Abstract Tail docking in lambs and castration in lambs and calves are common husbandry practices, both of which cause pain and discomfort, for which many industries recommend or require pain management. The purpose of this study was to assess the effective tissue concentrations of the current standard of care for pain mitigation in calves and lambs during castration or tail docking (injectable lidocaine) and to assess the ability of a lidocaine-loaded elastration band (LLB) to deliver effective concentrations into the scrotal or tail tissues over time. This work comprised four different field trials (n = 50/trial): 1) effective concentrations of injectable lidocaine in the scrotal tissue of dairy calves; 2) the in vivo delivery of effective concentrations of lidocaine from LLBs placed on the calf scrotums; 3) effective concentrations of injectable lidocaine in the scrotal and tail tissue of lambs; and 4) the in vivo delivery of effective concentrations of lidocaine from LLBs placed on the lamb scrotums and tails. Sensation in the tissue of interest was assessed by electrocutaneous stimulation. Sensation was correlated to tissue concentrations of lidocaine by analyzing sampled tissue for lidocaine content by High-Performance Liquid Chromatography (HPLC). Injectable lidocaine allowed for short-term anesthesia for up to 60 min calves, highlighting the importance of finding additional strategies to mitigate long-term pain. An effective concentration (EC) yielding 50% reduction in tissue sensation (EC50) of 0.635 (95% CI 0.462 to 0.829) mg/g was calculated for calf scrotal tissue. Based on HPLC data of processed biopsy samples taken over time, the LLBs yielded tissue concentartions of lidocaine that approached EC50 and exceeded EC95 at 2 and 72 h following application, respectively, and remained above those concentartions for at least 28 d after application. In lambs, injectable lidocaine allowed for short-term anesthesia for up to 180 min following injection. An EC50 of 0.174 (95% CI 0.125 to 0.248) mg/g was calculated for lamb scrotal tissue and an EC50 of 0.0765 (95% CI 0.0533 to 0.113) mg/g was calculated for lamb tail tissue. The use of the LLB provided tissue lidocaine concentrations that met or exceeded the EC50 for at least 21 to 28 d and, based on electrostimulation data, provided local anesthesia for at least 3 d when compared with a control band. The use of an LLB could provide a practical, long-duration alternative to injectable lidocaine for pain mitigation during castration and tail docking. Further studies are warranted to compare the use of LLBs to injectable local anesthetics.

This study aimed to assess the effective tissue concentrations of the current standard of care for pain mitigation in calves during castration (injectable lidocaine) and to assess the ability of a lidocaine-loaded elastration band (LLB) to deliver effective concentrations into the scrotal tissue over time. This study comprised two different trials: (1) effective concentrations of injectable lidocaine in the scrotal tissue; and (2) the in vivo delivery of effective concentrations of lidocaine from LLBs placed on the calf scrotums. Sensation in the scrotal tissue was assessed by electrocutaneous stimulation. Injectable lidocaine allowed for short-term anesthesia for up to 60 min, highlighting the importance of finding additional strategies to mitigate long-term pain. An elastomeric ligation band impregnated with lidocaine could provide a suitable alternative, as it yielded tissue levels of lidocaine that approached EC50 and exceeded EC95 at 2 and 72 h following application, respectively, and remained above those levels for at least 28 days after application. Further studies are warranted to compare the use of LLBs to injectable local anesthetics.

