Effects of bedding type on compost quality of equine stall waste: Implications for small horse farms

Abstract

Our objective in this study is to compare 4 of the most common bedding materials used by equine operations on the chemical and physical characteristics of composted equine stall waste. Twelve Standardbred horses were adapted to the barn and surrounding environment for 2 wk before the start of the study. Groups of 3 horses were bedded on 1 of 4 different bedding types (wood shavings, pelletized wood materials, long straw, and pelletized straw) for 16 h per day for 18 d. Stalls were cleaned by trained staff daily, and all contents removed were weighed and stored separately by bedding material on a level covered concrete pad for the duration of the study. Compost piles were constructed using 3 replicate piles of each bedding type in a randomized complete block design. Each pile was equipped with a temperature sensor and data logger. Water was added and piles were turned weekly throughout the 100-d compost process. Initial and final samples were taken, dried, and analyzed for DM mass, OM, inorganic nitrogen (nitrate-N and ammonium-N), electrical conductivity, and soluble (plant-available) nutrients. Data were analyzed using the GLM procedure, and means were separated using Fischer's protected LSD test (P < 0.05). No significant temperature differences were observed among the bedding materials. The composting process resulted in significant reductions (P < 0.05) in DM mass for each of the 4 bedding materials. The composting process resulted in significant reductions (P < 0.05) in OM and C:N ratio for all 4 bedding materials. The composted long straw material had greater concentrations of total Kjeldahl nitrogen (P < 0.05), nitrate-N (P < 0.05), and ammonium-N (P < 0.05) than the composted wood shavings. This study demonstrated that incorporating a simple aerobic composting system may greatly reduce the overall volume of manure and yield a material that is beneficial for land application in pasture-based systems. The straw-based materials may be better suited for composting and subsequent land application; however, factors such as suitability of the bedding material for equine use, material cost, labor, and availability must be considered when selecting a bedding material.

Recycling nutrients from horse manure: effects of bedding type and its compostability

“…Even during the spring and summer time, the temperature increased high enough for pathogen (Gajalakshmi and Abbasi 2008) as well as weed seed and animal parasite destruction (Johansen et al 2013) only in the manure containing pelleted straw bedding and the maximum heat peaks in all the manures were relatively short in duration. In several other studies, no great differences in the temperature development between manure composts containing different bedding materials have been observed (Airaksinen et al 2001, Larney et al 2008, Komar et al 2012. High compost heats have been maintained successfully despite extreme winter air temperatures (Larney and Hao 2007) and the thermal thresholds for eliminating pathogens (>55 ˚C for 15 d) easily exceeded (Larney et al 2008).…”

“…Larney and Hao (2007) reported dry matter losses of 20-30% during manure composting, Hao et al (2004) recorded a 30% dry mass loss for straw-bedded manure and 27% for wood bedded manure and in the study of Komar et al (2012), the dry mass reductions were 49% for pelletized straw manure and 40% for wood shavings manure. The rate of degradation is dependent on the quality of the C source and the initial C:N ratio of the substrate (Bernal et al 2009, Gajalakshmi andAbbasi 2008).…”

“…High compost heats have been maintained successfully despite extreme winter air temperatures (Larney and Hao 2007) and the thermal thresholds for eliminating pathogens (>55 ˚C for 15 d) easily exceeded (Larney et al 2008). However, in some experiments the temperatures adequate for manure hygienization have not been reached (Swinker et al 1997, Komar et al 2012). …”

“…For example, in the studies of Airaksinen et al (2001) peat-bedded horse manure was found to compost more efficiently than manure containing wood shavings, straw, hemp, linen, sawdust or newspaper, whereas N' Dayegamiye and Isfan (1991) found wood shavings manure to have superior composting characteristics in comparison to sawdust and peat moss manures. Swinker et al (1997) found sawdust to compost more readily than phone book paper or straw but Komar et al (2012) concluded that straw-based materials are better suited for composting than wood-based materials. These discrepancies can be explained by differences a) in the particle size of the substrates used, b) the proportion between dung, urine and the bedding material (C:N ratio), c) moisture content and d) process control, namely aeration (Gajalakshmi and Abbasi 2008).…”

Environmental Implications of Nitrogen Output on Horse Operations: A Review

“…For example, high pH and temperature favor increased ammonia emissions. Horse manure pH typically ranges from 7.7 to 8.2 when calculated from soiled stall waste, depending on the bedding source [11]. The pH of horse manure samples collected between 2007 and 2014 and analyzed at the Pennsylvania State University Ag Analytical Services Laboratory ranged from 6.9 to 8.2 with an average of 7.8, which allows for fairly rapid emission of ammonia into the atmosphere [12].…”