Effects of a Single Foot Rot Incident on Weight Performance of Feedlot Steers

Comparison of the welfare of beef cattle in housed and grazing systems: hormones, health, and behaviour

Animal welfare encompasses all aspects of an animal's life and the interactions between animals. Consequently, welfare must be measured across a variety of factors that consider aspects such as health, behaviour, and mental state. Decisions regarding housing and grazing are central to farm management. In this study, two beef cattle systems and their herds were compared from weaning to slaughter across numerous indicators. One herd ("HH") were continuously housed, the other ("HG") were housed only during winter. Inspections of animals were conducted to assess body condition, cleanliness, diarrhoea, hairlessness, nasal discharge, and ocular discharge. Hair and nasal mucus samples were taken for quantification of cortisol and serotonin. Qualitative behaviour assessments (QBA) were also conducted and performance monitored. Physical health indicators were similar between herds with the exception of nasal discharge which was more prevalent in HH (P < 0.001). During winter, QBA yielded differences between herds over PC1 (arousal) (P = 0.032), but not PC2 (mood) (P = 0.139). Through summer, there was a strong difference across both PC1 (P < 0.001) and PC2 (P = 0.002), with HG exhibiting more positive behaviour. A difference was found in hair cortisol levels, with the greatest concentrations observed in HG (P = 0.011), however such a pattern was not seen for nasal mucus cortisol, or for serotonin. Overall, providing summer grazing (HG) appeared to afford welfare benefits to the cattle as shown with more positive QBA assessments, but also slightly better health indicators, notwithstanding the higher levels of cortisol in that group.

Economic impact of digital dermatitis, foot rot, and bovine respiratory disease in feedlot cattle

Digital dermatitis (DD) has emerged in North American feedlots, although production and economic impacts are not fully understood. Objectives of this study were to: (1) estimate the economic impact of a single case of DD, foot rot (FR), and bovine respiratory disease (BRD) in feedlot cattle and (2) determine its impact on average daily gain (ADG). Feedlot cattle health and production records were available from two feedlots for a 3-yr interval. The dataset consisted of 77,115 animal records, with 19.3% (14,900) diagnosed with a disease. Diseased animals were categorized into five groups: DD, FR, BRD, other diseases (OT), and two or more diseases (TM), with a treatment cumulative incidence of 6.0%, 59.1%, 10.7%, 12.7%, and 11.5%, respectively. FR was the disease with the highest cumulative incidence in both heifers and steers (58.8% and 59.6%, respectively). Of all fall-placed cattle diagnosed with any disease, 48.1% of the cases were FR. DD affected the partial budget in five out of the eight groups of cattle, with the highest impact of DD seen in grass yearling heifers and grass yearling steers: $-98 and $-96 CAD, respectively, relative to their healthier counterparts. Healthy cattle had a significantly higher ADG when compared with DD cattle in five of the eight categories, ranging from 0.11 kg/d in winter-placed heifers to 0.17 kg/d in fall-placed steers. In the economic analysis, it was concluded that on an individual animal basis, BRD was the most impactful of all analyzed diseases, whereas DD was second, marking the importance of controlling and mitigating this foot condition. Identifying differential effects of diseases on a partial budget analysis and ADG of the types of cattle stratified by sex enables feedlot producers to focus control and mitigation strategies on specific groups.

Risk factors of digital dermatitis in feedlot cattle

Digital dermatitis (DD) has been reported in North American feedlots, although risk factors are not well characterized. Our objectives were to analyze: (1) foot and leg conformation and (2) pen hygiene, as potential variables that predispose feedlot cattle to DD. Production parameters in DD-affected cattle were compared with healthy cattle and with those diagnosed with more commonly known infectious lesion foot rot (FR). In total, 2,854 feedlot cattle in 11 pens in 2 feedlots were assessed (bi-weekly pen walks) throughout the feeding cycle. Pen condition was categorized as: “dry,” “mud present but has good bedding,” “more mud than bedding,” and “excessive mud.” Gait scoring was competed and cattle with abnormal gait or evident foot lesions (i.e., DD or FR) were restrained in a cattle chute for a close foot inspection (n=280), including scoring of foot angle and claw set and hind and side views of rear feet and legs. Cumulative incidence of DD (present or absent) and FR was 2.5% (71/2,854) and 11.6% (331/2,854), respectively. Foot and leg conformation was not significantly different between left and right sides or between cattle with (n=71) and without DD (n=209). Lameness was diagnosed in only 22% of cattle with DD. Cattle with DD gained 0.27 kg/d less compared with healthy cattle (mean ± SD: 1.29 ± 0.29 vs. 1.56 ± 0.27, P<0.05) and 0.4 kg/d less compared with FR (1.29 ± 0.29 vs. 1.69 ± 0.25). Presence of DD was not significantly different between pens with “dry” and “mud present but has good bedding,” but for pens with “more mud than bedding” or “excessive mud,” the risk of cattle having DD cases increased significantly [odds ratio (OR)=8.55, confidence interval (CI): 4.0–18.4 and OR=14.1, CI: 5.9–33.8, respectively]. In conclusion, it is important to keep good pen conditions to reduce the risk of DD, which can be managed through proper stocking density and strategic bedding, irrespective of foot and leg conformation.

