The experiment was conducted at La Garcipollera Research Station (Spain, 42◦ 37 N, 0◦ 30 W; 945 m a.s.l.). Eight Parda de
Montana˜ and 16 Pirenaica calves were used in the experiment. Animals were castrated at 8.2 ± 0.11 months of age by surgical
removal of the testes with local anesthesia and analgesia. During the 169-days winter housing period, the 24 steers received
a total mixed ration (TMR) composed of 50% alfalfa hay, 10% barley straw and 40% maize grain. Ingredients were chopped (3-
cm length) and proportions were calculated on as-such basis (9.1 mg/kg of dry matter (DM) -carotene, 20.5 g/kg DM lutein,
and 25.3 mg/kg DM -tocopherol contents) on an ad libitum basis. At the beginning of May, the steers (14.6 ± 0.11 months
old) were turned out to the valley meadows mainly composed of 80% Graminaceae, 4% Leguminosae and 16% other families
(276 mg/kg DM -carotene, 266 mg/kg DM lutein, and 43.8 mg/kg DM -tocopherol contents) and were supplemented daily
with 1.85 kg of dry matter (DM) maize grain (10.5 mg/kg DM -tocopherol content) per head until they were 17.0 ± 0.11
months old. From that moment, the finishing period started. Eight Parda de Montana˜ steers (PAM) and 8 Pirenaica steers
(PIM) grazed on the meadows and received 3.7 kg DM maize per head daily until they reached the target slaughter weight;
the other 8 Pirenaica steers were fed indoors (PII) the same dry TMR used during the winter housing period on an ad libitum
basis until they reached the target slaughter weight. Animals were weighed weekly throughout the experiment. For detailed
information about the feedstuffs, animal performance and carcass and meat characteristics, see Ripoll et al. (2014b).
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