Browsing by Author "Windeyer, M. Claire"

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    Impacts of calving management, calf risk factors, and difficult calvings on health and performance of beef calves
    (2019-08-28) Pearson, Jennifer M.; Windeyer, M. Claire; Pajor, Edmond Anthony; Campbell, John R.; Caulkett, Nigel; Lévy, Michael Z.
    Calf health and survival is crucial to successful cow-calf operations. Assisted calves are at a disadvantage compared to their herdmates because they may be injured, oxygen deprived, or less vigorous at birth. Determining evidence-based management practices to mitigate the effects of calving assistance on calf health and survival, as well as investigating risk factors associated with assisted calvings that affect transfer of passive immunity (TPI), morbidity, mortality, and growth, will help improve calf wellbeing. Therefore, the objectives of this thesis were to: benchmark the incidence of calving assistance and health outcomes, and describe current calving and colostrum management practices; to determine the impacts of subclinical trauma on calf vigour and TPI; and to investigate the impact of implementing pain mitigation at birth to assisted beef calves. Chapter 2 described current calving and colostrum management practices found on western Canadian cow-calf operations. Although the incidence of assisted calvings was low, the majority of producers assisted at least one calving, indicating the importance of understanding intervention and management strategies in compromised calves such as those assisted at birth. Chapter 3 quantified subclinical trauma associated with the degree of calving difficulty, and evaluated associations between subclinical trauma and calf vigour and TPI. Calves experiencing difficult births had elevated levels of subclinical trauma and decreased vigour. Subclinical trauma and reduced vigour were also associated with inadequate TPI. Chapters 4 and 5 investigated the clinical impacts of administering a non-steroidal anti-inflammatory drug to assisted beef calves at birth. In Chapter 4, calves administered meloxicam had greater average daily gain in the first week of life compared to placebo treated calves, but no effect was seen on pain and inflammatory mediators, vigour, TPI, health, or weaning growth. In Chapter 5, there was no effect of administering meloxicam to assisted calves on TPI, health, or growth, but vigour assessment and colostrum management were found to be important management tools associated with TPI, calf health, and growth. Therefore, calves assisted at birth experience subclinical trauma that affects their vigour and TPI. Pain mitigation strategies, vigour assessment, and colostrum management may be important tools to improve wellbeing in assisted beef calves.
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    Protocol for a systematic review of disease control strategies used to prevent infectious mortality and morbidity in pre-weaned beef calves
    (2021-05-07) Windeyer, M. Claire; Sanguinetti, V. Margarita; Agbese, Samuel; Ganshorn, Heather
    It is essential to optimize the production of calves in order to maximize economic returns to producers and the availability of feeder cattle and replacement stock for the industry. Morbidity and mortality in beef calves have negative impacts on beef operations and are associated with considerable economic damage (2,3). By implementing effective disease control strategies, morbidity and mortality caused by Bovine Respiratory Disease (BRD) and Neonatal Calf Diarrhea (NCD) may be reduced. Studies have shown that failed transfer of passive immunity (3–7), season of birth (8), herd size (2,3), assistance at calving (3,9), and purchasing adult cattle and using community pastures (10) are risk factors for morbidity and mortality in calves. Disease control strategies are an essential component of the health management of beef herds (11) and some preventive practices have shown financial benefits (12). Herd demographics and management practices alter the epidemiology of disease within the herd (13), with various strategies aiming to improve the animal environment, boost the immune system (14), and diminish animal exposure to potential pathogens (15). Risk factors associated with the multifactorial syndromes of BRD and NCD have been explored mainly in dairy calves (5–8), but there are a limited number of studies related to beef calves (16) and no efforts to summarize the available literature have been reported. A systematic review of the current scientific literature will be conducted focusing on colostrum management, vaccination strategies, biosecurity, biocontainment, metaphylactic use of antibiotics, and other strategies used to prevent mortality and morbidity caused by BRD and NCD in pre-weaned beef calves. To the best of our knowledge, there is no published systematic review on disease control strategies used in beef calves during the preweaning stage.
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    Protocol for the systematic review of strategies used in beef cattle to prevent or control internal or external parasites
    (2021-08) Agbese, Samuel; Sanguinetti, V. Margarita; Gilleard, John; Ganshorn, Heather; Windeyer, M. Claire
    This paper describes the protocol for a systematic review that will evaluate the following question: What strategies are most effective for the prevention or control of internal or external parasites in beef cattle herds? The overall objective of this systematic review is to critically assess and synthesize the current published knowledge on the aforementioned review question.