Thesis (M. App. Sc.)--University of Adelaide, Dept. of Animal Science, 1997? / Includes bibliographical references (leaves 107-130).

Thesis (M.Ag.Sc.)--University of Adelaide, Dept. of Animal Sciences, 1989. / Includes bibliographical references (leaves 196-220).

Thèse (Ph. D.)--Université Laval, 2004. / Bibliogr. Publié aussi en version électronique.

The objectives of this work were to investigate the effects of unconventional oils rich in phenolic compounds and rumen adaption on methane (CH4) gas production and rumen fermentation characteristics under in vitro rumen conditions. For this purpose, two sets of trials were conducted. In the first trial, the effects of blackberry, blueberry, raspberry, pomegranate, black seed and hemp oils on CH4 production and fermentation were examined in three 24 h batch culture experiments. Treatments in each experiment consisted of control (no oil supplement), control plus corn oil, or control plus two of the unconventional oils. Oils were added to rumen cultures at 500 mg/L (equivalent to 3.3 g oil/kg of diet dry matter (DM)). After 24 h of incubation, CH4 production was not different between the control and the corn oil treatments. Of the six unconventional oils tested, only hemp and blueberry oils reduced (P<0.05) CH4 production by 9-16% relative to the control and corn oil treatments. No significant differences were observed between treatments in dry matter digestibility (DMD) or total volatile fatty acids (tVFA). Except for a reduction (P<0.05) in acetate concentration with the raspberry oil, and an increase (P<0.05) in valerate concentration with the pomegranate oil, all other treatments had similar VFA concentrations. In the second trial, the effects of adding oregano essential oil (OEO) to adapted and unadapted rumen cultures on CH4 production and rumen fermentation were evaluated under in vitro condition. Rumen cultures were obtained from continues culture fermenters fed a control diet or control diet plus OEO at 250 mg/day for 10 days. The addition of OEO decreased (P<0.05) ii CH4 production only in adapted cultures. Total VFA and acetate concentrations were greater (P<0.05) in the unadapted than adapted cultures and their concentrations decreased (P<0.05) with the addition of OEO particularly when added to the adapted cultures. Propionate concentrations were also greater (P<0.05) in the unadapted than the adapted cultures and concentrations decreased (P<0.05) with the addition of OEO. Dry matter degradability and total gas production decreased (P<0.03) with the addition of OEO in both cultures and total gas production tended (P<0.13) to be lower when added to the adapted cultures. In conclusion, our results showed that hemp and blueberry oils were moderately effective in reducing rumen CH4 formation without compromising rumen fermentation and digestibility. Oregano Essential oil addition negatively affected rumen fermentation in both adapted and unadapted cultures and the effect was greater in the adapted cultures. The greater effects of OEO on CH4 production in the adapted cultures most likely due to the lower fermentation efficiency in these cultures.

No description available.

An understanding of characteristics of sheep and goat producers across the Southeast United States is crucial for the development and vitality of the small ruminant industry. The state of Mississippi (MS) is rich in animal agriculture, and sheep and goats display the potential to become an integral part of the state’s agricultural livelihood. However, sheep and goat producers are constantly combatting the negative effects gastrointestinal nematodes inflict upon their animals. With the anthelmintic resistance status rising across the globe, sustainable methods to control parasites in small ruminants are crucial. Therefore, small ruminant producers must develop an accurate targeted selective treatment (TST) for their herd or flock. The following studies sought to identify the demographic status of current small ruminant producers in the Southeast, as well as identify the most accurate parasitic indicators (FAMACHA© or body condition scoring, namely) that will contribute significantly to the development and use of TST in MS herds and flocks.

