The values of the temperature-humidity index and its influence on the performance parameters of dairy cows were monitored on four farms located in the southern part of the central Slovakia during a period of three years. The observed parameters included: the milk yield per cow per day, average milk speed and maximum milk speed. The thermal-humidity index was calculated based on a formula. The individual periods were divided according to the achieved THI. The results of dairy cows with a milk yield of 29 kg to 31 kg show that there is not a decrease in the milk yield per milking if the THI value is lower than 68. It was also found that there was a decrease in the milk yield per dairy cow in the robotic milking parlor for a THI value greater than 72. The influence of a THI value higher than 68 in these dairy cows results in a higher average milk speed, as well as a higher maximum milk speed. These two parameters are not yet in the main area of research interest. This study enriches the area with new knowledge, according to which dairy cows can show thermal stress by increasing the milk speed as well as the maximum milk speed.

Gálik R., Boďo Š. Staroňová L. (2015): Monitoring the inner surface of teat cup liners made from different materials. Res. Agr. Eng., 61 (Special Issue): S74-S78.The modern milking equipment consists of several rubber parts. Among these rubber parts, the most important is a teat cup liner, which provides direct contact force to teat tissue. Properties of teat cup liners directly affect the technical and technological process of milking, udder health condition and quality of obtained milk. The aim of the study is to specify the inner surface roughness of cup liners made from different materials. Roughness was measured using Surftest-301 Mitutoyo connected to a printer. Teat cup liners were monitored and evaluated at three different locations of the inner surface, every three months in primary production. The obtained results showed linear regression between the inner surface roughness of teat cup liners and exposure time. Significant differences of selected indicators of silicone liners were observed with P-value (0.029) < alpha (0.05). The model equation shows that if the value of cup liners exposure time increases by one month, inner surface roughness is likely to increase by approximately 0.039 μm.

The aim of this experiment was to analyse the influence of climatic factors on the thermal performance of separated liquid manure. The samples of organic bedding were collected from the lying area of dairy housing and preparatory store. The measurement of properties of recycled manure solids (RMS) was carried out in laboratory conditions. Samples were examined with determining the temperature effect on the thermal conductivity λ of 'dry' separated liquid manure (with a dry matter content of 60%) and 'wet' liquid manure (with a dry matter content of 26%), in air temperatures ranging from 0 °C to 40 °C. Subsequently, the thermal resistance of three selected types of cows lying structures was calculated for winter and summer boundary values. Based on the results of thermal conductivity and thermal resistance, it was observed that dry separated liquid manure as an alternative bedding has, in low temperature (up to 5 °C), the most suitable thermal performance if it is maintained in a dry condition (with a dry matter content of 60%). With increasing temperature (above 20 °C) and increasing humidity of bedding (below 26%), thermo-technical properties get worse; however, when comparing the thermal resistance of the cow bed structure with sandwich mattresses with a 50 mm layer of organic bedding and the deep cubicle filled with 200 mm of organic bedding, the thermal resistance of floor structure decreases by 7.6% or 18.4%, respectively. With a proper handling of the recycled organic bedding, it is possible to use its economic advantages.

The aim of the study was to determine the milking process quality through the temperature changes on teats. The measurements were conducted to evaluate the effect of partial vacuum 45 kPa and 40 kPa at the mammary gland. The measurements were done on a dairy farm at six Holstein breed dairy cows that were in the second stage of lactation. Temperature changes on teats were measured with thermal camera ThermoProTM TP8S IR during 2 days (morning milking and afternoon milking partial vacuum to 45 kPa, morning and afternoon milking with 40 kPa). The teats surface temperature was monitored before milking, after milking, 2 minutes after milking and 4 minutes after milking. The obtained results showed the increasing temperature during machine milking at both partial vacuums (45 kPa, 40 kPa). The highest temperature was reached immediately after milking. At the partial vacuum 45 kPa, the temperature increase was in morning and afternoon milking an average of +2.44 K. At partial vacuum 40 kPa the temperature increase was +1.93 K. Both temperature increases were statistically different (P > 0.05). The largest temperature decrease of teats was detected just two minutes after milking. Thermographic method used to assess the quality of milking process has proved to be useful because of the teat’s response to a machine milking process.

The paper focuses on the analysis of compliance with the technological discipline in silage quality assessment based on sampling the silage wall using thermal imaging and penetrometer method for silage compaction. Experimental measurements were done in a selected company, which has built a silage trough with a capacity of 6,624 m 3 , in which the maize (hybrid KWS -KALIFF FAO 440) with a 36% solids content was ensiled. A thermal camera ThermoPro TM TP8S IR and cone penetrometer Eijkelkamp were used for measurements. The results obtained suggest that also undesirable heating was found in the sampling area, since the maximum temperature at some places in the depth of 0.5 m reached a temperature of 36.4 °C. According to regression and correlation analysis, we found direct linear relationship between penetration resistance and penetration depth in a 6 m and 1.5 m height (R = 0.938 respectively R = 0.970).