Tail docking in lambs and castration in lambs and calves are common husbandry practices, both of which cause pain and discomfort, for which many industries recommend or require pain management. The purpose of this study was to assess the effective tissue concentrations of the current standard of care for pain mitigation in calves and lambs during castration or tail docking (injectable lidocaine) and to assess the ability of a lidocaine-loaded elastration band (LLB) to deliver effective concentrations into the scrotal or tail tissues over time. This work comprised four different field trials (n = 50/trial): 1) effective concentrations of injectable lidocaine in the scrotal tissue of dairy calves; 2) the in vivo delivery of effective concentrations of lidocaine from LLBs placed on the calf scrotums; 3) effective concentrations of injectable lidocaine in the scrotal and tail tissue of lambs; and 4) the in vivo delivery of effective concentrations of lidocaine from LLBs placed on the lamb scrotums and tails. Sensation in the tissue of interest was assessed by electrocutaneous stimulation. Sensation was correlated to tissue concentrations of lidocaine by analyzing sampled tissue for lidocaine content by High-Performance Liquid Chromatography (HPLC). Injectable lidocaine allowed for short-term anesthesia for up to 60 min calves, highlighting the importance of finding additional strategies to mitigate long-term pain. An effective concentration (EC) yielding 50% reduction in tissue sensation (EC50) of 0.635 (95% CI 0.462 to 0.829) mg/g was calculated for calf scrotal tissue. Based on HPLC data of processed biopsy samples taken over time, the LLBs yielded tissue concentartions of lidocaine that approached EC50 and exceeded EC95 at 2 and 72 h following application, respectively, and remained above those concentartions for at least 28 d after application. In lambs, injectable lidocaine allowed for short-term anesthesia for up to 180 min following injection. An EC50 of 0.174 (95% CI 0.125 to 0.248) mg/g was calculated for lamb scrotal tissue and an EC50 of 0.0765 (95% CI 0.0533 to 0.113) mg/g was calculated for lamb tail tissue. The use of the LLB provided tissue lidocaine concentrations that met or exceeded the EC50 for at least 21 to 28 d and, based on electrostimulation data, provided local anesthesia for at least 3 d when compared with a control band. The use of an LLB could provide a practical, long-duration alternative to injectable lidocaine for pain mitigation during castration and tail docking. Further studies are warranted to compare the use of LLBs to injectable local anesthetics.

The development of novel antimicrobial technologies for the food industry represents an important strategy to improve food safety. Antimicrobial photodynamic disinfection (aPDD) is a method that can inactivate microbes without the use of harsh chemicals. aPDD involves the administration of a non-toxic, light-sensitive substance, known as a photosensitizer, followed by exposure to visible light at a specific wavelength. The objective of this study was to screen the antimicrobial photodynamic efficacy of 32 food-safe pigments tested as candidate photosensitizers (PSs) against pathogenic and food-spoilage bacterial suspensions as well as biofilms grown on relevant food contact surfaces. This screening evaluated the minimum bactericidal concentration (MBC), minimum biofilm eradication concentration (MBEC), and colony forming unit (CFU) reduction against Salmonella enterica, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas fragi, and Brochothrix thermosphacta. Based on multiple characteristics, including solubility and the ability to reduce the biofilms by at least 3 log10 CFU/sample, 4 out of the 32 PSs were selected for further optimization against S. enterica and MRSA, including sunset yellow, curcumin, riboflavin-5′-phosphate (R-5-P), and erythrosin B. Optimized factors included the PS concentration, irradiance, and time of light exposure. Finally, 0.1% w/v R-5-P, irradiated with a 445 nm LED at 55.5 J/cm2, yielded a “max kill” (upwards of 3 to 7 log10 CFU/sample) against S. enterica and MRSA biofilms grown on metallic food contact surfaces, proving its potential for industrial applications. Overall, the aPDD method shows substantial promise as an alternative to existing disinfection technologies used in the food processing industry.

The primary objective of this study was to demonstrate the non-inferiority between lidocaine-impregnated ligation bands (LLBs) and control bands (CBs) with respect to the efficacy of castration and tail docking. Secondary objectives were to compare castration and tail-docking success, evaluate local site reactions, and compare average daily gain (ADG) between the treatment groups. A total of 238 male lambs were enrolled and randomly assigned to receive LLBs or CBs on their tail and scrotum. Lambs were weighed, had a health assessment, and the band site was observed on −3, 7, 14, 21, 28, 35, and 42 days after the bands were applied. A linear regression model was built to assess average daily gain, whereas a repeated measures model was used to evaluate body weight differences at each of the measured timepoints. Furthermore, logistic regression models were used to evaluate associations with casting outcomes. Few differences were noted between treatment groups with respect to casting success for the scrotum and tail and ADG over the entire experimental period. Non-inferiority calculations demonstrated no differences in tail docking and scrotal casting success, with casting occurring for the majority of animals by d 21 and d 42 for castration and tail docking, respectively. However, lambs receiving LLBs gained more weight from d −3 to 7 (+0.03 kg/d; 95% CI: 0 to 0.07), which may be an indication of effective pain control during the first week following band application. Overall, the use of an LLB does not affect the time to successful casting of the tail and could improve short-term growth when compared to a control band. Further studies are needed to compare LLBs to multimodal methods of pain relief.

