health, particularly children.