Fatty acid composition and oxidative stability of lambs’ meat as affected by a bioflavonoid antioxidant and fat sources

Abstract

________________________________________________________________________________ AbstractA study was conducted to investigate the effects of a synthetic or natural antioxidant and fat saturation, in a standard feedlot diet, on fatty acid composition and oxidative stability of lamb. The four dietary treatments consisted of the same basal diet providing 187 g crude protein (CP), 355 g neutral detergent fibre (NDF), and 71 g ether extract (EE) per kg dry matter (DM), differing in fat source (30 g/kg of either saturated beef tallow or unsaturated soybean oil) and type of antioxidant included (125 g/t of either a synthetic or natural antioxidant). Eighty four S.A. Mutton Merino lambs weighing 27.6 ± 1.7 kg were divided into four groups and randomly allocated to four dietary treatments (n = 21 lambs/treatment) subdivided into 7 replicates/treatment (n = 3 lambs/replicate). After an adaptation period of 8 days, all lambs received complete diets for a further feeding period of 41 days. At termination of the study, seven lambs per treatment, weighing 45.1 ± 3.0 kg, were randomly selected and slaughtered. Loin chops from each carcass were used for fatty acid, colour (a * values) and thiobarbituric acid reactive substance (TBARS) analysis. Meat colour was determined on days 0 and 7 after being stored at 4 ºC under fluorescent light. The malonaldehyde content per kg meat was determined on days 0, 7 and 90 after being stored at -18 ºC in the dark. It was found that dietary treatment had no effect on colour stability as depicted in a * values. The malonaldehyde content per kg meat was higher on days 0 and 90 for the unsaturated soybean oil treatment. Beef tallow inclusion resulted in an increase in palmitoleic acid, where soybean oil inclusion resulted in an increase in linoleic and α-linolenic acids in both lean and subcutaneous fat tissue. Natural antioxidant inclusion in the diet only increased the palmitoleic acid content of subcutaneous fat. The results suggested that the fatty acid profile of lamb meat can be favourably manipulated by the source of fat included in the diet. ________________________________________________________________________________

Effects of dietary beef tallow on performance, rumen fermentation, carcass traits and meat quality of growing lambs

“…Despite the differences in the FA profiles of the current experimental diets, none of the individual FAs in the meat was affected by the dietary BT (Table 4). This was not observed in another study, where inclusion of saturated tallow (30 g/kg DM) resulted in higher lamb muscle content of palmitoleic acid (C16:1c9) and monounsaturated fatty acids (MUFAs) (Booyens et al, 2012). One explanation for the lack of effect of dietary BT on fatty meat FA profile might be that FAs originating from BT are in the free form and not bound within triacyl glycerol molecules (Siebrits et al, 2009).…”

“…In sheep, two studies have evaluated the effects of replacing grains with BT on growth of finishing lambs, finding variable effects of 20 and 40 g BT/kg DM on average daily gain (ADG) and feed conversion (Ružić-Muslić et al, 2009;Ahmed et al, 2015). Booyens et al (2012) also indicated the possibility of altering the FA profile of meat from lambs by feeding different sources of fat. When supplemental fat replaces grains and byproducts the formulation of the entire diet should be considered.…”

Supplementation with Cashew Nut and Cottonseed Meal to Modify Fatty Acid Content in Lamb Meat

“…Thus, there is an increased interest in research on ways to modify the fatty acid composition of ruminant meat, especially in ways to reduce the concentration of SFAs and increasing that of PUFAs (Nieto and Ros ). The fatty acid profile of lamb meat can be favorably manipulated by altering the source of the fat included in the diet (Lee and others ; Booyens and others ). The complexity of ruminant digestion is determined mainly by its symbiotic ruminal microbiota, and this complexity will continue to challenge efforts to modulate meat quality, including its fatty acid composition (Bessa and others ).…”

Sustainable utilization of unsaleable walnut kernel in substitution for corn grain in the diet of fattening lambs improves growth performance and meat quality

“…Changes in meat FAs composition due to lipid supplementation are dependent on the FA pro le of the supplement, amount of lipid supplemented in the diet, form of lipid in the diet, processing of oilseeds, composition of the basal diet and duration of feeding supplement (Chikwanha et al 2018). Despite the microbial biohydrogenation in the rumen which extensively impacts the pro le of FAs deposited in body tissues; the FAs pro le of lamb meat can be favorably manipulated by altering the source of the fat included in the diet (Booyens et al 2012). Beside different processing methods to protect FAs from ruminal biohydrogenation, whole seeds may offer degrees of protection as the protein coat of oil bodies forms a barrier limiting biohydrogenation (Chikwanha et al 2018).…”