Prevalence and lameness-associated risk factors in Alberta feedlot cattle

Lameness in cattle is a health and welfare concern; however, limited information is available on risk factors and the relationship between lameness and common diseases like bovine respiratory disease (BRD). Therefore, the objectives of this study were to: 1) identify prevalence of lameness in feedlot cattle and related risk factors of cattle diagnosed as lame; and 2) determine associations between BRD occurrence and lameness. Feedlot cattle health records were available from 28 feedlots for 10 yr. The data set consisted of 663,838 cattle records, with 13.9% (92,156) diagnosed with a disease, including 32.3%, 46.0%, and 22.0% with lameness, BRD, and other diagnoses, respectively. Lameness was classified into four categories: foot rot (FR), joint infections (JI), lame with no visible swelling (LNVS), and injuries (INJ), with a prevalence of 74.5%, 16.1%, 6.1%, and 3.1%, respectively. Lameness was compared across cattle types (arrival date and weight) as well as age classification (calf vs. yearling), gender (steer vs. heifer), and season of placement in the feedlot (spring, summer, fall, and winter). Within the disease-diagnosed population, lameness represented 28.5% of treated fall-placed calves, 38.5% of winter-placed calves, and 40.8% of treated yearlings. Foot rot was the most common diagnosis with 74.5% of all lameness diagnoses, with winter- and fall-placed calves more likely to be diagnosed with FR compared to yearlings (OR: 1.19, 95% CI: 1.10–1.30 and OR: 1.46, 95% CI: 1.38–1.55, respectively). Joint infections were the second most common diagnosis (16.1%). Compared to yearlings, fall-placed calves had a higher odds (OR: 3.64, 95% CI: 3.12–4.24) for JI. Injuries and LNVS were the least common but again fall-placed calves had higher odds of this diagnosis compared to yearlings (OR: 2.26, 95% CI: 1.70–2.99 and OR: 9.10, 95% CI: 6.26–13.2, respectively). Gender was significantly different for JI as steers were less likely affected compared to heifers (OR: 0.687, 95% CI: 0.545–0.867), and more likely affected by LNVS (OR: 2.46, 95% CI: 1.57–3.84). Of all lameness-associated deaths, JI accounted for almost 50%. Finally, cattle diagnosed with BRD were subsequently more likely to be diagnosed with INJ, JI, or LNVS (P < 0.001 for all comparisons). In conclusion, animal type and gender were associated with type of lameness diagnoses, allowing feedlots to allocate resources to groups at highest risk and focus on early intervention strategies.

Incidence of lameness and association of cause and severity of lameness on the outcome for cattle on six commercial beef feedlots

OBJECTIVE To describe the incidence of specific causes of lameness and the associations of cause and severity of lameness on the outcome for cattle on commercial feedlots. DESIGN Dynamic population longitudinal study. ANIMALS Cattle on 6 commercial feedlots in Kansas and Nebraska during a 12-month period (mean daily population, 243,602 cattle; range, 223,544 to 252,825 cattle). PROCEDURES Feedlot personnel were trained to use a standardized diagnostic algorithm and locomotion score (LMS) system to identify and classify cattle by cause and severity of lameness. Information regarding lameness cause, severity, and treatments was recorded for individual cattle. Cattle were monitored until they left the feedlot (ie, outcome; shipped with pen mates [shipped], culled prematurely because of lameness [realized], or euthanized or died [died]). Incidence rates for various causes of lameness, LMSs, and outcomes were calculated. The respective associations of cause of lameness and LMS with outcome were evaluated. RESULTS Lameness was identified in 2,532 cattle, resulting in an overall lameness incidence rate of 1.04 cases/100 animal-years. Realized and mortality rates were 0.096 cattle/100 animal-years and 0.397 deaths/100 animal-years, respectively. Injury to the proximal portion of a limb was the most frequently identified cause of lameness followed by undefined lameness, septic joint or deep digital sepsis, and interdigital phlegmon (foot rot). As the LMS (lameness severity) at lameness detection increased, the percentage of cattle that died but not the percentage of cattle that were realized increased. CONCLUSIONS AND CLINICAL RELEVANCE Results provided clinically useful prognostic guidelines for management of lame feedlot cattle.

