5KAVOLELIS B, SATEIKIS I. Effective cowshed insulating ventilation system parameters [ J ]. Energy Buildings,2004, 36 ( 9 ) :969 - 973.
6ROUHA - MULLEDER C, IBEN C, WAGNER E, et al. Relative importance of factors influencing the prevalence of lameness in Austrian cubicle loose -housed dairy cows [ J ]. Prev Vet Med, 2009,92 (1/2) :123 - 133.
7SCOTY G B, KELLY K. Cattle cleanliness in different housing system[ J ]. Farm Building Progress, 1989,95:21 - 24.
8CALAMARI L, CALEGARI F, STEFANINI L. Effect of different free stall surfaces on behavioural, productive and metabolic parameters in dairy cows [ J ]. Appl Anim Behav Sci,2009,120 ( 1 ) :9 - 17.
9JEPPSSON K H. Volatilization of ammonia in deep - litter systems with different bedding materials for young cattle [ J ]. J Agr Eng Res, 1999, 73(1) :49 -57.
10GROENESTEIN C M, den HARTOG L A, METZ J H M. Potential ammonia emissions from straw bedding, slurry pit and concrete floors in a group- housing system for sows[ J]. Biosystems Eng,2006,95 (2) :235 -243.
