Ramos Fernanda, Marques Camila Balconi, Reginato Caroline Zamperete, de Souza Rodrigues Fernando, Sangioni Luis Antônio, Vogel Fernanda Silveira Flôres, Pötter Luciana
Departamento de Medicina Veterinária Preventiva (DMVP), Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, 97105-900, Brazil.
Departamento de Zootecnia, UFSM, Santa Maria, Rio Grande do Sul, Brazil.
Parasitol Res. 2018 Dec;117(12):3993-4002. doi: 10.1007/s00436-018-6108-z. Epub 2018 Oct 9.
The aim of the present study was to evaluate the effects of treatment with different anthelmintic compounds on the productivity of naturally infected calves and the economic viability of these treatments within extensive breeding systems employing different nutritional strategies after weaning. For this purpose, 4 farms with 42-60 calves naturally infected with gastrointestinal nematodes were selected. The calves were distributed into 6 groups (7-10 animals each) per farm and treated with ivermectin 1%, ivermectin 3.15%, eprinomectin 5%, levamisole 7.5%, albendazole 15%, and control group (no treatment). These animals were evaluated over an experimental period of 150 days. Levamisole 7.5% presented the best capacity for the reduction of eggs per gram (EPG) of feces in all herds evaluated, followed by albendazole 15% and eprinomectin 5%. Parasite resistance to multiple drugs was found in all herds, especially those of Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. For farm 1, differences in weight gain and EPG reduction percentages led to a difference of US$285.06 between the levamisole and ivermectin 3.15% groups. Similar findings were noted for the levamisole and ivermectin 1% groups of farm 3, with a difference of US$399.37 because of the final weight gain in these groups. For farms 2 and 4, the ivermectin 3.15% and control groups, respectively, were the most profitable; these unexpected results were possibly influenced by variables not measured during the experimental period. This study suggested that anthelmintic treatments should always precede an efficacy test, once they are demonstrated to be most profitable under adequate breeding conditions, to ensure adequate control of gastrointestinal nematode infection.
本研究的目的是评估在断奶后采用不同营养策略的粗放养殖系统中，用不同驱虫化合物进行治疗对自然感染犊牛生产力的影响以及这些治疗方法的经济可行性。为此，选择了4个农场，每个农场有42 - 60头自然感染胃肠道线虫的犊牛。每个农场的犊牛被分成6组（每组7 - 10头），分别用1%伊维菌素、3.15%伊维菌素、5%埃普利诺菌素、7.5%左旋咪唑、15%阿苯达唑进行治疗，以及设立对照组（不治疗）。在150天的实验期内对这些动物进行评估。在所有评估的牛群中，7.5%左旋咪唑降低粪便中每克虫卵数（EPG）的能力最强，其次是15%阿苯达唑和5%埃普利诺菌素。在所有牛群中都发现了寄生虫对多种药物的抗性，尤其是对库珀属、血矛线虫属、食道口线虫属和毛圆线虫属的抗性。对于农场1，体重增加和EPG降低百分比的差异导致左旋咪唑组和3.15%伊维菌素组之间相差285.06美元。农场3的左旋咪唑组和1%伊维菌素组也有类似发现，由于这些组的最终体重增加，相差399.37美元。对于农场2和4，分别是3.15%伊维菌素组和对照组最盈利；这些意外结果可能受到实验期间未测量的变量的影响。本研究表明，驱虫治疗应始终先进行疗效测试，一旦证明在适当的养殖条件下最具盈利性，以确保对胃肠道线虫感染进行充分控制。
