350 research outputs found
Novel methods for measuring the individual dry matter intake of cows
No full text© 2023 Nima NorbuIn south-eastern Australia, grazed pasture is the main feed source for dairy cows due to its inherent low cost. In order to increase stocking rate or per cow production, pasture is commonly supplemented with cereal grain or pelleted concentrates fed in the bail and conserved forage fed in the paddock. An ability to estimate dry matter intake (DMI) of individual cows in these systems would allow the formulation of supplementary rations that consider the amount of pasture ingested. It would also allow the identification of cattle that are efficient, or inefficient, at converting feed into milk, information that could then be incorporated into breeding programs. Measuring the pasture intake of grazing cows, however, has been problematic for many decades owing to the free-ranging nature of the grazing system. Measuring the intake of conserved forage in individual cows is similarly challenging when cows are group fed in the paddock. The most common current methods for measuring forage intake in grazing systems involve the use of indigestible markers such as N-alkanes or chromic oxide. The application of these techniques in commercial settings is limited because they are time-consuming, laborious and involve complex laboratory analyses. Thus, this thesis had the aim of using on-cow sensors to measure a range of quantifiable ingestive behaviors to assess whether they might be useful in future methods for predicting DMI.
A total of five experiments were conducted in an attempt to develop novel methods for measuring the DMI of cows. Three measurable ingestive characteristics potentially associated with intake, namely prehension bites, swallowed boli, and eructations, were considered and investigated using on-cow or near-cow sensors. The first and second experiments evaluated jaw movement sensors for use in quantifying prehension bites and mastication chews in cows fed in stalls and grazing. Two versions of RumiWatch converter software, 0.7.3.36 (RWC36) and 0.7.4.13 (RWC13), were validated against visual observations via video. There were differences in the performance of RumiWatch converters that were dependent upon cow diet. It was found that both RumiWatch converter versions 0.7.3.36 (RWC36) and 0.7.4.13 (RWC13) were better at quantifying prehension bites in grazing cows than in cows fed conserved forages in stalls. At the same time, both converters were better at quantifying mastication chews in cows fed in stalls than in grazing cows. However, RWC36 was more accurate for quantifying the feeding behavior of grazing cows than RWC13, while for stall-fed cows the reverse was true. Overall, both RumiWatch converter versions were better at quantifying prehension bites than mastication chews irrespective of the cows fed in stall or grazing experiment with a correlation score over 0.75 for prehension bites between the RumiWatch jaw movement sensor and video observation.
The third experiment was an initial investigation to test techniques for measuring number and mass of prehension bites, number and mass of swallowed boli, number of eructations and eructations per kg of dry matter ingested along with the relationship of these parameters with DMI. The experiment involved 28 lactating dairy cows that were fed pasture silage and fresh chicory in varying amounts. Prehension bites were recorded using the jaw movement halters, and ingested swallows were recorded using video cameras. Concurrently, a subset of 20 cows was fitted with microphones for the audio recording of swallows. This experiment allows a comparison of two indirect methods for counting swallows (video and audio counting methods). A subset of 10 cows offered ryegrass pasture silage was also fitted with near-cow gas sensors and gas samples from the nostril of the cow were conveyed from a sampling point through nylon tubing to measure eructations for 8 h. Simultaneously, respiration chambers recorded methane production for 8 h. Number of prehension bites was used for determining bite mass from the known DMI and, similarly, the number of swallows was counted from video recording and used to calculate bolus mass. Results showed that eructations and DMI were highly correlated, but eructations and methane production were not. The total number of eructations and other feeding behaviors were not correlated. Overall, these results suggested that eructations are quantifiable using commercially available gas sensors and it may be possible to test this method in future research for its accuracy in predicting DMI by counting the number of eructations. Results also showed that the number of prehension bites and the number of swallows was greater in cows offered fresh chicory than in pasture silage. Regardless of forage type, cows offered high amounts showed a greater number of prehension bites and a number of swallows than low amounts. Bite mass was greater in cows offered pasture silage than fresh chicory. Unexpectedly, cows offered a low amount of pasture silage showed a greater bite mass than the high amount, whereas bite mass in cows offered fresh chicory was not affected by the amount offered. Bolus mass was greater in cows offered pasture silage than fresh chicory. However, bolus mass in cows was not affected by the amount offered regardless of the forage type. Neither bite mass nor bolus mass was correlated with forage DMI in this experiment. Furthermore, bite mass in cows offered fresh chicory decreased over the time spent eating, while bolus mass remained constant in both forages. This result suggests that bolus mass is less variable than bite mass in dairy cows over time spent eating. The concordance between video recording and audio recording for swallows count was 0.84, indicating either of these methods may be useful in counting swallows.