(1) Background: It has been well established that castration and tail docking are both painful during and following the procedure, yet there are limited convenient and effective products to address both short-term and long-term pain. Lidocam Topical Gel (LTG) (4% lidocaine and 0.3% meloxicam) was developed to address industry needs for an effective and safe product to address animal welfare concerns regarding castration and tail docking in piglets. (2) Methods: Study 1: Male piglets aged 4–8 days of age were treated with LTG (n = 30) or a control gel (n = 30). Approximately 30 min after application of the gel, the piglets were surgically castrated and tail docked. The efficacy of pain control during the surgical procedures and post-procedure (24 h) pain and inflammation control were evaluated using both behavioral and physiological measurements. Study 2: Meloxicam residue depletion following LTG treatment was followed for 28 days. Study 3: Clinical and pathological safety were evaluated in five groups of eight piglets receiving LTG with: (1) no treatment, (2) nominal topical dose, (3) two times the nominal topical dose, (4) three times the nominal topical dose, and 5) one times the nominal topical dose and 2 mL of LTG by oral gavage daily for 3 days. (3) Results: LTG-treated piglets had a significant reduction in electrocutaneous stimulation response before the procedures and 4 and 24 h post-procedures. Stress vocalization intensity and duration were less in piglets receiving LTG during the surgical procedures. Plasma cortisol and substance P were significantly lower in LTG-treated piglets 3 h after castration and tail docking. The weight and average daily gain were significantly increased in piglets receiving LTG. LTG did not interfere with wound healing or cause irritation at the application sites. There were no abnormal clinical or pathological findings associated with the use of LTG at three times the nominal dose given daily for three days. As meloxicam persisted in the application site tissue, a slaughter withdrawal time of 24 days was determined. (4) Conclusions: When applied to the skin 30 min before castration and tail docking, LTG is effective in surgical pain control and provides post-surgical pain control for up to 24 h. LTG is safe for use in piglets and provides an acceptable withdrawal time for commercial use. LTG is a potentially effective product for commercial use for piglet castration and tail docking.

The objective of this study was to evaluate an easy to administer and economical oral nutritional supplement for neonatal lambs. Neonates are at risk of nutrient deficiencies because of maternal deficiencies, minimal body stores at birth and decreased nutritional intake. The pre-ruminant lamb relies solely on milk for adequate immunity and nutrition until they begin ingesting forages. Insufficiencies can lead to increased mortality and morbidity. However, deficiencies in the ewe are common due to variation in management, feeding and health protocols. A total of 10 lambs (5 sets of twins) were enrolled into the study. The lambs were divided into two groups (one twin from each set) received a treatment of an oral vitamin-mineral supplement (VitaFerst-Care) 3 mL and the control lambs a saline solution of 3 mL, all at 3 d of age (d0). Blood samples were collected, prior to, and again following supplementation (d 0, d 21) by jugular venipuncture. Vitamin A, vitamin E, iron (Fe) and selenium (Se) concentrations were determined in blood serum/plasma of the lambs by HPLC. Kidney and liver function markers were analyzed using HESKA DC5X veterinary analyzer to confirm the safety of the supplement. Variables tested included alkaline phosphatase (ALP), alanine aminotransferase (ALT), blood urea nitrogen (BUN), creatinine (CREA), glucose (GLU), total protein (TP), total bilirubin (T-BILI), albumin (ALB), phosphorus (PHOS), calcium (CA), cholesterol (CHOL), and gamma-glutamyl transferase (GGT). All lambs remained with their mothers. The average difference was calculated between d 21 and d 0 (baseline) for treated versus control animals for vitamin A, vitamin E, Se, and Fe. Significance was calculated using a two-tailed student’s t-test where P < 0.10 between d 21 control and treated animals. Control animals had an average vitamin E plasma concentration of 1.168 + 0.355 ppm on d 21, whereas treated animals had an average of 1.547 + 0.559 ppm. Significance was calculated at P = 0.09. Vitamin A, Fe and Se concentrations did not reach significance. Kidney and liver panel checks for animals in each group were not concerning. Future studies should look at modifying first and second sampling timepoints to be closer together. Based on results in calves with a similar study design, shortening the time between treatment and second sampling would give a clearer picture of how the neonatal supplement influenced the nutritional status of the treatment versus control animals.

