Browsing by Author "Pajor, Edmond Anthony"

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    Assessment and Mitigation of Pain During and After Castration in Beef Calves
    (2018-04-03) Meléndez Suárez, Daniela M.; Pajor, Edmond Anthony; Schwartzkopf-Genswein, Karen Shelley; Orsel, Karin; Janzen, Eugene D.; Caulkett, Nigel Anthony
    Castration is a painful common husbandry procedure done in order to reduce aggressive behaviour, avoid unwanted mating and improve meat quality. Physiological and behavioural changes indicative of pain/discomfort have been reported after castration; however castration is commonly performed without the use of pain control. There is a lack of science based guidelines on pain mitigation strategies for castration in beef calves. The objective of this thesis was to assess and mitigate pain associated with castration in young and weaned beef calves. The first part of the study focused on assessing acute pain. Indicators of acute pain were evaluated to assess the effect of band and knife castration in 1 week, 2 month and 4 month old calves, the effect of a single dose of subcutaneous meloxicam administered immediately before band and knife castration in 1 week old calves, and the effect of a single dose of subcutaneous meloxicam administered immediately before knife castration or the combination of knife castration and branding in 2 month old calves. The second part of the study consisted of assessing pain in weaned beef calves after knife castration up to 28 days after castration. Indicators of pain were evaluated to assess the effect of a single subcutaneous injection of meloxicam administered 6, 3 and 0 hours prior to knife castration and the administration of lidocaine or meloxicam alone or in combination prior to knife castration in weaned calves. Behavioural and physiological changes were observed after castration at all ages, however, a greater number of physiological and behavioural parameters showed differences in knife castrated compared to band castrated calves, after multiple painful procedures compared to single painful procedures and in older calves compared to young calves. A reduction in behavioural and physiological responses was observed in calves that received pain mitigation at different ages and after different castration methods. Effective and practical pain mitigation strategies identified at different ages and after different castration methods could be used to improve calf welfare post castration. These include subcutaneous administration of meloxicam to reduce pain and inflammation associated with castration and the use of lidocaine to block procedural pain.
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    Dairy Calf and Heifer (Holstein, Bos taurus) Management Practices in Western Canada: Current Status and Impacts on Animal Welfare
    (2016) Borges Bond, Guilherme; Pajor, Edmond Anthony; Barkema, Herman W.; Doepel, Lorraine S.; Weary, Daniel M.
    Calves are the future of the dairy enterprise but their management is often neglected. The objectives of this thesis were: 1) to describe young stock management practices in commercial dairy farms and the compliance of producers with Canadian guidelines and; 2) to analyse the effect of management practices on calf performance, health and welfare. Eighty-two farms were visited in Alberta and British Columbia (BC), Canada. Producers completed a survey about their pre-weaned calf management practices and their awareness and use of the Code of Practice for the Care and Handling of Dairy Cattle (COP, n = 67 farms). Compliance with calf management practices in the COP was moderate and did not change whether producers were aware or not aware of the COP. Few producers changed practices as a result of the COP. The second objective was divided in two sections. The first section, comprised of 2 cross sectional studies, body weight (BW) was estimated for all pre-weaned calves (0 to 8 weeks) and heifers (12 to 15 months, BC farms only). Animals were observed for signs of nasal discharge or diarrhea and assessed for failure of passive transfer of immunity (FPT). Calves fed more than 5L of milk by bottle and introduced to water between 4 and 8 weeks of age had higher BW. Feeding less milk and offering colostrum replacer were associated with increased odds of disease and FPT. Higher heifer BW was associated with higher calf BW in the same farm. In the second section, a study on the effects of milk allowances on water drinking behaviour of dairy calves, animals were fed milk replacer either ad libitum or at 10% BW with free access to water and dry feed. Calves fed restrictively drank more water immediately after weaning. Provision of water was most important during weaning transition and drinking behaviour patterns were compatible with response to stress. The results presented in this thesis demonstrate that different practices chosen by producers can impact calf performance, health and welfare. Therefore, increased producer awareness and use of science-informed practices are needed through additional outreach efforts.
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    Digital Dermatitis in Feedlot Cattle: Field Diagnosis and Economic Impact
    (2020-04-30) Cortés Saavedra, Julián A.; Orsel, Karin; Pajor, Edmond Anthony; Janzen, Eugene D.
