Date of Award

Summer 2022

Project Type


Program or Major

Animal and Nutritional Sciences

Degree Name

Master of Science

First Advisor

Andre F Brito

Second Advisor

Peter S Erickson

Third Advisor

Kayla Aragona


Limited research exists on supplementing seaweeds to prepartum cows and its effects on colostrum production and development of their calves in-utero and after birth. The high iodine (I) concentration of seaweeds is concerning, and previous research have shown that excess I supplementation to ewes inhibits immunoglobulin G (IgG) absorption in their lambs. The objectives of this study were: (1) evaluate the effects of incremental amounts of Ascophyllum nodosum (ASCO) meal supplementation (0, 57, and 113 g/d) to prepartum cows on colostrum production and subsequent growth, health, and blood concentrations of glucose, β-hydroxybutyric acid (BHBA), and thyroid hormones (TH) of their offspring after birth, and (2) compare ASCO meal versus a common I source [i.e., ethylenediamine dihydroiodide (EDDI)] on the same variables under objective 1. Forty Holstein dairy cows were blocked by lactation number and expected calving date and assigned to 1 of 4 treatments in a randomized complete block design. Treatments included: (1) EDDI supplemented to meet the National Research Council (NRC) 2001-recommended concentration of I [i.e., 0.5 mg I/kg of dry matter intake (DMI); control diet (CON)], CON plus 57 g/d of ASCO meal [low level (LO)], CON plus 113 g/d of ASCO meal [high level (HI)], and CON plus EDDI (124.8 mg/d) supplemented to match the amount of I provided by HI (EDDI diet). Iodine sources were top-dressed and manually mixed into the total-mixed ration (TMR) daily. Single degree freedom contrasts were used to statistically analyze the effects of adding incremental amounts of ASCO meal to the diet, as well as to compare HI versus EDDI.Within approximately 1 h of calving, colostrum was harvested from cows and weighed. Colostrum was analyzed for fat, protein, total solids, I, and IgG. Forty-one calves averaging (mean ± standard deviation) 43. 9 ± 4.54 kg body weight (BW) were assigned to their dams’ respective treatments and blocks, but they did not receive ASCO meal or EDDI. Calves remained on the study for (mean ± standard deviation) 56 ± 5 d. At birth, all calves were fed 750 g [dry matter (DM) basis] of colostrum replacer (CR), followed by 700 g CR 6 h after birth. At 24 h old, calves were offered 338 g (DM basis) of milk replacer (MR) (25% crude protein, 16% fat) twice daily until their final 7 d on experiment, where they were offered 338 g of MR once daily to facilitate weaning. Free choice textured starter (28% CP) and water were offered at 24 h of life until completion of the study. Blood samples were collected at 0 h and 24 h of age for IgG and TH analyses, and for TH at d 14, 28, and 56. Blood samples were taken weekly starting at wk 1 for BHB analysis. On d 5 of life, a xylose challenge was conducted by supplementing 0.5 g/kg BW of D-xylose in the MR, with blood samples taken before (0 h) and after D-xylose administration at 2, 4, 6, 8, and 12 h. Blood samples were analyzed for plasma xylose and glucose concentrations as proxies for absorption in the small intestine. Weekly measurements were recorded for BW, withers height, hip height, body length, heart girth, and hip width. Treatments did not affect colostrum yield, as well as protein, total solids, I, and IgG concentrations. Fat concentration of colostrum was greater in HI than EDDI cows, and there was a tendency for fat concentration in colostrum to decrease linearly with ASCO meal supplementation. However, colostrum fat yield was not changed. Treatments had no effect on intake of calf starter, MR, or total DM intake, and average daily gain (ADG) or feed efficiency. Heart girth, body length, and hip width were similar across treatments. Initial BW was greater in HI compared with EDDI calves, and BW tended to decrease linearly with the addition of ASCO meal. Weekly hip height and final withers height tended to be greater in HI versus EDDI calves. Final hip height and weekly withers height were greater in HI than EDDI calves. Plasma concentration of weekly total T4 responded quadratically to ASCO meal supplementation, with the lowest concentration occurring with the LO treatment. Weekly total T4/T3 ratio had a tendency to follow the same response as total T4. All other TH (total T3, and free T3, and T4) were unaffected by treatments. All calves obtained the minimum serum IgG recommendation for passive transfer (>10 g/L), and both 0 and 24 h serum IgG were not affected by treatments. However, there was a tendency for apparent efficiency of absorption to be lower in EDDI versus HI calves. Plasma concentration of weekly BHBA and final plasma BHBA responded quadratically to ASCO meal supplementation, with the lowest concentrations seen with LO. During the xylose challenge calves did not differ in D-xylose absorption; however, glucose absorption decreased linearly with ASCO meal supplementation. Overall, addition of ASCO meal to the dams’ diet did not negatively impact calf growth and metabolism or colostrum production and composition.