Presented at the Neonatal Society 2002 Summer Meeting.
Litten JC, Perkins KS, Clarke L
Department of Agricultural Sciences, Imperial College at Wye, University of London, Wye, Ashford, Kent, TN25 5AH, UK.
Introduction: Body shape has been shown to influence both the physical and behavioural development of the neonatal piglet (1). Dietary fat supplementation to the sows in late gestation increased both piglet weight gain and piglet survival (2). Supplementation of infant formula has been shown to increase the mental development of the human neonate (3). Due to similar brain physiology, the piglet is analogous to the human for studies of early postnatal neural development (4). The objective was to determine whether maternal dietary supplementation influenced the physical and behavioural development of differently shaped pigs.
Methods: Thirty-nine pregnant sows were randomly allocated to 5 dietary treatments as follows: standard diet (S: 3kg of Pigbreed Pioneer Pellets, BOCM: 12.4 MJ/kg, 3% fat) or the standard diet plus 30% extra energy derived from either excess pellets (E), palm oil (PO), soya oil (SO or a 50:50 mixture of palm and soya oil (M). Sows were allowed to give birth naturally at term (115 days) and physical development was assessed by weekly measurements of piglet body weight and crown-to-rump length (CRL) until weaning at 24-28 days. Piglet response to, and interaction with a ball for 1800 seconds on day 14 of neonatal life was used to calculate a numerical index of behavioural development as follows:
Behavioural developmental index (BDI) = (1800 – Ttime) + (1800 – Mtime).
Ttime = time taken to touch the ball (sec) and Mtime = time taken to move the ball (sec). Piglets were sub-divided into 3 groups based on ponderal index (PI: body weight /CRL 3: kg/m3): LOW (<10th percentile), NORMAL (11th-89th percentile) and HIGH (>90th percentile). General Linear Model and One way, ANOVA, were used to assess differences between each treatment groups.
Results: Increased energy supplementation significantly influenced the behavioural development of the piglets (P<0.01) but the degree of improvement was dependent on their body shape at birth (Table 1). In the LOW group, BDI was enhanced only in the E group (P<0.05). An improvement in BDI was also observed in NORMAL piglets born to sows fed the E, PO and SO diets (P<0.05) but this was not shown in M group. Conversely, BDI was similar, irrespective of dietary treatment in the HIGH group. Treatment did not affect growth rate in the NORMAL or HIGH groups but it did influence growth rate in the LOW group.
Table 1: Behavioural Developmental Index for each treatment and PI group
Values are means±SEM
Conclusion: In conclusion, dietary supplementation of additional energy to sows during late gestation significantly improved BDI of LOW and NORMAL neonatal pigs. This effect appears to be due to the addition of extra energy from a number of different sources rather than to fatty acid supplementation as previously described by other authors (3).
Acknowledgements: This work is partly funded by DEFRA. J.C.L. also wishes to thank Wye College for the provision of a PhD studentship.
References
1. Litten J. C., Corson, A.M., Drury, P.C. and Clarke, L. Early Human Development 2001, 66:57-58.
2. Cieslak, D.G., Leibbrandt, V.D. and Benevenga, N.J. Journal of Animal Science. 1983, 57:955-959.
3. Birch, E.E., Garfield, S., Hoffman, D.R. and Uauy, R. Developmental Medicine and Child Neurology. 2000, 42:174-181.
4. Purvis, J.M., Clandinin, T. and Hacker, R.R. Comparative Biochemistry and Physiology 1982, 72B:195-199.