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Cattle are among the animals with diurnal activity, which is due to the specific animal–environment relationship and the natural role wild cattle play in the ecosystem. As humans began domesticating, breeding these animals, they became an integral part of this relationship. This review article addresses the most important current issues: 1) a characterisation of contemporary knowledge on the biological determinants of the vision abilities of dairy cattle, 2) a discussion of the relationship between these abilities and animal health and performance, and 3) a characterisation of the light–animal relationship under husbandry conditions. The intricate link between the anatomical and physiological aspects of visual function in cattle and their circadian rhythms was emphasised. This connection directly influences cattle growth and development, as well as the health and performance of dairy cows during the long/short day photoperiods. The article also considers the possibility of managing dairy cows' photoperiod and light quality to enhance their performance and overall well-being. [ABSTRACT FROM AUTHOR]

One of the minor studied stress factors in cattle breeding is noise. Noise is any unwanted chronic or intermittent sound and the amount and type of noise sources are related to the cattle production system. The aim of the review was to highlight the literature regarding noise as a robust environmental stressor and the following impact on the behavioural, physiological and performance reactions of cattle. In addition, it was shown how often this problem is discussed in the scientific literature. Review was conducted with a search strategy of peer-reviewed articles written in English before June 2022. The systematic searches were performed using the Web of Science and Scopus databases with the integration of Boolean operators to string together words or phrases. It is recommended to create an environment around cows in which the acoustic stimuli affecting the animals are under their control. Therefore, if the sound source cannot be eliminated, animals should be able to choose places with a lower sound intensity appropriate for the perceptual abilities of cattle. On the other hand, attention is paid to the positive aspects of some groups of sound signals i.e. positive nature of music for cows and people during milking. The scientific publications analysed by the methodology drew attention to the repeatability of the discussed results. Further research on this subject should be considered because developing farms use modern solutions in barns which can negatively affect the acoustic comfort of cows, and their impact has yet to be determined. [ABSTRACT FROM AUTHOR]

This study aimed to assess the thermal environment, behaviour, hygiene, and lameness in dairy cows with different numbers of lactations housed in a compost-bedded pack barn system in a humid subtropical climate during autumn and winter. Between April and July 2016, behavioural and microclimatic environment assessments were conducted in a compost barn system, and hygiene and lameness assessments were performed. Crossbred cows in lactation (n = 10) were divided into two groups according to the number of lactations: primiparous and multiparous. Air temperature, relative humidity, and air ventilation speed were measured at 09:00, 12:00, and 15:00. The cows' hygiene and lameness were evaluated using subjective scores ranging from 1 to 4 and 1 to 5, respectively. The daytime behaviour assessment was performed as sampling 0/1, using the focal method. Primiparous cows showed a greater probability of walking (P<0.05) than multiparous cows between 09:20 and 11:20, and at 15:20, and increased the water intake at 14:00. Regarding the eating behaviour and the effect of time of day within each group (P<0.05), the cows ate more in the morning's early hours. The cows' hygiene scores were 1 or 2, and most cows presented scores of 1 or 2 for lameness. Our research has shown that microclimatic variables may influence the walking behaviour and water intake of primiparous cows during the hottest periods of the day, even during cold weather, in a humid subtropical climate. The dairy cows showed low hygiene and lameness scores, which indicates that the compost bar positively influenced cleanliness and locomotion comfort. [ABSTRACT FROM AUTHOR]

Heat stress in livestock is a function of macro- and microclimatic factors, their duration and intensity, the environments where they occur and the biological characteristics of the animal. Due to intense metabolic processes, high-producing dairy cows are highly vulnerable to the effects of heat stress. Disturbances in their thermoregulatory capability are reflected by behavioural, physiological and production changes. Expression of thermoregulatory behaviour such as reduction of activity and feed intake, searching for a cooler places or disturbances in reproductive behaviours may be very important indicators of animal welfare. Especially maintain of standing or lying position in dairy cattle may be a valuable marker of the negative environmental impact. Highly mechanized farms with large numbers of animals have the informatic system can detect alterations automatically, while small family farms cannot afford these type of equipments. Therefore, observing and analysing behavioural changes to achieve a greater understanding of heat stress issue may be a key factor for developing the effective strategies to minimize the effects of heat stress in cattle. The aim of this review is to present the state of knowledge, over the last years, regarding behavioural changes in dairy cows (Bos Taurus) exposed to heat stress conditions and discuss some herd management strategies provided mitigation of the overheat consequences. [ABSTRACT FROM AUTHOR]

