Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907, USA.
Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907, USA; College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
Environ Int. 2019 Oct;131:104931. doi: 10.1016/j.envint.2019.104931. Epub 2019 Jul 15.
Antibiotic use and ammonia (NH) emissions during animal production are two environmental issues of worldwide concern. However, the role of antibiotics on NH emissions is still unknown. This study evaluated the effects of rearing pigs without antibiotics on NH emissions from a swine experimental building starting with 657 piglets during a wean-to-finish production cycle of 154 days. Pigs were reared in two groups of 10 rooms that were divided into five 2-room pairs (P1-P5) and fed in nine dietary phases. Each pair consisted of one room without antibiotics (no antibiotics in the diet, water, or injectable) and another room as a positive control. Control animals were fed diets containing carbadox-10 (phases 1-4), chlortetracycline (CTC, phase 5), lincomix (phases 6-7), and tylan 40 (phases 8-9). Temperatures in the pig living space and the under-floor manure pit headspace were continuously measured. Ventilation rates at all wall fans and pit fans were obtained by continuous monitoring. Ammonia concentrations in the wall and pit fan exhaust air, and in room inlet air were measured with two multi-gas monitors. Only days that contained at least 18 h of data each day were validated and used. The study generated 1337 room-days of valid data of NH emission rates, with a data completeness of 88.6%. Daily mean NH emission patterns demonstrated large variations between the paired rooms and among different pairs. Within the individual 2-room pairs, no NH emission differences were found in P1 (rooms 1 and 2, p = 0.34) and P2 (rooms 3 and 4, p = 0.44). Significant differences were found in P3-P5 (p < 0.01). The antibiotic-free rooms emitted more NH from P3 and P4, but less NH from P5. However, the combined cycle mean NH emissions from the group of five antibiotic-free rooms and the group of five control rooms were 41.6 ± 10.5 and 39.4 ± 10.6 g d AU (mean ± standard deviation. AU = 500 kg live body weight), respectively. Therefore, there was no statistical difference in combined cycle mean NH emissions from rearing pigs with or without antibiotics (p = 0.78). This study also revealed that experiments with multiple replicates and long NH monitoring durations were necessary to avoid potential misinterpretation of experimental results.
在动物生产过程中，抗生素的使用和氨（NH）排放是两个受到全球关注的环境问题。然而，抗生素对 NH 排放的影响仍不清楚。本研究评估了在一个猪实验楼中，从断奶到育肥的 154 天生产周期中，不使用抗生素饲养 657 头仔猪，对 NH 排放的影响。猪被饲养在两组 10 个房间中，分为五个 2 个房间的对（P1-P5），并在 9 个饲养阶段中喂食。每对由一个不使用抗生素的房间（饲料、水或注射中均不含有抗生素）和另一个房间作为阳性对照组成。对照动物喂食含有卡巴多 10（阶段 1-4）、金霉素（CTC，阶段 5）、林可霉素（阶段 6-7）和泰兰 40（阶段 8-9）的饲料。猪生活空间和地下粪坑顶空的温度连续测量。通过连续监测获得所有墙壁风扇和坑风扇的通风率。使用两台多气体监测器测量墙壁和坑风扇排气以及房间进气口的氨浓度。只有每天至少包含 18 小时数据的日子才进行验证并使用。该研究共产生了 1337 天有效的 NH 排放率数据，数据完整性为 88.6%。配对房间之间和不同对之间的每日平均 NH 排放模式存在很大差异。在各个 2 个房间对中，在 P1（房间 1 和 2，p=0.34）和 P2（房间 3 和 4，p=0.44）中未发现 NH 排放差异。在 P3-P5 中发现了显著差异（p<0.01）。无抗生素的房间在 P3 和 P4 中排放更多的 NH，但在 P5 中排放更少的 NH。然而，五个无抗生素房间组和五个对照房间组的整个周期平均 NH 排放量分别为 41.6±10.5 和 39.4±10.6 g d AU（平均值±标准偏差。AU=500kg 活体体重）。因此，使用或不使用抗生素饲养猪的整个周期平均 NH 排放量没有统计学差异（p=0.78）。本研究还表明，需要进行多次重复实验和长时间的 NH 监测，以避免对实验结果的潜在误解。
