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Submitted to: Poultry Waste Management Symposium Proceedings
Publication Type: Proceedings Publication Acceptance Date: 10/23/2006 Publication Date: 11/9/2006 Citation: Miles, D.M. 2006. Broiler cake potential to emit ammonia. In: Proceedings of the National Poultry Waste Management Symposium,October 23-25, 2006, Springdale, Arkansas. p. 59-63. Interpretive Summary: Ammonia flux from the surface of broiler house bedding varies according to management scheme, physical and chemical properties, but also by whether its consistency is loose or compacted. The objectives of this study were to quantify ammonia generation potential between compacted samples, known as cake samples, from two farms having variable length of litter reuse (8 vs. 18 flocks), to compare cake sample size, and investigate the condition of the cake sample (whether broken or intact). Cake samples were collected near the center of houses to avoid feeder and waterer influences. Samples were housed in a chamber acid trap system for three days. Previous work has shown that leaving broken cake in houses can intensify ammonia production. The current results suggest that the ammonia generation potential of cake may be similar between farms without concern for litter age; that larger samples of cake, not surprisingly, emit more ammonia; and break up of same-size samples generates more ammonia. Thus, replicate studies may indicate a lack of farm effect so that management practices that reduce ammonia volatilization for cake handling may be simplified with confidence. The results for effect of size and condition should be further explored to determine methods for reducing emission potential, such as rapid drying of broken cake surfaces. Technical Abstract: Spatial differences for ammonia (NH3) flux from litter are evident within broiler houses especially when considering friable litter and caked surfaces. The objectives of this study were to quantify NH3 generation potential between different sources of cake (two separate farms having variable length of litter reuse), to compare sample size, and investigate the condition of the sample (whether broken or intact). Cake samples were collected approximately one-third of the length of the houses (48 m) from the tunnel fans, and width-wise near the center to avoid feeder and waterer influences. A randomized complete block (n=4 air supply manifolds) design compared 50 g single-piece cake samples, 50 g cake samples broken into four pieces, and 25g single-piece cake samples from two farms, 8 vs.18 flocks originally placed on pine shavings. Air passed over samples housed in individual 1000 mL containers where exhaust air and volatilized NH3 were captured in boric acid and titrated daily for three days. Previous work has shown that leaving broken cake in houses can intensify NH3 production. The current results suggest that the NH3 generation potential of cake can be similar between farms (p=0.8895) without concern for litter age. Two additional inferences emerge as related to exposure of moist surface area of cake samples: (1) that larger samples of cake, not surprisingly, emit more NH3 (p=0.0023) but, also, the rate of release is more rapid, and (2) break up of same-size samples generates more NH3 (p=0.0411). Provided the lack of farm effect is proven in replicate studies, management practices for cake handling may be simplified with confidence. The results for effect of size and condition should be further explored to determine methods for reducing emission potential, such as rapid drying of broken cake surfaces. |