The objectives of this study were to assess the pharmacokinetics and pharmacodynamics of the current standard-of-care for pain mitigation in lambs during castration and tail docking (injectable lidocaine) and assess the ability of Lidocaine-Loaded Bands (LLBs) to deliver therapeutic concentrations into the contacted tissues over time. The study was comprised of four different trials: (1) investigation of in vitro release of lidocaine from LLBs; (2) pharmacokinetics and pharmacodynamics of injectable lidocaine in scrotal and tail tissue; (3) pharmacokinetics and pharmacodynamics of in vivo delivery of lidocaine with LLBs placed on the tail and scrotum of lambs; and (4) a “proof-of-concept” study comparing the sensation of control- versus LLB-banded tail tissue over time. The use of injectable lidocaine provides effective short-term anesthesia for 120 to 180 min following the injection; however, additional strategies are needed to manage long-term pain. The use of an LLB could provide an alternative where tissue lidocaine concentrations meet or exceed the EC50 for at least 21–28 days and, based on electrostimulation data, provides local anesthesia for at least 3 days when compared to a control band. Further studies are needed to compare the use of an injectable local anesthetic to the LLBs.

The objective of this study was to evaluate the effects of the extended-term delivery of anesthesia on the physiological and behavioral signs of pain caused by band castration in 1-month-old bull calves. Forty-eight calves (37.04 ± 8.98 days of age) were homogenously assigned by age to one of three band castration protocols (n = 16/protocol); 1) regular elastrator bands (REG), 2) regular elastrator bands preceded by two 2-mL injections of lidocaine (REG+L; LIDO-2 with epinephrine, Rafter 8 Products Inc, Calgary, Canada), and 3) lidocaine elastrator bands (LBAND; Care-Ring, Chinook Contract Research Inc., Calgary, Canada). During the castration procedure, two observers scored (from 1 to 10) how much pain each animal was experiencing (visual analog score, VAS), number of body shakes and leg kicks for each calf. Calves were weighed on d -1, 0, 14, 28, 42, and 56. Hair cortisol concentration was measured on d -1, 28, and 56. Saliva cortisol concentration was measured right after castration, 60, 120, 240 minutes after castration, on d 1 and weekly thereafter until d 56. Flight speed (FS) was recorded on d -1, right after castration, 60, 120, 240 minutes after castration, d 1, and weekly thereafter until d 56. Calf behaviors in the pen indicative of pain and discomfort were recorded on d 0, 1, and weekly thereafter until d 56. The REG+L calves tended to have decreased (P = 0.09) VAS scores than REG calves. The average daily gain was greater (P < 0.01) from d 42 to 56 than from d 1 to 42, and from d 1 to 28 compared with d 28 to 42 in all treatment groups. The REG calves had decreased (P < 0.01) hair cortisol concentrations than both REG+L and LBAND calves. Saliva cortisol concentrations were greater (P < 0.01) 60 minutes after castration than any other sample time in all treatment groups. There was an interaction between treatment and time (P = 0.04), where only LBAND had a greater FS immediately after castration compared with d -1. When calves were observed in the pen there were no treatment effects (P > 0.10) but only time differences (P < 0.05) in the frequency of head turns, oral behaviors, tail flicks, and number of standing and walking bouts. The behavioral and physiological parameters assessed showed expected results on the effects of band castrating calves, while the administration of lidocaine via REG+L or LBAND did not show any pain mitigation effect compared with the standard industry banding method (REG).

