Influence of birth prematurity on colostrum composition and subsequent immunity of piglets.

Two groups of seven pregnant sows were farrowing either naturally after 111-114 days of gestation or prematurely after 109 days following an injection of 125 micrograms/animal of a prostaglandin analogue. Colostrum intake was controlled individually on piglets during the first 24 h of life. Measurements of IgG, IgA and IgM were performed on 3 samples of colostrum after 0, 12 and 24 h following the birth of the first piglet, then in the serum of the piglets, sampled at 4, 12 and 42 days of age. Then, we calculated the total amount of Ig intake during the first 24 h of life and an estimation of the Ig stores of each piglet on the basis of weight, blood volume, and hematocrit at different ages. Results showed a marked average difference in the birth weight in favour of mature piglets as well as an increased colostrum intake: 315 vs an average of 213 g for premature piglets. Considerable variations between sows were found in the initial level of colostral IgG, independently of the gestation length. Two thirds of the IgG intake by piglets occurred during the first 12 h. Total Immunoglobulin intake in the first day was respectively 15.8 g vs 25.1 g for premature or mature piglets. Total estimated Ig content in the serum of 4 day-old piglets was also lower for premature ones (2.55 vs 3.2 g/animal), representing 10 to 27% of the total amount of Igs ingested during the first day of life.(ABSTRACT TRUNCATED AT 250 WORDS)