Abstract #790
Section: Nonruminant Nutrition
Session: Nonruminant Nutrition: Immune support
Format: Oral
Day/Time: Wednesday 2:45 PM–3:00 PM
Location: Sebastian I-4
Session: Nonruminant Nutrition: Immune support
Format: Oral
Day/Time: Wednesday 2:45 PM–3:00 PM
Location: Sebastian I-4
# 790
Infection with porcine reproductive and respiratory syndrome virus (PRRSV) affects body protein deposition and alters amino acid metabolism in growing pigs.
Whitney D. Stuart*1, Thomas E. Burkey2, Nicholas K. Gabler3, Kent Schwartz3, Thu Dinh4, Cornelius F. M. de Lange5, David Klein1, John A. Dawson1, Anoosh Rakhshandeh1, 1Texas Tech University, Lubbock, TX, 2University of Nebraska-Lincoln, Lincoln, NE, 3Iowa State University, Ames, IA, 4Mississippi State University, Mississippi State, MS, 5University of Guelph, Guelph, ON, Canada.
Key Words: amino acid, kinetic, PRRS
Infection with porcine reproductive and respiratory syndrome virus (PRRSV) affects body protein deposition and alters amino acid metabolism in growing pigs.
Whitney D. Stuart*1, Thomas E. Burkey2, Nicholas K. Gabler3, Kent Schwartz3, Thu Dinh4, Cornelius F. M. de Lange5, David Klein1, John A. Dawson1, Anoosh Rakhshandeh1, 1Texas Tech University, Lubbock, TX, 2University of Nebraska-Lincoln, Lincoln, NE, 3Iowa State University, Ames, IA, 4Mississippi State University, Mississippi State, MS, 5University of Guelph, Guelph, ON, Canada.
Changes in plasma free amino acid (AA) kinetics reflect modification of AA metabolism in different metabolic states. Infectious diseases in growing pigs redistribute AA from body protein deposition (PD) toward processes involved in immune response. The aim of the current study was to quantify the effects of PRRSV infection on PD and AA metabolism. Twenty PRRSV-negative gilts (BW 9.4 ± 0.9 kg) were blocked by time, surgically catheterized, housed in metabolism crates, fed a corn-SBM based diet (ME 14 MJ/kg, SID Lys 11.5 g/kg), feed-restricted (550 g/d), and then inoculated intramuscularly with a live PRRSV. Blood samples were collected via the catheters at 0, 2, 4, 6, 8, and 10 d post inoculation, and assayed for blood chemistry, hematology, and serum viral load. Body temperature (BT) was monitored on a daily basis. N-balances were determined during a 3 d pre inoculation period and a 3 d post inoculation period. At the end of each N-balance period a single dose of [U-13C, U-15N] AA mixture (Lys, Met, Thr, Trp, Ile, Leu, Val, Phe, Gln) was infused intravenously to study plasma AA kinetics. For each pig and AA, an irreversible loss rate (ILR; disappearance of AA from plasma pool) was determined. Data were analyzed using a randomized complete block design (PROC MIXED in SAS). Blood chemistry, hematology, BT, and serum viral load results indicated that PRRSV injection induced effective immune system stimulation in pigs (P < 0.05). The PRRSV challenge reduced PD from 59.4 to 38.1 g/d, SE 4.56, but increased the ILR (µmol/kg BW/h) for Met (from 108 to 228, SE 26.7) and Thr (from 83 to 129, SE 11.5; P < 0.05). The ILR for other AA was not affected by PRRSV. These results suggest that PRRSV infection reduces PD and alters metabolism of Met and Thr in growing pigs. The increased ILR for Met and Thr in PRRSV challenged pigs could be associated with enhanced utilization of Met and Thr for synthesis of immune system metabolites and increased catabolism of these AA. This may increase dietary Met and Thr requirements of health challenged pigs, relative to requirements for other AA.
Key Words: amino acid, kinetic, PRRS
