Christian Ammon

Seasonal and diel variations of ammonia and methane emissions from a naturally ventilated dairy building and the associated factors influencing emissions

Understanding seasonal and diel variations of ammonia (NH3) and methane (CH4) emissions from a naturally ventilated dairy (NVD) building may lead to develop successful control strategies for reducing emissions throughout the year. The main objective of this study was to quantify seasonal and diel variations of NH3 and CH4 emissions together with associated factors influencing emissions. Measurements were carried out with identical experimental set-up to cover three winter, spring and summer seasons, and two autumn seasons in the years 2010, 2011, and 2012. The data from 2010 and 2011 were used for developing emission prediction models and the data from 2012 were used for model validation. The results showed that NH3 emission varied seasonally following outside temperature whereas CH4 emission did not show clear seasonal trend. Diel variation of CH4 emission was less pronounced than NH3. The average NH3 and CH4 emissions between 6a.m. and 6p.m. were 66% and 33% higher than the average NH3 and CH4 emissions between 6p.m. and 6a.m., respectively for all seasons. The significant relationships (P<0.0001) between NH3 and influencing factors were found including outside temperature, humidity, wind speed and direction, hour of the day and day of the year. The significant effect (P<0.0001) of climate factors, hours of the day and days of the year on CH4 emission might be directly related to activities of the cows.

Effects of different biochars and digestate on N2O fluxes under field conditions.

Field studies that have investigated the effects of char materials on the emission of nitrous oxide (N2O) are still scarce. Therefore, we conducted a field trial with bio- and hydrochars and measured N2O emissions for one whole year. It was hypothesised that the incorporation of chars reduces the emissions of N2O. Chars were produced by pyrolysis and hydrothermal carbonisation (HTC) using either maize silage or wood residues as feedstock. In addition, after production chars were post-treated with digestate in order to accelerate the ageing process of the chars. Chars and digestate were applied to the soil to raise the C content. Emissions of N2O were measured weekly and soil samples for inorganic nitrogen (N) and soil water-content were taken once a month. Additionally, the abundance of functional marker genes from denitrification (nosZ) was determined in October 2012 and in June 2013. The treatment with pure digestate emitted the most N2O compared to the control and char treatments. However, this was significant only in one case. There were no great differences between the char treatments due to high spatial variability and gene abundance of nosZ did not differ between treatments. Overall, emissions of N2O were relatively low. This was attributed to the heterogeneous distribution of the chars and the sandy soils that did not favour the production of N2O. To conclude, the emissions of N2O were mainly influenced by temperature and precipitation and to a minor extent by the type of char and post-treatment.

First investigations to refine video-based IR thermography as a non-invasive tool to monitor the body temperature of calves.

In this study, a video-based infrared camera (IRC) was investigated as a tool to monitor the body temperature of calves. Body surface temperatures were measured contactless using videos from an IRC fixed at a certain location in the calf feeder. The body surface temperatures were analysed retrospectively at three larger areas: the head area (in front of the forehead), the body area (behind forehead) and the area of the entire animal. The rectal temperature served as a reference temperature and was measured with a digital thermometer at the corresponding time point. A total of nine calves (Holstein-Friesians, 8 to 35 weeks old) were examined. The average maximum temperatures of the area of the entire animal (mean±SD: 37.66±0.90°C) and the head area (37.64±0.86°C) were always higher than that of the body area (36.75±1.06°C). The temperatures of the head area and of the entire animal were very similar. However, the maximum temperatures as measured using IRC increased with an increase in calf rectal temperature. The maximum temperatures of each video picture for the entire visible body area of the calves appeared to be sufficient to measure the superficial body temperature. The advantage of the video-based IRC over conventional IR single-picture cameras is that more than one picture per animal can be analysed in a short period of time. This technique provides more data for analysis. Thus, this system shows potential as an indicator for continuous temperature measurements in calves.

A comparative study among H2O-balance, heat balance, CO2-balance and radioactive tracer gas technique for airflow rates measurement in naturally ventilated dairy barns

