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hau ane Lil -------- 6 - TUESDAY, APRIL 18, 1995 FARM & COUNTRY LIFE The fundamental question you will ask yourselfis, "If I'm going to build a new barn, what type will I choose?" Two basic choices present themselves: free-stall or tie-stall. Then, decisions have to be made about milking, feeding, manure and ventilation systems and the equipment for stalls, mangers, etc. Amajor factor in the selec- tion of this equipment is the type of barn in which it will be put and the barn temperature that can be maintained during the winter. Some dairy farmers may remember the old barns that were once commonly found across Ontario. The hay mow was on the north side and above the cows and boards covered with sheet metal formed the barn's south side. With the thick layer of hay, our clever grandparents got an insulation value between RSI 3.5 and RSI 8.5 (R-30 and R-50) that offered protection from the north winds. Cracks in the wallsand around the boards, windows and doors provided most of the ventila- tion. Virtually all barns were tie-stall to accommodate milking by hand. : Tie-Stall or Free-Stall Now, walls and ceilings of modern tie-stall barns are well insulated to a value of RSI 3.5 or more (R-20, equiv- alent to 15 cm of fibreglass insulation) in order to main- tain abarn temperature of between 8 degrees C and 10 degrees C. Since these barns are tightly sealed, a ventila- tion system with suitable air inlets, circulation and exhaust fans must be well planned. Such barns could also be ventilated naturally. Despite suggestions that insulating a tie-stall barn is unnecessary, you must recall that a farmer spends 8 to 10 hours per day in the barn. So, a majority of farmers will invest more in construction and insulation in order to work in comfort. The tie-stall barn tends to be a good investment for a herd of up to 70 cows, plus replacements. When you consider the costs of the milking system, con- * ventional feeding system with separate concentrate and silage distribution, and solid manure system, a tie-stall barn proves to be less expensive than a free-stall barn. But, should your herd grow bigger than 70 cows, con- sider choosing a free-stall barn using total mixed-ration feeding and liquid manure and having a milking parlor and related features. Amajor reason for making this choice is labor. One person can work with 35 to 45 cows plus replacements in a tie-stall barn, but can handle 50 to 65 cows in a free-stall barn, depending on the degree of automation. Photo 1. New automatically-controlled, naturally ventilated dairy barn with a series of chimneys, vertically sliding side- wall panels completed with windbreaks. \ V hen planning a free-stall setup, remember that the operator will spend more than half of his or her time in the milking parlor - this is where the investment for warmth is needed. For the cow area, the barn could be cold, warm, or in between in temperature, that is, it could have a modified environment. Cold Barn Cold free-stall barns are very popular mostly for eco- nomic reasons. Their advantage is minimum investment cost. Acold barn has no insulation, or at most, a sheet of plywood on the underside of the metal roof. Often, part of the walls are covered by plastic curtains for natural ven- tilation, and a large continuous opening in the roof ridge. Ifitis-20 degrees C outside, such a barn will be -15 degrees C to -5 degrees C inside. It requires heated water Will it be cold, have a modified environment same or be warm? bowls and water pipes to be in the ground. You can expect that manure will freeze solid during January and February - slotted floors or mechanical scrapers can be used only with careful supervision. The principal problems with the cold barn concept are as follows: 1. Much rain and snow enters through the continuous ridge opening. 2. Frequent periods of fog inside the barn causing con- densation on the metal during autumn, winter and spring. 3. The cows experience uncom- fortable drafts. 4. There is overheating during summer. 5. The operator suffers general discomfort. With little or no insulation, maintaining high ventilation rates, even during the winter is essential. Much of the rain or » snow that enters at the ridge falls [w= on the feeding alley or the cows. |i An expensive cover over the ridge | may be built, or a "Dome" system | can be installed to fix the problem. Condensation on the wallsand Photo 2: Insulation helps to provide a good air quality for work- ceiling is a problem in cold barns. ers' and animals' comfort, If the roof and wall openings are closed to keep the barn warmer, humidity rises rapidly and condenses. The metal gussets of the roof trusses often rust after about 5 years. During autumn and spring, condensation can occur due to sudden outdoor temperature changes. Take the machinery shed as an example: It houses no livestock, yet has condensation on the metal on the north or west side. Imagine the conden- sation in a barn holding 100 