Fatty acid profile and intramuscular fat concentration ofMusculus longissimus thoracisin bulls fed grass silage harvested at one of three maturity stages, either with or without concentrate supplementation

Abstract

The study investigated the effect of plant maturity of grass silage on intramuscular fat (IMF) concentration and fatty acid profile in M. longissimus thoracis of bulls. From 7 to 8 months of age until slaughter, 36 bulls of Norwegian Red were offered grass silage harvested at three maturity stages ad libitum, with or without concentrate supplement. Increasing plant maturity decreased the proportion of α-linolenic acid in IMF (P = 0.04). Concentrate supplementation increased the proportions in IMF of linoleic acid (P < 0.001) and C20:3n-6 (P < 0.008), decreased all analysed n-3 polyunsaturated fatty acids (P ≤ 0.02), conjugated linoleic acid (P < 0.01) and trans vaccenic acid (P < 0.001). Polyunsaturated fatty acids n-6/n-3 ratios were in the range 1.0-2.1 and increased with plant maturity and concentrate supplementation. Results suggest that 'grass-fed beef' also may be produced indoors with grass silages in regions with short grazing season.

Effect of Different Roughage Sources in Fermented Total Mixed Ration and Energy Intake on Meat Quality, Collagen Solubility, Troponin T Degradation, and Fatty Acids of Native Thai Cattle Longissimus Muscle

“…The higher fermentation forage fat and carbohydrate, such as ruminal acetic acid as a precursor of fatty acid synthesis from NG-FTMR, could explain the higher levels of myristic acid, stearic acid, arachidic acid, oleic acid, arachidonic acid, and MUFA in the LT muscle of cattle fed NG-FTMR compared to cattle fed RS-FTMR. According to Randby et al [ 62 ], the chemical composition of silage—crude protein, crude fat, water-soluble carbohydrates, and metabolizable energy—decreased with increasing plant maturity. They also found that oleic acid and some of the MUFA in intramuscular fat decreased with increasing plant maturity.…”