Whole grains in the finishing of culled ewes in pasture or feedlot: Performance, carcass characteristics and meat quality

• Feedlot with whole grain corn and sorghum increased productive performance.
• Cull ewes finished on ryegrass pasture ensure better lipid stability and colouring.
• Animals fed on pasture had higher concentrations of CLA, linolenic and n-3 acids.
• The feedlot system increased the concentration of linoleic acid and the n-6/n-3 ratio.

In order to evaluate the performance, carcass characteristics and meat quality of culled ewes finished in pasture or exclusively with grain, 41 culled Polwarth ewes, were assigned to six treatments: RY (ryegrass pasture), RYGO (ryegrass and whole grain oats), RYGM (ryegrass and whole grain maize), GM (whole grain maize), GO (whole grain oats), GS (whole grain sorghum). The finishing system of the ewes influenced weight gain, wherein the GM and GS treatments increased daily weight gain. The GO treatment decreased the dressing percentage. Nonetheless, a*, h*, pH, cooking loss and tenderness were similar across dietary treatments. Using principal component analysis, the variables C18:2n6, h*, n6/n3, TBARS, total lipids, L* and b* were assigned as characteristics of meat from the feedlot animals, while the pasture finishing system produced meat with higher CLA and n-3 fatty acids but lower TBARS values indicating lipid stability.