3Phillipson A T, Reid R S. Studies of the toxicity of bracken (Pteris Aquilina) [J]. J Compar Pathol Thera, 1954, 64: 243- 259.
4Turner M A. Dietary potassium-sodium imbalance as a factor in the aetiology of primary ruminal tympany in dairy cows[J]. Vet Res Commu, 1981,5 (1) .. 159-164.
5Ueli B, Adrian S, Luzia T. Ultrasonography of the rumen of dairy cows[J]. BMC Vet Res, 2013,9 : 44.
6Turkar S, Uppal S K. Blood biochemical and ruminal liquor profile in buffaloes (Bubalus bubalis) showing omasal impac- tion[J]. Vet Res Commu, 2007,31 (8) : 967-975.
7Arias J L, Zurich L, Pedreros S. Cholinergic reactivity of the bovine fetal ruminal wall in vitro[J]. Vet Sci Commu, 1979,3 (1) :141-145.
