Abstract:
Animal Production in Australia Vol. 15 EFFECT ON PERFORMANCE OF ROUTINELY MOVING GROWING PIGS TO DIFFERENT PENS E.B. GREER* The growing pig's requirements for floor space increase with live weight. To maintain desired stocking densities in pens, pigs are commonly moved, or movedand-mixed, a number of times during the growing period. Either practice may impose stress on the animal but the extent to which performance may be altered as a result of this stress is unclear. The performance of pigs has been reduced by some systems of moving or moving-and-mixing (Teague 1963; Wright 1974 - pers.comm.) although movement alone has also been associated with increased weight gain (Anon. 1981). The effect of moving or moving-and-mixing groups of pigs growing from 20 to 100 kg was examined in a co-ordinated experiment on seven farms. Pigs.remained in one pen for the full period, rwere moved to a different pen every four weeks, or .were moved-and-mixed after eight weeks when they weighed about 50 kg. For treatment 3, half the pigs from each of two pens were mixed to form two new groups which were then placed in pens previously unoccupied by either of the original groups. All pens used on each farm were adjacent to minimise confounding any effect of movement with possible variations in micro-environment which might be introduced by moving between different areas of the shed. Pen floors were partly-slatted on six farms and solid concrete on the other. Although pen size varied between farms, stocking density was uniform. The diet normally used on each farm was fed ad libitum. TABLE 1 Effect on performance of moving or moving-and-mixing groups of pigs growing from 20 to 100 kg Fighting occurred when the pigs were mixed after eight weeks (treatment 3), but no adverse effects were apparent at slaughter 8 to 12 weeks later. Performance was not depressed by either of the movement strategies studied (Table 1). While moving pigs quietly from pen to pen within the same area of the shed did not affect growth, the response when the movement is to a distant area of the shed is unknown. The results suggest that any adverse effects of such movement which may be seen under commercial conditions are possibly due to variations in the micro-environment within the shed than to movement per se. The influence on performance of the fighting which would occur when pigs approaching slaughter weight are moved-and-mixed was not studied. The results indicate that floor space allowances for growing pigs can be increased by two common movement strategies with little detriment to performance. ANON. (1981). Feedstuffs. 53(42):16. 48:56. TEAGUE, H.S. (1963). Ohio Farm and Home Res. S *Agricultural Research and Veterinary Centre, Forest Road, Orange, N.S.W. 2800, 687