The fourth experiment examined the effect of feed type on the swallowed bolus mass, swallowing rate and evaluation of indirect methods for counting swallows in dairy cattle. Twelve fistulated lactating cows were randomly assigned to three replicated 4 x 4 Graeco-Latin square designs with four different forages: fresh chicory, fresh perennial ryegrass, alfalfa hay and perennial grass silage. Prehension bites were recorded using RumiWatch jaw movement sensors. Simultaneously, microphones and video cameras were used to record the number of swallows. Ruminal contents were evacuated approximately one-third, exposing the cardia, and then ingested boli were physically captured at the cardia of the rumen one by one over a 20-minute eating session. The fresh weight of each bolus was weighed and recorded, and then boli were oven-dried at 60°C for 48 h to determine the dry weight of each bolus. The results showed that bolus mass and swallowing rate were affected by forage type. Bolus mass was greater in cows offered conserved forages than in cows offered freshly cut forages, whereas the swallowing rate was greater in cows offered freshly cut forages than in cows offered conserved forages. Bolus mass and swallowing rate remained unchanged over the time spent eating. Bite mass was greater in cows that consumed conserved forages than freshly cut forages. However, there was no difference in total jaw movement per bolus between conserved and freshly cut forages offered to cows. Counting the number of swallows using both video and audio recordings showed good correlations with swallows counted via the manual collection of the boli. Detection percentages ranged between 68 and 77 for video recording and 92 and 96 for audio recording compared with physical capturing of boli. The lower detection percentage of swallows by video recording was attributed to the position of cows in the stalls during eating, which changed the ease with which swallows could be seen on the video recording despite using supplementary lighting and two cameras. Therefore, it is concluded that an on-cow microphone may form the basis for a future method for counting the number of swallows and therefore, potentially, dry matter intake.
The final experiment aimed to compare methods for estimating the DMI of cows. Twenty-four dairy cows were offered four amounts of perennial ryegrass pasture silage at 1.5 kg DM/cow, 3.0 kg DM/cow, 4.5 kg DM/cow, and ad libitum (6 kg DM/cow). The number of prehension bites was recorded using the RumiWatch jaw movement sensor, swallows were recorded using a microphone, and eructations using gas sensors for 5 h. Results showed cows offered ad libitum silage had a greater number of prehension bites and swallows than cows offered lower amounts of silage. There were no significant differences in bite mass, bolus mass, and eructations between levels of silage offered. The number of prehension bites, the number of swallows and the number of eructations were correlated with pasture silage eaten. The DMI of cows was estimated using the three methods (prehension bite counting method, swallow counting method and eructation counting method) and with two approaches to compare estimated DMI and measured DMI. The first approach used means from previous experimental data on bite mass (g DM/bite), bolus mass (g DM/bolus) and eructation/kg DMI while the second used a leave-one-experiment-out cross-validation process using data from the current experiment. The swallow counting technique was found to be the most accurate method of the three tested to estimate the DMI of cows by both approaches compared to the DMI estimated by the other two methods.
