Antonini C, Trabalza-Marinucci M, Franceschini R, Mughetti L, Acuti G, Faba A, Asdrubali G, Boiti C
Dipartimento di Patologia, Diagnostica e Clinica Veterinaria, Università degli Studi di Perugia, Italy.
J Anim Sci. 2006 Nov;84(11):3133-42. doi: 10.2527/jas.2006-136.
This work was undertaken to assess the long-term impacts of a ruminal transponder, used for electronic identification, on ruminal motility and on health and performance of cattle, as well as to study the electromagnetic effects on ruminal bacteria in vitro. A passive transponder (51.4 g, 67 x 17 mm) was delivered into the forestomachs of 8 calves, 32 bulls, 10 heifers, and 40 dairy cows. Final readability was 87.5% in calves, 96.9% in bulls, 90% in heifers, and 100% in cows at 481, 360, 650, and 601 d, respectively, after transponder administration. The transponder did not affect production or reproduction of cows over a 2-yr period, or performance of bulls, or mortality compared with control animals. Chewing movements per bolus were lower (P <0.01) in treated animals than in controls (49.6 vs. 52.2, 51.2 vs. 63.6, and 57.0 vs. 59.7 for bulls, heifers, and cows, respectively). Regurgitation frequency (number of boluses/10 min) tended to be greater in treated cattle: 12.4 vs. 11.3 (P = 0.07), 11.3 vs. 10.6, and 11.3 vs. 10.7 (P = 0.08) for bulls, heifers, and cows, respectively. Rumination patterns of calves fitted with transponders within the first weeks of life were similar to controls. During the experiment, 43 treated animals (8 calves, 29 bulls, and 6 cows) were slaughtered. Thirty transponders were localized in the reticulum (3 calves, 24 bulls, and 3 cows), 11 in the rumen (4 calves, 4 bulls, and 3 cows), and 2 were not recovered (1 calf and 1 bull). Within the calves, 57% of the boluses were found in the rumen. In 8 reticula (2 calves and 6 bulls) and 1 rumen (1 cow), an impression left by physical contact of the transponder was observed, although histological examination did not reveal specific lesions in the mucosa of the dystrophic areas. In strained, whole ruminal contents incubated in vitro, pH values were lower after 24 and 48 h (P <0.001) of continuous exposure to an electromagnetic field induced by the transponder-reading system. After 48 h of incubation, total bacterial numbers and NH3-N concentration were greater (P <0.001) in exposed flasks than in controls. These data indicate that the transponder may alter, via mechanical action, the reticuloruminal mucosa and rumination patterns. Furthermore, the transponder may increase, via its electromagnetic action, the growth rate and metabolic activity of ruminal bacteria.
本研究旨在评估用于电子识别的瘤胃应答器对牛的瘤胃蠕动、健康及生产性能的长期影响，并研究其对瘤胃细菌的体外电磁效应。将一个无源应答器（51.4克，67×17毫米）植入8头犊牛、32头公牛、10头小母牛和40头奶牛的前胃。应答器植入后，犊牛、公牛、小母牛和奶牛在481、360、650和601天时的最终可读率分别为87.5%、96.9%、90%和100%。与对照动物相比，应答器在两年时间内未影响奶牛的生产或繁殖、公牛的性能或死亡率。处理组动物每团食糜的咀嚼次数低于对照组（P<0.01）（公牛、小母牛和奶牛分别为49.6次对52.2次、51.2次对63.6次、57.0次对59.7次）。处理组牛的反刍频率（每10分钟食糜团数）有增加趋势：公牛、小母牛和奶牛分别为12.4次对11.3次（P = 0.07）、11.3次对10.6次、11.3次对10.7次（P = 0.08）。出生后第一周内佩戴应答器的犊牛的反刍模式与对照组相似。实验期间，宰杀了43头处理组动物（8头犊牛、29头公牛和6头奶牛）。30个应答器位于网胃（3头犊牛、24头公牛和3头奶牛），11个位于瘤胃（4头犊牛、4头公牛和3头奶牛），2个未找回（1头犊牛和1头公牛）。在犊牛中，57%的食糜团位于瘤胃。在8个网胃（2头犊牛和6头公牛）和1个瘤胃（1头奶牛）中，观察到应答器物理接触留下的印记，尽管组织学检查未发现营养不良区域黏膜的特异性病变。在体外培养的瘤胃全内容物中，连续暴露于应答器读取系统产生的电磁场24小时和48小时后，pH值较低（P<0.001）。培养48小时后，暴露烧瓶中的细菌总数和NH3-N浓度高于对照组（P<0.001）。这些数据表明，应答器可能通过机械作用改变网瘤胃黏膜和反刍模式。此外，应答器可能通过其电磁作用提高瘤胃细菌的生长速率和代谢活性。
