Enhancing unsaturated fatty acids in ewe's milk by feeding rapeseed or linseed oil

Abstract

The aim of our research was to evaluate whether rapeseed and linseed oils used as feed additives to ewe's diets allow to achieve the higher secretion of unsaturated fatty acids into milk with extended emphasis on the conjugated linoleic acid concentration. Two experiments were carried out on 6 lactating ewes in two independent 3 × 3 Latin square designs. In each feeding cycle the animals were subjected to one of the treatments: (1) without oil supplementation, (2) with 3.5% of rapeseed oil (RS) or linseed oil (LS), (3) with 7.0% of rapeseed oil or linseed oil. Feeding diets rich in mono- and polyunsaturated fatty acids to lactating ewes under our experimental conditions resulted in demanded changes in milk fatty acid content without causing milk fat depression or modification of other milk constituents. Milk fat was improved in unsaturated fatty acids including C18:2 c9 t11 CLA isomer without changing the milk fat concentration. The C18:2 c9 t11 concentration increased from 0.03 (FAME, %) in the control group to 0.21 and 0.12 (FAME, %) in groups receiving 3.5 and 7% RS, respectively. The diet with 7% LS also elevated the C18:2 c9 t11 level in milk from 0.04 (FAME, %) in the control group to 0.11 (FAME, %). Hence a conclusion is drawn that plant oils may be an important source of monoenic and also polyenic fatty acids in milk, however, our research and analysis of literature data indicate that results are strictly dietary and supplement-dependent.

Dietary effect of silage type and combination with camelina seed on milk fatty acid profile and antioxidant capacity of sheep milk

“…Supplementing the ewes' diet with camelina seeds doubled the FA level in the diet and improved their profile through the increase in PUFA n-3 concentrations and the decrease in the proportions of saturated FAs (Table 2). Although the plant belongs to the Crucifera family, camelina seeds have a high content of PUFA, especially α-linolenic acid (C18:3 n-3), which is comparable with the concentrations in linseed (Hurtaud & Peyraud, 2007;Cieslak et al, 2010). The antioxidant capacity of the diets registered higher values with the MS diets because wilting of the grassy meadow for 24 hours probably led to the destruction of antioxidizing factors such as carotenoids and tocopherols, since 80% of the carotenoid content of grass is known to be destroyed in the process of making hay (Chauveau-Duriot et al, 2005).…”

“…Because camelina seed contains a high concentration of long-chain unsaturated FAs (total PUFA: 65.8%; linoleic acid: 22.1%; α-linolenic acid: 43.7% (Mierlita et al, 2011)), its FA spectrum is similar to that of fish oil (AbuGhazaleh et al, 2007;Hunter & Roth, 2010) and linseed (Hurtaud & Peyraud, 2007;Cieslak et al, 2010). Seeds rich in linoleic acid (e.g.…”

Changes in the composition of goat colostrum and milk fatty acids during the first month of lactation

“…The percentage of polyunsaturated FAs varied from 4.4 to 4.8%. Relatively low concentration of polyunsaturated FAs, which is typical of milk fat of ruminants, may be increased by supplements of plant oils or oilseeds as shown in lactating ewes fed diets supplemented with rapeseed or linseed oil (Cieslak et al, 2010). Medium-chain FAs (caprylic, capric and lauric) made up 8.7% of the FAs in the colostrum and increased to 11.1% on the fourth day of lactation.…”

Effects of breed on milk fatty acid profile in dairy ewes, with particular reference to <i>cis-9, trans-11</i> conjugated linoleic acid

“…In our study we determined that the atherogenic index had lower values (P <0.01) in Turcana ewes' milk fat than in that of Spanca ewes (1.67 vs. 3.11). This may be related, for example, to the increased concentration of cis-9, trans-11 C18:2 CLA, which is now described as having antiatherogenic properties (Cieslak et al, 2010).…”