Overall, this thesis offers insights into measuring three ingestive behaviors possibly related to DMI. It provides an investigation of the relationship of each ingestive behavior, measured using an on-cow or near-cow sensor, with DMI. Then three sensor-based methods for estimating DMI were compared following the validation of two indirect methods for counting swallows with physical capturing of boli. The swallow counting method provided the best estimate of DMI. Therefore, this investigation provides invaluable insights into the future use of an on-cow microphone to count swallows for intake estimation either in cows fed conserved forages in stalls or grazing conditions
Yak mortality in free-range grazing systems: A case study in Laya Block, Bhutan
No full textYak farming is economically and culturally vital to highland communities, providing protein-rich products in harsh environments. Despite their resilience, yak mortality presents a serious challenge. This study aims to examine the causes of yak mortality to inform effective management strategies for sustaining this essential species. Data were collected through face-to-face interviews using semi-structured questionnaires via the Epicollect5 mobile application. All 53 herders from Laya Block were interviewed to gather information on mortality causes, herders’ characteristics, and income.Approximately 94.3% of herders reported yak mortality, with an annual mortality rate of 7.9% and a mean loss of 5.3 yaks per household. Yak mortality is primarily caused by wildlife depredation, which accounts for 58.8% of total proportional mortality. On average, each household loses 3.1 yaks annually to wildlife predation, representing a 4.6% mortality rate relative to the total yak population. The second leading cause is Gid (Coenurosis), responsible for 23.7% of deaths, with an average of 1.2 yak losses per household and a 1.9% mortality rate per total population. Other factors such as winter fodder shortages, accidents, harsh winter conditions, and natural causes contribute smaller shares to the overall yak mortality. However, no significant difference in mortality rates was observed between the two leading causes across age groups (P 0.05), indicating equal vulnerability and highlighting the urgent need for intervention strategies to mitigate these challenges and promote the conservation of this vital ruminant species in highland communities
Author Correction: The fusion–fission optimization (FuFiO) algorithm (Scientific Reports, (2022), 12, 1, (12396), 10.1038/s41598-022-16498-4)
No full textThe original version of this Article contained an error in the spelling of the author Nima Darabi which was incorrectly given as Nima Darabai. The Article also contained an error in the Equation in the Analyses based on competitions on evolutionary computation (CEC) section, under the subheading ‘Computational time and complexity analyses’ where “ O(FuFiO) ” was incorrectly given as “ O(FFO)”
Application of dynamic Bayesian network to performance assessment of fire protection systems during domino effects
No full textThe propagation of fire in chemical plants â also known as fire domino effects - largely depends on the performance of add-on passive and active protection systems such as sprinkler systems, water deluge systems, emergency shut down and emergency blow down systems, fireproofing, and emergency response. Although such safety barriers are widely employed to prevent or delay the initiation or escalation of fire domino effects, their inclusion in the modeling and risk assessment of fire domino effects has hardly been taken into account. In the present study, the dynamic evolution of fire protection systems has been investigated qualitatively using event tree analysis. To quantify the temporal changes and their impact on the escalation of fire domino effects, a dynamic Bayesian network methodology has been developed. The application of the methodology has been demonstrated using an illustrative case study, considering a variety of fire scenarios, target installations, and firefighting systems
THE STRUCTURE OF AUTHORING IN NIMA YUSHIJ'S POETRY: A BAKHTINIAN READING
