Heat stress (HS) significantly impacts dairy farming, prompting interest in precision dairy farming (PDF) for gauging its effects on cow health. This study assessed the influence of the Temperature–Humidity Index (THI) on rumination, eating, and locomotor activity. Various parameters, like rumination time, drinking gulps, chews per minute, and others were analyzed. The hypothesis was that precision dairy farming technology could help detect HS. Nine healthy Lithuanian Black-and-White cows were randomly selected for the trial. RumiWatch noseband sensors recorded behaviors, while SmaXtec climate sensors monitored THI. The data collection spanned from 14 June to 30 June. Cows in the THI class ≥ 72 exhibited reduced drinking time (51.16% decrease, p < 0.01), fewer chews per minute (12.9% decrease, p < 0.01), and higher activity levels (16.99% increase, p < 0.01). THI showed an inverse correlation with drinking time (r = −0.191, p < 0.05) and chews per bolus (r = −0.172, p < 0.01). Innovative technologies like RumiWatch are effective in detecting HS effects on behaviors. Future studies should explore the impact of HS on RWS biomarkers, considering factors such as lactation stage, number, yield, and pregnancy.

This study delves into the effects of subclinical ketosis (SCK) and subclinical acidosis (SCA) on various parameters related to dairy cow rumination, eating, drinking and locomotion behavior. The research hypothesized that these subclinical metabolic disorders could affect behaviors such as rumination, feeding, and locomotion. A total of 320 dairy cows, with a focus on those in their second or subsequent lactation, producing an average of 12,000 kg/year milk in their previous lactation, were examined. These cows were classified into three groups: those with SCK, those with SCA, and healthy cows. The health status of the cows was determined based on the milk fat–protein ratio, blood beta-hydroxybutyrate, and the results of clinical examinations performed by a veterinarian. The data collected during the study included parameters from the RumiWatch sensors. The results revealed significant differences between the cows affected by SCK and the healthy cows, with reductions observed in the rumination time (17.47%) and various eating and chewing behaviors. These changes indicated that SCK had a substantial impact on the cows’ behavior. In the context of SCA, the study found significant reductions in Eating Time 2 (ET2) of 36.84% when compared to the healthy cows. Additionally, Eating Chews 2 (EC2) exhibited a significant reduction in the SCA group, with an average of 312.06 units (±17.93), compared to the healthy group’s average of 504.20 units (±18.87). These findings emphasize that SCA influences feeding behaviors and chewing activity, which can have implications for nutrient intake and overall cow health. The study also highlights the considerable impact of SCK on locomotion parameters, as the cows with SCK exhibited a 27.36% reduction in the walking time levels. These cows also displayed reductions in the Walking Time (WT), Other Activity Time (OAT), and Activity Change (AC). In conclusion, this research underscores the critical need for advanced strategies to prevent and manage subclinical metabolic disorders within the dairy farming industry. The study findings have far-reaching implications for enhancing the well-being and performance of dairy cattle. Effective management practices and detection methods are essential to mitigate the impact of SCK and SCA on dairy cow health and productivity, ultimately benefiting the dairy farming sector.

The aim of this study was to evaluate the influence of the temperature and humidity index on reticulorumen parameters such as temperature, pH, rumination index, and cow walking activity levels. Throughout the experiment, the following parameters were recorded: reticulorumen pH (pH), reticulorumen temperature (RR temp.), reticulorumen temperature without drinking cycles, ambient temperature, ambient relative humidity, cow walking activity levels, heat index, and temperature–humidity index (THI). These parameters were registered with particular smaXtec boluses. SmaXtec boluses were applied on 1 July 2022; 24 days were the adaptation period. Measurements started at 25 July 2022 and finished at 29 August 2022. The THI was divided into two classes: THI < 72 (comfort zone) and THI ≥ 72 (higher risk of thermal stress). Cows assigned to the 2nd THI class had lower average values for pH, temperature, and rumination index, but not walking activity levels. The mean differences ranged from 0.36 percent in temperature to 11.61 percent in walking activity levels (p < 0.01). An analysis of the THI revealed a significant positive linear relation with hours, where the THI had a tendency to increase on average by 0.2403. The reticuloruminal pH showed a negative linear relation with hours, where the reticuloruminal pH had a tendency to decrease on average by 0.0032, p < 0.001. Data analysis revealed a significant positive linear relationship between walking activity levels and hours, where walking activity levels had a tendency to increase on average by 0.0622 steps per hour, p < 0.001. The rumination index was not significantly related to hours (p < 0.005), although the rumination index had a tendency to increase by 0.4376 per hour, p > 0.05. The influence of HS on reticulorumen parameters increased the risk of acidosis and cows’ activity levels. HS had a negative impact on reticulorumen pH, temperature, and the rumination index. A higher THI (≥72) increased the risk of ruminal acidosis and decreased cows’ physical activity levels. From a practical point of view, we can use innovative tools for the detection of HS and its impact on reticulorumen parameters and cow walking activity levels.

