The effect of litter type on broiler performance, litter quality and ammonia concentrations.

Since the ban on the use of animal products and antibiotics in animal feed in the EU, poultry farms have been experiencing problems with wet litter. Drier litter leads to lower ammonia (NH3) emissions and reduces the formation of foot lesions. This trial studied the effect of litter type on performance, litter quality and NH3 concentrations at litter level. Six litter materials were tested: wood shavings, flax, peat, maize silage, wheat straw and flax pellets. The feeding program consisted of a starter (d0 to d10), a grower (d10 to d28) and a finisher (d28 to d39). 2160 Ross 308 male broilers, divided over six treatments received the same diets with a crude protein content of 20.5%, 19.5% and 18.5% during each phase, respectively. Each treatment was replicated six times. For the total period, highest feed intake (P < 0.001) and body weight (P = 0.011) was obtained for birds housed on peat. There was a significant treatment effect for growth (P = 0.035) and feed conversion (P = 0.020), however, the post-hoc analysis showed no further distinction between the treatments. Peat had a lower moisture content than wood shavings (P = 0.008) at d38 and neither differed significantly from the other treatments. Peat, maize silage and flax pellets received the best litter quality scores at d38 (P < 0.001). However, NH3 concentrations was highest for peat and wheat straw (P = 0.024). Birds kept on wheat straw and wood shavings had the highest incidence of foot lesions at d38 (P < 0.001). The higher density of these materials (and therefore thicker litter layer) reduced bathing and scratching by the birds, which may have led to wetter litter and the formation of a crust on top. These conditions are conducive to the formation of foot lesions. The higher NH3 concentrations for peat may be due to its thinner layer, lower moisture content and the absence of a crust on top of the litter through which NH3 can volatilize more easily.