Effect of dietary protein source on feed intake and small intestinal morphology in newly weaned piglets

An experiment was designed to study the effect of dietary protein source on feed intake and on small intestinal morphology in newly weaned piglets. In total, 108 piglets were used, without access to creep feed during the suckling period. Piglets were weaned at 27 days of age. They were fed ad libitum one of two iso-nitrogenous experimental diets, which differed in their protein composition and contained either skim milk powder (SMP) or hydrolysed feather meal (FM), the latter component having low ileal protein digestibility. Diets contained equal amounts of indispensable amino acids. On day 4 postweaning, 18 piglets with a similar high feed intake were selected within each dietary treatment and sampled for small intestinal morphology on days 4, 7, or 14 postweaning. The dietary protein source did not affect feed intake during the first three days after weaning. From days 0 (day of weaning) to 2, the mean feed intake increased from 28.9 (S.D. 45.2) to 202.1 (S.D. 129.9) g day(-1) piglet(-1). In the second week, the feed intake of the selected piglets receiving the SMP diet was higher (P < 0.05) than that of the piglets receiving the FM diet. Villus height and crypt depth were significantly higher for the piglets fed the SMP diet when compared to those fed the FM diet. It is concluded that SMP had a positive effect on villus height, this effect being mediated through its high degree of ileal protein digestibility rather than through its stimulatory effect on feed intake. (C) 2003 Elsevier B.V. All rights reserved.