The aim of our study was to investigate and quantify the impact of heat stress on the milk fat-to-protein ratio (F/P) and the metabolic profile in dairy cows, utilizing in-line registration methods for accurate and real-time data collection. This study was carried out in Lithuania at coordinates 55.819156, 23.773541, from 1 June 2023 until 31 August 2023. Milk composition, including fat and protein, was measured using a BROLIS HerdLine in-line milk analyzer from Brolis Sensor Technology, Vilnius, Lithuania. During the general clinical examinations (twice per week), blood samples were collected and determined for GLU—blood glucose concentration; BHB—blood β-hydroxybutyrate concentration; AST—aspartate transaminase activity; GGT—gamma-glutamyltransferase activity; and NEFAs—non-esterified fatty acids. The parameters based on the Temperature–Humidity Index (THI) were categorized into two groups: group 1, consisting of THI values less than 72, representing the comfort zone, and group 2, with THI values of 72 or higher, indicating a greater risk of thermal stress. Specifically, group 2 exhibited an 8.6% increase in the F/P ratio compared to group 1 (p = 0.049). Additionally, there was a 4.2% decrease in glucose levels in group 2 (p = 0.056) and a notable 5.8% decrease in albumin levels compared to group 1 (p < 0.001). We found a very weak, non-significant correlation between humidity and the milk fat-to-protein ratio (r = 0.043, p = 0.447) and a similarly negligible correlation with Beta-Hydroxybutyrate (BHB; r = 0.046, p = 0.417). We observed significant changes in milk composition, particularly an increase in the milk fat-to-protein ratio, and alterations in metabolic indicators like glucose, albumin, and liver enzymes. These changes, indicative of a negative energy balance and altered metabolic processes such as gluconeogenesis and lipolysis, correspond to previous research. The adoption of advanced tools, such as the BROLIS HerdLine analyzer, is recommended for the real-time monitoring of milk composition, which assists in the early detection of negative energy balances and metabolic issues. It is also crucial to adjust feeding practices to maintain energy balance during periods of high THI and to conduct regular health checks with a special focus on cows in early lactation.

Subclinical hypocalcemia (SCH) is one of the most prevalent metabolic disorders in early-lactation dairy cows, yet its multifaceted physiological effects are often overlooked due to the absence of clinical symptoms. This study aimed to characterize SCH through an integrative assessment of blood biochemical markers, in-line milk composition, and sensor-derived behavioral traits. Seventy-five Holstein cows between 2 and 21 days in milk were classified into hypocalcemic (group 1) (Ca < 2.0 mmol/L; n = 20) and healthy (group 2) groups (n = 55). Blood samples, milk data, and rumination metrics were evaluated, and group differences were analyzed using Welch’s t-test and Pearson correlations. Cows with SCH exhibited significantly lower concentrations of Ca, PHOS, Mg, ALB, TP, GLUC, and Fe, indicating disruptions in mineral balance, protein metabolism, and energy status. Hepatic indicators (AST, ALT, GGT) did not differ between groups, whereas CREA was significantly lower in hypocalcemic cows, suggesting altered muscle metabolism rather than impaired renal function. Although differences in milk yield, composition, and rumination time did not reach statistical significance, hypocalcemic cows showed consistent biological tendencies toward reduced milk components and lower milk temperature. Correlation analysis revealed strong physiological linkages among Ca, ALB, P, TP, and Fe, underscoring the interconnected nature of mineral and protein metabolism in early lactation. These findings demonstrate that SCH is associated with coordinated biochemical and behavioral changes even in the absence of clinical signs. Integrating blood biomarkers with real-time sensor data provides a more comprehensive understanding of calcium-related metabolic challenges and highlights the potential of precision-livestock technologies for early detection. Future studies incorporating ionized calcium and longitudinal sampling are needed to refine diagnostic thresholds and improve predictive monitoring of SCH in dairy herds.

Balantioides coli is an enteric ciliated protozoan detected in cattle, but the association between microscopic B. coli counts and precision dairy-farming indicators remains poorly understood. This cross-sectional study evaluated associations between microscopic B. coli counts and behavioral, production and milk-composition traits in 83 clinically healthy Holstein cows in parity 2–4 and 20–100 days in milk. Fecal samples were examinated using sedimentation and modified McMaster methods and abundance was expressed as microscopic counts per field of view. Automated farm systems provided eating and rumination times, daily milk yield, milk fat-to-protein ratio, lactose concentration and somatic cell count. Zero-order correlations between microscopic B. coli counts and all evaluated indicators were weak and non-significant (r = 0.027–0.190). After adjustment for parity and days in milk, a modest positive correlation was observed with lactose concentration (partial r = 0.296, p = 0.007). The remaining adjusted correlations were weak or negligible and statistically non-significant: eating time (r = 0.105), rumination time (r = 0.036), daily milk yield (r = 0.060), milk fat-to-protein ratio (r = 0.064) and log10-transformed somatic cell count (r = 0.015). Overall, microscopic B. coli abundance showed limited association with the evaluated indicators, and the lactose finding should be regarded as exploratory.