Sow behavior on the day of farrowing: The main determinant of early piglet growth among maternal ability traits

Abstract Large White and Meishan sows differ in maternal ability and early piglet growth. We investigated the relationships between piglet growth over three periods after birth (D0-D1, D1-D3 and D3-D7; D0 starting at the onset of farrowing) and 101 maternal traits, grouped into 11 blocks according to the biological function they describe. Within and between breed variation was exploited to account for a maximum of variability. The objective was to quantify the contribution of maternal traits to early piglet growth. The relationships were analyzed with multiblock and triadic partial analyses. Several behavioral traits (standing activity, reactivity, postural) and functional traits (body reserves, teat quality) at farrowing had substantial contributions to piglet growth from D0 to D7. Sow aggressiveness towards piglets and time spent standing at D0 were unfavorably correlated to D1-D3 growth. Time spent lying with udder exposed at D0 was favorably correlated to D1-D3 growth. The farrowing duration was negatively correlated to growth from D0 to D3. Furthermore, D3-D7 growth was positively correlated to feed intake in the same period. Several behavior traits and some functional traits play part in early piglet growth, with a greater contribution of sow behavior in the critical period around farrowing than in later days.