Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Agriculture, Food and Environment


Animal Science

First Advisor

Dr. Jeffrey M. Bewley


The objective of the first study was to quantify the effects of feeding Schizochytrium sp. microalgae (SP-1, Alltech, Inc., Nicholasville, KY) on milk fat and DHA content. Eight cows were fed: 0, 100, 300, or 600 g of algae per day. Fat percentage was greater (P < 0.05) for cows on treatments 0 g and 100 g than for cows on treatments 300 g and 600 g (P < 0.05). Docosahexaenoic acid in milk was greater for cows on treatment 300 and 600 than for cows on treatment 0 and 100 (P < 0.05).

The objective of the second study was to assess yeast supplementation effects on high and low forage dairy cow diets. Four cows were assigned to 1 of 4 treatments: 1) low forage (LF), 2) low forage with 10 g/d yeast (Yea-Sacc®; Alltech Inc., Nicholasville, KY; LFY), 3) high forage (HF), or 4) high forage with 10 g/d yeast (HFY). Only rumination time and DMI were influenced by treatment (P < 0.01). Dry matter intake was 17.05, 13.41, 19.44, and 20.29 ± 1.40 kg/d and rumination time was 442.88, 323.09, 433.34, and 475.50 ± 21.93 min/d for cows on the LF, LFY, HF, and HFY treatments, respectively.

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