Intramuscular fat and melting point variation in sheep supplemented with Spirulina

Spirulina (Arthrospira platensis) is a highly nutritious and edible microalga, but knowledge about the productive response of sheep to Spirulina supplementation is scanty and its impact on intramuscular fat deposition in lambs largely unknown. We tested the hypothesis that Spirulina lowers intramuscular fat levels and improves meat tenderness at low levels of supplementation without detrimental effects on eating quality. Therefore. the objective of this study was to investigate the influence of varying levels of Spirulina supplementation on Longissimus dorsi intramuscular fat (IMF) content and fat melting point (FMP) in crossbred sheep. Twenty four, prime lambs sired by Dorset, White Suffolk, Black Suffolk and Merino rams were weaned at six months of age and subjected to a nine-week feeding trial at 3 levels of Spirulina supplementation including a control group (0%), and low (10% wt!vol) and high (20% wt/vol) levels. Each treatment group had a random allocation of 8 lambs balanced by gender ( ewes and wethers), body condition score (average of 3.1 ± 0.4) and body weight (average of 37.6 ± 5.2 kg). Lambs in the low and high supplementation groups were drenched daily with Spirulina prior to being released for grazing with the control group. Lambs were slaughtered in a commercial abattoir and Longissimus dorsi muscle samples taken for laboratory determination of IMF and FMP. Intramuscular fat and melting point data were subjected to statistical analyses utilizing General Linear Model procedures in SAS with sire breed, sex, Spirulina level and their second-order interactions fitted as fixed effects and sire as a random variable. It was evident that the higher the level of Spirulina supplementation, the lower the fat content in which IMF significantly (p<0.05) dropped from 2.1 ± 0.3% in the control group, to 1.6 ± 0.2% and 1.4 ± 0.1% in the low and high supplementation groups, respectively. FMP values were similar between the control (44.0 ± 0.6 °C) and high (44.2 ± 0.2° C) supplementation groups, but significantly lower (p<0.01) in the low (42.9 ± 0.7°C) treatment group. These results suggest that Spirulina supplementation at a I 0% inclusion level has the potential to produce leaner, healthier meats containing more monounsaturated and long-chain polyunsaturated fatty acids with low fat melting points, with relatively little impact on overall eating quality when compared to meat from lambs at either 0% or 20% supplementation levels

Degummed crude canola oil, sire breed and gender effects on intramuscular long-chain omega-3 fatty acid properties of raw and cooked lamb meat

Background: Omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) confer important attributes to health-conscious meat consumers due to the significant role they play in brain development, prevention of coronary heart disease, obesity and hypertension. In this study, the ω3 LC-PUFA content of raw and cooked Longissimus thoracis et lumborum (LTL) muscle from genetically divergent Australian prime lambs supplemented with dietary degummed crude canola oil (DCCO) was evaluated. Methods: Samples of LTL muscle were sourced from 24 first cross ewe and wether lambs sired by Dorset, White Suffolk and Merino rams joined to Merino dams that were assigned to supplemental regimes of degummed crude canola oil (DCCO): a control diet at 0 mL/kg DM of DCCO (DCCOC); 25 mL/kg DM of DCCO (DCCOM) and 50 mL/kg DCCO (DCCOH). Lambs were individually housed and offered 1 kg/day/head for 42 days before being slaughtered. Samples for cooked analysis were prepared to a core temperature of 70 °C using conductive dry-heat. Results: Within raw meats: DCCOH supplemented lambs had significantly (P < 0.05) higher concentrations of eicosapentaenoic (EPA, 20:5ω3) and EPA+docosahexaenoic (DHA, 22:6ω3) acids than those supplemented with DCCOM or DCCOC; Dorset sired lambs contained significantly (P < 0.05) more EPA and EPA+DHA than other sire breeds; diet and sire breed interactions were significant (P < 0.05) in affecting EPA and EPA+DHA concentrations. In cooked meat, ω3 LC-PUFA concentrations in DCCOM (32 mg/100 g), DCCOH (38 mg/100 g), Dorset (36 mg/100 g), White Suffolk (32 mg/100 g), ewes (32 mg/100 g) and wethers (33 mg/100 g), all exceeded the minimum content of 30 mg/100 g of edible cooked portion of EPA+DHA for Australian defined ‘source’ level ω3 LC-PUFA classification. Conclusion: These results present that combinations of dietary degummed crude canola oil, sheep genetics and culinary preparation method can be used as effective management tools to deliver nutritionally improved ω3 LC-PUFA lamb to meat consumers

Arthrospira platensis: a novel feed supplement improves meat eating quality of Australian lamb