No full textThis thesis employs Mikhail Bakhtin’s notion of architectonics to examine the poetry of Nima Yushij, the father of “New Persian Poetry.” The architectonic structure of Nima’s poems presupposes an authorial position situated outside the whole of the work. Outsideness provides the author with the distance that is necessary for consummating the hero and all other elements inside the work’s environment in determinate spatial and temporal boundaries. As Bakhtin puts it, only in this way can the author acquire a surplus of seeing that is required for adopting a valuational stance in relation the hero and the work as a whole. To Bakhtin, the author’s valuational stance toward the hero is the essence of the aesthetic product. This valuational position vis-à-vis the other, which generates what Michael Holquist calls the “structure of authoring,” is enacted on multiple levels in Nima’s poems as the hero, and sometimes the narrator, also perform the authorial function vis-à-vis other characters inside the poem, i.e., fixing them in determinate spatial and temporal boundaries. Of course, from the author’s perspective, the hero and the narrator are also situated inside the poem and occupy specific horizons in its environment. In this sense, their authoring activity is not a precisely aesthetic activity. Nevertheless, Nima utilizes the hero and the narrator’ activity to foreground the structure of authoring inside the poem, to make its dynamics “viewable.” This is a point that I will try to elucidate fully in the course of this study.Doctor of Philosophy (PhD
Transcranial Ultrasound Stimulation for the treatment of Substance Use Disorders: A scoping review of clinical and preclinical studies
No full textScoping Revie
History of Buddhism in Mongolia in Essay of Kensur Ngawang-Nima “Coverage of Classical Sources on History of Buddhism”
No full textThe article considers a part of the essay “Coverage of classical sources on the history of Buddhism” by the outstanding Buryat scholar Lama Kensura Ngawang-Nima, dedicated to the history of the spread of Buddhist teachings in Mongolia. Some biographical information of the author of the essay is introduced. The materials of the fragment under study are presented, on the basis of which we can say that the author divides the spread of Buddhism in Mongolia, like many researchers, into three stages. Secular and religious figures who played an important role in the spread and formation of Buddhism among the Mongols are noted in the article. It is indicated that when writing his historical treatise, Kensur Ngawang-Nima relied on the works of his famous predecessors, such as the 5th Dalai Lama Ngawang Lobsan Gyatso, Taranatha Gunga Nyingbo, Thukwan Chokyi Nyima, etc., and a part of the essay devoted to the history of Buddhism in Mongolia, based on the work “Golden Book / Altan Debter” by the famous Mongolian scholar Lama Shagdaryn Zava Damdin. The peculiarity of the historical treatise under study is that it is the only known and published work written by a Buryat in the Tibetan language in the genre of Tibetan historical literature — choichzhun
Special issue: Risk-based approaches to design and operation of process systems
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Safety and Security Scienc
Security vulnerability assessment of gas pipelines using discrete-time Bayesian network
No full textSecurity of chemical and oil & gas facilities became a pressing issue after the terrorist attacks of 9/11, due to relevant quantities of hazardous substances that may be present in these sites. Oil & gas pipelines, connecting such facilities, might be potential targets for intentional attacks. The majority of methods addressing pipeline security are mostly qualitative or semi-quantitative, based on expert judgment and thus potentially subjective. In the present study, an innovative security vulnerability assessment methodology is developed, based on Discrete-time Bayesian network (DTBN) technique to investigate the vulnerability of a hazardous facility (pipeline in this study) considering the performance of security countermeasures in place. The methodology is applied to an illustrative gas pipeline in order to rank order the pipeline segments based upon their criticality.Safety and Security Scienc
Cost-effective fire protection of chemical plants against domino effects
No full textThe propagation of fire-induced domino effects in chemical plants largely depends on the primary fire scenario, on separation distances between the units, and on the presence of fire protection barriers. Passive and active safety barriers are widely employed to prevent or delay the initiation or propagation of domino effects. In the present study, a methodology has been developed based on Bayesian network to account for the impact of such safety barriers on the propagation of fire domino scenarios. The Bayesian network has been extended to a limited memory influence diagram in order to identify a cost-effective allocation of additional safety barriers to further mitigate the fire propagation. The application of the methodology has been demonstrated using a chemical tank farm. The results are in good agreement with the results of a graph theoretic approach developed in a previous study, proving the reliability of the developed methodology in cost-effective protection of process plants.Safety and Security Scienc
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