    Digital dermatitis (DD) has emerged in North American feedlots, although feedlot performance and risk factors are not fully elucidated. Objectives of this thesis were to evaluate two potential risk factors associated with DD: foot and leg conformation and pen condition, as well as identify the economic impact of DD in feedlot cattle. No significant difference was detected between foot and leg conformation in cattle with and without DD. However, pens with “more mud than bedding” increased significantly the odds of cattle with DD (OR=8.55, CI: 4.0-18.4), as well as pens with “excessive mud” (OR=14.1, CI: 5.9-33.8). Also, pens with “more mud than bedding” and “excessive mud” had animals with significantly less ADG (-0.12 and -0.36 kg/d, respectively), compared to animals in dry pen condition. Hence, it is recommended to keep good pen conditions to decrease the odds of cattle developing DD, as it would increase feedlot performance. This can be managed through proper stocking density and strategic bedding, regardless of cattle’s foot and leg conformation. For the economic impact, not all type of cattle with DD were negatively affected, but fall placed steers, winter placed heifers and grass yearlings had a loss between $72 - $98 CAD per animal for the whole feeding period, compared to healthy cattle. Also, cattle with DD gained between 0.11 – 0.17 kg/d less relative to healthy cattle.
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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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    On-farm control of digital dermatitis in dairy cows
    (2019-07-30) Jacobs, Casey Elizabeth; Barkema, Herman W.; Orsel, Karin; Kastelic, John P.; Pajor, Edmond Anthony; Mason, Steve
    Digital dermatitis (DD) is an infectious foot lesion causing painful skin erosions which can lead to large economic and welfare implications. Currently, it is the most common foot lesion affecting dairy cattle in much of the world. Control of DD includes detection, prevention, and treatment of lesions to minimize their impact. This thesis aims to elucidate epidemiology of DD by investigating on-farm methods of detection, prevention, and treatment to generate new knowledge regarding DD control. The detection methods studied included pen walks for young stock and infrared thermography. Aspects of prevention included an evaluation of a novel footbath product and a systematic review and network meta-analyses to determine the most appropriate footbath protocol for prevention of DD. The treatment component investigated the routine treatment of DD lesions with commercially available products compared to negative and positive controls. Pen walks were able to detect DD in young stock and identified DD on 39% of farms with a mean prevalence of 1.4%. Increasing age and a high lactating DD prevalence were associated with increased DD presence in young stock. Infrared thermography was adequate to identify ulcerative, erosive lesions; however, image analysis is cumbersome and should be standardized and automated for use as a detection device. The novel footbath product evaluated was inferior to both copper sulfate and non-interference protocols and is not recommended for prevention of DD. The systematic review and network meta-analysis of footbath protocols available in the literature identified ≥ 5% copper sulfate used ≥ 4 times/wk as superior to no treatment and water for the treatment of DD lesions; however, no footbath protocol was identified as superior to any other for the prevention of DD. Routine treatment of DD lesions with commercially available topical applications was no more effective than saline (negative control) in clinically curing active lesions to nonactive stages over the 8-wk study. Routine detection, combined with consistent prevention practices and prompt treatment of DD lesions should be included in comprehensive DD control programs to maximize DD control and limit the negative consequences of DD.
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    The economic impacts of calving interventions and effects of a non-steroidal anti-inflammatory drug on behaviour and physiological parameters of beef cows and calves assisted at calving
    (2023-05-12) Lucio Rodriguez, Cecilia; Pearson, Jennifer Mackay; Windeyer, Claire M.K.; Pajor, Edmond Anthony; Larson, Katherine Alice; Tucker, Cassandra B.
    Cows and calves that have a difficult calving often experience negative consequences in their health and productivity, leading to economic losses for the producer. Knowing the economic impact of a difficult calving could impact the decisions that producers, veterinarians, and researchers make regarding the management of cow-calf pairs. Therefore, the aims of this thesis were to estimate the cost, revenue, and profit of assisted cows and calves in the western Canadian context and to study the impact on behaviour and physiology of using a pain mitigation strategy in cows and calves assisted at calving. Chapter 2 estimated the cost, revenue, and profit of assisted and unassisted calvings by using historical records from western Canada cow-calf operations. Cow-calf pairs assisted at calving had a higher cost and therefore lower profit than unassisted pairs. This suggests that producers should consider preventative management strategies to decrease the impact of this event. Chapter 3 investigated the effects of the use of a non-steroidal anti-inflammatory drug administered to cows and calves assisted at calving on physiological and behavioural changes related with pain and cow-calf bonding. Calves that received meloxicam displayed more play behaviour and were more active during the first 24 hours after birth than calves that received placebo. No other differences between treated and untreated cattle were observed. Beef calves assisted at calving may benefit from pain mitigation strategies after an assisted calving to decrease pain and inflammation. With this information producers, veterinarians, and researchers can make informed, economic decisions to increase the health and productivity and improve the welfare of beef cows and calves.