In this study, we investigated the influence of a silvopastoral system on the thermal environment, behaviour and thermoregulation of dairy heifers in a subtropical climate. The experiment was conducted on a dairy farm in Southwest Paraná, Brazil, during the summer of 2014. Crossbred Holstein × Jersey dairy heifers (n = 10) were used in a split-plot design. The fixed effects in this study include time of day (9:00–10:00, 13:00–14:00, and 17:00–18:00 h) under silvopastoral or open pastures conditions, which were the main-plot and split-plot factors, respectively. To assess the environmental conditions in both systems, air temperature, relative humidity and wind speed were recorded. In addition, the temperature-humidity index was calculated based on the microcli-mate measurements. Respiratory rate and hair coat surface temperature of heifers were measured in both groups during time of day (30 days). Diurnal behaviour using focal observations with 0/1 sampling was observed. Data were analysed using Bayesian inference with a mixed effects model. The air temperature was higher (P<0.05) in open pasture conditions than the silvopasture system. Temperature-humidity index values for the silvopasture system were lower than open pasture during the hottest hours of the day. Regarding thermoregulation responses, there was an interaction between time of day and pasture environment (P<0.05). Heifers showed lower respiratory rates and hair coat surface temperature values (P<0.05) when access to shade was provided, mainly during the hottest periods in the afternoon. In addition, there was also an interaction between rumination and water intake (P<0.05), which indicates a higher rumination frequency for animals in the silvopasture system during the hottest period, as well as a higher water intake frequency for heifers in open pasture during midday. These findings imply that the arrangement of trees in a silvopasture system provides better thermal comfort conditions for dairy heifers raised in a subtropical climate. [ABSTRACT FROM AUTHOR]

A trend of global warming has been observed over the last few years and it has often been discussed whether there is an effect on livestock. Numerous studies have been published about heat stress in cattle and its influence on the physiology and productivity of animals. Preventing the negative effects of heat stress on cattle is essential to ensure animal welfare, health and productivity. Monitoring and analysis of physiological parameters lead to a better understanding of the adaptation processes. This can help to determine the risk of climate change and its effects on performance characteristics, e.g. milk yield and reproduction. This, in turn, makes it possible to develop effective measures to mitigate the impact of heat load on animals. The aim of this article is to provide an overview of the current literature. Studies especially about the physiological and productive changes due to heat stress in cattle have been summarised in this review. The direction of future research into the aspect of heat stress in cattle is also indicated. [ABSTRACT FROM AUTHOR]

Abstract Dairy cows are exposed to heat stress, the risk of which is increasing due to climate change. This could result in significant changes in the cows’ lying time behaviour. The presented study shows the relationship between heat stress determined with the use of the Temperature Humidity Index (THI) and the daily lying time of 40 Holstein-Friesian dairy cows. Based on the calculated value of THI, two periods were specified, a neutral period (with a maximum daily THI value below 68) and warm period (with minimal daily THI value above 73). The obtained results were processed using analysis of the Spearman’s correlation coefficient with significance at P<0.05. The results showed a decrease in daily total lying time between the neutral and warm periods from 11.3 to 9.4 h/d. During the warm period, the correlation between cows’ lying time and increased THI shows that the relationship is significant inversely proportional, but in the neutral period that correlation was not significant. A decrease in the percentage of the lying cows and average lying time per hour was also noticeable between the daytime and night-time in warm periods, which was 2 times less than in the neutral period. [ABSTRACT FROM AUTHOR]

