University of Nebraska researchers have confirmed earlier work indicating that sow parity affects the health status of her progeny.

The research team evaluated litter performance and the production and passive transfer of immunoglobulins (Ig) {antibodies} in Parity 1 (P1) dams vs. Parity 4 (P4) dams and their progeny.

Immunoglobulin A (IgA) antibodies protect the mucosal surfaces from infection. Immunoglobulin G (IgG) antibodies provide protection against viruses, bacteria and antitoxins and are found in most tissues and plasma.

Researchers found:

Litter weight tended to be greater for P4 progeny compared to P1 progeny.

Dam parity didn't appear to influence circulating Ig in dams during gestation or at farrowing. But IgA concentrations were generally higher for P4 sows than P1 gilts in samples of colostrum and milk. And serum IgG concentrations were greater for P4 progeny compared to P1 progeny across all preweaning samples.

Dams (Large White × Landrace) were first-parity gilts and fourth-parity sows that farrowed over a 22-day period. Dams were housed in stalls during gestation and moved to farrowing crates about five days prior to their expected farrowing date.

All piglets from each litter were weighed on Day 0, 7, 14 and 19 (weaning).

Blood samples were collected from sows during gestation on Day 90 and 114 and a final time after farrowing.

Samples during lactation were obtained at Day 0 (colostrum), Day 7 (mid-lactation) and Day 14 (late-lactation).

Blood samples were collected from six piglets from each litter on Days 1, 7 and 14.

Dam and litter performance are illustrated in Table 1. Data shows parity had no effect on number of pigs/litter or on litter weaning weights.

But P4 dams tended to have pigs with heavier bodyweights compared to P1 dams, and P4 dams had less preweaning mortality and heavier litter weaning weights.

Figure 1 depicts progeny bodyweights of gilts (P1) and Parity 4 (P4) sows. The P4 progeny had heavier bodyweights among all time points from farrowing to weaning than P1 progeny.

Researchers acknowledged that they expected to observe greater differences in dam and litter performance, but based on previous work, it's possible that the greatest differences in performance occurs between P1 and P2 or P3 dams.

IgG and IgA antibodies in P1 and P4 dams during gestation and after farrowing are represented in Figure 2. While IgA increased as the dams approached farrowing, IgG levels declined over time, with the lowest concentrations observed at farrowing. Researchers suggest this result may contribute to the higher levels of IgA in mid- and late-lactation milk as compared to IgG.

IgG and IgA antibodies in colostrum and milk during lactation are shown in Figure 3. IgG concentrations were unaffected by parity. But IgG antibodies averaged among both parities were greater for colostrum than mid- and late-lactation samples. For IgA, concentrations tended to be greater in P4 dams than P1 dams, and again the greatest concentrations were observed during early lactation (colostrum).

There were no parity-by-time interactions for IgG or IgA antibodies in serum from P1 and P4 progeny (Figure 4). However, among all time points, piglets from P4 dams had greater circulating IgG than P1 dams. Parity had no effect on IgA levels in P1 and P4 progeny, but P1 progeny had lower (numerically) IgA levels compared to P4 progeny at Days 1 and 7.

In conclusion, it appears that mature dams (P3+) may provide their progeny with performance advantages due to their contributions of passive immunity. However, future research is needed to determine if these observations are consistent throughout the sow's reproductive lifetime.

Researchers: Erin Carney, Huyen Tran, Justin Bundy, Roman Moreno, Matthew Anderson, Jeffrey Perkins, Phillip Miller and Thomas Burkey, all of the University of Nebraska. Contact Burkey by phone (402) 472-6423, fax (402) 472-6362 or e-mail tburkey2@unl.edu.