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) as a supplement 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 treatment groups: Control (0%), low (10%wt/vol) and high (20%wt/vol) comprising 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 utilising 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. 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 to the low (7.6±0.2) and control (8.0±0.2) groups 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 to meat from animals at either 0% or 20% supplementation levels. This will enable prime lamb 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.