Preliminary results of research at the University of Nebraska suggest that health status, as indicated by circulating immunoglobulin concentrations in baby pigs, may be affected by dam parity.

Researchers investigated the health status of different parities by evaluating the ability of Parity 1 (P1) and Parity 3 (P3) dams to produce and passively transfer immunoglobulins (IgA and IgG) to their offspring.

General observation is that P1 progeny have reduced health status compared to progeny from older sows (Table 1). But these differences in health status of pigs from different dam parities have not been fully clarified.

The objective of the University of Nebraska study was to provide baseline information to gain a greater understanding of parity health differences by evaluating production and transfer of immunoglobulins from dams of increasing parity to their progeny.

Large White x Landrace females were part of an ongoing sow longevity experiment at the University of Nebraska.

After farrowing, 4-5 piglets from five, Parity 3 sows and four, Parity 1 gilts were randomly selected for analysis.

Three parameters were evaluated to assess the health status of progeny derived from different parities:

• Circulating concentrations of IgA and IgG in P1 and P3 dams;

• Concentrations of IgA and IgG during lactation in colostrum and mid- and late-lactation milk; and

• Circulating concentrations of IgA and IgG in P1 and P3 progeny.

Whole blood was obtained from each dam 24 hours pre-farrowing and from dam progeny at 0, 8, 15, 20 (weaning), 29 and 37 days post-farrowing.

The concentrations of IgA and IgG in serum obtained from P1 and P3 females 24 hours prior to parturition are depicted in Figure 1. The values for both immunoglobulins are within normal ranges.

However, P3 females had greater concentrations of both IgA and IgG compared to P1 females. The higher stress load on P1 females may dampen their immune response, researchers noted.

This trend for differences in circulating concentrations of immunoglobulins at the time of parturition did not continue when IgA and IgG concentrations were evaluated in colostrum and milk samples from the same females (Figure 2). The IgA and IgG concentrations observed in colostrum samples obtained within 12 hours of farrowing were greater than immunoglobulin levels detected in milk samples obtained at mid- or late lactation.

“Although differences exist in immunoglobulin concentrations in the serum of these same females, it was somewhat surprising that no differences in colostrum or milk immunoglobulin concentrations were observed during lactation,” says lead researcher Thomas E. Burkey.

Figure 3 depicts circulating IgA and IgG concentrations in P1 and P3 progeny at several time points following parturition. The progeny of P3 females had greater levels of IgG compared to the progeny of P1 females at every time point evaluated, with a similar trend observed for IgA.

Progeny immunoglobulin concentrations from birth to about 2 weeks of age are almost completely due to passive transfer from the dam. Baby pigs rely on passive transfer of immunity via colstrum, and milk from the dam until they can mount their own immune response at 2 to 5 weeks of age.

Researchers: Thomas E. Burkey, Phillip S. Miller, Rodger K. Johnson, Duane E. Reese and Roman Moreno, all of the University of Nebraska. Contact Burkey at (402) 472-6423.