Interaction of CP levels in maternal and nursery diets, and its effect on performance, protein digestibility, and serum urea levels in piglets

anglais. peer reviewed

anglais. Reduced protein levels in nursery diets have been associated with a lower risk for post-weaning diarrhea, but the interaction with crude protein (CP) levels in maternal diet on the performance of the offspring remains unclear. The objective of this study was to determine the effect of protein content in sow gestation and piglet nursery diets on the performance of the piglets until slaughter. This was studied in a 2x2 factorial trial (35 sows, 209 piglets), with higher or lower (H or L) dietary CP in sow diets (168 vs 122 g CP/kg) during late gestation. A standard lactation feed was provided for all sows (160 g CP/kg). For both sow treatments, half of the litters received a higher of lower CP in piglet nursery diet (210 vs 166 g CP/kg). This resulted in four possible treatment combinations: HH, HL, LH and LL, with sow treatment as first and piglet treatment as second letter. For each phase, all diets were iso-energetic and had a similar level of essential amino acids. Ps*p is the p-value for the interaction effect between sow and piglet treatment. In the nursery phase (3.5 – 9 weeks of age), a tendency towards interaction between piglet and sow treatments with feed efficiency (Ps*p= 0.08) was observed with HH having the highest gain:feed ratio (G:F) (0.74±0.01), LH the lowest (0.70±0.01) and the other two groups intermediate. In the growing-finishing phase, an interaction was observed between the piglet and sow diets with decreased G:F for LH (Ps*p=0.04) and a tendency towards interaction with increased daily feed intake for LH (Ps*p=0.07). The sow diet showed a tendency towards a long-lasting effect on the dressing percentage and meat thickness of the offspring, which was higher for the progeny of H sows (Ps<0.01 and Ps=0.02, respectively). At 23 weeks, serum urea concentrations tended to be lower for the HH and LL groups (Ps*p=0.07). Fecal consistency scores were higher at day 10 – day 14 after weaning for piglets from L sows (Ps=0.03 and Ps<0.01, respectively). At day 7 after weaning, fecal consistency score was higher for piglets fed the higher protein diet (Pp<0.01). At 8 weeks of age, the apparent total tract digestibility of CP (ATTDCP) interacted between piglet and sow diet (Ps*p=0.02), with HH showing the highest digestibility values. In conclusion, the protein levels in sow late-gestation and piglet nursery diet interacted with feed efficiency, ATTDCP and serum urea concentrations in the nursery phase.