title: Effect of feed withdrawal and handling intensity on longissimus muscle glycolytic potential and blood measurements in slaughter weight pigs.
abstract: This study was carried out to evaluate the effect of feed withdrawal and handling intensity on blood acid-base responses and muscle glycolytic potential in slaughter-weight pigs. Sixty crossbred pigs (BW = 107.7 +/- 0.56 kg; 44 barrows and 16 gilts) were used in a randomized complete block design with a 2 x 2 factorial arrangement of treatments: 1) feed withdrawal (0 vs. 24 h), and 2) handling intensity (low vs. high). The high-intensity handling treatment consisted of moving the pigs through a passage (12.2 m long x 0.91 m wide) for eight laps using an electric goad two times per lap. Pigs in the low-intensity handling treatment were moved at their own pace through the passage for eight laps using a livestock panel and paddle. Biopsy samples were collected from the LM at the beginning of feed withdrawal, at the end of the handling procedure, and 4 h after handling. Blood samples were collected 2 h before and immediately after the handling procedure. There were no interactions between feed withdrawal and handling intensity for any of the variables measured. Feed withdrawal decreased (P < 0.05) baseline and posthandling body temperature (38.85 vs. 38.65 degrees C; SEM = 0.060 and 39.70 vs. 39.37 degrees C; SEM = 0.04, respectively) and blood glucose, lowered (P < 0.05) baseline partial pressure of oxygen and partial pressure of carbon dioxide, and increased (P < 0.01) baseline and posthandling plasma free fatty acid concentrations. High-intensity handling produced higher (P < 0.01) posthandling lactate and glucose, and lower (P < 0.01) posthandling blood pH (7.33 vs. 7.18 +/- 0.02, respectively), bicarbonate, base excess, and total carbon dioxide than low-intensity handling. Longissimus muscle glycolytic potential of fasted pigs was lower (P < 0.01) than in fed pigs at the end of the handling procedure (177.2 vs. 137.0 micromol/g of wet tissue; SEM = 10.08, respectively). There was no effect of handling intensity on longissimus muscle glycolytic potential. Feed withdrawal did not attenuate the blood acid-base changes caused by handling; however, the combination of feed withdrawal and handling decreased muscle glycolytic potential.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana, 61801, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Bertol
authors.forename: M
authors.initials: M
authors.lastname: Ellis
authors.forename: M J
authors.initials: MJ
authors.lastname: Ritter
authors.forename: F K
authors.initials: FK
authors.lastname: McKeith
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology; D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D001784:Blood Gas Analysis / Q000662:veterinary; D001831:Body Temperature / Q000502:physiology; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D006003:Glycogen / Q000032:analysis; D006019:Glycolysis / Q000502:physiology*; D006234:Handling, Psychological; D016018:Least-Squares Analysis; D008297:Male; D008460:Meat / Q000592:standards; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D011897:Random Allocation; D013552:Swine / Q000502:physiology*; D013997:Time Factors
chemical_list: D006003:Glycogen