Effects of cow reproductive status, parity and lactation stage on behaviour and heavy breathing indications of a commercial accelerometer during hot weather conditions.

Heat stress presents one of the most urgent challenges to modern dairy farming, having major detrimental impacts on cow welfare, health, and production. Understanding the effect of cow factors (reproductive status, parity, and lactation stage) on the physiological and behavioural response to hot weather conditions is essential for the accurate detection and practical application of heat mitigation strategies. To study this, collars with commercial accelerometer-based sensors were fitted on 48 lactation dairy cows to record behaviour and heavy breathing from late spring to late summer. The temperature-humidity index (THI) was calculated from measurements of 8 barn sensors. We found that, above a THI of 84, cows in advanced pregnancy (>90 days) spent more time breathing heavily and less time eating and in low activity than other cows, while cows in early pregnancy (≤90 days) spent less time breathing heavily, more time eating and in low activity. Cows with 3+ lactations showed less time breathing heavily and in high activity and more time ruminating and in low activity than cows with fewer lactations. Although lactation stage interacted significantly with THI on time spent breathing heavily, ruminating, eating, and in low activity, there was no clear indication at which lactation stage cows were more sensitive to heat. These findings show that cow factors affect the cow's physiological and behavioural response to heat, which could be used to provide group-specific heat abatement strategies, thereby improving heat stress management.

Nutrient Losses during Winter and Summer Storage of Separated and Unseparated Digested Cattle Slurry.

Management factors affect nutrient loss during animal manure slurry storage in different ways. We conducted a pilot-scale study to evaluate carbon (C) and nitrogen (N) losses from unseparated and digested dairy slurry during winter and summer storage. In addition to season, treatments included mechanical separation of digestate into liquid and solid fractions and bimonthly mixing. Chemical analyses were performed every 2 wk for the mixed materials and at the start and end of storage for unmixed materials. The parameters examined allowed us to estimate C and N losses and examine the factors that determine these losses as well as emission patterns. Gas measurements were done every 2 wk to determine the main forms in which gaseous losses occurred. To evaluate the effect of separation, measured losses and emissions of separated liquid and solid fractions were mathematically combined using the mass separation efficiency of the mechanical separator. Nutrient losses were mainly affected by climatic conditions. Losses of C (up to 23%) from unseparated, unmixed digestate and of N (38% from combined separated fractions and from unseparated digestate) were much greater in summer than in winter, when C and N losses were <7%. Mixing tended to significantly increase N losses ( < 0.1) only in winter. Mechanical separation resulted in lower GHG emissions from combined separated fractions than from unseparated digestate. Results indicate that to maximize the fertilizer value of digested slurry, dairy farmers must carefully choose management practices, especially in summer. For separated digestates, practices should focus on storage of the liquid fraction, the major contributor of C and N losses (up to 64 and 90% of total losses, respectively) in summer. Moreover, management practices should limit NH, the main form of N losses (up to 99.5%).

Effects of feed delivery frequency in different environmental conditions on time budget of lactating dairy cows.

This study aimed to examine the influence of feed delivery frequency and environmental conditions on daily time budget of lactating dairy cows. The study was carried out in two commercial dairy farms with Holstein herds. Fifty lactating dairy cows milked in automatic milking units (AMS farm) and 96 primiparous lactating dairy cows milked in a conventional milking parlour (conventional farm) were exposed to different frequencies of feed delivery replicated in different periods of the year (warm and mild) that were characterized by different temperature-humidity indices (THI). On each farm, feeding treatments consisted of two different feed delivery frequencies (1× and 2× on the AMS farm; 2× and 3× on the conventional farm). All behaviours of the cows were monitored for the last 8 d of each treatment period using continuous video recording. The two data sets from different farm systems were considered separately for analysis. On both farms, environmental conditions expressed as THI affected time budgets and the pattern of the behavioural indices throughout the day. The variation in the frequency of feed delivery seems to affect the cow's time budget only in a limited way. Standing time of cows on the conventional farm and the time spent by cows in the milking waiting area on the AMS farm both increased in response to increased feeding frequency. Although feed delivery frequency showed limited influence on cow's time budget, the effect on standing time could be carefully considered, especially on farms equipped with AMS where the type of cow traffic system (e.g., milking first) might amplify the negative consequences of more frequent feed delivery. Further investigations are required to evaluate the effect of THI and feed delivery frequency on other aspects of behavioural activity.

Effect of a Biological Additive on Nitrogen Losses from Pig Slurry during Storage.

