Barns housing high yielding cows should provide optimal environmental conditions in order to enable full potential milk production levels for cows.
This goal has not always been taken into consideration. The first dairy farmers in Israel, who emigrated from Eastern European countries over a century ago, constructed barns based on previous concepts suitable for their traditional European background.
Initially, the basic barn type built was “tied stalls”. In addition to the fact that the cows were tied for most of the day, this barn type was ill-suited because of its low roof, resulting in poor ventilation. At that time, cows were of smaller stature and milk production was lower. Later, due to the intensive breeding programs, cows increased their body size as well as milk production. Consequently, cows became more exposed to heat-stress conditions. One way of alleviating heat stress was to construct open yards to enable greater heat dissipation. These open yards were used for many years up until the year 2000, until environmental restrictions prohibited their use to prevent underground water contamination caused by slurries.
The following step in designing dairy cow barns was to build a loose housing barn with a straw bedding area of approximately 5 to 8 square meters per cow. During those days, the price of straw was low and almost all dairy farmers switched to this system of housing cows. However, this type of construction did not relieve cows from unsuitable physiological conditions throughout the year because the required addition of straw for bedding increased the cows’ proximity to the roof. Moreover, changing the level of the bedding surface caused the cows to be ill-positioned regarding the feed manger, resulting in ineffective feed consumption, which inhibited optimal milk yields.
During the 70s, a new housing system was “imported” from California: the corral. This type of barn included a narrow bedding area under the roof, situated from east to west, allowing for appropriate drying of the straw bedding. It also maintained a low roof and small bedding area per
cow. A concrete floor surrounding the bedding area enabled cows to use open yards for heat dissipation during the cooler hours of the day. Cows had to walk across the sunexposed open yards in order to gain access to the feeding alleys, thus limiting, once again, optimal food consumption and consequently – milk yields. Covering this area with mesh netting during the summer months helped to substantially reduce the impact of heat stress on the cows. However, the environmental requirements set at the beginning of the year 2000, basically enforcing farmers to prevent rain water to combine with manure, caused the farmers to adopt a barn design that had been initially developed in the Lachish region (semi-arid conditions) in the southern region of Israel. This barn type took its name (Lachish) from the name of the region. It allocates a larger resting area per cow-underroof in order to save bedding costs. The feeding table was constructed along one side of the barn with an adjacent corridor of concrete, with a roof having but one slope. This type of barn was later upgraded and renamed “loose-housing” barn.
The loose-housing barn is characterized by a two-sloped roof with a feeding table in the middle, serving two sides at a time. On each side there is a feed alley built of concrete with water troughs located between the feeding alley and the bedding area. The previously existing forementioned “corrals” were upgraded to these types of barns.
During the past forty years, another type of barn was constructed: the free-stall barns. In the beginning, they were built solely on farms located in hilly regions. The main reason for the preference of this type of barn was due to the scarcity of available land. The original model consisted of a barn with concrete slats, so that manure could be accumulated underneath and pumped out bi-annually. The free-stalls were adjacent to the concrete slats. Straw above the concrete floor served as a bedding layer and years later rubber mats were used in substitution of the straw.
However, cows in those barns did not use the stalls as was expected, due to errors in design, and they preferred lying down on the concrete slats. Consequently, many cows suffered from injured teats as a result of being trodden upon by the other cows. In many farms, stalls were removed and replaced with open yards that were reconstructed to enable cows to lie down in a more comfortable area. By the 1980s, the construction of this type of barn was discontinued.
During the past five years, this type of barn has been readapted according to the recommended dimensions from the United States. However, there is great diversity among farms regarding the success in implementing this type of barn. In some large farms where both the loose-housing and free-stall type of barns were built, field experiments have shown the advantages of the loose-housing type in terms of milk production, fertility, and physical condition of hooves and legs. In fact, loose-housing is the predominant type of barn used in Israel.
The question regarding which features would be the most efficient in barn building was still unanswered until three years ago, when a comprehensive study was conducted based on data collected from meteorological stations. The study was carried out in 40 barns located all over the country during the summers of 2004 and 2005. In each barn, two meteorological recording devices were installed inside the barns, 2.2 meters above the bedding level, in the direction of the predominant wind and another device was placed in the open field. Ambient temperature, relative humidity, radiation, wind velocity and direction were measured every minute, and then averaged at ten- minute intervals. A heat-stress model simulating the ambient temperature where the cow begins to increase its respiratory rate as a response to heat-stress conditions was employed. This model took into account: wind velocity, relative humidity and physiological parameters relating to cows with a milk yield of 45 kg. and 3.5%milk fat, fur depth of 3 mm, and calculated the threshold temperature (TT) at which the animal begins to increase its respiratory rate.
Results showed that the optimal barn type for high milking cows is loose-housing (vs. free-stall), which is situated perpendicular to the redominant wind, open-roofed, open ridged, with roof margins of approximately 5 meters in height, roof slope with a gradient of 19% – 22%, and a width between 30 – 35 meters. A barn situated parallel to the predominant wind requires higher roof margins and a narrower width.
Thus, after many years of improvement and modernisation we now know what the optimal features are for barns built for high yielding cows. Proper installation and cooling systems contribute in enabling the Israeli Holstein cow to reach its potential for milk production and support the fact that the Israeli Holstein cow has the highest level of milk production in the world.