Abstract

Research regarding the association of fatty acids (FA) with corn stubble in feedlot lambs is limited. FA dietary supplements can reduce the digestibility of neutral detergent fibre (NDF). However, it is not known if the NDF amount added with corn stubble and FA source in the diet can influence the content of polyunsaturated fatty acids (PUFA) and the conjugated linoleic acid (CLA), all of which are related to meat quality. In this study, 96 male-lambs (29 ± 4.9 kg) were assigned in two dietary NDF levels [25% (NDF-25) and 29% (NDF-29)] and four supplemental fat treatments [no supplemental (C), 3% CLA-60, 3% Safflower oil (SAF) and 3% linseed oil (LIN)] evaluated in a 2 × 4 factorial arrangement of treatments. Compared with CLA diets, diets supplemented with SAF and LIN contained more C18:2. Dietary forage level did not affect average daily gain, feed efficiency, or carcase characteristics (p = .56). With NDF-29 increased meat protein content (2%, p < .05). Meat chromatic b* values were greater (p = .02) with NDF-25. Control vs. supplemental lipids (SL) MUFA and PUFA increased in the muscle with SL. The endogenous level of CLA in muscle improved (p < .05) in the muscle with SL. Juiciness meat increased with both NDF levels and lipid supplements (p = .06). In conclusion, protein content and juiciness in the meat improve with NDF-29 (as corn stubble) on a diet. Similarly, SAF and LIN increase the content of PUFA and CLA in meat.

• Highlights

• A slight increase of NDF from 25% to 29% added with corn stubble within an iso-energetic diet, change the colour and some sensory variables of the lamb meat.

• Safflower and linseed oils included in the diet at 3% improve the content of conjugated linoleic acid in lamb meat.

• The General Quality index in the meat sensory analysis is not affected by inclusion levels of fibre (NDF 25 vs. 29) and lipids (3%) in the diet of hair lambs.