RESUMO
This study was designed to determine the effect of prenatal lipopolysaccharide (LPS) exposure on the postnatal metabolic response to an LPS challenge in beef heifers. Pregnant, crossbred cows ( = 50) were assigned to a prenatal immune stimulation (PIS; = 25; administered 0.1 µg/kg BW LPS subcutaneously 233 ± 15d of gestation) or saline treatment group (Control; = 25). Birth and weaning BW of calves were collected. There was not (> 0.05) a treatment × gender interaction for birth weight or 205-d adjusted weaning BW. Treatment did not affect (> 0.05) birth BW, but steers and heifers of PIS cows had greater ( < 0.02) 205-d adjusted weaning BW than offspring from Control cows. From the 2 prenatal treatment groups, heifer calves ( = 12 PIS, 11 Control) were identified at weaning (238 ± 15 d of age) to subsequently receive an LPS challenge. On d 0, heifers were fitted with indwelling jugular catheters and were moved into individual pens. On d 1, heifers (fed at 0600 h) were challenged i.v. with LPS (0.5 µg/kg BW) at 0 h (1000 h). Blood samples were collected at 30-min intervals from -2 to 8 h and again at 24 h relative to the LPS challenge. There was a treatment × time interaction ( < 0.01) for cortisol; PIS heifers had greater cortisol from 4 to 6.5 h post-LPS challenge ( < 0.001). There was a treatment × time interaction ( = 0.04) for serum glucose such that glucose was greater ( = 0.01) in PIS than Control heifers at 0.5 h, but was greater in Control than PIS heifers at 2, 4.5, and 7 h post-LPS challenge. This resulted in overall time ( < 0.01) and treatment ( < 0.01) effects such that Control heifers had greater glucose concentrations than PIS heifers. There was a tendency ( = 0.10) for a treatment × time interaction for serum NEFA, such that NEFA was greater in Control than PIS heifers at -2, -1.5, and 7 h relative to the LPS challenge ( ≤ 0.02). Also, there were time ( < 0.01) and treatment effects ( < 0.01) for NEFA with Control heifers having greater NEFA than PIS heifers. Serum BUN was affected by a treatment × time interaction ( < 0.01). Concentrations of BUN were greater in PIS heifers from -1.5 to -1 h, 1 to 2 h, at 4 h, and from 5 to 24 h relative to the LPS challenge. These results demonstrate postnatal growth and the metabolic responses of weaned beef calves can be significantly altered with a single exposure to LPS in utero.
