The Research On Application Effect Of Calf Hutch Technology In Cold Region

The calf pen was designed for calves from birth to weaning. Currently large-scale cattle farms were equipped with separate calf pen mainly including indoor and outdoor ones or calf hutches, which should be selected to used inside or outside according to the climatic variability. Generally in the case of suitable climate, calves were reared in indoor calf pens after birth. Then7to10days later they were brought into outdoor calf pens or calf hutches. Calf pens or calf hutches required clean, dry, well-ventilated condition, adequate light and to prevent wind and moisture. However, in cold environment the temperature was too low to utilize calf hutches into production widely.The experiment was designed to produce a calf hutch which were more suitable to cold environment according to the climatic characteristics of the winter in northern China and based on experience of previous research, and took it into feeding trials of nurturing calves. Determinations of environmental and physiological indicators, measurements of growth performance, animal behavioral observations and recordings were used to explore its effect of application.Experiment1Design and material of calf hutchThe calf hutch designed in this experiment included the barn outside and hutch inside. The barn outside utilized single slope design and its front side was covered by double-layer plastic film which was68～70°angle from the ground in order to ensure more use of heat produced by solar radiation as far as possible. The hutch included two parts that were the rear of hutch and playground. Materials produced by calf hutch were constituted by double light color plates and benzene board whose bulk density was12kg/m3. Also it had characteristics including the strength, light weight, corrosion resistance and insulation effect.The test result showed that calf hutches of the experimental design could be applied into actual production of calves in cold region.Experiment2Determinations of environmental indicatorsThe trial period was60d and the temperature range was from-30℃to-5℃. The experiment used single factor random allocated design and20healthy newborn Holstein calves were divided into two groups. Control group calves were reared in single pens of the barn in accordance with the conventional model and experimental group calves were reared in calf hutches (One half of each group’s calves were the male and others were the female). After7days of colostrum fed, weight differences were not significant (P>0.05) between two groups and the experiment began. Environmental indicators including temperature, humidity and intensity of illumination were determined both in calf barn and calf hutch daily. The experimental results showed that the temperature, humidity and intensity of illumination in calf hutch were more suitable for calves’ growth compared to calf barn. Also differences of the temperature and humidity both in the front or rear of calf hutch were not significant (P>0.05).Experiment3Determinations of growth performanceAfter the end of the pre-feeding (1st day during the trial period), twenty calves were weighed. Also they were weighed20calves on the30th and60days during the trial period, meanwhile body sizes of calves (height, oblique length, chest and cannon bone) were measured with observing and recording health conditions of calves. The experimental results showed that during the trial period body weight and daily gain of calves reared in hutches were not significantly different from calves reared in the barn (P>0.05). Body sizes of calves reared in hutches had higher values than those of calves reared in the barn, the only exception was for the cannon bone. Also calves reared in hutches had higher values than calves reared in the barn in terms of diarrhea, respiratory disease circumstance and mortality.Experiment4Determinations of physiological indicators and behavioral observationsThe experimental time of determinations of physiological indicators and behavioral observations was from January7th to January21st2012. Five days as a test cycle, the first two days of each cycle were pre-observation period (transition period) and on the3rd day20calves were observed by continuous video recording of24h. Then the4th and5th day were for determinations of physiological indicators. The experimental results showed that changes daily of rectal temperature, heart rate and respiratory rate of calves between inside hutch and barn were not significantly different (P>0.05). Changes daily of ears ’and tail’s skin temperatures of calves in hutches were higher than those in the barn. Skin temperatures of calves’ fore or hind limbs at12:00and17:00, other parts only at12:00in hutches were higher than those in the barn. In terms of maintenance behaviors, calf hutch’s environment was more suitable for calves’growth and had no significant impact on physiological behaviors of calves. Also comforts of resting behaviors of calves in hutches were better than those in the barn. In addition, the total time of calves’ maintenance behaviors in the rear of hutches was longer than those in the front of hutches. The time calves’standing behaviors lasted in the front of hutches was longer, but their sleeping time was much less than that in the rear of hutches.Overall, calf hutches of the experimental design utilized in cold region were feasible. Advantages of using calf hutches technology to breed calves were to provide a well-comfortable rearing environment for calves and to improve their animal welfare. Also it could contribute to calves’growth, ensure their growing healthily and improve the survival rate of calves.