Additives applied to animal manure slurries can affect the chemical composition and the biological processes of slurries during storage, with possible improvement of their management and reduction of environmental problems. Some new formulations are marketed claiming a nitrogen (N) removal effect due to denitrification, with the consequence of a reduced N content in the manure after storage. This study evaluated the effects of one of these commercial additives (BACTYcomplex) on slurry characteristics and N losses at a commercial piggery. The additive was applied to four different sectors of the piggery, each with an independent under-floor slurry pit; four other sectors served as controls without treatment. Pits were emptied every 4 wk, and the manure was analyzed for total and ammonia-N and total and volatile solids. Slurry samples from the last month of the on-farm assessment were removed and stored thermostatically in vessels external to the piggery. A subsample of slurry that was treated with the additive at the piggery was treated with an additional dose of additive at the beginning of long-term storage. The additive did not change the composition of the slurry during in-house storage (4 wk duration). During the 155 d of external thermostatic storage, the total solids content of treated slurry was reduced by 18% compared with control slurry, but the N content and composition of treated slurry was unaffected. The additive had a positive effect in accelerating the stabilization of the slurry but did not modify N losses.

Greenhouse Gas and Ammonia Emissions from Slurry Storage: Impacts of Temperature and Potential Mitigation through Covering (Pig Slurry) or Acidification (Cattle Slurry).

Storage of livestock slurries is a significant source of methane (CH) and ammonia (NH) emissions to the atmosphere, for which accurate quantification and potential mitigation methods are required. Methane and NH emissions were measured from pilot-scale cattle slurry (CS) and pig slurry (PS) stores under cool, temperate, and warm conditions (approximately 8, 11, and 17°C, respectively) and including two potential mitigation practices: (i) a clay granule floating cover (PS) and (ii) slurry acidification (CS). Cumulative emissions of both gases were influenced by mean temperature over the storage period. Methane emissions from the control treatments over the 2-mo storage periods for the cool, temperate, and warm periods were 0.3, 0.1, and 34.3 g CH kg slurry volatile solids for CS and 4.4, 20.1, and 27.7 g CH kg slurry volatile solids for PS. Respective NH emissions for each period were 4, 7, and 12% of initial slurry N content for CS and 12, 18, and 28% of initial slurry N content for PS. Covering PS with clay granules reduced NH emissions by 77% across the three storage periods but had no impact on CH emissions. Acidification of CS reduced CH and NH emissions by 61 and 75%, respectively, across the three storage periods. Nitrous oxide emissions were also monitored but were insignificant. The development of approaches that take into account the influence of storage timing (temperature) and duration on emission estimates for national emission inventory purposes is recommended.

Development of a New Wearable 3D Sensor Node and Innovative Open Classification System for Dairy Cows' Behavior.

Monitoring dairy cattle behavior can improve the detection of health and welfare issues for early interventions. Often commercial sensors do not provide researchers with sufficient raw and open data; therefore, the aim of this study was to develop an open and customizable system to classify cattle behaviors. A 3D accelerometer device and host-board (i.e., sensor node) were embedded in a case and fixed on a dairy cow collar. It was developed to work in two modes: (1) acquisition mode, where a mobile application supported the raw data collection during observations; and (2) operating mode, where data was processed and sent to a gateway and on the cloud. Accelerations were sampled at 25 Hz and behaviors were classified in 10-min windows. Several algorithms were trained with the 108 h of behavioral data acquired from 32 cows on 3 farms, and after evaluating their computational/memory complexity and accuracy, the Decision Tree algorithm was selected. This model detected standing, lying, eating, and ruminating with an average accuracy of 85.12%. The open nature of this system enables for the addition of other functions (e.g., real-time localization of cows) and the integration with other information sources, e.g., microenvironment and air quality sensors, thereby enhancing data processing potential.

Dairy Cow Behavior Is Affected by Period, Time of Day and Housing.

Dairy cow behavior is affected by external and endogenous factors, including time of year, barn microclimate, time of day and housing. However, little is known about the combined effects of these factors. Data were collected on eight farms in Northern Italy during summer, winter and a temperate season. The temperature-humidity index (THI) was recorded using environmental sensors, whereas cow behavior was monitored using leg accelerometers and cameras. Period, time of day and their interaction all significantly affected lying, standing and feeding behavior. However, although THI had a significant negative effect on lying and a positive effect on standing during daytime (all p < 0.001), during nighttime, it only had a significant negative effect on lying duration and mean lying bout duration (p < 0.001 for both). There was also significant variation between farms in all behavioral parameters, as well as interactions with period and time of day. For instance, farm differences in lying duration were more pronounced during daytime than during nighttime. These findings show how housing can interact with other factors, such as period of the year and time of day, and illustrate the influence of barn structure and farm management on cow behavior and, consequently, their welfare.