The objective of this study was to evaluate an easy to administer and economical oral nutritional supplement for neonatal calves. Neonates are at risk of nutrient deficiencies because of maternal deficiencies, low body stores at birth and low nutritional intake. The pre-ruminating calf relies solely on milk for adequate immunity and nutrition until they begin ingesting forage. Insufficiencies can lead to increased morbidity and mortality. However, deficiencies in the cow are common due to variation in management, feeding and health protocols. A total of 21 beef calves in year 1 and 40 in year 2 were enrolled in the study. The calves were divided into experimental and control groups which received a vitamin-mineral supplement (VitaFerst-Care) and a saline solution at 1-3 days of age, respectively. Blood samples were collected, before, and again after supplementation (d 14 in yr 1 and d 3 in yrr 2) by jugular venipuncture. Iron and selenium concentrations were determined in blood serum of a subset of calves (n = 21 in yr1, n = 40 in yr2) by ICP-MS. All beef calves remained on their mothers. In yr 1, control calves had stable iron concentrations at 1.35 + 0.62 ppm (d 0) and 1.33 + 0.77ppm (d 14), with 50% of calves deficient. Iron concentrations in treatment calves increased slightly from 1.17 + 0.56 ppm to 1.43 +0.65 ppm. In yr 2, iron concentrations of control calves changed slightly from 1.69 + 0.91 ppm (d 0) to 1.98 +2.24 ppm (d 3). The iron concentrations in treatment calves further increased from 1.86 + 0.67 ppm to 2.33 + 2.16 ppm. Selenium concentrations were deficient in all calves in yr 1 (0.06 + 0.01 ppm) and year 2 (0.07 + 0.02 ppm) with no significant changes between treatment groups. This research provides insight regarding the severity and prevalence of nutrient deficiencies in newborn calves. All calves in the study were deficient in selenium, and between 30 to 50% were deficient in iron each year. Following supplementation, there was no significant increase in blood mineral concentrations between d 0 and d 14; however, between d 0 and d 3 there was a significant increase in blood iron concentration of calves.

Food-borne pathogens are a serious challenge in food handling, processing, and packaging systems. The growth of microbial biofilms on food handling surfaces further complicates the management of the microbial contamination of food. Microorganisms within biofilms are difficult to eradicate with chemical disinfectants, with an increased likelihood of survival and the subsequent contamination of food. Therefore, a biofilm approach is needed in food safety and hygiene studies. Since many factors, such as strain, cell density, surface type and texture, environmental stress, and so forth, can affect biofilm formation and disinfectant efficacy, we evaluated the responses of biofilms formed by three food-borne bacterial pathogens on eight hard surfaces to seven chemical disinfectants. The three bacteria showed different capacities to colonize the surfaces. Similarly, chemical disinfectants also varied in efficacy, on surfaces and with pathogen species. One-, two-, and three-way interactions of strain, surface, and disinfectant were observed. The results generated demonstrate that the fine-tuning of sanitization strategies along the food production, processing, and packaging chain can be achieved in specific scenarios by accounting for two- and three-way interactions among bacteria, surface, and disinfectant.

