Cross-Ventilated Barns for Dairy Cows

Abstract

Critical factors in the selection of the type of housing for dairy cattle are cost, animal comfort, worker’s efficiency, durability, and a favorable return on investment. Since the first low-profile cross-ventilated barns (LPCV) was built in South Dakota in 2005, at least 6 more facilities have been built in this state using this technology, and dozens of them in the rest of the country. Although LPCVs’ are a new concept for dairy similar year-round controlled environ-ment housing systems have been used for a long time in the swine and poultry industries. In the U.S., the number of dairy farms with more than 500 cows has increased recently by 18%, from 2,795 dairies in 2001 to 3,300 in 2012. However, nearly 60% of the cows in the US are housed in these larger operations. The LPCV design would be suitable for these larger dairy operations. One peculiarity of LPCVs’ is that they require less building area than convention-al barns housing a similar number of cows. The surface area needed to build a 16-row LPCV barn is 25,200 m². However, the area required to build four conventional barns of 4 rows each is 43,400 m². Although both examples have 1,920 freestalls the area required increases by 70 % in the conventional system. The area needed per cow goes from 13.6 m² in 16-row LPCV to 22.9 m² in 4-row conventional barns. This aspect is particularly important to consid-er in parts of the world where increased population is making agricultural land prices incom-patible with profitable livestock production. The interior is similar to conventional barns with the main difference being the presence of baffles that hang approximately half-way from the ceiling. The function of these baffles is to increase air velocity and redirect it towards the freestalls. To reduce the height in the center of the barn, the slope of the roof changes from 4:12 pitch in conventional barns to 0.5/12 pitch in LPCV. The height of the side walls is iden-tical in both types of facilities, but because there’s less roof slope, the height at the center of the barn is lower in the LPCV, thus the name low-profile. On one of the side walls, there are exhaust fans, and on the opposite side there is the air intake, thus the name cross-ventilated. The access doors to the alleys are situated on the front end, similar to conventional barns. An important consideration with LPCV barns is to have an adequate artificial lighting system due to the fact that the building is completely enclosed. It is necessary for the walls and ceil-ing to be well insulated in order to minimize the problems with condensation in the winter and heat transmission by radiation in the summer. This publication will extensively discuss the main advantages and drawbacks of LPCV’s as well as specific dimensions and other rele-vant considerations.