Design and application effect of yak barn with window and insulated barn in alpine region

Abstract: In order to solve the problems of low productivity of yaks and degradation of pasture quality caused by traditional grazing methods in alpine pasturing areas, the study draws on the feeding technology of common beef cattle, combined with the actual conditions of high-cold pastoral areas, a barn with windows and a uninsulated barn in Hongyuan County, Sichuan Province were designed, which were put into production to compare the effect in practice after completing construction. Barn with windows had been built in double slope style with light steel structure, the size of the barn with windows was 63 m × 9 m × 3.2 m, and the breadth of this barn were 6 m. Barn located at 15°east of south. In order to increase the indoor solar area in the whole winter, roof solar belts and long windows with 1.5 m high were set up on the south, according to the sun sunshine. The north side had set up 21 windows with 1.5 m × 1.5 m to reduce the cold air infiltration, which is conducive to yak breeding. Besides, in order to meet the yak ventilation requirements, ventilation chain was set with height of 0.16 m under the eaves. The yaks in the barn with windows were feed with free stall mode, mechanical feeding, mechanical and manual cleaning combined, drinking warm water with drink sink. The size of the uninsulated barn was 63 m × 7.5 m × 3.2 m, and the style was same with the barn with windows, except there were no roof solar belts and no walls on the south, the yarks could walk to the playground. The yaks in the uninsulated barn were feed with free stall mode, manual feeding, manual cleaning, drinking water with by themselves. After the completion of the cattle house, the yak was raised according to the test requirements, and the environment and production index of the two types of yak houses were measured. The results showed that, the temperature of the two barns were 4.17 and ?1.02 ℃, the maximum temperature difference was 8.23 ℃, the relative humidity of the two barns were 43.25% and 30.94%, and the CO2 of the two barns were 1313 and 669 mg/m3, which meant that the difference was significant (P <0.05). The content of NH3 in two barns were 0.55 and 0.59 mg/m3, and the wind speed in two barns were 0.30 and 0.06 m/s, but the difference was not significant (P>0.05). The two barns' weight gain were 0.30 and ?0.06 kg/(day?head), and the difference was very significant (P<0.01). The feed intake were 4.04 and 3.96 kg/(day?head), the difference was not significant. The profits of each yark in barn with windows exceed that of uninsulated barn about 190.60 yuan per month on average. The temperature of insulated barn was higher than that of uninsulated barn, and the weight gain was faster, so barn with windows is more applicable than uninsulated one when considering of economic feasibility, and the environment is more comfortable.