Noise is defined as unwanted sound, whether chronic or periodic, and can be described in a variety of terms, including its frequency, intensity, frequency spectrum, and sound pressure shape over time. The sources of noise can be technical devices, various hydraulic systems, the engines of various machines, routine work (opening and closing doors, repairing stalls, talking of workers, feeding), mechanical ventilators, animal activities, including climbing barriers, chewing barriers, vocalizations of cows. Good farms in terms of noise level are considered to be those with a noise level up to 70 dB, while farms with a noise level above 70 dB are problematic. Noise levels above 70 dB also have a detrimental effect on cow welfare, and this is associated with a high number of somatic cells in milk. When milking dairy cows, the noise level should not exceed 65–70 dB, or if it exceeds this value, it should be for a short time, as this can lead to health disorders in humans and animals in the medium term.

The goal of this research was to evaluate milking temperament and its relationship with test-day milk (TDMY0) yield in Bulgarian Murrah buffaloes. This study involved 90 buffalo cows reared under a tie-stall production system which were milked twice a day with a milking pipeline. The behavioral responses of the buffaloes were reported during preparation for milking and during actual milking. The average temperament score during preparation for milking was 1.83, and 1.93 during milking itself. The most common reaction was leg lifting (18.9%), followed by cows moving on the stall bed (10%), definite kicking (9.9%), and 13.3% managing to remove the milking cluster during milking. The frequency of buffaloes showing adverse reactions (scores 4 and 5) increased considerably during milking compared to preparation for milking. Repeated scoring of temperament during the same lactation did not show a significant difference in the frequency of temperament assessments both in preparation for milking and during milking. The minimal difference may be due to the accuracy of the assessment or a momentary change in the condition of the animals during the two scorings. Cows with the most unwanted milking behavior (scores 5 and 4) had the highest LS means for TDMY, 8.18 kg and 7.65 kg, respectively. The reasons for these buffaloes remaining until later lactations was their high milk yield and the injection of oxytocin before milking, which helps them to be fully milked.

Background and Aim: Rising global temperatures and increasing humidity levels are intensifying the risk of heat stress (HS) in high-yielding dairy cattle. The temperature–humidity index (THI) is a standard metric for evaluating thermal stress in livestock. This study aimed to assess seasonal and diurnal variations in temperature, relative humidity, and THI within a milking parlor and determine their compliance with established thermal comfort thresholds for dairy cows. Materials and Methods: The study was conducted in a glass-roofed, windowless milking parlor housing 400 Holstein–Friesian cows in Bulgaria. Microclimatic parameters (temperature, relative humidity, and THI) were measured during three daily milking sessions (morning, noon, and evening) at 3 time points (start, middle, and end) over a 12-month period. Measurements were taken inside the parlor and 10 m outside. Statistical analysis involved one-way analysis of variance and post hoc tests using STATISTICA version 10. Results: Summer and spring exhibited the highest mean and peak temperatures (up to 31.4 °C), while winter showed the highest relative humidity (82.39%). THI values peaked in summer, reaching levels classified as “danger” for dairy cows. Morning milking generally recorded lower temperatures and THI. Seasonal variation significantly influenced all microclimatic indicators (p < 0.001), while milking sequence significantly affected temperature and THI (p < 0.05). Conclusion: In-parlor thermal conditions, especially during summer, exceeded comfort thresholds and posed a risk for HS. The study underscores the urgent need to revise livestock housing regulations to include THI-specific standards for milking parlors. Incorporating real-time microclimatic monitoring can enhance animal welfare and productivity in dairy systems. Keywords: dairy cows, heat stress, microclimate, milking parlor, seasonal variation, temperature–humidity index, thermal comfort.

The study took place in a dairy cattle farm with 500 Holstein-Friesian cows. Animals were reared under conditions of a freestall housing system and milked in a 2 × 8 "Herringbone" type milking parlor. Noise level reporting was performed three times during each milking (at start, in the middle, and at the end of milking) during the morning, midday, and evening milkings, every month within one year. The noise level in the working environment was measured by means of a Lutron SL-4023SD sound meter. The highest average noise values were recorded during the winter season, especially during the midday and evening milking, 75–76 dB, with deviations reaching over 80 dB. The next season, in terms of noise level, was the summer season, with average values of 72–74 dB. A study on noise levels in a “fishbone” type milking parlor found average values corresponding to moderately high noise levels, exceeding 65–70 dB. Such levels may negatively affect the welfare of dairy cows, as maximum values above the permissible limits were also recorded, particularly during the winter season. Therefore, it is recommended to optimize technological processes in order to reduce noise levels during milking as much as possible, which is essential both for the operators (milkers) and for the comfort of the animals.

The study was conducted in the milking parlor of a cattle farm with a capacity of 400 cows of the Holstein-Friesian breed. The milking installation was a double 8 "Herringbone" type without windows, and the roof was constructed of glass. The reporting of temperature, air humidity and temperature-humidity index (THI) was performed three times during each milking (at the start, in the middle and at the end of milking) with measurements repeated during the morning, noon and evening milking. The highest mean and maximum daytime air temperature values were recorded in summer and spring. Although the average values for the spring season were lower than those for summer (by about 4 ⁰ C), the maximum values reached were equally high – 31.4 ⁰ C. In terms of relative air humidity, the highest mean values were reported for the winter sea-son – 82.39%. For the other seasons, the relative humidity values were on average high and close in value - from 62.51 to 67.46%. In THI, the highest average daily and maximum values were re-ported in the summer months - 73.41 and 80, respectively.