The main aim of the presented investigation was to determine the effect of the air thermal conditions variability on cow's milking performance in summer in a moderate climate. The analyses covered the summer months of 2012-2013 (June-September) and shorter, several-day periods characterized by the times of elevated or high air temperatures and by the declines and increases in milking performance. The research was conducted in a free stall barn for Holstein-Friesian cows. The study showed that the thermoneutral temperature for high yielding cows decreases gradually with the registered increasingly warmer summer periods. The decreases in milk yield already commence at an air temperature equal to 20°C and also depend on the dairy cattle sensitivity. July and August, with a high number of hot days, caused that in September the cows responded faster to a worsening of thermal conditions and the decline in milking performance happened almost simultaneously with the air temperature change, at milking yield recovery after the period of 3-4 d (r=-0.84, P<0.04). The percent duration in the individual temperature ranges which caused a decrease of milk yield was also determined. In June, and at the beginning of July, this was 90% of the time with temperatures above 20°C, and simultaneously 45% above 25°C occurred to milking performance decrease (r=-0.89, P<0.02). In September, this was only 30% of the time with temperatures above 20°C (r=-0.91, P<0.01). [ABSTRACT FROM AUTHOR]

Cattle show a high sensitivity to changeability of microclimate conditions and heat stress that causes changes in the welfare and behaviour of cows. The presented study aimed at determining the relationship between the temperature humidity index (THI) value during the summer period and daily behaviour of dairy cows, including eligibility of lying boxes. All these aspects were measured under real production conditions. The investigated area, where microclimate conditions measurements were conducted, was a free-stall barn with single and double boxes, with manure and feeding alleys, housing 40 Holstein-Friesian cows. Observations were made on the behaviour of the cows based on a preference test concerning their choice of the best areas with respect to three ranges of THI values: neutral (N), warm (W) and hot (H). During the warm and hot period the research demonstrated a positive correlation between the level of THI and the share of standing cows (in period W - P<0.03 and H - P<0.008), and an inversely proportional one between the level of THI with participation of lying down cows (periods: W - P<0.06; H - P<0.004) and the length of their laying bouts in double boxes. The double boxes area was predominantly occupied, whereas single boxes area was the least often used. The occupation of manure alley areas was positively correlated with the level of THI. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of free-stall barn orientation relative to cardinal points on the insolation area and on the surface temperature of selected stalls in the summer period. The results of the experimental research were subjected to model analysis of the distribution of area of insolation into a barn. The studies showed that the surface of insolated stalls is heated to a temperature of 40°C, and in extreme cases up to 58°C. Taking into account the body temperature of cows (38-39°C), it can be concluded that the heat transfer from animals' body to the environment, and thus the possibility of their cooling, were difficult. This is confirmed by observations of the behaviour of cows obtained from the video monitoring. Large differences were found in thermal conditions in the southern and northern stall areas, which in the midday hours were up to 10°C. The impact of clouds occurring during observations, included in the studies, contributed to the reduction of temperature of the stalls surface. During hot weather, short, ten-minute appearance of clouds, caused a decrease of the temperature of stalls surface by approx. 2.5°C. On this basis, it can be concluded that the use of shadings in building environment in the noon hours could limit the heating up of stalls and thus contribute to improving the living conditions of cows in barn. [ABSTRACT FROM AUTHOR]

The research aimed at determining the most significant parameters affecting the microclimate of milking parlours, such as temperature, relative humidity and air movement in a parallel milking parlour in real operating conditions. The research was conducted in the summer period, when the risk of heat stress in cattle is higher. To check welfare of cows during milking, days with air temperature >25°C and days with temperature equal or lower than 25°C were analysed. Observation and analysis were performed for air flow in milking parlour, range of supplied air stream and how air movement affects cattle. It was observed that the irregular distribution of air movement led to the development of diverse air velocity in different zones of the milking parlour (0.2-9.0 m∙s-1). As a consequence, the conditions inside the barn were not homogenous for all the cattle. A significant effect of the cows and external air temperature (which depends indirectly on orientation of the milking parlour relative to cardinal directions) on temperature increase (approx 6°C) was concluded, with relative air humidity at the level of 85-90%, during the milking, which led to systematic decrease of microclimatic comfort for cattle. Based on the conducted research, it was concluded that the design of ventilation systems in parallel milking parlours should be preceded by increased research not only on ventilation system efficiency but also on the distribution of flow ventilated air. [ABSTRACT FROM AUTHOR]