Ruminants play an essential role in supplying nutrients to the global population. Despite notable advancements in the livestock industry, there is a rising demand for animal protein products and a pressing need for sustainable practices. Consequently, it is imperative to focus on improving efficiency and sustainability across the environmental, economic, and social dimensions of the livestock system. Precision livestock farming (PLF) technologies have emerged as a potential solution to enhance sustainability by integrating individual animal monitoring and automated control over animal productivity, environmental impacts, health, and welfare parameters. Although PLF holds promise for improving livestock management practices, its widespread adoption is hindered by challenges including the high costs associated with implementation, data ownership, and implementation across different environments. he overarching aim of this research was to investigate and propose solutions to the challenges that limit the extensive implementation of wearable technologies in livestock systems. The primary objective of the first study was to develop and assess the utility of an open-source, low-cost research wearable technology equipped with Bluetooth for monitoring ruminants in a confined setting. The study successfully demonstrated the functionality and cost-effectiveness of this technology and its potential for monitoring ruminants' behavior in research and practical applications. Building upon the success of the technology in intensive systems, the subsequent study focused on updating the wearable sensor for deployment in extensive systems. This was achieved by incorporating LoRa data transmission and enabling real-time monitoring of livestock location. The study effectively demonstrated the feasibility of the updated technology for real-time monitoring of livestock in extensive grazing systems. In continuation of testing the feasibility of sensors, the subsequent experiment aimed to assess the accuracy and precision of a low-cost wearable sensor photoplethysmography (PPG) sensor in monitoring heart-rate (HR) of sheep housed under high-temperature conditions. The results revealed poor accuracy and precision in detecting HR changes using the PPG sensor. Future studies should explore alternative sensor deployment methods and data analytics techniques to improve the accuracy of a PPG sensor in detecting HR in livestock animals. The follow-up study focuses on evaluating the suitability of a continuous glucose monitor (CGM) designed for humans in measuring interstitial glucose concentrations in sheep, as a potential replacement for traditional blood glucose measurements. The findings demonstrated great potential of CGM in detecting changes in glucose concentrations in sheep. However, the study`s limitations such as the small sample size, warranting further investigation with a larger sample size and potential standardization with laboratory analysis bore implementing CGMs as a replacement for traditional glucose measurement methods in research. The limited expansion of technology application in extensive livestock systems, in contrast to confined operations, can be attributed to challenges such as limited battery life and data transmission. To overcome these limitations, edge processing techniques which involve performing data processing, analytics, and decision-making closer to the data source, have been proposed as cost-effective strategy for enhancing the usability of inertial measurement unit systems (IMU) in monitoring grazing animal behavior. Therefore, the objective of the fifth study was to explore different classification techniques suitable for edge processing using an open-source IMU. Analysis of variances, logistic regression, support vector machine, and random forest were evaluated for classifying grazing, walking, standing, and lying behaviors. The random forest model achieved the highest accuracy (93%) in classifying grazing using 1-minute interval. Moreover, the algorithms were compared considering a periodic snapshot of data with intervals of 3 or 5 seconds, and interesting revealed no significant impact on algorithm accuracy on differentiating behavior of grazing cows using IMU systems. Heat stress has negative impacts on animal behavior, welfare, and productivity. While IMU systems have been used to detect behavioral changes in thermoneutral conditions, their effectiveness on heat-stressed animals remains unclear. The objective of the last study was to investigate changes in sheep behavior using a low-cost IMU and the influence of ambient temperature in the algorithms ability to classify behaviors. Eating, lying, standing and ruminating while standing and lying were classified during exposure to different ambient temperature patterns. The algorithm demonstrated acceptable accuracies in differentiating behaviors under thermoneutral conditions, but its performance was impaired when tested outside the thermal range. Future research should focus on developing algorithms that account for different environmental conditions to improve the accuracy of IMU in classifying animal behavior. Collectively, these investigations contribute to enhancing the applicability of technologies in livestock systems. / Doctor of Philosophy / The global population relies on ruminant animals, such as cattle and sheep, for essential nutrient. However, with the increasing demand for animal protein products, there is a growing need for sustainable practices in the livestock industry. Precision livestock farming (PLF) technologies have emerged as a potential solution to enhance sustainability by enabling individual animal monitoring. However, challenges such as data ownership and accessibility and high costs, impair its adoption. To overcome these challenges and enhance the applicability of wearable sensors in livestock systems, this research aimed to explore potential solutions. The objective of the first study was to develop and evaluate an open-source, low-cost wearable technology equipped with Bluetooth for monitoring ruminants in confined settings. The study successfully demonstrated the functionality and cost-effectiveness of this technology for monitoring ruminant behavior. Building up the success of the technology in intensive systems, the subsequent study focused on updating the wearable sensor for deployment in extensive systems. This was achieved by incorporating LoRa data transmission, enabling real-time monitoring of livestock. The study effectively demonstrated the feasibility of and potential of the updated technology for real-time monitoring in extensive livestock systems. Continuing with the feasibility testing of technologies, the next experiment aimed to assess the accuracy and precision of a low-cost photoplethysmography (PPG) sensor in monitoring heart rate (HR) in sheep housed under high-temperature conditions. Unfortunately, the results indicated poor accuracy and precision in detecting HR changes using the PPG sensor. Future studies should explore alternative sensor deployment methods and data analysis techniques to improve the accuracy of PPG sensors for HR monitoring in livestock animals. The followed study focused on evaluating the suitability of a continuous glucose monitors (CGM) designed for humans to measure interstitial glucose concentrations in sheep and potentially replacing traditional blood glucose measurements. The findings demonstrated the potential of CGMs to detect changes in glucose but limitations such as the small sample size suggest the need for further investigations with a larger sample size and potential standardization with laboratory analysis before implementing CGM as a replacement for traditional glucose measurement methods in research. In extensive systems, where technology adoption has been slower compared to confined operations, edge processing techniques are proposed as a cost-effective strategy to monitor grazing animal behavior using inertial measurement unit systems (IMU). In the fifth study, different classification techniques were explored using an open-source IMU, including analysis of variances, logistic regression, support vector machine, and random forest. The random forest model achieved high accuracy (93%) in classifying grazing behavior with a 1-minute interval. Surprisingly, algorithm accuracy was not affected when snapshot in time was performed. The final study focused on using a low-cost IMU to investigate sheep behavior under varying ambient temperature conditions. While algorithm performed well under thermoneutral conditions, its accuracy decreased outside the thermal range. Future research should focus on algorithms that account for different environmental conditions to improve IMU accuracy in classifying behavior. These investigations contribute to enhancing technology's applicability to in livestock systems by addressing challenges and developing practical solutions to improve livestock management and animal well-being.

