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The objective was to estimate responses in growth and carcass traits in the NE Index line (I) that was selected 19 generations for increased litter size. Responses in pure-line, F1 and 3-way cross litters were compared. In Exp 1, 694 gilts that were retained for breeding, including 448 I and control (C) and 246 F1 I and C by Danbred™ Landrace (L), were evaluated. Direct genetic effects of I and C did not differ for backfat or days to 230 lb; however, I had 0.24 in2 smaller longissimus muscle area (LMA) than C (P < 0.05). F1 gilts had -0.13 in less backfat, 0.67 in2 greater LMA and –31 d less to 230 lb than pure-line gilts (P < 0.05). Exp 2 used individually-penned barrows and gilts including 43 I and C, 77 F1 produced from pure-line females mated to (L) or Danbred® USA DH boars (T), and 76 3-way crosses produced from F1 females mated to T boars. Direct genetic effects of I did not differ from C for average daily feed intake (ADFI), average daily gain (ADG), feed conversion (FC), days to 250 lb, backfat (BF), LMA, ultimate pH of the longissimus, longissimus Minolta l* score, and % lean estimated by TOBEC. Responses (I minus C) in growth and carcass merit did not differ when measured in pure-line and crossbred pigs. Interactions between responses in F1 and pure lines were not significant except for pH. F1 and 3-way cross pigs averaged 0.51 lb/d greater ADFI, -0.53 less feed/gain and 0.44 lb/d more ADG than pure-line pigs (P < 0.01). F1 and 3-way crosses had -0.35 in less BF, 0.89 in2 greater LMA, 6.2 % greater lean, and 5.3 higher Minolta l* score than pure lines (P < 0.05). No correlated responses to selection for increased litter size in overall growth or carcass traits occurred. Mating Line I to leaner, faster growing sires will increase ADFI, ADG, LMA, and percentage lean , decrease feed/gain ratio, decrease backfat, and lighten meat color.