Researchers from Agri-Food and Biosciences Institute, Hillsborough, and Agri-Food and Biosciences Institute, Belfast, United Kingdom used 48 dairy-breed bulls (i.e. 18 Holstein-Friesian, 6 Norwegian, 4 Norwegian × Holstein-Friesian, 12 Holstein × Norwegian and 8 Jersey × Holstein-Friesian) for this trial.
Initial live weight (LW) of the bulls was 350 ± 30.9 kg and average age was 11 ± 0.7 months.
Grass silage was fed ad libitum and concentrates were fed daily on top of the silage. Concentrate intake was adjusted to ensure that total metabolizable energy intake from the supplement component of the diet (i.e. concentrate plus linseed) was constant among all treatments.
Animals were slaughtered at a target LW at slaughter of 540 kg and so were slaughtered in three batches after 120, 147 and 185 days on experiment.
Substitution of a proportion of the concentrate diet with extruded linseed had no effects on animal performance (i.e. dry matter intake, LW gain or carcass characteristics).
Meat quality was also not affected by dietary treatment. Substitution of a proportion of the concentrate diet with extruded linseed decreased palmitic acid (C16:0) and arachidonic acid (C20:4) concentrations, saturated:unsaturated fatty acid (FA) ratio and the n-6:n-3 polyunsaturated FA (PUFA) ratio in muscle.
Trans vaccenic acid (C18:1 t11), α-linolenic acid (C18:3n-3), n-3 PUFA and the ratio of PUFA:saturated (P:S) FA in muscle were increased by the linseed treatment.
Manipulating fatty acid composition
Results demonstrate the ability to manipulate the FA composition of the meat of dairy bulls by substituting a proportion of the concentrate diet with extruded linseed, with no detrimental effects on their performance or instrumental meat quality.
“Effects of substitution of a proportion of the concentrate in grass silage/concentrate-based diets with extruded linseed on performance and meat quality of dairy bulls” byL.E.R. Dawson and V.B. Woods (Agri-Food and Biosciences Institute, Large Park, Hillsborough, Co. Down BT26 6DR, United Kingdom) and A.M. Fearon, B.W. Moss (Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9, United Kingdom)
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