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 aim of the present research was to study the influence of the calving season in conditions of the upcoming climate changes on the productive traits of dairy cows in Bulgaria. The study was conducted on a cattle farm with a capacity of 500 dairy cows, which were loose-housed in open free-stall barns (shed-type). In the research, 286 lactations of 199 Holstein cattle from the studied farm were included. The cows with the highest average milk yield for lactation—8522.2 kg—calved in the spring, while the cows with the lowest milk yield—8082.7 kg—calved in the summer. Cows that calved in the spring had the highest maximum daily milk yield (lactation peak)—38 kg—whereas cows that calved in the summer had the lowest—35.7 kg. Regarding the composition indicators of milk, fat, and protein content, no significant effect of the calving season was found, but there was a tendency for the lowest values for the percentage of fat in milk to be reported for cows that calved in the summer—3.68%—and the highest for those calved in the spring—3.71%. Regarding the percentage of protein in the milk, the lowest values were observed for cows that calved in autumn—3.19%—and the highest for cows that calved in summer—3.27%.

The aim of the study was to investigate the possibility of using infrared thermography (IRT) as a tool for monitoring the physiological condition of dairy cows. The goal was to monitor cows at normal temperatures. As physiological parameters began to change with the onset of heat stress, the study focused on a group with temperature and humidity index (THI) values below 72. The study monitors the surface temperature at various points on the body, rectal temperature (RT) and Frequency of Breathing. Those parameters were chosen because they give the most accurate data on physiology and can be objectively measured. Thermography images of the udder surface temperature (UST), leg surface temperature (LST) and shoulder surface temperature (SST) of the cows were taken. Surface temperatures were extracted from the photos using specialized software. The data were processed and analyzed statistically. The correlation coefficient between UST and SST was 0.90, between RT and Frequency of Breathing was 0.65, between LST and UST it was 0.45 and between LST and SST - 0.39. In conclusion, it can be said that IRT can be used to monitor the physiological condition of dairy cows.

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 signaling pathway of fatty acids in the context of obesity is an extensively explored topic, yet their primary mechanism of action remains incompletely understood. This study aims to examine the effect of docosahexaenoic acid (DHA) on some crucial aspects of adipogenesis in differentiating 3T3-L1 cells, using palmitic acid-treated (PA), standard differentiated, and undifferentiated adipocytes as controls. Employing 60 µM DHA or PA, 3T3-L1 preadipocytes were treated from the onset of adipogenesis, with negative and positive controls included. After eight days, we performed microscopic observations, cell viability assays, the determination of adiponectin concentration, intracellular lipid accumulation, and gene expression analysis. Our findings demonstrated that DHA inhibits adipogenesis, lipolysis, and glucose uptake by suppressing peroxisome proliferator-activated receptor gamma (Pparg) and G-protein coupled receptor 120 (Gpr120) gene expression. Cell cytotoxicity was ruled out as a causative factor, and β-oxidation involvement was suspected. These results challenge the conventional belief that omega-3 fatty acids, acting as Pparg and Gpr120 agonists, promote adipogenesis and enhance insulin-dependent glucose cell flux. Moreover, we propose a novel hypothesis suggesting the key role of the co-repressor G protein pathway suppressor 2 in mediating this process. Additional investigations are required to elucidate the molecular mechanisms driving DHA’s anti-adipogenic effect and its broader health implications.

Ketosis is one of the most common metabolic disorders in high-yielding dairy cows in early lactation. It has a negative impact on milk yield, reproduction, and general health of the animals. The present review aims to systematize and critically analyze current scientific data on the monitoring, diagnosis, prevention, and treatment of subclinical and clinical ketosis, with the aim of developing an applicable protocol for good veterinary medical practices (GMP). Based on the comparative analysis method of data from the literature and clinical practice, β-hydroxybutyrate (BHBA) in blood is confirmed as the gold standard for diagnosis with specificity and sensitivity above 90%. Indicators such as fat/protein (F/P) > 1.4 and NEFA > 0.4 mmol/L, as well as reduced citrate content in milk, have been evaluated as useful screening tools, although with lower diagnostic value. Despite the advantages of some indirect methods (such as F/P), critical analysis shows that they are strongly influenced by physiological status, lactation stage, and diet and cannot replace direct blood tests. Preventive approaches emphasize the importance of stable nutrition in the pre- and post-calving period, restriction of ketogenic feeds, and use of oral glucose precursors. Literature analysis shows that propylene glycol is effective, but with prolonged use it can reduce appetite. Combined antiketotic products have also been introduced, providing not only energy support but also liver protection. Particular attention has been paid to monensin (applied in the commercial product “Kexxtone”)—a polyether antibiotic with sustained release, which reduces the incidence of ketosis by over 50% and increases milk yield in the first weeks after calving. However, its high cost, antibiotic nature, and need for veterinary supervision limit its universal use. The treatment protocol is differentiated according to the clinical type: glucose I. V. and propylene glycol in type I ketosis and avoidance of glucocorticoids in suspected type II (hepatic steatosis). In the critical analysis It is noted that improper use of glucocorticoids can lead to a worsening of the condition. A structured protocol for DVMP (Dairy Veterinary Medical Practice) is proposed, which includes targeted metabolic monitoring (NEFA, BHBA, F/P); proven preventive regimens (Kexxtone, propylene glycol, balanced rations), and staged prevention and treatment according to the form of ketosis. The adaptation of good practices to the scale of the farm and the level of knowledge and skills of the staff for their correct application remains a challenge. Providing training, a standardized control log, and access to field diagnostic tools is key to the success of any protocol.