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|Title:||Effects of Elevated Environmental Temperature on Passive Immunity in Swine|
|Author(s):||Machado Neto, Raul|
|Department / Program:||Dairy Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Biology, Animal Physiology|
|Abstract:||The effect of moderate heat stress on transference in swine has been investigated. The sows subjected to 31.6(DEGREES)C (treatment "H") in an environmental chamber, during last two weeks of gestation showed increased (P < 0.01) rectal temperature, respiratory rate and levels of cortisol compared to the control animals subjected to an environmental chamber (21.2(DEGREES)C treatment "CHC") and University farm (21.9(DEGREES)C, treatment "FC") during the same period.
The first lacteal secretion and the piglets blood serum at farrowing time showed higher (P < 0.01) levels of cortisol compared to the piglets farrowed from sows maintained in control treatments.
Concentration of total protein, globulin and immunoglobulin G decreased linearly toward parturition, however neither the correlation coefficient nor the average concentration showed a significant difference among the treatments. Albumin, in the same period, kept fairly stable, showing no trend or significant difference in the concentrations among the treatments. The decrease observed in total protein and globulin was mainly due to the immunoglobulin G decrease which is transported from blood serum to the mammary gland in the last two weeks of gestation.
Total protein and immunoglobulin concentration were measured in colostrum at farrowing time, 24 hours and 48 hours post-partum. The average values for total protein and immunoglobulin G were lower in the treatment H, however no statistical significant difference was found among the treatments.
In the piglets the levels of total protein, albumin, globulin and immunoglobulin G at farrowing time did not show significant differences among treatments. After colostrum ingestion by the piglets, the concentrations of all blood serum components measured increased drastically in the first 24 hours. Total protein, after an initial increase in the first 24 hours, remained fairly stable. Immunoglobulin G and globulin decreased in all treatments after the initial increase in the first 24 hours. There was no significant differences in the decreasing rate of globulin, however the average concentration in treatment H was significantly lower (P < 0.01) compared to CHC and FC. Immunoglobulin G in treatment H showed lower average (P < 0.01) concentration and the decreasing rate obtained in the linear regression until day 20th post-partum was also lower (P < 0.01) compared to the regression coefficient in CHC and FC in the 28 day post-partum period.
Mortality and gain of weight was registered between farrowing and weaning (28th day post-partum) and the treatments showed no significant effect on the data obtained.
The results suggest that the higher levels of cortisol observed in the sows serum, under higher temperature, might be the factor responsible for higher levels of cortisol in the piglets at farrowing time which consequently determined lower absorption of immunoglobulin in their piglets systemic immunity then throughout the whole period studied, systemic immunity in the young pig in all treatments is far from optimum. It must be appreciated that while systemic immunoglobulin G levels may indicate the general immune status of the animal, circulating immunoglobulins in general give no indication of the specificity of immunity that may be present or developed in the tissue immune system, such as the intestinal tract, which must be more important in the infection prevention in the young.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.
|Date Available in IDEALS:||2014-12-14|