Spatiotemporal characteristics and driven forces of nitrogen flow of dairy farms in China: Based on a comprehensive model combined with production practices and embedding localized parameters.

This study developed a comprehensive nitrogen (N) flow model utilizing localized data in 2000-2019. Enhancements were conducted upon previous models: (1) variations in feed N intake of cows across different production phases was considered; (2) N emission in the Intergovernmental Panel on Climate Change (IPCC) and the European Monitoring and Evaluation Program and the European Environment Agency (EMEP/EEA) was incorporated; (3) emission factor (EF) of NH was corrected based on local climate; and (4) field application of manure was excluded from the system boundary to accommodate China's production status. The effects of farm scale (LF, ≥100 heads; SF, <100 heads) and manure management strategies (dry-cleaning and slurry) were considered.

Behavioral Transition Path and Pivotal Nodes Regulating Attack in Initial Encounters between Unfamiliar Pigs.

This study leverages the inherent curiosity of pigs and their competitive nature among conspecifics to explore behavioral transition paths and critical nodes that govern aggression during initial encounters between unfamiliar individuals. Two consecutive experiments were designed to investigate these dynamics under controlled conditions. In Experiment 1, unfamiliar pigs engaged in one-on-one fights with quick retreats, displaying a simple behavioral sequence of looking followed by attacking.

Effects of Herd Establishment Time and Structure on Group-on-Individual Aggression Intensity in Farm Pigs.

Aggression in farm animals affects welfare. Although one-on-one aggression was studied, group-on-individual aggression remains unresolved. This study aimed to examine how herd establishment times and structures influence aggression intensity (AI) of herds towards unfamiliar pigs.

Interindividual distances and orientations of laying hens under 8 stocking densities measured by integrative deep learning techniques.

Interindividual distances and orientations of laying hens provide quantitative measures to calculate and optimize space allocations for bird flocks. However, these metrics were often measured manually and have not been examined for different stocking densities of laying hens. The objectives of this study were to 1) integrate and develop several deep learning techniques to detect interindividual distances and orientations of laying hens; and 2) examine the 2 metrics under 8 stocking densities via the developed techniques.

Improving adsorption effect of modified carbon felt on microorganisms in pig houses.

The pathogenic microorganisms in the air have a significant impact on piglet growth and even biosecurity of pig industry. Carbon felt-based microbial adsorption shows great potential in reducing the misuse of chemical disinfectants in pig houses. However, poor biocompatibility and low adsorption efficiency hinder the application of carbon felt for microbial control in animal husbandry.

The effects of cow-related factors on rectal temperature, respiration rate, and temperature-humidity index thresholds for lactating cows exposed to heat stress.

The objectives of this study were to investigate the effects of the cow-related factors on rectal temperature (RT) and respiration rate (RR) of lactating dairy cows under different heat stress (HS) conditions and establish the temperature-humidity index (THI) thresholds at which RT and RR begin to increase for cows in China. Cow-related factors included body posture (standing and lying), milk yield (<26 kg/d, ≥ 26-39 kg/d, and ≥39 kg/d), days in milk (≤60 d, > 60 and ≤ 150 d, and >150 d), and parity (1, 2, and ≥3). Records of RT, RR, and individual characteristics were collected from July to October 2020 on a commercial dairy farm in Northern China, where 826 Holstein lactating cows were measured.

Evaluation of Thermal Indices as the Indicators of Heat Stress in Dairy Cows in a Temperate Climate.

Many thermal indices (TIs) have been developed to quantify the severity of heat stress in dairy cows. Systematic evaluation of the representative TIs is still lacking, which may cause potential misapplication. The objectives of this study were to evaluate the theoretical and actual performance of the TIs in a temperate climate.

Classifying Ingestive Behavior of Dairy Cows via Automatic Sound Recognition.

Determining ingestive behaviors of dairy cows is critical to evaluate their productivity and health status. The objectives of this research were to (1) develop the relationship between forage species/heights and sound characteristics of three different ingestive behaviors (bites, chews, and chew-bites); (2) comparatively evaluate three deep learning models and optimization strategies for classifying the three behaviors; and (3) examine the ability of deep learning modeling for classifying the three ingestive behaviors under various forage characteristics. The results show that the amplitude and duration of the bite, chew, and chew-bite sounds were mostly larger for tall forages (tall fescue and alfalfa) compared to their counterparts.

Effects of Airspeed on the Respiratory Rate, Rectal Temperature, and Immunity Parameters of Dairy Calves Housed Individually in an Axial-Fan-Ventilated Barn.

At many modern dairy farms, calves raised in barns are kept in individual stalls separated by solid partitions, which act as barriers. Ventilation fans blowing air perpendicular to these stalls only provide the optimal airflow to the first few calves, while those further away receive a slower airflow. To ascertain whatever effects different airflow speeds may have on the health of animals kept in stalls located at increasing distances from ventilation fans, we divided a select group of 43 Holstein dairy calves into six subgroups based on age, and each subgroup was subjected to either a specified high-speed or low-speed airflow as follows: (1) Six 3-day-olds received high-speed airflow (D3-HA); (2) Six 3-day-olds received low-speed airflow (D3-LA); (3) Eight 19 (±3)-day-olds received high-speed airflow (D19-HA); (4) Eight 19 (± 3)-day-olds received low-speed airflow (D19-LA); (5) Eight 29 (±3)-day-olds received high-speed airflow (D29-HA); and (6) Seven 29 (±3)-day-olds received medium-speed airflow (D29-MA).