The major problem of natural ventilation is the lack of accurate measurement methods for air exchange rates (AER) which is crucial for emissions quantification. This paper aims at comparing four methods and to recommend thereof one method for further developments. Thirty six experiments were performed to study the AERs in a naturally ventilated dairy barn through four summer seasons and three winter seasons. AERs were determined using moisture (H2O) balance, heat balance (HB), CO2-balance and radioactive tracer gas technique (TGT). The statistical analyses were correlation analysis, regression model, ANOVA and t-test. Continuous measurements of CO2 concentrations, temperature and relative humidity inside and outside the barn were performed. H2O-balance showed reliable results through winter and slightly acceptable results through summer. HB showed slightly acceptable results through summer and unsatisfactory results through winter. CO2-balance showed unexpected high differences to the other methods in some cases. TGT showed reliable results compared to all methods and is independent on physiological parameters. Therefore, TGT should be further developed. The airflow rates (AFRs), subject to TGT, were 0.12 m3 s-1 m-2, 1.15 m3 s-1 cow-1, 0.88 m3 s-1 LU-1 (LU is livestock unit of 500 kg), 395 m3 s-1 and 470 kg air s-1 through summer, and 0.08 m3 s-1 m-2, 0.83 m3 s-1 cow-1, 0.64 m3 s-1 LU-1, 275 m3 s-1 and 328 kg air s-1 through winter. AERs were 37, 81, 63 and 62 h-1 through summer, and 40, 143, 61 and 39 h-1 through winter subject to H2O-balance, HB, CO2-balance and TGT, respectively.

The effects of quarter-individual milking in conventional milking parlours on the somatic cell count and udder health of dairy cows.

The objective of this study was to examine the quarter health status of quarter-individually and conventionally milked cows. The MultiLactor®, a quarter-individual milking system (MULTI), has single guided tubes which provide milking on the quarter level with a low system vacuum level (37 kPa), sequential pulsation and periodic air inlet. The conventional milking system (CON) was equipped with a milking cluster where the system vacuum level was adjusted to 40 kPa. A total of 84 German Holstein cows, randomly divided into two groups, were included in the study. Over a period of 32 trial weeks, quarter foremilk samples were taken every week to determine somatic cell count (SCC). Bacteriological examinations and udder palpation were conducted at three different times. During the trial period, median SCC of quarter foremilk samples in both groups did not exceed the threshold value of 100,000 cells/ml. The results of the F test showed that the milking system (P = 0.0587) and days in milk (DIM) (P = 0.8066) had no significant effects on the quarter health status. On the other hand, lactation (P = 0.0396), quarter health status in the previous week (P < 0.0001) and trial week (P = 0.0061) affected quarter health status significantly. The estimated probabilities of the occurrence of a suspicious quarter (SCC > 100,000 cells/ml) were 19.97% (CON) and 31.72% (MULTI). However, the test of differences in the Least Square Means (LSM) showed no significant differences (P = 0.0585) between CON and MULTI. The estimated probability of quarters becoming suspicious during the first lactation was 12.51% for both groups. With an increasing number of lactation, the probability of a quarter becoming suspicious clearly increased (2nd lactation: 32.73% and 3rd lactation: 36.19%). The results also showed that the percentage of quarters with bacteriological findings revealed a stronger increase over time for MULTI than for CON.

Implementation of Radioactive 85Kr for Ventilation Rate Measurements in Dairy Barns

Quantifying gaseous emissions from naturally ventilated animal buildings is a particularly difficult task and associated with large uncertainties. One aspect is to measure the ventilation rate and then to quantify the gaseous emissions. Therefore, the ventilation rate was determined by two methods, simultaneously. Fifteen field experiments were carried out to study the ventilation rate in a naturally ventilated dairy barn located in Northern Germany during three consecutive winter seasons. The air exchange rates and then the ventilation rates were determined by the decay of the radioactive tracer Krypton-85, and the carbon dioxide (CO2) balance which is the reference method. Afterwards, the results were compared with each other by developing a linear regression model and carrying out Pearson correlation analysis. During each field experiment, continuous measurements of gas concentrations (NH3, CO2, CH4, and N2O) inside and outside the building and 85Kr tracer gas experiments were carried out. Meanwhile, the microclimatic and climatic conditions were measured and recorded. The tracer gas technique was further developed for better application through winter measurements. Where, eight combination factors were tested which are: 85Kr line release source vs. 85Kr point release source, average a-values vs. sum impulses, selected radiation counters vs. all radiation counters. The differences between the reference method and the eight factor combinations were tested using the ANOVA model. The results showed that the best factor combinations were: (1) line release source considering the impulses recorded by selected radiation counters and implementing the sum method of all impulses where high R-square value of 0.82 and reliable parameter estimate of 1.00±0.19 were found for this combination, and (2) point release source considering the impulses recorded by all radiation counters and implementing the sum method of all impulses where high R-square value of 0.91 and reliable parameter estimate of 1.19±0.15 were found for this combination. The average gaseous emissions through the different winter seasons, subject to the reference method, were 2.9, 14.5, 1785, and 1.6 g h-1 AU-1 for NH3, CH4, CO2, and N2O respectively.

