# Can Biochar Improve the Sustainability of Animal Production?
## 4 In-House Applications  
Air quality is a major concern for the welfare of the confined animals and the caretakers as well as the surrounding communities. There is a need to reduce emissions from livestock production by addressing odors directly in the animal houses. [PERSON] et al. [93] studied the impacts of pine shaving biochar addition, at 0.97 kg m\({}^{-2}\), to pine shaving poultry litter on bird health and performance and the water holding capacity (WHC) of the litter. It is essential to maintain a litter moisture content of 20-30% in poultry houses to minimize the microbial activity and NH\({}_{3}\) volatilization. The results for mortality and footpad lesions were inconclusive and produced statistically insignificant data. However, body weight and body weight gain were 3% higher for the biochar treatment (\(p<0.1\)). Overall, there were no adverse effects of using biochar in bedding on the birds. In the second phase of the study, [PERSON] et al. [94] tested the impacts of biochar particle size and application rate on the water holding capacity (WHC) of the litter. Particle size was divided into three categories: fine (\(<\)0.25 mm), medium (0.25-0.85 mm), and coarse (\(>\)0.85 mm). Biochar was mixed with pine shavings at application rates of 0, 10, 20, 30, 40, 50, 75, and 100% \(w/w\). The coarse particle size was 11% more effective at increasing the WHC of the litter than fine particle size. While application rates of 75 and 100% had the highest WHC, these rates are not practical in normal production. However, each 1% increase between 10 and 20% equaled 1.9 and 1.2% increases in WHC for medium and coarse biochar, respectively. Greater than 20% resulted in incrementally small improvements in WHC, reducing the return on investment. These results are significant since the manure moisture content determines the decomposition method: aerobic versus anaerobic and therefore the types and concentrations of pollutants released. [PERSON] et al. [94] also tested biochar as a poultry litter amendment for NH\({}_{3}\) volatilization, as well as bird welfare parameters, such as the carcass quality, body weight, and feed consumption. They utilized peanut shell biochar as well as pine-chip- and coconut-husk-based biochar soaked in 53% H\({}_{2}\)SO\({}_{4}\). The peanut shell biochar had a pH value of 9.2, whereas both acidified biochars had a pH of 2.0. The live bird trial applied treatments at comparable rates to commercial acidifying litter amendments: 0.24, 0.37, and 0.73 kg m\({}^{-2}\). No significant differences in bird performance were detected. The peanut shell biochar was not effective at adsorbing NH\({}_{3}\), due to its high pH and greater hydrophobicity compared to the acidified biochars. The acidified pine-bark and coconut-husk biochars reduced NH\({}_{3}\) emissions by 43 and 52%, respectively. Manure properties have a great impact on the quality of fertilizer for land application. [PERSON] et al. [95] also studied biochar as a poultry litter amendment, with a focus on NH\({}_{3}\) emissions, nutrients retained in the litter, and bird performance. Miscanthus grass and biochar were applied at 0, 5, 10, and 20% inclusion rates to once-used, traditional pine-shaving bedding litter. Measurements were taken 20 weeks after application. There was no significant difference in the NH3 concentrations from any of the treatments. However, the litter properties after the 20 week trial showed significant results. The increase in biochar addition resulted in increased levels of phosphorus, sodium, potassium, calcium, magnesium, copper, pH, and total Kjeldjal nitrogen. The most notable results were a 3.4\(\times\) increase in phosphorus at a 20% addition, as well as a 14.15\(\times\) and 6.50\(\times\) increase in ammonia-N and nitrate-N, respectively. Nitrates, as the primary source of plant N, translate to positive impacts in land application. The inclusion of 20% biochar resulted in a 3% increase in body weight as well as a 4% increase in feed intake at week 20.