Effects of Cold Stress and Ammonia Concentration on Productive Performance and Egg Quality Traits of Laying Hens.

In a cold climate, ensuring indoor air quality and heat preservation simultaneously has always been a difficult problem in the poultry house. The current study was carried out in order to determine the effects of chronic low temperature and ammonia concentration on productive performance and egg quality of commercial laying hens. 576 18-week-old Hy-line Brown hens were used in this study.

Optimization and Modeling of Slightly Acidic Electrolyzed Water for the Clean-in-Place Process in Milking Systems.

To find an environmentally friendly and energy efficient alternative to acidic detergent for a milking system clean-in-place (CIP) process, this study investigated the feasibility of applying slightly acidic electrolyzed water (SAEW) alone to wash the system by cleaning soiled stainless steel (304) pipes, rubber gaskets, and PVC milk hoses, which were used in the milking system. The results showed that SAEW with appropriate parameters could achieve the same or even better hygienic effects compared with commercial detergent. Using response surface models, the SAEW parameters required to clean stainless steel were optimized at 9.

Evaluation of thermal indices based on their relationships with some physiological responses of housed lactating cows under heat stress.

Thermal indices as environmental risk indicators have been used to assess heat stress of dairy cows. The present study aimed to evaluate the predictive performance of the typical cattle-related thermal indices by comparing their prediction to heat stress levels and associations with some physiological responses. The study was conducted from August to September 2019 in a naturally ventilated barn in Jiangsu, China.

Effects of chronic heat stress and ammonia concentration on blood parameters of laying hens.

Less evidence is available currently to reveal whether the immune system and productivity of laying hens change under long periods of ammonia exposure in hot climate. The present study was conducted to determine the effects of chronic exposure to high temperature and ammonia concentrations on health, immune response, and reproductive hormones of commercial laying hens. A total of five hundred and seventy six 20-week-old laying hens (Hy-Line Brown) were used in this study.

Concentration and size distribution of particulate matter in a new aviary system for laying hens in China.

Particulate matter (PM) from poultry production facilities may strongly affect the health of animals and workers in the houses, and PM emitted to the ambient air is an important pollution source to the surrounding areas. Aviary system is considered as a welfare friendly production system for laying hens. However, its air quality is typically worse as compared with conventional cage systems, because of the higher PM concentration of indoor air and other airborne contaminants.

Analysing the Motions of Spray Droplets on a Cow's Surface to Relieve Heat Stress.

Exploring the behaviour of sprayed water droplets on dairy cow hair during the spraying process is of great significance to improve the effects of this process on cooling a dairy cow's body. In this paper, we use a high-speed camera to examine the sprayed droplets of different diameters and then analyse the experimental results. The results show that the movements of sprayed droplets on the simulated dairy cow (SDC) surface can be divided into four categories: random scattering, aggregation, multiple deformations and flow slipping.

Metabolomics Reveals that Crossbred Dairy Buffaloes Are More Thermotolerant than Holstein Cows under Chronic Heat Stress.

Heat stress (HS) threatens the worldwide dairy industry by decreasing animal production performance and health. Holstein cows and dairy buffaloes are the most important dairy animals, but their differences in the metabolic mechanism of thermotolerance remain elusive. In this study, we used serum metabolomics to evaluate the differences in thermotolerance between Holstein cows and crossbred dairy buffaloes under chronic heat stress (HS) and thermal-neutral conditions.

Influence of deployment time and surface wind speed on the accuracy of measurements of greenhouse gas fluxes using a closed chamber method under low surface wind speed.

As a convenient method, the closed chamber method has been applied to determine gaseous emission fluxes from fully open animal feeding operations despite the measured fluxes being theoretically affected by deployment time, wind speed over the emitting surface and detected gas mass. This laboratory study evaluated the effects of deployment time (0 to 120 min) and external surface wind speed (ESWS) (0.00, 0.

Salvianolic Acid B Inhibits Aβ Generation by Modulating BACE1 Activity in SH-SY5Y-APPsw Cells.

Alzheimer's disease (AD) is a neurodegenerative disease in humans. The accumulation of amyloid-β (Aβ) plays a critical role in the pathogenesis of AD. Previous studies indicated that Salvianolic acid B (SalB) could ameliorate Aβ-induced memory impairment.

Carbon dioxide and methane emissions from the scale model of open dairy lots.

Unlabelled: To investigate the impacts of major factors on carbon loss via gaseous emissions, carbon dioxide (CO2) and methane (CH4) emissions from the ground of open dairy lots were tested by a scale model experiment at various air temperatures (15, 25, and 35 °C), surface velocities (0.4, 0.7, 1.

Greenhouse gas emissions from dairy open lot and manure stockpile in northern China: A case study.

Unlabelled: The open lots and manure stockpiles of dairy farm are major sources of greenhouse gas (GHG) emissions in typical dairy cow housing and manure management system in China. GHG (CO(2), CH(4) and N(2)O) emissions from the ground level of brick-paved open lots and uncovered manure stockpiles were estimated according to the field measurements of a typical dairy farm in Beijing by closed chambers in four consecutive seasons. Location variation and manure removal strategy impacts were assessed on GHG emissions from the open lots.

Effects of neoprene mat on diarrhea, mortality and foreleg abrasion of pre-weaning piglets.

Modern commercial swine farrowing crates are typically equipped with slatted iron floor to improve management efficiency (e.g., ease of manure handling, cleanliness of the farrowing crates and hence improved animal hygiene).