MARGRA Lamb Eating Quality and Human Health-Promoting Omega-3 Long-Chain Polyunsaturated Fatty Acid Profiles of Tattykeel Australian White Sheep: Linebreeding and Gender Effects

Abstract

Health-conscious consumers increasingly demand healthier, tastier, and more nutritious meat, hence the continuous need to meet market specifications and demand for high-quality lamb. We evaluated the longissimus dorsi muscle of 147 Tattykeel Australian White (TAW) sheep fed on antioxidant-rich ryegrass pastures exclusive to MAGRA lamb brand for meat eating quality parameters of intramuscular fat (IMF) content, fat melting point (FMP) and omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). The aim was to assess the impact of linebreeding and gender on pasture-fed lamb eating quality and to test the hypothesis that variation in healthy lamb eating quality is a function of lamb gender and not its antioxidant status or inbreeding coefficient (IC). After solid-phase extraction and purification, phenolics and antioxidant enzyme activities were analysed by high-performance liquid chromatography and mass spectrometry. IMF and fatty acid composition were determined using solvent extraction and gas chromatography, respectively. IC was classified into low (0–5%), medium (6–10%) and high (>10%) and ranged from 0–15.6%. FMP and IMF ranged from 28 to 39 °C and 3.4% to 8.2%, with overall means of 34.6 ± 2.3 °C and 4.4 ± 0.2%, respectively, and n-3 LC-PUFA ranged from “source” to “good source” levels of 33–69 mg/100 g. Ewes had significantly (P ˂ 0.0001) higher IMF, C22:5n-3 (DPA), C22:6n-3 (DHA), C18:3n-6, C20:3, C22:4n-6, C22:5n-6, total monounsaturated (MUFA), PUFA and Σn-3 fatty acids and lower total saturated fatty acids (SFA) and FMP, than rams. As IC increased, there were no differences in FMP and IMF. Folin–Ciocalteu total phenolics, ferric reducing antioxidant power and antioxidant activities of glutathione peroxidase, catalase and superoxide dismutase enzymes did not differ by either gender or IC. This study provides evidence that IC is inconsequential in affecting antioxidant status, IMF, FMP and n-3 LC-PUFA in linebred and pasture-fed TAW sheep because the observed variation in individual fatty acids was mainly driven by gender differences between ewes and rams, hence the need to accept the tested hypothesis. This finding reinforces the consistent healthy eating quality of MARGRA lamb brand from TAW sheep regardless of its linebred origin.

Nutritional Enhancement of Health Beneficial Omega-3 Long-Chain Polyunsaturated Fatty Acids in the Muscle, Liver, Kidney, and Heart of Tattykeel Australian White MARGRA Lambs Fed Pellets Fortified with Omega-3 Oil in a Feedlot System

“…The level of incorporation and abundance of both monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids in the muscle is consistent with previously reported intramuscular fatty acid compositions [56,57]. A review of pre-clinical and human trials with conjugated linoleic acid CLA (C18:2n-6) revealed positive effects on cancer, obesity, and atherosclerosis [58,59], and the muscle in the present study had significantly incorporated levels of CLA and ALA (C18:3n-3).…”

Next Generation Sequencing of Single Nucleotide Polymorphic DNA-Markers in Selecting for Intramuscular Fat, Fat Melting Point, Omega-3 Long-Chain Polyunsaturated Fatty Acids and Meat Eating Quality in Tattykeel Australian White MARGRA Lamb

“…The Poll Dorset and Texel were used as positive control and the Rambouillet as the negative control in assessing extracted genomic DNA, polymerase chain reaction products, and next-generation sequencing procedures in the laboratory. Details of the muscle biopsy procedure and laboratory analyses of IMF, FMP, and fatty acid composition had already been published [2] and are only briefly summarized below.…”

“…The biopsy procedure for sampling the Longissimus dorsi muscle from the 12th-13th ribs was first described in cattle [20] and modified in sheep [2]. Pewan et al [2] published the details of the biopsy procedure in sheep, and these will not be repeated here.…”

“…Details of the procedures for laboratory analysis of intramuscular fat were published by Pewan et al [2], Holman et al [21], and Flakemore et al [22] and will not be repeated here.…”

“…Eating quality is the single largest determinant of consumer acceptability and satisfaction with meat products. The eating and nutritional quality of lamb is influenced by intramuscular fat (IMF) content [1], fat melting point (FMP), tenderness, juiciness, flavor [2], and health-promoting omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) that optimize retinal, maternal, and childhood brain functions while minimizing the risks associated with cardiovascular and chronic diseases [3,4].…”