Skip to main content
ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #305628
Title: Interactions of corn meal or molasses with a soybean-sunflower meal mix or flaxseed meal on production, milk fatty acids composition, and nutrient utilization in dairy cows fed grass hay-based diets

Author
item BRITO, ANDRE - University Of New Hampshire
item PETIT, HELENE - Agri Food - Canada
item PEPEIRA, ANDRE - University Of New Hampshire
item Soder, Kathy
item ROSS, SHARA - University Of New Hampshire

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2014
Publication Date: 11/10/2014
Citation: Brito, A.F., Petit, H.V., Pepeira, A.B., Soder, K.J., Ross, S. 2014. Interactions of corn meal or molasses with a soybean-sunflower meal mix or flaxseed meal on production, milk fatty acids composition, and nutrient utilization in dairy cows fed grass hay-based diets. Journal of Dairy Science. 98:443-457.

Interpretive Summary: Improving milk fatty acid profile may have human health benefits. We looked at the effect of feeding molasses versus flaxseed to organic dairy cows on milk production and milk fatty acid content. Cows fed flaxseed produced more enterolactone, a lignan that may have human health benefits. However, these cows also produced less milk, which may reduce farm income. More research is needed to improve the beneficial components of milk without negatively impacting milk production.

Technical Abstract: We investigated the interactions of molasses or corn meal [nonstructural carbohydrate (NSC) sources] with flaxseed meal or a soybean-sunflower meal protein mix [rumen-degradable protein (RDP) sources] on animal production, milk fatty acids profile, and nutrient utilization in organic Jersey cows fed grass hay diets. Eight multiparous and 8 primiparous organically managed Jersey cows averaging 135 +/- 49 days in milk and 386 +/- 61 kg of body weight in the beginning of the study were randomly assigned to 4 replicated 4 × 4 Latin squares with a 2 × 2 factorial arrangement of treatments. Each period lasted 19 d with 14 d for diet adaptation and 5 d for data and samples collection. Cows were fed diets composed by a common mixed-mostly grass hay (69% of diet dry matter) plus 1 of the following 4 concentrate blends (31% of diet dry matter): 1) liquid molasses plus flaxseed meal, 2) liquid molasses plus a protein mix containing soybean meal and sunflower meal, 3) corn meal plus flaxseed meal, or 4) corn meal plus a protein mix containing soybean meal and sunflower meal. Data were analyzed for main effects of NSC sources, RDP source, and the NSC × RDP source interactions. No effect of NSC source was observed for nutrient intake and milk yield. However, 4% fat-corrected milk and energy corrected milk were significantly reduced in cows fed liquid molasses due to decreased concentration and yield of milk fat. Diets with liquid molasses resulted in increased concentration and yield of milk enterolactone, thus indicating that this mammalian lignan can be modulated by energy source with different NSC profiles. Overall, NSC and RDP source profoundly changed the milk fatty acid profile likely as a result of differences in fatty acid intake, delta**9 -desaturase indexes, and ruminal biohydrogenation pathways. Feeding liquid molasses improved N utilization through reduction of plasma urea N, milk urea N, and urinary N excretion. Effects of RDP source were observed for yields of milk, fat, and lactose, which significantly decreased in cows fed flaxseed meal diets. Feeding flaxseed meal diets dramatically increased the concentration and yield of milk enterolactone due to the high concentration of secoisolariciresinol diglucoside in flaxseed. Significant NSC × RDP source interactions were observed for milk urea N, feed efficiency, and the sums of saturated, monounsaturated and polyunsaturated fatty acids. Further research is needed to elucidate the negative responses of flaxseed meal on yields of milk and milk components.