Muizelaar Wouter, Groot Maria, van Duinkerken Gert, Peters Ruud, Dijkstra Jan
Wageningen Livestock Research, Wageningen University & Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Animal Nutrition Group, Wageningen University & Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Foods. 2021 Mar 10;10(3):584. doi: 10.3390/foods10030584.
Enteric methane (CH) is the main source of greenhouse gas emissions from ruminants. The red seaweeds (AT) and contain halogenated compounds, including bromoform (CHBr), which may strongly decrease enteric CH emissions. Bromoform is known to have several toxicological effects in rats and mice and is quickly excreted by the animals. This study investigated the transfer of CHBr present in AT to milk, urine, feces, and animal tissue when incorporated in the diet of dairy cows. Twelve lactating Holstein-Friesian dairy cows were randomly assigned to three treatment groups, representing the target dose (low), 2× target dose (medium), and 5× target dose (high). The adaptation period lasted seven days, and subsequently cows were fed AT for 22 days maximally. The transfer of CHBr to the urine at days 1 and 10 (10-148 µg/L) was found with all treatments. On day 1, CHBr was detected in the milk of most cows in the low and medium treatment groups (9.1 and 11 µg/L, respectively), and detected in the milk of one cow in the high treatment group on day 9 (35 µg/L). Bromoform was not detected in milk and urine at day 17, nor at concentrations above the detection limit in feces and collected animal tissues. Two animals (low) were sacrificed, and their rumen wall showed abnormalities. Upon histological examination, signs of inflammation became visible. Animals regularly refused the feed or distinctively selected against AT. In conclusion, within the confines of the present experiment, CHBr does not accumulate in animal tissue, but can be excreted in urine and milk.
肠道甲烷（CH）是反刍动物温室气体排放的主要来源。红海藻（AT）含有卤代化合物，包括溴仿（CHBr），其可能会大幅降低肠道CH排放。已知溴仿对大鼠和小鼠有多种毒理学作用，且动物能快速将其排出体外。本研究调查了将含于AT中的CHBr添加到奶牛日粮中后，其在牛奶、尿液、粪便和动物组织中的转移情况。12头泌乳期的荷斯坦 - 弗里生奶牛被随机分为三个处理组，分别代表目标剂量（低）、2倍目标剂量（中）和5倍目标剂量（高）。适应期持续7天，随后奶牛最多饲喂AT 22天。所有处理组在第1天和第10天均发现CHBr转移至尿液中（10 - 148微克/升）。在第1天，低剂量和中剂量处理组的大多数奶牛的牛奶中检测到CHBr（分别为9.1和11微克/升），高剂量处理组在第9天有1头奶牛的牛奶中检测到CHBr（35微克/升）。在第17天，牛奶和尿液中未检测到溴仿，粪便和采集的动物组织中也未检测到高于检测限浓度的溴仿。处死了2头（低剂量组）动物，其瘤胃壁出现异常。经组织学检查，可见炎症迹象。动物经常拒绝采食该饲料或明显对AT有选择性拒食。总之，在本实验范围内，CHBr不会在动物组织中蓄积，但可通过尿液和牛奶排出。