Presented are results of a study on the influence of air temperature and humidity on milk production by 174 Holstein-Friesian cows kept in a free stall barn. Occurrence of heat stress in three technological groups of cows with help of temperature-humidity index (THI) was specified. The result of heat stress was a decrease in milk yield. There was a strong correlation found (P=0.05) between minimum THI, temperature and milk yield. Delay of decrease in milk production as related to maximum temperature (TMAX) in most cases was 2 days (P=0.05). Significant differences were shown between THI average hourly values (from 1 to 6 units) in particular areas of the barn when the average daily THI >68. Duration of total air temperature exceed 21°C in each technological group was investigated. It was concluded that the number of hours above the critical temperature for the cows in group 1 was 90 and 42-44 for the remaining groups, which resulted in the largest decrease in milk yield in group 1. The obtained results indicate the need to evaluate the microclimate parameters in several specific places related to the existence in the barn technological groups. Predicting the risk of heat stress should take into account the zoning in the barns related to variations of temperature and humidity conditions. This will enable the selection of appropriate functional, utility and technical solutions to maintain optimum welfare of cows in free stall barn. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on indoor ammonia (NH3) concentrations in the air in a free-stall barn. The differences in measurement results mainly depended on the season and weather conditions. The study also showed a significant correlation (P<0.01) between the NH3 concentration and temperature, relative humidity and air movement velocity inside the barn. The lowest NH3 concentration was recorded in the summer (0.0 ppm) in the presence of high air temperatures, low humidity and increased exchange of ventilated air. In winter during severe frosts, highest ammonia concentration (8.0 ppm) was noted, caused by limited ventilation. The highest daily ammonia concentration was usually recorded during the night. This was due to increased relative air humidity and low air velocities. It was concluded that the average level of ammonia of 2.73 ppm during the entire year was significantly below values defined as harmful for animals and people. [ABSTRACT FROM AUTHOR]

The paper presents the influence of temperature, relative air humidity, air movement velocity and solar radiation on forecasting the risk of heat stress in dairy cows in a free-stall barn during hot weather seasons. THI and adjusted THI indexes were calculated for the periods in which the air temperature exceeded 28°C in the barn, and when it reached 25°C. Based on the THI values obtained during the heat, which ranged from 63 to 83, the occurrence of heat stress in cattle was stated. Heat stress also caused a decrease in milk yield, from about 22 kg to about 18 kg in the technological group. The calculated THIadj values (83 to 90), taking into account the solar radiation and air movement velocity, indicated also the occurrence of health-threatening conditions for cattle. On the fourth day of heat the maximum daily value of THI in the first measurement point was 83 with THIadj of 90, while in the second point THI was 82 and THIadj was 87. This indicated the occurrence of significant differences in microclimatic conditions in the occupied zone of the same technological group. The influence of investigated microclimate factors on the formation of THIadj in the researched zone of the barn was stated. No proper method of its determination was also stated. The analysis of the impact of air movement velocity on THIadj value (P<0.05) and the solar radiation (P<0.05) demonstrated the importance of these parameters in forecasting heat stress in cows in the barn. [ABSTRACT FROM AUTHOR]

Evaluated were changes of temperature and relative air humidity inside a free-stall barn affecting the welfare of cows of three technological groups during a hot summer. The effects of selected microclimate parameters of the barn have been assessed based on the THI (temperature-humidity index) in relation to milk production. The research revealed that the animals suffered from thermal stress which resulted in decreased milk production in particular groups. The paper presents information about percentage values of this decrease and time needed to regain the original state. It also points out the need to determine THI not only for the entire barn but also for its various zones occupied by particular technological groups of cows with different levels of milk production. The authors highlight that the THI index is quite a useful tool for predicting thermal stress in particular sections of the barn. Yet, it is necessary to improve the methodology of THI calculation in order to include more microclimate elements, mainly air movement. [ABSTRACT FROM AUTHOR]