Effects of full litter reuse with or without chemical amendment on measures of welfare and performance on three Australian broiler farms

Abstract

There are pressures on some sectors of the Australian broiler industry to reuse poultry litter for multiple batches of chickens. We investigated the effects of reused litter on bird performance, welfare, litter pH and moisture, and air ammonia concentrations on three commercial farms (A, B, and C) across NSW, Australia. On each farm, the litter inside six sheds was assigned to one of three treatments: 1) a full cleanout replenished with new litter (NL); 2) litter reuse in the entire shed following heaping and turning (RL); and 3) RL plus the addition of a commercial acidifying litter amendment (RL+A). In the RL and RL+A sheds, chicks were placed directly on reused litter. Bird performance, welfare, and litter measurements were made on days 0, 7, 14, and 35. Feed conversion ratios (adjusted to 2.45kg) on a whole farm basis were 1.868, 1.839 and 1.920 for farms A, B, and C, respectively. Day 35 weights were highest on RL on all 3 farms but the effect of litter treatment on mortality varied between farms, with some indication that placing chicks on reused litter less than 3 days after re-spreading increased early mortality. On all three farms, welfare measures provided no evidence of sustained reduction in welfare status of birds on reused litter, nor any clear benefits or disadvantages of litter amendment. Litter moisture content and pH varied significantly with treatment and time on all farms. On the reused litter treatments, moisture content increased steadily on all farms between placement and day 35, with no effect of litter amendment. The litter amendment also failed to lower the pH of the reused litter at any time; however, it did appear to have a reducing effect on air ammonia concentrations relative to the RL treatment on farms B and C. In conclusion, bird performance and welfare can be maintained on reused litter if managed properly.