A Review of Welfare Indicators of Indoor-Housed Dairy Cow as a Basis for Integrated Automatic Welfare Assessment Systems.

For on-farm welfare assessment many automatic methods have been developed to detect indicators of reduced welfare. However, there is still a need to integrate data from single sources to obtain a complete picture of the welfare of an animal. This review offers a basis for developing integrated automatic systems to assess dairy cow welfare by providing an overview of the main issues that challenge cow welfare (e.g., lameness) and of well-established indicators that could detect these issues on the farm. Based on a literature review of 4 reviews on cow welfare in general and 48 reviews on single welfare issues, we identified 18 different major welfare issues and 76 matching indicators that could be detected automatically on the farm. Several indicators, e.g., feed intake, showed a consistent association with welfare across many different issues. Although some of these indicators are discussed critically, this means there are many indicators that potentially could detect reduced welfare in general. Other types of indicators could detect one specific welfare issue, e.g., increased respiratory rate for heat stress. These different types of indicators combined provide a basis to develop integrated automatic systems that ultimately would help farmers to detect welfare problems at an early stage.

Relating Lying Behavior With Climate, Body Condition Score, and Milk Production in Dairy Cows.

Attention on animal behavior and welfare has been increasing. Scientific knowledge about the effect of behavior and welfare on animals' production augmented and made clear the need of improving their living conditions. Among the variables to monitor in dairy cattle farming, lying time represents a signal for health and welfare status as well as for milk production. The aim of this study is to identify the relationship among the lying behavior of dairy cows and milk production, body condition score (BCS), weather variables, and the temperature-humidity index (THI) in the barn from a dairy farm located in Northern Italy. One-year data were collected on this farm with sensors that allowed monitoring of the environmental conditions in the barn and the activity of primiparous lactating cows. Principal components analysis (PCA), factor analysis (FA), generalized linear model select (GLMSelect), and logistic analysis (LA) were carried out to get the relationships among variables. Among the main results, it emerges that the effect of weather parameters is quite restrained, except for THI > 70, which negatively affects the lying time. In addition, the most productive cows are found to lie down more than the less productive ones, and the parameters of milk production, lying time, and BCS are found to be linked by a similar trend.

Sound Analysis to Predict the Growth of Turkeys.

Protocols for manual weighing of turkeys are not practical on turkey farms because of the large body sizes, heavy weights and flighty nature of turkeys. The sounds turkeys make may be a proxy for bird weights, but the relationship between turkey sounds and bird weights has not been studied. The aim of this study was to correlate peak frequency (PF) of vocalization with the age and weight of the bird and examine the possibility using PF to predict the weight of turkeys. The study consisted of four trials in Egypt. Sounds of birds and their weights were recorded for 11 days during the growth period in each trial. A total 2200 sounds were manually analyzed and labelled by extracting individual and general sounds on the basis of the amplitude and frequency of the sound signal. The PF of vocalizations in each trial, as well as in pooled trails, were evaluated to determine the relationship between PF and the age and weight of the turkey. PF exhibited a highly significant negative correlation with the weight and age of the turkeys showing that PF of vocalizations can be used for predicting the weight of turkeys. Further studies are necessary to refine the procedure.

Effect of ammonia stripping and use of additives on separation of solids, phosphorus, copper and zinc from liquid fractions of animal slurries.

To increase the sustainable reuse of animal manure as fertiliser, in many cases suitable treatment techniques are needed to modify the composition and obtain a balanced nutrient content. This study was conducted to evaluate the best strategies to remove solids, P, Cu and Zn, using two additives Ca(OH)2 and Al2(SO4)3, in combination with an ammonia stripping process. The assessment was carried out on five type of liquid fractions derived from the mechanical separation of: raw pig slurry, pig digested slurry, pig digested slurry after ammonia stripping, pig and cattle digested slurry, pig and cattle digested slurry after ammonia stripping. After the addition of the chemicals, the liquid fractions were mixed and then separated using a static filter. The contents of total solids P, Cu and Zn were determined. The additives effectively improved separation efficiencies which depended on the type of slurry and additive used. The P separation efficiencies ranged from 72% to 93% using Al2(SO4)3, and from 20 to 74% using Ca(OH)2. The use of Al2(SO4)3 always had a more consistent effect on the removal efficiencies than Ca(OH)2. The ammonia stripping process, reducing the alkalinity of the digested liquid fractions, facilitated a higher concentration of elements in the separated fraction. With the addition of Al2(SO4)3 to digestate after stripping the concentration of P, Cu and Zn in the solid fraction generally increased when compared to the same liquid fraction without stripping. The addition of Ca(OH)2 might be effective in removing P before the stripping process with the additional benefit to raise pH and improve the ammonia removal efficiency. These findings indicate that solid-liquid separation of animal manure slurries, assisted by chemical additives and coupled with ammonia stripping, can be a viable option for improving the sustainable use of animal manure as a fertiliser.

