PSVII-6 Comparative fatty acid profiling of Australian White and F1 Australian White × Rideau muscle.

Abstract The meat from Australian White (AW) sheep is known by its excellent eating quality, due to increased marbling, and a fatty acid profile high in long chain omega-3 fatty acids, which are associated with cardiovascular health and brain function in humans. Rideau Arcott is a dam-line breed characterized by enhanced prolificacy, good body conformation and growth rates. Crossbreeding can be a promising strategy to combine desirable traits of both breeds while mitigating the high costs of maintaining purebred herds. Therefore, the aim of this study was to compare the intramuscular fat (IMF) characteristics and fatty acid profile of purebred AW and AW x Rideau F1 lambs (F1R). Samples from the Longissimus dorsiof 20 AW and 20 F1R lambs were collected at slaughter to analyze the IMF content, fat melting point (FMP), and the fatty acid profile. Results revealed that F1R lambs exhibited lower FMP and higher total fatty acids, including saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids, compared to AW lambs (P ≤ 0.05). Additionally, the increase in IMF (%) had a quadratic effect (P≤ 0.05) on total SFA, MUFA, and PUFA concentrations in F1R lambs, peaking at 2.0–2.5% IMF, whereas in AW lambs, these values increased linearly with IMF (%). Among the SFAs, capric (C10:0), myristic (C14:0), palmitic (C16:0), and stearic acid (C18:0) concentrations were higher (P ≤ 0.05) in F1R lambs. Similarly, greater concentrations of palmitoleic (C16:1), oleic (C18:1), and eicosenoic acid (C20:1), classified as MUFAs, were found in F1R lambs. For PUFAs, total omega-3 and omega-6 concentrations were higher (P ≤ 0.05) in F1R than in AW lambs. Specifically, linoleic (C18:2N6), α-linolenic (C18:3N3), and γ-linolenic acid (C18:3N6) were more abundant in F1R lambs, while arachidonic acid (C20:4N6) was lower (P ≤ 0.05). In conclusion, crossbreeding AW with Rideau Arcott sheep resulted in F1 lambs with lower FMP, which may be favorable in sensory characteristics of the meat, such as juiciness and flavor. Moreover, the differences in FMP between breeds may be due to higher concentrations of both MUFAs and PUFAs, including key omega-3 and omega-6 fatty acids in F1R meat. These characteristics contribute to a favorable fatty acid profile that potentially improves meat quality and aligns consumers’ preferences for nutritionally superior meat products.