Attaie Rahmat, Bsharat Mohammed, Mora-Gutierrez Adela
Prairie View A&M University, Cooperative Agricultural Research Center, P.O. Box 519, MS 2008, Prairie View, Texas 77446, USA.
J Food Prot. 2016 Jun;79(6):1013-20. doi: 10.4315/0362-028X.JFP-15-200.
Antibiotics are widely used in animal husbandry, and the presence of antibiotic residues in milk is a health hazard. The objectives of this study were to determine residual amounts of oxytetracycline in the milk of three breeds of goats using high-pressure liquid chromatography (HPLC) analysis and screening tests. It was also essential to explore the safe withdrawal period of oxytetracycline in lactating goats and examine the applicability of Charm ROSA and SNAP screening tests. The qualitative results of these tests were compared with the quantitative results of the HPLC method. Fifteen milking does, five each from the Alpine, LaMancha, and Nubian breeds, were selected from the herd at Prairie View A&M University. Milk samples containing antibiotic residues were deproteinized by HCl and acetonitrile, and then oxytetracycline was extracted from the supernatant. The residues of oxytetracycline in goat's milk up to 110 h after injection were qualitatively detected using the Charm ROSA test. Similarly, the SNAP test detected the antibiotic residues in milk up to 110 h after treatment. The HPLC results indicated that oxytetracycline residues in milk from Alpine goats were below the tolerance level (300 ng/ml) 82 h after drug treatment (72 h for LaManchas, 58 h for Nubians); however, the results of the screening tests would indicate longer withdrawal periods for milk from the breeds of goats studied, which would result in economic losses to goat's milk producers. The results of this study also indicated that oxytetracycline was not stable in raw goat's milk at refrigeration temperature or during pasteurization and that the concentrations decreased significantly. Commercial goat's milk is usually exposed to several hours of refrigeration and then to pasteurization. The results of this study indicated that, if oxytetracycline was present in raw goat's milk, the concentration would decrease significantly before it was marketed.
抗生素在畜牧业中被广泛使用，而牛奶中抗生素残留的存在对健康构成危害。本研究的目的是使用高压液相色谱（HPLC）分析和筛选试验来测定三种品种山羊奶中土霉素的残留量。探索土霉素在泌乳山羊中的安全停药期并检验Charm ROSA和SNAP筛选试验的适用性也很重要。将这些试验的定性结果与HPLC方法的定量结果进行比较。从普雷里维尤农工大学的畜群中挑选了15只产奶母羊，每个品种（阿尔卑斯山羊、拉曼查山羊和努比亚山羊）各5只。含有抗生素残留的牛奶样品用盐酸和乙腈进行脱蛋白处理，然后从上清液中提取土霉素。使用Charm ROSA试验对注射后长达110小时的山羊奶中土霉素残留进行定性检测。同样，SNAP试验检测处理后长达110小时的牛奶中的抗生素残留。HPLC结果表明，药物处理后82小时，阿尔卑斯山羊奶中的土霉素残留低于耐受水平（300纳克/毫升）（拉曼查山羊为72小时，努比亚山羊为58小时）；然而，筛选试验的结果表明，所研究的山羊品种的牛奶停药期更长，这将给山羊奶生产商带来经济损失。本研究结果还表明，土霉素在冷藏温度下的生山羊奶中或巴氏杀菌过程中不稳定，浓度会显著降低。市售山羊奶通常会经过数小时冷藏然后进行巴氏杀菌。本研究结果表明，如果生山羊奶中存在土霉素，其浓度在上市前会显著降低。