Effects of Feeding Frequency on the Lying Behavior of Dairy Cows in a Loose Housing with Automatic Feeding and Milking System.

Management systems in modern dairy farms is an important issue in relation to animal comfort and welfare. The objective of this study was to determine the effect of feed delivery frequency on the behavior patterns, visits to an automatic milking system (AMS) and on milk production of lactating dairy cows. The study was conducted on a commercial dairy farm with automatic feeding and milking systems. Feeding treatments consisted of two different frequencies, high feed delivery frequency (11 deliveries per day) and low feed delivery frequency (six deliveries per day). Lying behavior of 20 dairy cows was electronically monitored. The results obtained showed that 11 deliveries per day feed delivery frequency decreases the number of long-duration lying bouts, which may indicate that a very high feeding frequency disturbs the cows during their resting periods and thus influences both animal comfort and milk production. High feeding frequency may disturb the duration of lying bouts and alter the pattern of lying behavior throughout the day, affecting mainly the lying time during the 60 min before and following the provision of fresh feed. Delivering feed at a low frequency allow cows to distribute more evenly their lying time over the course of the day and improve their utilization of an AMS.

Effects of Climatic Conditions on the Lying Behavior of a Group of Primiparous Dairy Cows.

Currently, lying behavior can be assessed using continuous observations from sensors (e.g., accelerometers). The analysis of digital data deriving from accelerometers is an effective tool for studying livestock behaviors. Despite the large interest in the lying behavior of dairy cows, no reference was found in literature regarding the prediction of lying behavior as a function of the interaction of environmental parameters. The present study aimed to evaluate the influence of climatic conditions (temperature-humidity index, solar radiation, air velocity and rainfalls) on the lying behavior of a group of primiparous dairy cows, using data from accelerometers, and develop a prediction model to identify and predict the lying behavior of dairy cows as a function of the effects of environmental conditions. Results from the. GLM Procedure (SAS) showed that the model was highly significant (p < 0.001) and the r2 was 0.84. All of the effects in the model resulted in being highly significant (p < 0.001). This model, if validated properly, could be a valid early warning system to identify any deviation from the expected behavior, and to assess the effectiveness of thermal stress mitigation strategies.

Nitrogen removal from digested slurries using a simplified ammonia stripping technique.

This study assessed a novel technique for removing nitrogen from digested organic waste based on a slow release of ammonia that was promoted by continuous mixing of the digestate and delivering a continuous air stream across the surface of the liquid. Three 10-day experiments were conducted using two 50-L reactors. In the first two, nitrogen removal efficiencies were evaluated from identical digestates maintained at different temperatures (30°C and 40°C). At the start of the first experiment, the digestates were adjusted to pH 9 using sodium hydroxide, while in the second experiment pH was not adjusted. The highest ammonia removal efficiency (87%) was obtained at 40°C with pH adjustment. However at 40°C without pH adjustment, removal efficiencies of 69% for ammonia and 47% for total nitrogen were obtained. In the third experiment two different digestates were tested at 50°C without pH adjustment. Although the initial chemical characteristics of the digestates were different in this experiment, the ammonia removal efficiencies were very similar (approximately 85%). Despite ammonia removal, the pH increased in all experiments, most likely due to carbon dioxide stripping that was promoted by temperature and mixing. The technique proved to be suitable for removing nitrogen following anaerobic digestion of livestock manure because effective removal was obtained at natural pH (≈8) and 40°C, common operating conditions at typical biogas plants that process manure. Furthermore, the electrical energy requirement to operate the process is limited (estimated to be 3.8kWhm-3digestate). Further improvements may increase the efficiency and reduce the processing time of this treatment technique. Even without these advances slow-rate air stripping of ammonia is a viable option for reducing the environmental impact associated with animal manure management.

Manure management practices in Lombardy (Italy).

The Lombardy Region of Italy has used a specialised software package, GIARA, to implement an integrated environmental management system that assists farmers in the preparation and submission of nutrient management plans. These are submitted on diskette to a central authority in order to build a regional database of manure utilisation linked to a GIS. At present, the database includes plans for more then 5500 farms representing more then one million cattle and 3.5 million pigs. The information contained in the database allows an evaluation of manure management practices in the Region. Some indicators like nitrogen amount per hectare varies from 100 to 300 kg at the same level of crop requirement and therefore do not seem adequate to evaluate the pollution risk at farm level.