Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Dairy Science

First Advisor

Jill L. Anderson


Dairy, Fatty acid, Flax oil, growth


Utilization of flax oil is new to the livestock industry, and limited research has been done to see the benefits of feeding the highly unsaturated oil to both dairy calves and lactating cows. Two studies were conducted to evaluate the potential benefits of flax oil as a lipid supplement. The first study compared the supplementation of two plant based oils to growing dairy calves. Thirty-six female Holstein calves in individual hutches were used in a 12-wk randomized complete block design study. Treatments were: 1) control (CON) with no oil, 2) 80 g/d of flax oil (FLAX), and 3) and 80 g/d of soy oil (SOY). Pre-weaning the oils were fed with the milk and post-weaning the oils were topdressed on starter pellets. Calves were fed 2.83 L of pasteurized milk 2×/d during wk 1 to 5 and 1×/d during wk 6. Pellets and water were fed ad libitum. The calves were evaluated on body frame growth, health conditions, dry matter intake, nutrient digestibility, blood metabolite profiles, rumen fermentation, and plasma fatty acid concentrations. Dry matter intakes were greater in CON than FLAX with SOY similar to both. Calf BW and gain: feed were similar but had treatment × wk interactions. The ADG, body condition scores, withers heights and other frame measurements including hip height, heart girth, paunch girth, body length and hip width were similar among treatments. Fecal scores were similar overall but had an interaction of treatment × wk with SOY having greater fecal scores during weaning and the last two weeks. Body temperatures and respiratory scores were similar. Plasma urea nitrogen concentrations were not different among treatments. Concentrations of plasma beta-hydroxyl butyrate were greater for the CON calves compared to the two oil treatments. Plasma cholesterol was greater in the oil treatments compared to CON. Plasma triglycerides were greater in SOY. A tendency was observed for plasma glucose to be less in SOY. Total concentration of plasma fatty acids was increased with the oil supplements and proportion of individual fatty acids were altered. Supplementing flax and soy oil maintained growth performance compared to CON in the pre-weaning period when fed with milk, but decreased intake and BW during the last two weeks of the post-weaning period when fed with starter pellets. In addition, supplementing flax oil and soy oil maintained PUN concentrations, but altered circulating lipid and energy metabolism. This study demonstrates that the supplementation of plantbased oils to young calves affects their metabolic profile, does not affect body growth, and decreases intake when compared to a diet with no oil supplementation. The second study investigated the potential benefits of supplementing encapsulated flax oil to high producing Holstein dairy cows. Eight multiparous and 4 primiparous Holstein cows (73 ± 40 d in milk, 694 ± 71 kg of body weight) were used in a 3-wk randomized complete block design study. Cows were fed a basal diet containing 52% forages and 48% concentrates on a dry matter basis. Treatments were: 1) control (CON) with no oil, and 2) 250 g/d of encapsulated flax oil (FLAX). The DMI was not affected by inclusion of the encapsulated flax oil. Milk production, milk fat and milk protein had no differences between treatments. Plasma concentrations of glucose, triglyceride and cholesterol were similar among both treatments. Rumen ammonia tended to be less in the FLAX cows. All major VFA were similar between treatments. During the short 3 wk study minimal milk fatty acids differences were observed between treatments. However, since the cows on the FLAX treatment produced an average of 0.12 kg/d more of fat in their milk the total amount of the fatty acids was numerically greater than the CON treatment. Supplementing encapsulated flax oil, maintained lactation performance when compared to CON and increased milk fat percentage. Further research would be beneficial in both the calves and cows to validate the results of these preliminary evaluations on flax oil supplementation.


South Dakota State University


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