Influence of sows' parity on performance and humoral immune response of the offspring

Primiparous sows (PP) have higher nutrient requirements, fewer piglets born with lower birth weight and growth performance than multiparous sows (MP). The aim of the current study was to investigate the effect of parity of sow (PP or MP) on the growth performance and humoral immune response of piglets. A total of 10 PP and 10 MP (3rd to 5th parity) sows were used. There were 4 treatments in a 2 × 2 factorial arrangement, with piglets from PP sows suckled by PP or MP sows, and piglets from MP sows suckled by PP or MP sows. Average daily gain (ADG) of piglets during the lactation period, and ADG, average daily feed intake (ADFI) and gain:feed ratio (G:F) from weaning to 144 days of age were controlled, and concentrations of immunoglobulins G (IgG) and major acute phase protein (Pig-MAP) were measured as markers of humoral immune response throughout the study.

Total ADG was higher in piglets born from MP than in those born from PP (669 vs. 605 g/day; standard error of the mean (SEM) = 15.5, n = 5; P = 0.001) and in piglets suckled by MP than in piglets suckled by PP (655 vs. 620 g/day; SEM = 15.5, n = 5, P = 0.037). Total ADFI was higher for pigs born from MP than for those born from PP (1592 vs. 1438 g/d, SEM = 42.2, n = 5, P < 0.001). Total G:F tended to be higher for pigs suckled by MP than for those suckled by PP (0.43 vs. 0.41, SEM = 0.006, n = 5, P = 0.076). At weaning, IgG serum concentration was higher (30.0 vs. 17.8 mg/mL, SEM = 4.98, n = 15, P = 0.013) in pigs suckled by MP than in piglets suckled by PP. However, IgG concentrations were higher for pigs born from PP than for pigs born from MP on days 116 (P < 0.001) and 144 (P = 0.088). Pig-MAP tended to be lower in pigs suckled by MP than in pigs suckled by PP on days 40 and 60 of age (P < 0.10).

The research indicates that the growth performance and humoral immune response of the offspring of PP is improved by cross-fostering with MP. These results open the possibility of an interesting strategy for improving the growth of litters from PP, that is easier to apply than current programs based on parity segregation, which implies a separate building site to house gilts, first parity sows and their offspring.