MIKROKLIMATO TYRIMAI SAITINĖJE KARVIDĖJE (Studies Microclimate in a Tied Cowshed)

Abstract

Atlikus eksperimentinius tyrimus nustatyta natūralios vėdinimo sistemos efektyvumas saitinėje karvidėje. Karvidėje naudojama natūrali plyšinė vėdinimo sistema. Šaltuoju metų laiku tyrimais nustatyta, kad tvarto santykinė oro drėgmė neviršijo rekomenduojamas normas, didžiausias drėgnis užfiksuotas buvo 94,1 %, o temperatūra fermoje nebuvo nukritus žemiau 0 ^oC. Nustatyta, kad mikroklimatas karvidėje didžiąją metų dalį atitinka reikalavimus. Norint sukurti gerą mikroklimatą saitinėse karvidėse, rekomenduojama tvarte neįrengti perdengimo, įrengti natūralaus tipo plyšinę vėdinimo sistemą, tvarto sienose įrengti šviesą praleidžiančias užuolaidas.

The health and high productivity of dairy cows need to be ensured in order to create sustainable dairy production. Therefore, it is very important to create a good microclimate in the barns. Most of the microclimate problems are in cowsheds, where it is difficult to ensure that the air is warm and humid. The aim of the research is to investigate and evaluate the microclimate in the warm and cold periods of the year in a tethered cowshed.

The studies were performed in a production tethered cowshed with about 300 cows. The cowshed uses a natural slit ventilation system. Hourly air temperature and relative humidity were recorded hourly in the barn and outside during the studies.

The evaluation of milk production indicators showed that the milk yield was the highest in October, the average milk yield per cow was 18.7 kg per day. The largest decrease in milk production was recorded in January, the average milk yield per cow was 15.2 kg per day. Milk fat content was 4.68%, protein -3.64%.

The microclimate of the cowshed was found to meet the recommended microclimate requirements for air temperature and relative humidity. Experimental studies in the cowshed found a compromise between air temperature and humidity. The temperature in the cowshed did not fall below 0 ^oC during the cold and high humidity and condensation on the roof structures were avoided. During cold weather, the relative humidity of the barn does not increase by more than 95%. During the heat, the temperature in the cowshed is 3.5-4.6 ^oC lower than in the open air, and in winter, when the outdoor temperature drops to minus 15 ^oC, the temperature in the barn is 4.0-7.5 ^oC.

The humidity in the barn increases only for short periods and meets the requirements almost in all periods of the year. In a cowshed, it is possible to achieve warm and humid and clean air in the barn - low gas concentrations. The most important thing is that there is no overlap (ceiling) in the barn and that there is more space for the animal, that no urine accumulates in the barn and that there are not many open surfaces from which water and various gases (usually ammonia) evaporate.

 The maximum recommended air temperature of 25 ^oC was exceeded for several days in May and June. The heat lasted briefly and adverse effects on the cows were avoided. Humidity in the cowshed increased only for short periods (2-3 hours per day).

It is possible to maintain a good microclimate in the cowshed without the use of mechanical devices - fans, but by using natural ventilation methods. Recommendations for the formation of the optimal microclimate in cowsheds: do not install overlaps in cowsheds; to install a natural type slit ventilation system; install light-transmitting curtains on the walls of the barn.

The purpose of the barn is to create good conditions for animals. The most important thing is that the air in the barn is clean. It is necessary to install an efficient ventilation system in the barn and to build the barn properly. In summer, it is necessary to control and limit the access of direct sunlight to the barn. The barn must protect the cows from the cold winter wind, rain and snow and provide shade from the hot summer sun.