The physiological and behavioral responses of steers to gaseous ammonia in simulated long distance transport by ship.

Ammonia (NH3) can accumulate in high density cattle accommodation during live export shipments and could potentially threaten the animals' health and welfare. The effects of 4 NH3 concentrations, control ( 0.05) on hematological parameters or body weight. Twenty-eight days after exposure to NH3, the steers' pulmonary macrophage activity and neutrophil levels had returned to normal. It was concluded that ammonia concentrations of 30 and 45 ppm induced temporary inflammatory responses which indicate an adverse effect on the welfare of steers

Structuring the problematic situation of smallholder beef farming in Central Java Indonesia: using systems thinking as an entry point to taming complexity

Improving smallholders’ performance remains a seemingly intractable central issue for beef farming development in Indonesia. Studying a complex system such as beef farming requires a systemic approach. This paper reports on the combined use of three complementary systems approaches to structure and subsequently model the problem situation as the first research step towards seeking effective solutions. System Dynamics (SD) is considered to be a powerful methodology for taming the complexity of a system. However its problem identification stage has been criticized as being insensitive to the multiple interests and power structures likely to occur in a smallholder system. This study aimed to explore the possibility of combining Soft System Methodology (SSM) and Critical System Heuristics (CSH) to overcome that limitation and accommodate multiple perspectives including smallholder views on system improvements. A series of interviews and workshops involving 2 farmer groups was undertaken in Central Java, Indonesia. The benefits of inclusion of CSH in the research protocol included its ability to embrace the opinions of the less-powerful stakeholders - the farmers. Thus, for the stakeholders, it provides a better understanding of the system than provided by a combination of SD and SSM, and thereby the potential for facilitating development of more effective interventions

Indirect calorimetry: assessing animal response to heat and cold stress

Calorimetric thermal stress studies where indirect calorimetry is used as a tool to estimate energy expenditure have been undertaken since this technique was developed. Some examples of these studies are presented in this chapter. The measurement of gas exchange by means of an open-circuit respiration chamber have been done in studies where climate needs to beconstant but also in studies where animal reactions to differences in climate as part of the experimental design. In the past and in present, animal studies are done in chambers with and without integrated climate controls. Changing climate factors, e.g. temperature, relative humidity, and air speed, may change an animal’s physiological responses. As climate can also affect energy metabolism it is necessary to have a well-designed, accurate and reliable air conditioning system inside a respiration chamber to rule out the unwanted effects of an uncontrollable climate. In this chapter important issues related to the design of climate controlin respiration chambers are described and methods for improving accuracy are discussed. We conclude that the design of chambers with and without climate control should be undertaken by those that understand animal biology as well as technicians and engineers. Furthermore, the basic physics of heat measurement are discussed and we elaborate about possible biasesfrom biological factors and physical factors and how to deal with them

Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography

Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49\ua0days. RT frequencies were scanned every 15\ua0min, whilst DLs logged every 30\ua0min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11\ua0% of data, whilst 11 of the 12 DLs had 0\ua0% data loss. IRI was only interpretable in 35.8\ua0% of images recorded. Pearson correlations between DL and RT were strong for both BT (r\ua0>\ua00.94, P\ua0\ua00.80, P\ua

Extent and economic effect of heat loads on dairy cattle production in Australia

Objective: To investigate the extent of heat load problems, caused by the combination of excessive temperature and humidity, in Holstein-Friesian cows in Australia. Also, to outline how milk production losses and consequent costs from this can be estimated and minimised. Procedures: Long-term meteorological data for Australia were analysed to determine the distribution of hot conditions over space and time. Fifteen dairy production regions were identified for higher-resolution data analysis. Both the raw meteorological data and their integration into a temperature-humidity thermal index were compiled onto a computer program. This mapping software displays the distribution of climatic patterns, both Australia-wide and within the selected dairying regions. Graphical displays of the variation in historical records for 200 locations in the 15 dairying regions are also available. As a separate study, production data from research stations, on-farm trials and milk factory records were statistically analysed and correlated with the climatic indices, to estimate production losses due to hot conditions. Results: Both milk yields and milk constituents declined with increases in the temperature-humidity index. The onset and rate of this decline are dependent on a number of factors, including location, level of production, adaptation, and management regime. These results have been integrated into a farm-level economic analysis for managers of dairy properties. Conclusion: By considering the historical patterns of hot conditions over time and space, along with expected production losses, managers of dairy farms can now conduct an economic evaluation of investment strategies to alleviate heat loads. These strategies include the provision of sprinklers, shade structures, or combinations of these

Physiological and behavioral responses of sheep to gaseous ammonia

Ammonia can accumulate in highly stocked sheep accommodation, for example during live export shipments, and could affect sheep health and welfare. Thus, the objective of this experiment was to test the effects of 4 NH(3) concentrations, 4 (control), 12, 21, and 34 mg/m(3), on the physiology and behavior of wether sheep. Sheep were held for 12 d under a micro-climate and stocking density similar to shipboard conditions recorded on voyages from Australia to the Middle East during the northern hemispheric summer. Ammonia increased macrophage activity in transtracheal aspirations, indicating active pulmonary inflammation; however, it had no effect (P > 0.05) on hematological variables. Feed intake decreased (P = 0.002) in proportion to ammonia concentration, and BW gain decreased (P < 0.001) at the 2 greatest concentrations. Exposure to ammonia increased (P = 0.03) the frequency of sneezing, and at the greatest ammonia concentration, sheep were less active, with less locomotion, pawing, and panting. Twenty-eight days after exposure to NH(3), the pulmonary macrophage activity and BW of the sheep returned to that of sheep exposed to only 4 mg/m(3). It was concluded that NH(3) induced a temporary inflammatory response of the respiratory system and reduced BW gain, which together indicated a transitory adverse effect on the welfare of sheep