The use of animal manures to replace commercial fertilizer has increased the economic and environmental sustainability of agriculture. However, this practice has resulted in excess P being applied to the soil in some areas. Excess P may run-off into surface water and leach in the ground, causing eutrophication. Decreasing the amount of P fed and improving the utilization of P are two possible nutritional solutions to this problem. Two experiments were conducted to investigate the effects of levels of dietary P, chemical form of P, and phytase supplementation in ruminants. For Exp. 1, 24 steers (average BW = 229 kg) were allotted to two diets containing 0.12 and 0.19% dietary P for a 112-d growth trial. The steers were individually full-fed, weighed every 14 d, and blood samples were collected every 28 d. The steers fed the 0.12% P diet had increased (P<0.02) ADG during the first 28 d, after which there were no differences. They also had higher (P<0.05) feed intake. By d 56 serum P for the 0.12% P group was lower (P<0.01), and this difference continued for the remainder of the trial. For Exp. 2, 18 wether lambs (average BW = 23 kg) were allotted to the following six diets for each of two metabolism trials: 1) a negative control diet deficient in P, 2) control diet supplemented with inorganic P, 3) control diet supplemented with phytic acid, 4) control diet supplemented with phytic acid and phytase, 5) control diet supplemented with cottonseed meal, and 6) control diet supplemented with cottonseed meal and phytase. Each metabolism trial was preceded by a 5 wk depletion phase in which the lambs were fed a low-P diet. The metabolism trials consisted of a 10 d preliminary period followed by a 10-d collection of feces and urine. On the final day ruminal fluid, blood, and saliva were collected. At the end of the second metabolism trial 10th rib bones were collected from each lamb. Absorption of P was lowest (P<0.0001) for the low-P treatment, compared to the other treatments. There was no treatment effect on saliva P. Ruminal fluid P was higher (P<0.05) for lambs receiving P supplementation. Within supplementation treatments, ruminal fluid P was higher (P<0.05) for lambs fed organic P than for those fed inorganic P. Feeding CSM resulted in higher (P<0.001) ruminal fluid P than phytic acid. The addition of phytase to the diets with organic P resulted in more (P<0.04) P in the ruminal fluid. There was a decrease (P<0.003) in serum P associated with the low-P treatment. There was no difference in bone ash or breaking strength. / Master of Science

Nitrogen excreted by ruminants may negatively impact the environment, and N not retained is not utilized for growth and production. Experiments were conducted to examine the effect of 48 h oscillation of two levels of low ruminally degradable dietary CP on N metabolism in lambs and performance of steers. In Exp. 1, a metabolism trial was conducted with 28 lambs (31 kg), allotted to four different diets: 8% CP, 10% CP, 12% CP, and 8% and 12% CP diets oscillated every 48 h. After adaptation, transition, and preliminary periods, feces and urine were collected for 10 d. Ruminal fluid and blood samples were taken at the end of collection and again 2 d later. In Exp. 2, 24 crossbred steers (228 kg) were allotted to four diets: 1) 7.5% CP, 2) 9% CP, 3) 10.5% CP, and 4) 7.5% and 10.5% CP diets oscillated every 48 h. Feed intake was measured during the 112 d study, and ADG and gain to feed ratio were calculated. Cattle were weighed every 14 d and blood samples were taken every 28 d. In Exp. 1, N retention was lowest (P < 0.05) for the lambs fed the 8% CP diet, with no differences among lambs fed the other diets. Differences in urinary N excretion accounted for most of the differences in total N excretion. Ruminal NH3-N and BUN levels were greater in animals fed higher amounts of CP. Ruminal pH and VFA concentrations were not affected by diet. In Exp. 2, feed intake did not differ among steers fed different diets. Average daily gain was lowest for cattle fed the 7.5% CP diet. No significant difference was evident for ADG between steers fed the 7.5/10.5% CP oscillating diet and those fed the 9% or the 10.5% CP diet. Gain to feed ratio was lower (P < 0.05) for steers fed the 7.5% CP diet compared to steers fed all other diets. Blood urea N level was higher for cattle fed the 10.5% CP diet than those fed the two lower CP levels, and differences were usually significant (P < 0.05). No consistent significant difference in BUN levels existed between steers fed the 7.5/10.5% CP oscillating diet and those fed the 9% and 10.5% CP diets continuously. Oscillating two levels of low ruminally degradable dietary CP every 48 h had no significant effect on N retention in lambs nor on the performance of steers compared to animals fed the same level of CP daily in these experiments. / Master of Science

