Effects of handling intensity and live weight on blood acid-base status in finishing pigs

• Published in: Journal of animal science Vol. 82; no. 8; pp. 2405 - 2409
• Main Authors: Hamilton, D.N, Ellis, M, Bertol, T.M, Miller, K.D
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01.08.2004; American Society of Animal Science; Oxford University Press
• Subjects: acid-base balance; Acid-Base Equilibrium - physiology; Anatomy & physiology; Animal behavior; animal handling; Animal Husbandry - methods; Animal productions; animal stress; animal welfare; Animals; barrows; Bicarbonates - blood; Biological and medical sciences; Blood; Body Temperature; body weight; Body Weight - physiology; Carbon Dioxide - blood; electric current; Female; finishing; Fundamental and applied biological sciences. Psychology; gender differences; gilts; Handling (Psychology); Hogs; Hydrogen-Ion Concentration; Male; Oxygen - blood; Partial Pressure; physical activity; Random Allocation; Sex Factors; Swine - blood; Terrestrial animal productions; Vertebrates; Weight; Farming animal; Intensity; Weight; Blood; Pig; Live Weight; Acid-Base Balance; Vertebrata; Meat animals; Mammalia; Stressor; Artiodactyla; Ungulata; Handling
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/2004.8282405x

The objective of this study was to determine the effect of live weight on the plasma acid-base response of pigs subjected to various handling intensities. Eighty pigs (equal numbers of barrows and gilts) were used in a completely randomized block design with a 2 x 2 x 2 factorial arrangement of the following treatments: 1) live weight (light [104 kg] vs. heavy [128 kg]), 2) handling intensity (low vs. high), and 3) gender (barrows vs. gilts). Before the handling test, pigs were weighed, venous blood samples were taken to establish baseline levels, and rectal temperature was measured. Pigs were allowed to rest for 2 h before being subjected to the handling treatments, which consisted of moving the pigs through a course (12.2 m long x 0.91 m wide), for a total of eight laps. Animals on the high-intensity treatment were moved rapidly through the course and subjected to a total of 16 single shocks (two shocks per lap) with an electric livestock goad, whereas pigs on the low-intensity treatment were moved at their own pace using a moving panel and a paddle. Rectal temperature and a venous blood sample were taken immediately after handling and at 2 h after handling. Blood plasma was assayed for pH, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), saturated oxygen (SO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess, and lactate. Live weight had no effect on the baseline measurements. After handling, light pigs had higher (P < 0.05) blood SO2 (65.6 vs. 57.2 +/- 2.80%) and showed a greater (P < 0.05) increase in PO2 from baseline to post-handling than heavy pigs (15.6 vs. 8.3 +/- 2.63 mmHg). Post-handling, pigs on the high- compared with the low-intensity handling treatment had greater (P < 0.001) lactate (19.1 vs. 4.9 +/- 0.56 mmol/L) and PO2 (51.6 vs. 36.5 +/- 2.44 mmHg) with lower (P < 0.001) TCO2 (18.6 vs. 34.7 +/- 0.64 mmol/L), pH (7.02 vs. 7.36 +/- 0.015), HCO3 (16.7 vs. 33.0 +/- 0.62 mmol/L), and base excess (-14.2 vs. 7.5 +/- 0.75) values. There were no effects of gender on blood measurements or rectal temperatures. Results from this study highlight a major effect of pig handling intensity, a limited effect of live weight, and no effect of gender on blood acid-base responses to handling.