Effects of tail docking and teeth clipping on the physiological responses, wounds, behavior, growth, and backfat depth of pigs

The objective of this experiment was to compare the effects of tail docking and teeth clipping on the growth and behavior of pigs. Pigs (n = 126) from 21 litters (6 pigs/litter) were blocked by birth weight, and assigned at 3 d of age within blocks to either teeth clipping and tail docking (processed) or control (sham-processed). Vocalizations of pigs were recorded during the procedures, and behavior was observed during the lactation, nursery, and growing periods. Blood samples were collected on d 21 to measure serum IgG concentrations. Wounds on the body and tail were assessed by inspecting both sides of the body and tail at 70, 110, and 160 d of age, whereas BW were recorded at 10, 21, 70, and 160 d of age. Fat and LM depths were measured ultrasonically on growing pigs at 160 d of age. Clipped and docked pigs vocalized more (1.06 vs. 0.62 s; P < 0.01) during processing, and processed pigs were observed lying alone more often (P = 0.03) during the 3 d after processing and the entire suckling period; however, teeth clipping and docking did not (P >= 0.14) alter the frequency that pigs spent suckling, standing, huddling, playing/fighting, or sitting during the first 3 d or between 5 and 15 d after processing. Social behavior during the nursery (P >= 0.23) and grower phases (P >= 0.18) was unaffected by clipping and docking, but processed pigs rested more (P = 0.03) during the nursery period and were less (P <= 0.01) interested in exploratory behaviors during both phases, especially during pen (P <= 0.04) and enrichment investigations (P <= 0.02). Teeth clipping and tail docking reduced ADG between 10 and 21 d (P = 0.01) and 21 to 70 d of age (P = 0.04), resulting in lighter BW at 21 (P = 0.01) and 70 d of age (P = 0.08) compared with sham-processed pigs. However, 160-d BW (P = 0.62), d 70 to 160 ADG (P = 0.23), and G:F (P >= 0.15) were not affected by teeth clipping and tail docking. Additionally, there was no difference between sham and processed pigs for fat depth (P >= 0.05), LM depth (P = 0.93), or estimated percent muscle (P = 0.27). Even though tail docking and teeth clipping appear to produce short-term pain and distress, results of this experiment indicate that leaving the teeth and tails intact have no detrimental effects on mortality, morbidity, live performance, or carcass merit of growing-finishing pigs.