Enhancing the Nutritional Value of Red Meat through Genetic and Feeding Strategies

Consumption of red meat contributes to the intake of many essential nutrients in the human diet including protein, essential fatty acids, and several vitamins and trace minerals, with high iron content, particularly in meats with high myoglobin content. Demand for red meat continues to increase worldwide, particularly in developing countries where food nutrient density is a concern. Dietary and genetic manipulation of livestock can influence the nutritional value of meat products, providing opportunities to enhance the nutritional value of meat. Studies have demonstrated that changes in livestock nutrition and breeding strategies can alter the nutritional value of red meat. Traditional breeding strategies, such as genetic selection, have influenced multiple carcass and meat quality attributes relevant to the nutritional value of meat including muscle and fat deposition. However, limited studies have combined both genetic and nutritional approaches. Future studies aiming to manipulate the composition of fresh meat should aim to balance potential impacts on product quality and consumer perception. Furthermore, the rapidly emerging fields of phenomics, nutrigenomics, and integrative approaches, such as livestock precision farming and systems biology, may help better understand the opportunities to improve the nutritional value of meat under both experimental and commercial conditions.

Lipid Oxidation and Colour Stability of Lamb and Yearling Meat (Muscle Longissimus Lumborum) from SheepSupplemented with Camelina-Based Diets after Short-,Medium-, and Long-Term Storage

This study investigated the impact of feeding pelleted diets containing camelina (Camelina sativa L. Crantz) hay (CAHP) or camelina meal (CAMP) as a supplement compared with a control pellet (CONP) diet, without vitamin E fortification. The fatty acid profile, retail colour, and lipid oxidative stability of lamb and yearling meat (m. longissimus lumborum) stored for short-, medium-, or long-periods (2 days (fresh), 45 days and 90 days) under chilled to semi-frozen conditions were determined. The CAMP diet altered key fatty acids (p < 0.05) in a nutritionally beneficial manner for human health compared to the other diets, with increased total omega-3, decreased omega-6 fatty acids and decreased omega-6/omega-3 ratio of muscle. Muscle vitamin E concentration was lower (p < 0.05) for both camelina diets (CAMP and CAHP) when compared with the CONP diet, with the average concentrations less than 1 mg/kg muscle for all three treatments. Animal type and storage length were factors that all affected (p < 0.05) colour and lipid oxidative stability of meat. These results emphasise the importance of vitamin E concentration in meat stored for extended periods under semi-frozen conditions to maintain desirable meat colour during retail display, and to avoid off-flavour development of the cooked meat.

Reducing the level of nutrition of twin-bearing ewes during mid to late pregnancy produces leaner prime lambs at slaughter

The Australian prime lamb industry is seeking to improve lean meat yield (LMY) as a means to increasing efficiency and profitability across the whole value chain. The LMY of prime lambs is affected by genetics and on-farm nutrition from birth to slaughter and is the total muscle weight relative to the total carcass weight. Under the production conditions of south eastern Australia, many ewe flocks experience a moderate reduction in nutrition in mid to late pregnancy due to a decrease in pasture availability and quality. Correcting nutritional deficits throughout gestation requires the feeding of supplements. This enables the pregnant ewe to meet condition score (CS) targets at lambing. However, limited resources on farm often mean it is difficult to effectively manage nutritional supplementation of the pregnant ewe flock. The impact of reduced ewe nutrition in mid to late pregnancy on the body composition of finishing lambs and subsequent carcass composition remains unknown. This study investigated the effect of moderately reducing ewe nutrition in mid to late gestation on the body composition of finishing lambs and carcass composition at slaughter on a commercial scale. Multiple born lambs to CS2.5 target ewes were lighter at birth and weaning, had lower feedlot entry and exit weights with lower pre-slaughter and carcass weights compared with CS3.0 and CS3.5 target ewes. These lambs also had significantly lower eye muscle and fat depth when measured by ultrasound prior to slaughter and carcass subcutaneous fat depth measured 110 mm from the spine along the 12th rib (GR 12th) and at the C-site (C-fat). Although carcasses were ~5% lighter, results showed that male progeny born to ewes with reduced nutrition from day 50 gestation to a target CS2.5 at lambing had a higher percentage of lean tissue mass as measured by dual energy X-ray absorptiometry and a lower percentage of fat during finishing and at slaughter, with the multiple born progeny from CS3.0 and CS3.5 target ewes being similar. These data suggest lambs produced from multiple bearing ewes that have had a moderate reduction in nutrition during pregnancy are less mature. This effect was also independent of lamb finishing system. The 5% reduction in carcass weight observed in this study would have commercially relevant consequences for prime lamb producers, despite a small gain in LMY.