Mitigation of ammonia and greenhouse gaseous emissions from naturally ventilated sloping-floor cattle housing using bedding additives

Abstract

The renewed interest for straw-based cattle housing systems, driven by concerns over animal health and welfare in conventional cubicle barns, has increased the importance of naturally ventilated sloping-floor and other litter barns. However, these housing systems contribute substantially to anthropogenic ammonia (NH 3 ) and greenhouse gaseous emissions. Therefore, this study evaluated the effectiveness of zeolite, lava meal and sandy soil as bedding additives for mitigating gaseous emissions from the sloping-floor barn. Four barn units, each housing eight young beef bulls, were assigned to one of four treatments: (i) control with straw application at rate of 5 kg livestock unit (LU) −1 day −1 , and straw applied at the same rate (5 kg LU −1 day −1 ) supplemented with (ii) zeolite, (ii) lava meal and (iii) sandy soil at rates of 0.5, 1.0, and 1.65 kg LU⁻¹ day⁻¹ , respectively. Gaseous emissions were quantified through static flux chamber, while total N (TN) losses were calculated through mass balance approach based on differences between TN of inputs and outputs. All bedding additives mitigated NH 3 emissions by 85% than control; however, had no effect on CH 4 emissions. The TN losses were decreased by 23, 37 and 50% with lava meal, sandy soil and zeolite, respectively. Overall, measured N emissions through NH 3 -N and N 2 O-N from the barn was 11% of TN losses while remainder 89% was most probably attributed to di-nitrogen (N 2 ), a harmless gas. Overall, zeolite was most effective additive to mitigate CO 2 , N 2 O and NH 3 , whereas sandy soil provides cheap and readily available resource for reducing NH 3 emissions.