Effects of olive and fish oil Ca soaps in ewe diets on milk fat and muscle and subcutaneous tissue fatty-acid profiles of suckling lambs

Abstract

Enhancing healthy fatty acids (FAs) in ewe milk fat and suckling lamb tissues is an important objective in terms of improving the nutritional value of these foods for the consumer. The present study examined the effects of feeding-protected lipid supplements rich in unsaturated FAs on the lipid composition of ewe milk, and subsequently in the muscle and subcutaneous adipose tissues of lambs suckling such milk. Thirty-six pregnant Churra ewes with their new-born lambs were assigned to one of three experimental diets (forage/concentrate ratio 50 : 50), each supplemented with either 3% Ca soap FAs of palm (Control), olive (OLI) or fish (FO) oil. The lambs were nourished exclusively by suckling for the whole experimental period. When the lambs reached 11 kg BW, they were slaughtered and samples were taken from the Longissimus dorsi and subcutaneous fat depots. Although milk production was not affected by lipid supplementation, the FO diet decreased fat content ( P < 0.001), whereas the OLI milk FA profile resembled that of the Control diet. In contrast, although FO drastically diminished the contents of stearic and oleic acids ( P < 0.001), all the saturated even-numbered carbon FAs from 6:0 to 14:0 increased ( P < 0.05). FO also produced the highest levels of c9,t11-18:2 (2.21%) and n-3 FAs, 20:5 n-3 (0.58%), 22:5 n-3 (0.48%) and 22:6 n-3 (0.40%). The high levels of trans-11 18:1 (7.10%) obtained from the FO diet would suggest that Ca soaps only confer partial protection in the rumen. In contrast, the lack of significant differences in trans-10 18:1 levels ( P > 0.05) and other trans-FAs between Control and FO treatments would indicate that FO treatment does not alter rumen biohydrogenation pathways under the assayed conditions. Changes in dam milk FA composition induced differences in the FA profiles of meat and fat depots of lambs, preferentially incorporated polyunsaturated FAs into the muscle rather than storing them in the adipose tissue. In the intramuscular fat of the FO treatment, all the n-3 FAs reached their highest concentrations: 0.97 (18:3 n-3), 2.72 (20:5 n-3), 2.21 (22:5 n-3) and 1.53% (22:6 n-3). In addition, not only did FO intramuscular fat have the most cis-9, trans-11 18:2 (1.66%) and trans-11 18:1 (3.75%), but also the lowest n-6/n-3 ratio (1.80) and saturated FA content were not affected. Therefore, FO exhibited the best FA profile from a nutritional point of view.

Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils

“…Similar results have been reported by Jenkins (2000) in steers fed with rapeseed oil rich in oleic acid, in which an increase in the t 11-18:1 content from 1.72% to 4.22% was observed. Likewise, Pérez Alba et al (1997) and Gallardo et al (2014) reported a drastic increase in the content of trans-18:1 and t 11-18:1 isomers, respectively, in dairy sheep that were also offered calcium soap of olive oil. However, Hristov et al (2005), in a study comparing sunflower oil rich in linoleic acid (76.5% linoleic acid) and sunflower oil rich in oleic acid (76.5% oleic acid) in concentrate lot steers, found no differences in the content of t 11-18:1 or c 9,t 11-18:2.…”

“…These isomers could be transferred to milk fat or meat fat. A small number of studies carried out with olive oil in dairy sheep (Pérez Alba et al, 1997;Gómez-Cortés et al, 2008;Gallardo et al, 2014), feedlot lambs ) and suckling lambs (Manso et al, 2011;Gallardo et al, 2014) have reported an increase in oleic acid, a substantial increase in a wide variety of trans-monoene isomers and an increase in c9,t11-18:2 in milk and meat. Spain is the world's most important producer of olive oil, and when it is refined for human consumption a large quantity of by-products are formed, which are often used in animal feeds.…”

Immune and oxidative response to linseed in the diet of periparturient Holstein cows

“…Extensive research with dietary n-3 fatty acid sources has focused on changing milk fatty acid composition (Shingfield et al, 2005;Lejonkleva et al, 2013;Nudda et al, 2013;Gallardo et al, 2014), disregarding the effect of n-3 fatty acids on the immune system or oxidative stress in dairy cows. The aim of this research was to determine the influence of dietary replacement of n-6 with n-3 polyunsaturated fatty acids (PUFA) on cellular immunity and oxidative stress in the transition period of dairy cows.…”

State of the art in rumen lipid protection technologies and emerging interfacial protein cross‐linking methods

“…Besides variation in experimental conditions, the large variation in transfer efficiencies between experiments also might be related to differences in protection efficiency, probably induced by variation in production procedures of the Ca salts. Generally, very inconsistent results are found in literature dealing with Ca salts of unsaturated FA, but most of them reported an incomplete protection, supported by the many BH intermediates which were found in milk and/or rumen fluid .…”