Effect of milk chocolate product on week-1 feed intake and growth performance of weanling pigs.

Experiments were conducted to assess the effect of dried whey (DW; 70% lactose) or milk chocolate product (MCP; 20% lactose and 60% sugars) on wk-1 feed intake and growth performance of pigs. Diets contained 1.60, 1.40, 1.40, and 1.20% total Lys for phase 1 (d 0 to 7), 2 (d 7 to 14), 3 (d 14 to 21), and 4 (d 21 to 35), respectively. Pigs were blocked by initial BW; sex and littermates were balanced across treatment; treatments were replicated with a minimum of 5 pens of 4 pigs each. Pigs were weaned at 24, 19, and 24 d of age with an initial BW of 6.5, 6.0, or 6.3 kg for Exp. 1 to 3, respectively. In Exp. 1 and 2, the treatments were 1) negative control (NC), no lactose added, 2) positive control (PC) with DW, 3) 25% replacement of the level of DW of the PC diet with MCP (25MCP), and 4) 50% replacement of the level of DW of the PC diet with MCP (50MCP). The level of DW or combinations of DW and MCP were 20, 10, and 5% for phases 1, 2, and 3 respectively. A common diet with no lactose was fed during phase 4. In Exp. 3, the treatments were 1) NC, 2) PC, and 3) 100% replacement of the level of DW of the PC diet with MCP (100MCP). In the combined data of Exp. 1 and 2, daily collected feed intake during wk 1 was increased (P < 0.10) from d 3 to 7 for the PC pigs; on d 2, 3, 4, and 7 for the 25MCP pigs; and from d 2 to 7 for the 50MCP pigs compared with the NC pigs. There was no difference (P > 0.10) on any day of wk 1 among pigs fed the PC and MCP diets. During phase 1, ADG and ADFI were increased (P < 0.10) for the PC, 25MCP, and 50MCP pigs compared with the NC pigs, but G:F was not affected (P > 0.10). During phases 2, 3, 4, and overall, there were no differences (P > 0.10) in growth performance among pigs fed the PC and MCP diets. In Exp. 3, collected daily feed intake during wk 1 was increased (P < 0.10) from d 2 to 5 for PC pigs and on d 1 and 2 for the 100MCP pigs compared with the NC pigs. However, there was no difference (P > 0.10) on any day of wk 1 between the PC and 100MCP pigs. Growth performance was not affected (P > 0.10) during any phase of the experiment. Combined data from Exp. 1, 2, and 3 using the NC and PC diets indicated that dietary DW increased (P < 0.10) final BW and increased ADG and ADFI during phases 1, 2, 3, and overall. These results indicate that partial or total replacement of DW with MCP had no effect on wk-1 feed intake or growth performance of weanling pigs and that MCP could be considered as a formulation alternative to DW.