Effect of Birth Weight and Age at Tail Docking and Ear Notching on Behaviour and Physiological Responses of Piglets03 June 2014
Results from this Canadian study suggest that it is better to postpone tail-docking and ear-notching of low-birthweight piglets until the third day of life than on day 1.
Selection for high prolificacy has resulted in litters comprising a large number of low-birthweight (LBW) piglets. Given their presence in over 75 per cent of litters and increased mortality rate, it is clear that a greater understanding of LBW piglet management is required for both animal welfare and productivity, according to K.E. Bovey of the University of Guelph in Canada and co-authors there and with Agriculture and Agri-Food Canada.
In this study, published in Journal of Animal Science, the researchers compared the effects of tail docking and ear notching LBW and average-birth-weight (ABW) piglets at one or three days of age on suckling, behaviour, passive transfer of immunoglobulins and growth.
Six piglets per litter from 20 litters (n=120 piglets) were used in a 2×2 complete block design. Piglets were weighed at birth and designated as LBW (0.6 to 1.0kg) or ABW (≥1.2kg) and 'processed' (tail docked and ear notched) at either one or three days of age.
Vocalisations were recorded during the procedures. The acute behavioural responses were observed for 10 minutes after the procedure. Piglets were observed for six hours after birth and after the procedure to determine their presence at nursing bouts. On day 5, blood samples were collected to determine concentrations of serum immunoglobulins (IgA and IgG) and IGF-I.
Piglet weights were recorded at birth and on days 5, 14 and 21.
During the procedures, LBW piglets produced fewer (P=0.03) calls than ABW piglets. Piglets from either birth weight category produced a similar number (calls/s; P = 0.29) of high-frequency calls (≥1,000 Hz), which are indicative of pain and distress, although the average frequency (Hz) of these calls was greatest (P=0.05) for ABW piglets processed on day 3.
Immediately following the procedures, LBW piglets spent more (P=0.005) time dog-sitting and less (P=0.005) time lying than ABW piglets.
When observed with the sow, LBW males spent more (P=0.001) time alone and had the lowest (P=0.007) attendance at nursing bouts compared with LBW females and all ABW piglets.
Concentrations of serum IgA (P=0.06) and IgG (P=0.04) and plasma IGF-I (P=0.003) were lower for LBW than ABW piglets regardless of age of processing although the magnitude of these differences was likely not of biological significance.
Average-birth-weight piglets may be less reactive to the acute effects of the procedures on day 1 than on day 3, concluded Bovey and co-authors. Given the decreased likelihood of a LBW piglet surviving to weaning (P=0.001), they added, delaying processing until three days age for LBW piglets may eliminate unnecessary procedures.
Bovey K.E., T.M. Widowski, C.E. Dewey, N. Devillers, C. Farmer, M. Lessard and S. Torrey. 2014. The effect of birth weight and age at tail docking and ear notching on the behavioral and physiological responses of piglets. J. Anim. Sci. 92:1718-1727. doi: 10.2527/jas.2013-7063
You can view the full report (fee payable) by clicking here.