The purpose of this study was to evaluate in vivo release concentrations of lidocaine into scrotal neck tissues and tail tissues following the application of lidocaine-loaded elastrator bands (LLBs) at acute time points (0.5, 1, 2, 24, and 72 hours) and chronic time points (14, 21, 28, and 35 days). To correlate the reaction of an animal to peripheral variable nerve stimulation with scrotal tissue lidocaine concentration. To correlate cortisol and substance P concentrations in treated animals at baseline (time 0) and 24, 72, 14, 21, 28, and 35 days to a control group. Fifty lambs were divided into ten groups consisting of Acute Pain Groups: Group A: 5 intact males. After baseline body weights, blood samples, and electro-cutaneous responses were collected, animals were band-castrated and tail-docked via LLBs on day 0, time (T) = 0. At T = 0.5 hr, the band was removed, and an electro-cutaneous response was measured at the tissue at the band sites. Punch tissue biopsies (including skin and subcutaneous tissue) were collected from the areas in direct contact with the band at each site for a total of 4 biopsies per animal. Group B: repeat of group A with the band removed and animal tested at T = 1 hr, Group C: T = 2 hr, Group D: T = 24 hr, Group E: T = 72 hr, Chronic Pain Groups: Group F: T = 14 d, Group G: T = 21 d, Group H: T = 28 d, Group I: T = 35 d, Control Group: Group J: repeat of group A except animals were band castrated and tail-docking with control bands (i.e., no lidocaine) on day 0. Body weight was recorded at T = 0 and 14, 21, and 28 d. A blood sample was collected at T = 0, 24, 72 hr, then T = 8, 21, 28, and 35 d. LLBs yielded decreased stimulation scores by 1 hr (60 min) post-banding with the tails and by 2 hr (120 min) for the scrotums. There were no adverse events or device failures (i.e., band breakage or failure to castrate/ tail-dock) observed during this study. Lidocaine-infused bands hold promise for reducing pain associated with castration and tail docking in lambs.

Depending on the year, during the winter months, cattle begin to rub bare patches on their skin due to pruritus which leads to concern from cattle producers, especially the purebred breeders. Upon further investigation by veterinarians, the cause is not always caused by lice, as many may think. This study aimed to provide insight into the cause and potential prevention/treatment of pruritic beef cattle in western Canada by examining herds that met the study’s criteria of having more than 30% of the herd exhibiting pruritus. Seven herds were examined in the winter of 2023: one from Manitoba, two from Saskatchewan, and four from Alberta. Producers from each herd completed a detailed survey on treatments, nutrition, and environmental conditions and provided feed, water, and bedding samples. Within each herd, five cattle considered non-pruritic, and ten cattle considered pruritic by visual appraisal were enrolled for standard data collection consisting of documentation and photos of skin lesions localized to pruritic areas, general health clinical exam, lice exam/collection, mite exam/collection of hairs, skin hydration (corneometer), blood chemistry and vitamin/minerals, and kidney/liver enzymes for mycotoxins. A subset of the group (1 non-pruritic and 4 pruritic) was selected for advanced data collection, including dermal hypersensitivity (grass, alfalfa, grain, weeds, and molds) measured by swelling score and infrared camera temperature measurement compared with positive and negative controls, skin punch biopsies for eosinophils (IgE) and liver biopsies for copper levels. Only 21/101 cattle had lice (18 animals < 10 lice per 6.5 cm2). No significant correlation was observed between cattle with lice and being pruritic (P > 0.05). Dermal hypersensitivity was very low across both pruritic and non-pruritic cattle and was not different (P > 0.05). Skin hydration readings within animals comparing pruritic and non-pruritic areas on their body showed only one herd having significantly (P < 0.05) drier skin on pruritic locations compared with normal locations. Vitamin A, E, and copper blood analysis showed no significant difference between pruritic and non-pruritic cattle. However, liver biopsy copper levels were (P = 0.01) less in pruritic than non-pruritic cattle. Results suggest that the cause of pruritic cattle is not necessarily a result of intense lice infestations but rather multifactorial in nature, and a decision tree for producers and veterinarians should be developed to aid in determining the correct course of action to alleviate pruritic cattle in the field.

