Fatty acid composition of beef steers as affected by diet and fat depot

Abstract

Subcutaneous and perirenal fatty acid (FA) profiles were compared in steers fed a control diet (70 : 30 red clover silage (RC) : barley concentrate), a diet with sunflower seed (SS) substituted for barley, and diets with 15% or 30% wheat dried distillers' grain with solubles (DDGS-15 and DDGS-30) substituted for RC and SS. Perirenal fat (PRF) versus subcutaneous fat (SCF) had greater proportions of total saturated FA (SFA) and branched chain FA (BCFA), and lower proportions of total and major cis-monounsaturated FA (c-MUFA). Addition of SS to the diet did not change the proportions of total and major c-MUFA and n-6 polyunsaturated FA (PUFA), but led to decreases in the proportions of total and major SFA, BCFA and n-3 PUFA. Progressive substitutions with DDGS led to no further changes in the proportions of total and major SFA and n-3 PUFA, but decreased the proportions of BCFA and c9-16:1, and increased the proportions of c9-18:1 and n-6 PUFA. Feeding SS and DDGS-15 diets yielded the largest proportions of total and major t-18:1 (t11-and t13-/t14-18:1) isomers in PRF and conjugated lineolic acid (CLA) isomers (t7,c9-and t9,c11-18:2) in SCF, but responses were diminished when feeding the DDGS-30 diet. Subcutaneous fat versus PRF from steers fed SS and DGGS diets had larger proportions of non-conjugated 18:2 biohydrogenation products (i.e. atypical dienes) than the control diet. Overall, feeding SS and DDGS-15 diets raised the proportions of t11-18:1 in PRF and c9,t11-18:2 in SCF, which have potential human health benefits, but feeding DDGS-30 was less effective.

Comparison of fatty acid profile of three adipose tissues in Ningxiang pigs

“…(2012) showed a similar result in Celta pigs. Similar results were also shown in other livestock, such as lambs ( Szumacher-Strabel et al., 2004 , Castro et al., 2005 ) and steers ( Turner et al., 2015 , Mapiye et al., 2015 ). This might be a common phenomenon in pigs or even in mammals.…”

“…This dissimilarity of PA and DSA could be majorly related to the proportion of stearic acid. This is also the same with the study of lambs ( Szumacher-Strabel et al., 2004 , Castro et al., 2005 ) and steers ( Turner et al., 2015 , Mapiye et al., 2015 ). Generally, the less mature adipose tissues situated externally, such as subcutaneous adipose, and the more saturated adipose tissues situated internally, such as PA ( Lee et al., 2011 , Jiang et al., 2013 ).…”

Citrus and Winery Wastes: Promising Dietary Supplements for Sustainable Ruminant Animal Nutrition, Health, Production, and Meat Quality

“…The increase in percentages of PUFAs and their biohydrogenation products in ruminant meat varies with the level of citrus and winery by-products fed [29,41]. Overall, the proportion of PUFAs in ruminant meat has been reported to increase linearly with dietary levels of citrus and winery by-products up to 200 g/kg DMI, beyond which rumen function is impaired [42]. Besides increasing the proportion of PUFAs, especially those purported to have human-health-promoting properties such as n-3 and n-6 PUFAs, as well as rumenic and vaccenic acids [29,86], Table 5 shows that the addition of citrus and winery by-products below <150 kg tends to lower monounsaturated fatty acids (MUFAs) and saturated fatty acids (SFAs) in ruminants.…”

“…In vitro and in vivo studies have reported that bioactive compounds from citrus and winery by-products such as polyphenols and essential oils protect the dietary PUFAs from biohydrogenation in the rumen, and/or suppress the growth and metabolism of rumen microbes responsible for biohydrogenation, particularly those involved in the last step, which is the conversion of vaccenic acid to stearic acid [29,41]. In this regard, selective inhibition of Clostridium proteoclasticum without influencing Butyrivibrio fibriosolvens results in more PUFAs and their biohydrogenation products, such as vaccenic and rumenic acids, bypassing rumen biohydrogenation and being subsequently incorporated into animal tissues [42]. High levels of citrus and winery by-products (≥200 g/kg DM) in the diet seem to be more effective in modulating the fatty acid profile of ruminant meat [29,43].…”

“…Feeding citrus and winery by-products as dietary supplements was reported to increase the proportion of omega-3 and omega 6 PUFAs and their biohydrogenation products ( Table 5). This could be ascribed to the selective inhibition by bioactive compounds of Clostridium proteoclasticum without influencing Butyrivibrio fibriosolvens, which results in greater bypass of PUFAs and their biohydrogenation products reaching the small intestines for subsequent absorption and deposition in the muscle [5,42]. The increase in percentages of PUFAs and their biohydrogenation products in ruminant meat varies with the level of citrus and winery by-products fed [29,41].…”