Fresh Forage and Solin Supplementation on Conjugated Linoleic Acid Levels in Plasma and Milk

Abstract

Two experiments were run concurrently to determine the effect of fresh forage consumption on the production and proportions of plasma and milk fat vaccenic acid (VA), conjugated linoleic acid (CLA), and linolenic acid in diary cattle. In experiment 1, the cows consumed 50, 65, and 80% of their feed intake as pasture with the remainder of intake as a barley-based concentrate. The proportion of VA in milk fatty acids increased 12% when pasture intake increased from 50 to 65% of total dry matter intake and VA, CLA, and linolenic acid proportions increased 26, 18, and 27%, respectively, as pasture increased from 65 to 80% of dietary intake. In experiment 2, fresh forage was compared to conserved hay (cut from the same pasture the previous summer) to determine the effect on plasma and milk fat VA, CLA, and linolenic acid. Also, the effect of crushed solin seed (a flax cultivar that is high in linoleic acid) supplementation to the fresh forage diet was determined. Fresh forage compared to conserved hay in the diet, increased the proportion of CLA in the plasma very low density lipoproteins (VLDL) fraction by 71% but had no effect on linolenic acid. Supplementation of the fresh forage diet with a linoleic acid source increased VA and CLA in the plasma VLDL fraction 25 and 58% and slightly decreased the proportion of linolenic acid. Fresh forage, compared to conserved hay, increased milk fat VA and CLA proportions by 22 and 15%. Supplementing the fresh forage diet with linoleic acid from crushed solin seed further increased milk fat VA and CLA proportions 41 and 25%. Solin supplementation in a lactation diet is a superior method to increase CLA levels in milk fat than feeding fresh forage alone.

Effect of extruded whole soybean dietary concentrate on conjugated linoleic acid concentration in milk in Jersey cows under pasture conditions

“…This may be related to differences in the nutritional composition of the herbage, which has also been shown to affect the fatty acid composition of milk (Dewhurst et al, 2006). In this respect, lower CLA contents in milk have been observed with more mature pasture, and this effect has been attributed to the declining quality and quantity of the herbage (Lock & Garnsworthy, 2003;Ward et al, 2003). This is in agreement with the present work, in which the lowest CLA values were obtained in late December and January, when the herbage presented the poorest nutritional quality (see Table 2).…”

Efecto de la edad de rebrote sobre el perfil de ácidos grasos en gramíneas tropicales

“…La composición de los ácidos grasos (AG) en gramíneas tiene especial importancia por su efecto sobre el perfil lipídico en la carne y la leche de los rumiantes (Dhiman et al 1999;White et al 2001;Ward et al 2003;Loor et al 2003;Shingfield et al 2013). En humanos, la grasa de la leche ha sido relacionada con problemas de salud, especialmente, con enfermedades coronarias, niveles altos de lipoproteínas de baja densidad (LDL) y arteriosclerosis, debido a su contenido alto de ácidos grasos saturados (70 %) y al contenido bajo de ácidos grasos insaturados (30 %) (Jensen 2002).…”

Conjugated linoleic acid content in milk of Chilean Black Friesian cows under pasture conditions and supplemented with canola seed (Brassica napus) concentrate

“…In this respect, lower CLA contents in milk have been observed with more mature pasture. This effect has been attributed to the declining quality and quantity of the herbage (Lock & Garnsworthy, 2003;Ward et al, 2003;Avilez et al, 2012). In exp.…”

“…For instance, it has been reported that fresh forage (Khanal et al, 2005;Dewhurst et al, 2006;Butler et al, 2008; Conjugated linoleic acid content in milk of Chilean Black Friesian cows under pasture conditions and supplemented with canola seed (Brassica napus) concentrate Rego et al, 2008) and diets supplemented with plant oils, high in linoleic acid Stanton et al, 2003) increase CLA concentration in milk fat. Within the seeds of oilseeds, rapeseed (Brassica napus) has been used in TMR (total mixed ration) diets in dairy cows (Bayourthe et al, 2000, Chouinard et al, 2001Ward et al, 2002;Chichlowski et al, 2005;Chen et al, 2008;Neves et al, 2009;Lerch et al, 2012b). However, the information about its utilization as a supplement under grazing conditions is limited and contradictory (Stanton et al, 1997;Lawless et al, 1998;Fearon et al, 2004;Lerch et al, 2012b).…”