This study investigated the effects of dystocia on milk production, somatic cell count, reproductivity, disease, and milk production. A total of 2159 cows across 21 dairy farms in Alberta, Canada were enrolled in this study. Multivariable models were created to explore associations between outcome variables and calving ease score. In total, 89.5% of calvings were unassisted, 6.1% were an easy pull, and 4.3% were a moderate–hard pull. Cows that had a moderate–hard pull produced 4.01 kg less milk, 0.12 kg less volume of milk fat, and 0.12 kg less milk protein per day than those that had an unassisted calving. No difference was found between calving ease groups with respect to SCC. Cows with a moderate or hard pull produced 510 kg less milk per lactation than unassisted cows. Cows with a moderate to high level of assistance at birth had a higher hazard of being culled over the duration of their lactation. Cows with an easy pull had increased odds of developing a retained placenta. It is evident that assistance at calving, particularly a moderate–hard pull, is associated with significant impacts on future milk production and risk of being culled; therefore, efforts should be made to minimize dystocia and prevent these impacts.

A dipotassium phosphate bolus (K Phos-Boost) has been developed to treat both hypophosphatemia and hypokalemia, as the clinical signs of both conditions are similar and occur in the early post-partum period. The objective of this research was to evaluate the efficacy and application of the bolus for prevention and treatment of metabolic diseases that are common in dairy production systems. Study 1 (Pharmacokinetic study): Healthy post-partum cows were either untreated or received two K Phos-Boost boluses at times 0, 24, and 48 h. Blood was taken at t = 0, 2-, 4-, 6-, 8-, 10-, 24-, and 52-h post-treatment for analysis of total serum minerals. There was an increase in serum phosphorous to normal levels within 2 h of treatment with the bolus, but control cows remained hypophosphatemic. Serum potassium was significantly elevated 2 h after bolus administration relative to control, while calcium, magnesium, sodium, and chloride levels were not affected by the K Phos-Boost bolus. Study 2 (Downer Cow Treatment): K Phos-Boost boluses were provided to cows that were unresponsive to intravenous calcium therapy and had been unable to stand for over 24 h (“downer cows”). Most cows (16 of 19) treated with two boluses were standing without assistance between 1 and 24 h after treatment and the serum phosphorous was increased to normal levels in five of five tested animals. Study 3 (Ketosis Treatment): cows with clinical ketosis were provided with propylene glycol and K Phos-Boost boluses (n = 29) or only propylene glycol (n = 23). Cows treated with the K Phos-Boost bolus showed a more rapid recovery by increased milk production (3.9 kg/day) and rumination rate (97 min/day). Study 4 (Health Promotion): cows in herds with >40% post-partum hypophosphatemia received K Phos-Boost boluses (n = 130) or no treatment (n = 146) following calving. There was a trend for treated 2nd-lactation animals to have higher milk production after 30 DIM (49.1 vs. 46.2 kg/day; P = 0.09). There were no significant differences between control and bolus treated animals in the incidence of subclinical ketosis, post-calving total health events, or culling rates. The K Phos-Boost bolus is a novel product and has the potential to treat and prevent several important metabolic diseases in dairy cattle. The studies described in this paper are early investigations and further research should be conducted to demonstrate the applications of a dipotassium phosphate bolus in dairy cows.

Bacterial wilt is a re-emerging disease on dry bean and can affect many other crop species within the Fabaceae. The causal agent, Curtobacterium flaccumfaciens pv. flaccumfaciens (CFF), is a small, Gram-positive, rod-shaped bacterium that is seed-transmitted. Infections in the host become systemic, leading to wilting and economic loss. Clean seed programs and bactericidal seed treatments are two critical management tools. This study characterizes the efficacies of five bactericidal chemicals against CFF. It was hypothesized that this bacterium was capable of forming biofilms, and that the cells within biofilms would be more tolerant to bactericidal treatments. The minimum biocide eradication concentration assay protocol was used to grow CFF biofilms, expose the biofilms to bactericides, and enumerate survivors compared to a non-treated control (water). Streptomycin and oxysilver bisulfate had EC95 values at the lowest concentrations and are likely the best candidates for seed treatment products for controlling seed-borne bacterial wilt of bean. The results showed that CFF formed biofilms during at least two phases of the bacterial wilt disease cycle, and the biofilms were much more difficult to eradicate than their planktonic counterparts. Overall, biofilm formation by CFF is an important part of the bacterial wilt disease cycle in dry edible bean and antibiofilm bactericides such as streptomycin and oxysilver bisulfate may be best suited for use in disease management.

