Genetic and dietary enhancement of n-3 fatty acids in sheep meat

Experiments were carried out to determine the effect of supplementing purebred and crossbred weaner lambs with Spirulina on fatty acid composition and the expression of fat metabolism and lipogenesis related genes in the muscle, adipose, liver, heart and kidney organs. The transcription levels of Aralkylamine N-acetyltransferase (AANAT), Adrenergic beta-3 receptor (ADRB3), B-cell translocation gene 2 (BTG2) and Fatty acid synthase (FASN) genes provided consistent evidence that 10% dietary supplementation with Spirulina increased prime lamb growth and meat quality through heavier liveweights, longer body lengths (BL) and enhanced polyunsaturated fatty acid (PUFA) compositions under pasture-fed management. Under simulated drought conditions when sheep lose weight and body condition, supplementation with Spirulina compensated for weight loss and sequestrated for sheep production losses. The transcription levels of AANAT, ADRB3, BTG2 and FASN genes under simulated drought conditions assisted in shedding light on the underlying biological mechanisms at the molecular level; significant increases in n-3 and n-6 fatty acids were observed in lambs supplemented with 10% Spirulina indicating a positive impact on meat quality performance. A single nucleotide polymorphism (SNP) study was carried out to determine the effect of ADRB3 gene mutations on the growth performance of purebred and crossbred sheep. SNP analyses revealed that Black Suffolk breed was less mutated compared to other breeds resulting in higher liveweight and an improved PUFA profile. Taken together, these results suggest that in crossbred sheep production, supplementation with Spirulina, a linoleic acid (LA) and α-linolenic acid (ALA) rich diet induced SFA depression and an increase in PUFA