The Eect of Stocking Density in Transit on the Carcass Quality and Welfare of Slaughter Pigs: 2. Results from the Analysis of Blood and Meat Samples P. D. Warriss, a * S. N. Brown, a T. G. Knowles, a J. E. Edwards, a P. J. Kettlewell b & H. J. Guise c a Division of Food Animal Science, School of Veterinary Science, University of Bristol, Langford, Bristol BS40 5DU, UK b Silsoe Research Institute, Wrest Park, Silsoe, Bedford MK45 4HS, UK c Cambac JMA Research, Manor Farm, Draycot Cerne, Chippenham, Wiltshire SN15 5LD, UK (Received 14 April 1997; revised version received 26 March 1998; accepted 24 April 1998) ABSTRACT In a trial involving 2496 pigs, the in¯uences on blood pro®le and pork quality of stocking densities ranging from 201 to 321 kg m 2 were examined. The pigs came from four dif- ferent farms and were killed in 16 weekly batches. They were transported for on average 3 hr and held in lairage for 1 hr. Higher stocking densities resulted in more physical stress to the pigs based on the activity of the enzyme CPK in the blood. Stocking density did not apparently aect psychological stress and high densities did not result in dehydration. The colour, water holding capacity and instrumentally-determined texture of the pork from the carcasses of the pigs were not aected by stocking density. The experimental design and precision of the measurements were sucient to detect numerous dierences in blood pro- ®le and pork quality between pigs from the four source farms. These dierences probably related to dierent degrees of stress-susceptibility. The results suggest that the highest stocking density examined (321 kg m 2 ) is unacceptable for the transport of pigs. The second highest density (281 kg m 2 ) produced relatively little evidence of an adverse eect on the welfare of pigs. It may be scienti®cally acceptable for short journeys (3 hr) but not for longer ones where pigs need more space to lie down. # 1998 Elsevier Science Ltd. All rights reserved INTRODUCTION Most countries in Europe appear to use stocking densities of 0 . 35 to 0 . 46 m 2 /100 kg (217 to 286 kg m 2 ) for the transport of slaughter pigs (Warriss, 1995a). These values are equivalent to stocking rates of between 2 . 4 and 3 . 2 pig m 2 for animals weighing 90 kg. Warriss (1994) suggested that an ideal ®gure might be 0 . 45 m 2 /100 kg (222 kg m 2 ) or 2 . 5 pig m 2 . This provides a slightly greater area than that required for sternal recumbency Meat Science, Vol. 50, No. 4, 447±456, 1998 # 1998 Elsevier Science Ltd. All rights reserved Printed in Great Britain PII:S0309-1740(98)00057-6 0309-1740/98 $19.00+0.00 447 *To whom correspondence should be addressed. Fax: 0117 928 9324.