The Usability of a Pressure-Indicating Film to Measure the Teat Load Caused by a Collapsing Liner.

Prevention of damage to the teat and mastitis requires determination of the teat load caused by a collapsing liner. The aim of this study was to test a pressure-indicating film designed to measure the pressure between a collapsing liner and artificial teats. The Ultra Super Low and the Extreme Low pressure-indicating films were tested on two types of artificial teat. The experiments were performed with a conventional milking cluster equipped with round silicone liners. For each teat and film type, 30 repetitions were performed. Each repetition was performed with a new piece of film. Kruskal-Wallis tests were performed to detect differences between the pressure values for the different teats. The area of regions where pressure-indication color developed was calculated to determine the most suitable film type. Both film types measured the pressure applied to both artificial teats by the teat cup liner. Thus, the pressure-indicating films can be used to measure the pressure between a collapsing liner and an artificial teat. Based on the results of the present investigation, a pressure-indicating film with the measurement ranges of both film types combined would be an optimal tool to measure the overall pressure between an artificial teat and a collapsing liner.

Postpartum changes in the lying behavior of sows in farrowing crates

ABSTRACT The objective of the study was to compare the behavior of sows before and after farrowing with a focus on lying behavior and side preference in a lateral position. Collecting information on normal and deviant behaviors may consequently improve the care and welfare of animals and severe variations can indicate possible welfare issues. The study was conducted on a farrow‐to‐finish‐farm with 14 crossbred sows. For each sow, behavior was analyzed by video observation (continuous sampling) on 2 days, one before (3 or 4 days after transfer to the trial compartment) and one after farrowing (second day after farrowing). The duration and frequency of lying on the left side, lying on the right side, lying on the abdomen, standing, sitting, and lying down per sow and day were compared for these 2 days. The total time that sows spent lying increased significantly (P = 0.01) on the second day after farrowing compared with the analyzed day before farrowing. The time spent lying on the right side and facing the udder to the piglet nest also increased significantly (P = 0.02) after farrowing. For the other postures (i.e., lying on the left side, lying on the abdomen (P > 0.05), sitting, standing, lying down [P ≤ 0.03]), the duration as well as the sum of changes in posture decreased after farrowing. On the test day before farrowing, sows spent a total of 85% of the day in a lying position (35% on the left side, 39% on the right, and 11% on the abdomen). The total lying time increased to 96% per sow and day on the second day after farrowing (31% on the left side, 58% on the right, and 7% on the abdomen). After farrowing, the lying duration of sows increased, and they preferred to lie on the body side facing the piglet nest. The sows spent the most time in a lateral lying position, which is information that should be used to adjust farrowing crates to improve the welfare of sows.

Field study analysis of the influences of deworming regimens and housing conditions on parasites and sperm output in 21 European boar studs

The current study reports the parasitological results of a quality control audit in 21 European boar studs. Field investigations were performed over a 2-year period (2012-2013) during the winter and spring. From each stud, an average of 30 (range, 25-33) individual faecal samples and ejaculates from 615 randomly selected Pietrain boars were analysed. Statistical analysis revealed a significant effect (P < 0.0001) of deworming regimen (DR) × age class of boar (A) and housing condition (H) × A on the presence of parasites. A second model indicated a significant effect (P = 0.0262) of DR × H × A on the presence of parasites. Sperm output was significantly affected (P < 0.0001) by the DR. Based on this study, recommendations for deworming AI boars are proposed.

ASSESSMENT OF CONTINUOUS VAGINAL LOGGER-BASED TEMPERATURE MONITORING IN FEVER-INDUCED GILTS

The aim of this study was to identify a low risk method to induce fever in gilts and to evaluate vaginal sensors for temperature monitoring. Therefore, a rhinitis atrophicans vaccine was used to induce fever to evaluate sensors and behavioral patterns. During 11 trials, two of four animals were injected with 2 mL of the vaccine Porcilis AR-T DF (Intervet) and the other two animals were treated with 2 mL of 0.9% NaCl as controls. A temperature logger (TRIX-8, LogTag Recorders, Auckland, New Zealand) was used to continuously monitor the vaginal temperature. Additionally, rectal temperatures were measured four times daily. The water consumption, food intake and locomotion behaviors of the animals were analysed one day before treatment and during the day of the treatment. The vaccine induced fever in all gilts, which occurred approximately 5.87 h after vaccination. The vaginal logger temperatures and the rectal temperatures showed a linear correlation in 21 vaccinated gilts (r = 0.86; p