Larsson A, Dimander S-O, Rydzik A, Uggla A, Waller P J, Höglund J
Department of Parasitology (SWEPAR), National Veterinary Institute and Swedish University of Agricultural Sciences, SE-751 89 Uppsala, Sweden.
Vet Parasitol. 2006 Dec 20;142(3-4):197-206. doi: 10.1016/j.vetpar.2006.07.017. Epub 2006 Sep 12.
To evaluate non-chemical strategies to control pasture-borne parasites in first-season grazing (FSG) cattle, a 3-year grazing trial was conducted during 2002-2004 on naturally infected pastures on a commercial beef cattle farm in Sweden. A uniform pasture was divided in 4 equal 2 ha paddocks onto each of which 10, 5-9 months old dairy breed steer calves were allocated at turn-out in May each year. Two strategies were evaluated: (1) turn-out onto pasture which had been grazed the previous year by second-season grazing (SSG) steers, followed by a move to aftermath in mid-July (RT) and (2) supplementation with concentrate and roughage for 4 weeks from turn-out (FD). Comparisons were made with an untreated (UT), and an anthelmintic treated control group (DO). Animal parasitology and performance were monitored monthly throughout the 20 weeks grazing period. Additional sampling occasions were performed on day 9 (for coccidia) and 10 weeks after turn-out (mid-July). Due to clinical parasitic gastro-enteritis (PGE), salvage treatments were performed on all animals in group FD approximately 7 weeks after turn-out in 2003 and of three animals in group UT 5 weeks after turn-out in 2004. In 2003, the geometric mean oocyst excretion 9 days after turn-out was approximately 150,000 opg of mainly Eimeria alabamensis in group FD, and in 2004 approximately 180,000 opg in group UT. Apart from the DO group, geometric mean faecal egg counts (FEC) were between 80 and 400 epg 4 weeks after turn-out. Mean serum pepsinogen concentrations (SPC) of approximately 3.6 U tyrosine were recorded in the FD and UT groups from late August 2002. In 2003 and 2004, mean concentrations in these groups were between 4.1 and 7.2 U tyrosine 8 weeks after turn-out. By the end of the three grazing seasons the average weight gain difference compared to the DO group was for FD -29, -38 and -5 kg and for RT -4, -21 and +14 kg, and compared to the UT group -18, +2 and +22 for FD and +7, +19 and +41 kg for group RT. In conclusion, the rotation control strategy showed promising results, whereas the strategic feeding was poor from a parasite control standpoint.
为评估控制头季放牧（FSG）牛群中牧场传播寄生虫的非化学策略，2002年至2004年在瑞典一个商业肉牛场的自然感染牧场上进行了一项为期3年的放牧试验。将一片均匀的牧场分成4个相等的2公顷围场，每年5月放牧时，在每个围场上分配10头5至9月龄的奶牛品种阉牛犊。评估了两种策略：（1）放牧前一年由第二季放牧（SSG）阉牛放牧过的牧场，然后在7月中旬转移到放牧后的草地（RT）；（2）从放牧开始补充4周的精饲料和粗饲料（FD）。与未处理组（UT）和驱虫处理对照组（DO）进行比较。在整个20周的放牧期内每月监测动物寄生虫学和生产性能。在第9天（针对球虫）和放牧后10周（7月中旬）进行额外采样。由于临床寄生虫性胃肠炎（PGE），2003年放牧后约7周对FD组所有动物进行了挽救治疗，2004年放牧后5周对UT组的3只动物进行了挽救治疗。2003年，放牧后9天，FD组主要为阿拉巴马艾美耳球虫的卵囊排泄几何平均数约为150,000个/克粪便，2004年UT组约为180,000个/克粪便。除DO组外，放牧后4周粪便虫卵计数（FEC）几何平均数在80至400个/克粪便之间。从2002年8月下旬开始，FD组和UT组的平均血清胃蛋白酶原浓度（SPC）记录为约3.6 U酪氨酸。2003年和2004年，这些组放牧后8周的平均浓度在4.1至7.2 U酪氨酸之间。到三个放牧季节结束时，与DO组相比，FD组的平均体重增加差异分别为-29、-38和-5千克，RT组为-4、-21和+14千克；与UT组相比，FD组为-18、+2和+22千克，RT组为+7、+19和+41千克。总之，轮牧控制策略显示出有希望的结果，而从寄生虫控制角度来看，策略性饲喂效果不佳。