La question du bien-être des animaux d’élevage et plus particulièrement celle de la douleur fait l’objet d’une attente sociétale grandissante. Cependant, l’évaluation de la douleur chez l’animal, et par voie de conséquence de l’efficacité des traitements antalgiques, reste très complexe en médecine vétérinaire, en expérimentation ou en élevage. Elle s’appuie principalement sur les modifications de comportement ou de paramètres physiologiques du système nerveux autonome, de l’axe hypothalamo-hypophysaire ou encore des processus inflammatoires. Néanmoins, les indicateurs généralement utilisés ne sont pas tous spécifiques de la douleur "ressentie" par l'animal mais peuvent également indiquer un niveau de stress ou de perturbations physiologiques et métaboliques liés au traumatisme. Chez les carnivores domestiques ou les chevaux, une approche combinant des indicateurs spécifiques de chacune des voies sollicitées dans les processus douloureux a été développée. Aucune démarche équivalente n'a été validée chez les animaux de rente. Cette thèse conduite sur ovin et bovin avait pour objectifs : 1) de développer une approche multiparamétrique d'évaluation de la douleur, ou de situations potentiellement douloureuses, 2) de tester ses performances dans différentes situations considérées douloureuses (douleurs somatiques et/ou viscérale : mammites, castration et pose de canules digestives), et 3) sur la base de cette approche d’évaluer l'efficacité de protocoles antalgiques utilisés en élevage ou en expérimentation animale. Nous montrons que (i) l’approche multiparamétrique est plus performante qu’une approche voie par voie, (ii) les modifications du comportement, de l’axe hypothalamo-hypophysaire et de l’inflammation discriminent des situations potentiellement douloureuses quel que soit le type de douleur alors que les modifications liées au stress oxydant sont davantage liées aux situations présentant des douleurs d'origine viscérale et somatique, (iii) l’approche multiparamétrique différencie les périodes les plus critiques à prendre en charge en fonction de la douleur ressentie et (iv) il est possible de proposer des ajustements des traitements antalgiques en utilisant les renseignements fournis par chacune des voies évaluées. En prenant en compte l'ensemble des principales voies impliquées dans les processus douloureux, l’évaluation de la douleur ressentie, peut donc être plus sensible et spécifique. Néanmoins, l’approche multiparamétrique gagnera à être simplifiée et devra être validée dans d'autres situations douloureuses, notamment dans le cas de douleurs neuropathique, avant d'être proposée sur le terrain aux vétérinaires, éleveurs ou expérimentateurs. / There is a growing societal concern regarding farm animal welfare and especially pain assessment. However, pain assessment in animals and the efficiency of analgesic treatments remains very complex in veterinary medicine, animal experimentation or farming. Pain assessment is mainly based on behavioural changes or physiological responses related to the autonomic nervous system, hypothalamic-pituitary axis or inflammatory processes. Nevertheless, the indicators usually used do not always reflect pain experienced by animals but can also reflect the level of stress or physiological and metabolic disturbances related to trauma. Combinations of pathway-specific indicators involved in pain have been developed in various animal species (carnivore pets and horses), but no equivalent approach has been validated for farm ruminants yet. The main objectives of this thesis were 1) to develop a multiparametric approach to assess pain in sheep and cattle, 2) to test its performances in different painful situations (somatic and/or visceral pain: mastitis, castration and digestive cannulas), and 3) to assess the efficiency of analgesic treatments currently used in farming or research. We showed that (i) the multiparametric approach is more efficient than a single pathway approach (ii) changes in behaviour, hypothalamic-pituitary axis, and inflammation discriminate potentially painful situations regardless of the type of pain, whereas changes related to oxidative stress are related to visceral and somatic painful situations, (iii) the multiparametric approach differentiates the most critical periods requiring specific pain management (to be managed according to the pain), and (iv) it is possible to adjust the analgesic treatments according to the information provided by the assessment of each pathway. In conclusion, taking into account the main pathways involved in painful processes, allows a more sensitive and specific pain evaluation. Further research should aim at simplifying the multiparametric approach and validating it against other painful situation (especially neurological pain) before proposing it for practical-use on field by veterinarians, farmers and researchers.