Performance and carcass traits of pigs submitted to different programs of feed restriction from 30 to 118 kg

The aim of this work was evaluate the animal performance, the carcass characteristics and the weight of the organs of digestive system of pigs submitted to different periods of feed restriction. A total of 40 barrows, Landrace × Large White were distributed to randomized block design, to four feed restriction programs, five replications and two animal per experimental unit. Four restrict programs were evaluated: one control, with ad libitum feeding during the 86 days of experiment, and others three, with restriction of 20% in the feed intake in relation to control group, during 21 days, at 30, 50 or 70 kg BW. Performance characteristics as daily feed intake, daily weight gain and the feed conversion of the animals were evaluated. Carcass characteristics, as hot and cold carcass weights, length and carcass dressing, subcutaneous fat thickness, Longissimus dorsi muscle depth, lean meat yield, lean meat amount and loin eye area were evaluated. Also were evaluated organs weights, as liver, stomach, small and large intestine. The costs of each program were evaluated to observe their viability. Feed conversion, considering total experimental period, was better for the animals kept on feed restriction from 70 kg BW. The carcass characteristics evaluations and organs weights did not differ among feed restriction programs. The costs analysis showed a better relation for feed restriction from 70 kg BW. In all feeding programs, the feed restriction followed by ad libitum feeding promoted a compensatory gain effect for all treatments.

alimentary efficiency; feed intake; performance; weight gain

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