1Chinook Contract Research Inc., Airdrie, AB, Canada; 2Sjoert Zuidhof Consulting, Okotoks, AB, Canada; 3Alberta Agriculture and Forestry, Airdrie, AB, Canada; 4Alberta Veterinary Laboratories Ltd., Calgary, AB, Canada Purpose: Neonatal calf diarrhea (NCD) is a major cause of death and economic loss in the cattle industry. Although NCD is caused by a variety of nutritional factors and non-bacterial pathogens, treatment typically includes systemic antimicrobial therapy, even for non-severe cases that are more likely to have non-bacterial causes. Novel, non-antimicrobial therapies are needed to reduce antimicrobial use and optimize production efficiency. Methods: This production-level study compared the efficacy of activated charcoal to that of an antimicrobial regimen for treating mild-to-moderate cases of NCD, and identified the most common etiological agents. Calves diagnosed with non-severe diarrhea were randomly allocated into 3 treatment groups (n = 86 per group): group A received a standard antimicrobial regimen, B received both antimicrobials and activated charcoal, and C received activated charcoal only. Animals were monitored over the course of 7 days for mortality and recovery from diarrhea. Fecal samples were collected upon enrollment (day 0) and on day 7 to assess the presence of major NCD-causing pathogens. Results: Mortality was higher for groups B and C relative to A, although this difference was only statistically significant for group B vs A. No significant difference in the number of recovered animals was observed among the treatment groups, although group C was significantly slower to recover than A or B. The vast majority of day 0 samples were positive for non-bacterial organisms (mainly rotavirus and Cryptosporidium parvum), which decreased significantly by day 7 regardless of treatment group. Conclusion: Antimicrobials only moderately improved outcomes for non-severe diarrhea cases relative to activated charcoal. Thus, systemic antimicrobial treatment is likely unnecessary for the majority of NCD cases and should be limited to severe cases.

Purpose: Calcium supplement boluses vary greatly in content and bioavailability. Methods: In vivo dissolution and bioavailability studies were conducted to compare commercial calcium supplement boluses with various contents of calcium chloride and calcium carbonate. The products studied included: Bolus 1 (high calcium chloride, no calcium carbonate), Bolus 2 (medium calcium chloride, medium calcium carbonate), and Bolus 3 (low calcium chloride, high calcium carbonate). A bolus was placed in a pre-weighed coarse mesh net for 30, 60, 90, 120, 180, and 240 minutes to measure dissolution rates in the rumen of fistulated animals. To measure calcium uptake, 27 Holstein cows (second and third lactation) were randomly allocated to one of three oral calcium protocols: Treatment 1 (two high calcium chloride boluses at time 0); Treatment 2 (one high calcium chloride bolus at time 0 with a second bolus 12 hours later); or Treatment 3 (two high calcium carbonate boluses at time 0). Treatments were initiated within 12 hours following calving and this was considered time 0. Results: Bolus 1 was the quickest to dissolve (<90 minutes), followed by Bolus 2 (<240 minutes). The high calcium carbonate bolus (Bolus 3) remained after 240 minutes in vivo with a minimum of 75% of the original bolus weight still intact. Cows with severe hypocalcemia (<1.8 mmol/L) responded with a higher serum calcium increase than cows with milder hypocalcemia (>1.8 mmol/L, <2.12 mmol/L). The high calcium carbonate bolus group (Treatment 3) did not show a rapid increase in serum calcium as compared to the high calcium chloride groups (Treatments 1 and 2). The animals receiving Treatment 1 had a greater and more persistent serum calcium response than animals receiving Treatment 2. Conclusion: The study outcome suggests that calcium chloride/calcium sulfate boluses are more effective at generating a serum calcium response than boluses containing high amounts of calcium carbonate and that two boluses administered rapidly after calving may be more effective than the traditional treatment of giving 2 boluses 12 hours apart.