Agriculture & Food, Volume 11, 2023

Rezumat: Bedding material is expensive; therefore, it is commonly reused after windrowing in the grow-out phase in commercial turkey houses in the United States. Bedding material is significant to keep the high moisture away from the birds, which can deteriorate their performance and welfare. This study aimed to determine the relationship between litter moisture and particle size distribution in commercial turkey houses at the end of the grow-out phase (average 118 days of age). Composite litter samples were collected from turkey barns (N=17), then subsamples in triplicate were dried and material separated by vibration on 10 various pore sizes of sieves ranging from 25.40 mm to 0.15 mm, plus the remainder. The material remaining on each sieve was weighed and expressed as a percentage of material retained. For used bedding, on sieve sizes 1-3, a total of 8 samples were collected (N=7 rice hulls, N=1 wood shavings), and from sieve size 4 onward, N=10 (N=7 rice hulls, and N=3 wood shavings). A total of 7 samples were collected from fresh bedding placed in the barn at the start of the grow-out phase (N=4 rice hulls, N=2 wood shavings, N=1 combination of rice hulls and wood shavings). For the used bedding, the litter moisture was positively correlated with large particles, i.e., sieve 1 correlated very strongly (>25.40 mm, r=0.81, P=0.015), and it tended to correlate with sieve 2 (19.05 mm, r=0.64, P=0.086). A negative correlation was revealed between litter moisture and finer particles, i.e., sieve 6(1.68 mm, r=-0.78, P=0.008), sieve 7(1.19 mm, r=-0.95, P=0.0000), sieve 8(0.84 mm, r=-0.95, P=0.0000), sieve 9(0.60 mm, r=-0.83, P=0.003, sieve 10(0.30 mm, r=-0.73, P=0.016), and remainder(<0.15 mm, r=-0.81, P=0.005). No relationship was found for fresh bedding between moisture content and particle size distribution. The relationship between litter moisture and particle size distribution indicated that on used litter, coarse particles are associated with higher litter moisture, and fine particles are related to lower litter moisture. It is assumed that the accumulated mixture of feather, spilled feed, and excreta influenced the characteristics of litter, including water releasing capacity and water holding capacity, besides other information such as litter depth, number of times the litter is being used, length of growing period, and in the case of various bedding materials, further studies are needed.