cows! To reduce condensation in cold barns, a strip of 10cm | to 15 cm (4" to 6") is left open along the eave; however, "I cold air currents make the barn drafty for the cows and, very often, snow blows through the eave and soffit, end- ing up in the cow stalls. Also, the sun can cause serious overheating during summer. Metal becomes hot and irradiates inside the barn. The cows feel this radiation during the day and may reduce their feed consumption when they become too hot. Cases of pneumonia have been reported during the summer in uninsulated barns. During the day, the cows get hot, but as night arrives, the barn temperature | drops rapidly, creating thermal stress for them. Finally, people are more sensitive to temperature and | humidity than cattle. The comfort of the people who work in the barn should be considered. Remember: "No insulation, no ventilation, no comfort." Modified Environment Amodified-environment barnis lightly insulated with 3cmto5em(1"to 2") of rigid foam insulation covered with 9.5 mm (3/8") plywood. This provides insulation val- ues in the range of RSI 1to 2 (R-6 to R1-11). Such barns cost about $1.50 to $2 per square foot (0,093 m2) more than cold barns which is equivalent to an increase in investment of between $135 and $180 per cow. Yet, the extra cost offers many advantages. There is almost no problem with water or manure freezing, almost no condensation on the roof and walls, and with the use of an automatic control for natural ventilation or fans, there is better ventilation during winter. Normally the thermostats of an automatically controlled natural ventilation system are adjusted to between 2 degrees C and 4 degrees C, which ensures the comfort of workers and cows. During summer, the insulation reduces the solar heat gain which is detrimental to both cow and worker performances. Ga Re Se archers and extension per- sons still find the issue of spending money on insu- lation controversial. Some experiments done in the USA show that the milk production of dairy cows is tion and rain infiltration in the barn apparently does not affect the cows' milk production. On the other hand, research from Europe shows a reduc- tion in milk yield and changes in the milk composi- tion for barn temperatures below 5 degrees C. No data on this subject is available from Canadian studies. Since the extra investment per cow space for a modified environment dairy barn is about $150, cost-conscious - producers could easily estimate that only a slight increase in milk production would be necessary to recoup the costs of this investment. Also, extra insulation serves as inexpensive insurance against the risk of health pro- blems associated with poor air quality. From a survey performed by a team of OMAF and Agriculture Canada engineers, deterioration of wood and plate gussets has been reported especially in barns with --, noor very little insu- lation. Some wood turned black, attacked by mildew, and some sheet metal and truss gussets were rusted. : Advanced deteriora- tion could resultin structural failure or the need for major repairs. Warm Barn Awarmbarnis, by definition, wellinsu- ~ lated with 15 ¢m to 20 cm of fibreglass, giv- ing an insulation val- ue between RSI 3.5 and RSI 4.5 (R-20 and R-28). Its interior is finished in metal siding, plywood, or new plastic vinyl. The addition- al cost compared to a cold barn ranges from $5 to $7.50 per square foot. This represents $450 to $675 per cow, depending on the type of insulation used. Awarm barn maintains a temperature of 8 degrees C to 10 degrees C during most of the winter and is not directly affected by the sun during summer. But the question arises as to whether it is worth the investment. Supplemental Heat When the outside temperature falls below -25 degrees C and the wind is blowing, even well-insulated warm barns are unable to maintain an inside temperature of 10 degrees C. Most dairy barns in the Canadian Prairies are equipped with supplemental heating, but having this is rare in Ontario. : The main goal of adding extra heat is to support enough ventilation to get rid of moisture. In cold weather so much energy is lost through the ceiling, walls, and foundation, that not enough energy is left for adequate ventilation. Consequently, the humidity level rises, causing the fog commonly seen in some barns. - With some supplemental heat, the energy needed to ventilate properly and exhaust the moisture is available. As well, the desired inside HEAT REQUIRED (walls\cow) temperature ---- of the barn TEMPERATURES warm @ Modified @ can be SllP -20°C - 128 maintained. Table 1 25°C 150 205 presents the ? -30° 47 estimated 30°c 313 3 heating ANNUAL HEATING | requirements ($ per cow) $1.70 $2.78 and associat- ed annual costs for a typical 100 cow, free-stall dairy barn of either the warm or modified-environment type, in the Ottawa area. : Table 1: Supplemental Heat Requirements for a Warm or Modified- Environment, 100-Cow, Free-Stall Barn inthe OttawaArea. Please Turn to Page 9 bo 4 4