Abstract :
Thirty-two intact male Pelibuey lambs with an average weight of 21.2 kg were randomly
assigned to four treatment rations in a completely random design. The four experimental
rations contained incremental levels of dry waste mycelium: 0, 2.7, 5.4 and 8.1%. The study
was 75 days long, with 15 days for adaptation of lambs to their pens and a 60-day experimental
period in which dry matter (DM) intake, daily weight gain, and feed efficiency were
determined. At the end of the study, lambs were slaughtered, and their carcasses weighed
and marbling scores determined. Results show a quadratic effect on DM intake (P = 0.035)
and ADG (P = 0.006). Both DM intake and ADG first increased before declining as mycelium
level increased in the diet. Gain:feed decreased linearly (P < 0.001) with an increase in waste
mycelium in the diet. Carcass characteristics, such as hot and chilled carcass weight and
hot and chilled dressing percent, and carcass marbling score, were not affected (P > 0.10).
Marbling score of the carcasses ranged from traces to modest marbling.
