Abstract #M320

Section: Ruminant Nutrition
Session: Ruminant Nutrition I
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall B

# M320
Milk enterolactone and fatty acid profile in dairy cows offered flaxseed meal and incremental amounts of liquid molasses.
C. P. Ghedini¹, A. F. Brito^*1, D. C. Moura², A. S. Oliveira³, R. A. V. Santana⁴, ¹Department of Biological Sciences, University of New Hampshire, Durham, NH, ²Programa de Pós Graduação em Ciência Animal, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil, ³Instituto de Ciências Agrárias e Ambientais, Universidade Federal de Mato Grosso–Campus Sinop, Sinop, MT, Brazil, ⁴Instituto Federal de Educação, Ciência e Tecnologia do Norte de Minas Gerais–Campus Arinos, Arinos, MG, Brazil.

Enterolactone (EL) is a mammalian lignan originated from the microbial fermentation of flaxseed in the rumen, and it has been linked to potential human health benefits. However, there is limited information about the impact of liquid molasses (LM) or ground corn (GC) on the microbial output of EL in the rumen and EL transfer to milk. There is also scarce information about the effect of LM or GC or LM:GC mixtures on milk fatty acid (FA). Our objective was to investigate the impact of replacing GC with incremental amounts of LM on milk concentrations of EL and FA. Sixteen multiparous Jersey cows were assigned to treatment in a replicated 4 × 4 Latin square design with 21-d periods. Diets were fed as TMR and consisted (DM basis) of 52% grass-legume baleage, 8% grass hay, 8.5% soyhulls, 2.5% roasted soybean, and 15% flaxseed meal. Ground corn was replaced by LM at 0, 4, 8, or 12% of diet DM. Diets averaged 9.7 and 0.0%, 7.0 and 1.7%, 4.3 and 3.3%, and 1.64 and 5.0% of starch and LM-added sugars, respectively; CP and NDF concentrations averaged 19.0 and 43.5% across diets. Results are presented in Table 1. Concentration of milk EL and Σ branched-chain FA was not affected by treatments. Milk 18:0, c-9 18:1, and c-9, c-12 18:2 decreased linearly, whereas c-9, t-11 18:2 and c-9, c-12, c-15 18:3 increased linearly with replacing GC with LM. These results may be associated with decreased intake of 18-C or shifts in ruminal biohydrogenation. Σ odd-chain FA responded quadratically to LM supplementation, suggesting changes in ruminal microbiota. Overall, changing the dietary NSC profile in cows fed flaxseed meal did not alter milk EL, but affected milk FA. Table 1. Milk enterolactone and FA (g/100 g)

Item	Molasses:Corn ratio (% diet DM)					P > F
Item	0:12	4:8	8:4	12:0	SEM	L	Q
Enterolactone, nM	246	324	251	324	62.1	0.57	0.58
18:0	11.0	10.7	10.3	9.94	0.32	<0.01	0.78
c-9 18:1	13.6	13.1	13.1	12.9	0.42	<0.01	0.59
c-9, c-12 18:2	1.35	1.36	1.30	1.25	0.03	<0.01	0.10
c-9, t-11 18:2	0.54	0.55	0.56	0.59	0.02	0.03	0.34
c-9, c-12, c-15 18:3	0.62	0.62	0.65	0.66	0.05	0.04	0.60
Σ odd-chain	2.04	2.06	2.09	2.20	0.07	<0.01	0.03
Σ branched-chain	1.93	1.94	1.91	1.94	0.04	0.98	0.47

Key Words: dairy cow, enterolactone, flaxseed meal