Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/1999
Publication Date: N/A
Technical Abstract: Our objective was to evaluate possible interactions between environmental temperature (ET) and the neonatal pig's ability to cope with an endotoxin challenge. Male pigs (n=28; 24 h old) were placed in ET controlled chambers maintained at 18 or 34 deg C (n=14/ET). Rectal temperatures (RT) were measured every 15 min for 3 h following an i.p. injection of saline (Cont; n=7/ET) or lipopolysaccharide (LPS; 150 ug/kg; n=7/ET). Pigs were sacrificed following the 3-h period for tissue and blood collection. There was a TIME x ET x TRT interaction (P<.0001) for RT such that LPS pigs exposed to 18 deg C experienced a period of hypothermia while RT for LPS pigs at 34 deg C did not differ from that of Cont pigs at 34 deg C. There was also an ET x TRT interaction (P=.014) for body weight (BWT) change such that LPS pigs maintained at 18 deg C lost the most BWT during the 3-h period. Serum ACTH tended to be greater (P=.094) in pigs maintained at 18 deg C, but was not affected by LPS treatment. There was an ET x TRT interaction (P=.0013) for serum cortisol (CS) such that LPS pigs maintained at 18 deg C had a greater increase in serum CS compared to LPS pigs at 34 deg C. Serum prolactin (PRL) was reduced (P<.017) in pigs maintained at 18 deg C compared to pigs maintained at 34 deg C; however, there was no effect of LPS on serum PRL. There tended (P=.098) to be an ET x TRT interaction such that LPS increased serum PRL at 18 deg C but had no effect on serum PRL at 34 deg C. There was an ET X TRT interaction (P<.016) for serum tumor-necrosis factor alpha (TNF) such that LPS increased serum TNF in pigs maintained at 18 deg C, but had no effect on serum TNF in pigs maintained at 34 deg C. These results indicate that acute exposure to a cold ET can compromise a neonatal pig's ability to cope with an endotoxin challenge.