Feeds and feeding account for a substantial cost of sheep production, hence the quest for alternative sources of nutrients that can facilitate fast growth in prime lambs without comprising meat eating quality is a continuous research endeavour. This study examined the effect of daily oral drenching of grazing prime lambs with a highly nutritious and edible blue-green microalga commonly referred to as Spirulina (Arthrospira platensis) for nine weeks on meat eating quality and consumer acceptability. The prime lambs were weaners from Merino ewes sired by Dorset, White Suffolk, Black Suffolk and Merino rams randomly allocated to 3 levels of Spirulina supplementation (0, 10 and 20% wt/vol) with 8 lambs per treatment. The lambs were balanced by gender (ewes and wethers), body condition score (average of 3.1 ± 0.4) and body weight (average of 37.6 ± 5.2 kg). Lambs were slaughtered in a commercial abattoir and Longissimus dorsi muscle samples barbequed. A consumer tasting panel subjectively evaluated the sensory meat eating qualities of tenderness, juiciness, aroma, appearance and overall liking. The data were subjected to statistical analyses utilizing the GLM procedures in SAS with sire breed, sex, Spirulina level and their second-order interactions fitted as fixed effects and sire as a random variable. The consumer panel detected highly significant (p<0.001) differences in meat tenderness with the high supplementation group being the least tender (6.8 ± 0.2) compared with the low (7.6 ± 0.2) and control (8.0 ± 0.2) treatments out of a maximum possible score of 10. These results indicated that Spirulina supplementation at a 10% inclusion level produced leaner, healthier meats with relatively little impact on overall eating quality when compared with meat from animals at either 0% or 20% supplementation levels. This will enable prime Iamb producers to make informed decisions regarding the most economically viable use of Spirulina in their flock in targeting potential new niche markets. The study also supports the hypothesis that Spirulina lowers intramuscular fat levels and improves meat tenderness at low levels of supplementation without detrimental effects on eating quality

Spirulina supplementation, sire breed, sex and basal diet effects on lamb intramuscular fat percentage and fat melting points

The effects of Spirulina supplementation, sire breed, sex and basal diet on intramuscular fat percentage (IMF) and fat melting point (FMP) in crossbred and purebred Merino lambs were investigated. Over two consecutive years, a total of 48 lambs was randomly allocated into feeding trials that utilised either ryegrass or Lucerne hay basal diets. Each treatment group had 8 lambs balanced by sire breed (Black Suffolk, Dorset, Merino, White Suffolk), sex (ewes, wethers), and Spirulina supplementation level (CONTROL - unsupplemented, LOW - 50ml, MEDIUM – 100ml, and HIGH – 200ml). Each feeding trial lasted for 9-weeks after 21 days of adjustment. Post-slaughter, IMF content of the Longissimus dorsi et lumborum muscle was determined using solvent extraction and FMP measured using the 'slip-point' method. Spirulina supplementation level influenced both IMF content and FMP in which MEDIUM Spirulina supplementation led to a decrease in IMF (1.98%) and FMP (42.97°C) compared to 3.18% and 44.44°C, respectively, in the LOW supplementation treatment group. Sire breed was a significant source of variation in FMP as purebred Merinos had the highest (45.63°C) and Black Suffolk crossbreds the lowest (41.53°C). Ewe lambs had higher IMF than wether lambs (2.52 vs 2.12%). Lambs on the ryegrass basal diet had lower IMF and FMP than their counterparts on Lucerne. Significant interactions between sire breed and supplementation level suggest a variety of nutritional management combinations that prime lamb producers can utilise to optimise meat quality for increasingly health-conscious consumers

Omega-3 fatty acids, nutrient retention values, and sensory meat eating quality in cooked and raw Australian lamb

This study evaluated omega-3 intramuscular fatty acids in the longissimus thoracis et lumborum of commercially prepared Australian lamb loin chops. Meats, denuded of external fats were cooked by means of conductive dry-heat using a fry grilling hot plate, to a core temperature of 70 °C. An untrained consumer panel assessed meat appearance, aroma, tenderness, juiciness, taste and overall liking. Results showed no compositional alterations (P > 0.05) to omega-3 fatty acids due to cooking treatment, whereas on absolute terms (mg/100 g muscle) omega-3 fatty acids significantly (P < 0.05) increased. The mean EPA + DHA content of the cooked meat at 32.8 ± 2.3 mg/100 g muscle exceeded the minimum 30 mg/100 g per edible portion required for the defined Australian classification as 'source' long-chain (≥ C20) omega-3 for cooked lamb. A 3.4% intramuscular fat content in the initial raw meat was sufficient to maintain acceptable overall sensory eating quality. Results endorse the application of this cooking method to enable delivery of health beneficial long-chain omega-3 fatty acids of commercially prepared Australian lamb loin chops to consumers without impediments to sensory eating properties