Evaluation of the prevalence of digital dermatitis and the effects on performance in beef feedlot cattle under organic trace mineral supplementation

Bovine digital dermatitis (DD) is a contagious and multifactorial disease that leads to painful, ulcerative lesions of the skin near the heel-horn border of the foot, most commonly in dairy cattle. With regard to beef cattle, the pathogenesis and etiology of DD has not been widely reported or studied over the past several decades. A longitudinal field trial in a commercial feedlot was conducted to compare prevalence and effects of DD in beef steers provided a diet supplemented with a novel formulation of inorganic and organic trace mineral sources (OTM diet) compared to a diet provided with similar levels of trace minerals solely from inorganic sources (CON diet). A secondary objective was to evaluate the prevalence of DD and the potential effects on growth performance and carcass yield and quality. One thousand seventy-seven steers were assigned to 1 of the 2 treatment groups (CON diet or OTM diet) based on location of their home pens which were situated in 1 of 2 barns. All pens in the B barn (group B) were assigned to the OTM diet, and all pens in the A barn (group A) were assigned to the CON diet. The study was conducted in 2 phases: adaptation phase (AP) comprising the initial 60 d of feeding CON and OTM diets and postadaptation phase (PAP) which lasted until cattle were sent to harvest. In the AP, pens in group B had a greater proportion of steers (54.03%) with DD lesions compared to pens in group A (26.72%). During the PAP, the relative risk of observing an increased DD prevalence was significantly ( < 0.05) higher in CON group compared to OTM group. Growth performance, final live weight, and hot carcass weight were negatively impacted when steers were observed to have active DD lesions (M2 lesions) compared to steers with no M2 lesions over the study period. For ADG, a calculated loss per steer of 0.08 kg/d from type I (no M2 lesions) to type II (one M2 lesion; SE = 0.028; = 0.003) and loss of 0.14 kg/d from type I to type III (multiple M2 lesions; SE = 0.038; = 0.0003) were observed. A significant BW loss of approximately 10.06 kg (SE = 4.18; = 0.022) and a mean reduction of 5.5 kg per steer in HCW (SE = 2.74; = 0.043) were also found between type I and type II steers.

Economic impacts of lameness in feedlot cattle

Lameness is an important health issue in feedlot cattle; however, there is a paucity of information regarding its economic impact. Decision tree models are excellent tools for assessing costs of disease such as the net return (net return = benefit – cost). Models were developed using expert opinion, literature and retrospective feedlot data provided by Vet-Agri Health Services (VAHS, Airdrie, Alberta, Canada) collected from 2005 to 2015 on individually treated cattle (n = 30,940) from 28 feedlots. The objective was to estimate net return of various lameness diagnoses and impacts of cattle type, season of treatment, and extreme high and low cattle prices. Cattle were diagnosed as lame according to the following categories: foot rot, foot rot in heavy cattle (BW > 363 kg at treatment), injury, lame with no visible swelling, and joint infection. Records consisted of arrival and treatment weight, cost of treatment, and cattle deaths. Records included cattle types classified as: fall calves (heifer and steer), winter calves (heifer and steer) and yearling cattle (heifer and steer). Lastly, variables ADG, days on feed (DOF), and Season (spring, summer, fall, and winter) were created. Models estimated net return using cattle slaughter prices for healthy cattle that reached a slaughter weight of 635 kg and for three possible outcomes for each diagnosis after final treatment: cattle that recovered after treatment and reached a slaughter weight of 635 kg; cattle that were removed before they reached slaughter weight; or cattle that died. Compared to undiagnosed cattle with 1.36 kg/d ADG, cattle diagnosed with foot rot and foot rot heavy cattle had the highest ADG until first treatment (1.14 and 1.57 kg/d, respectively) and differed significantly (P < 0.05) compared to cattle diagnosed with injuries (0.87 kg/d), lame with no visible swelling (0.64 kg/d), and joint infections (0.53 kg/d). Yearling steers had the most positive returns compared to all other cattle types. Cattle with lighter arrival weight had lower ADG and increased economic losses after treatment compared to heavier weighted cattle on arrival. Based on average slaughter prices over a 10-yr period for healthy cattle, return was $690. Return after final treatment for cattle with foot rot was $568, foot rot in heavy cattle was $695, and injury was $259. However, joint infections and lame with no visible swelling had negative returns of –$286 and –$701, respectively.

Mobility Scoring of Finished Cattle

Lameness is among the most important welfare and production issues affecting dairy cattle. Recently, it has received significant research emphasis. Certain events in 2013 within the cattle industry heightened the focus on mobility issues in finished cattle. Scoring systems are needed in the finished cattle industry to capture and measure mobility issues at packing facilities. The North American Meat Institute Animal Welfare Committee helped facilitate the creation of a scoring system to evaluate mobility of cattle at packing plants, providing the cattle industry with a tool to benchmark and improve the welfare of finished cattle.

Impact of oral meloxicam administered alone or in combination with gabapentin on experimentally induced lameness in beef calves

This study examined the pharmacokinetics and analgesic effect of oral meloxicam (MEL) administered alone or in combination with gabapentin (GABA) in an experimental bovine lameness model. Eighteen male British × Continental beef calves aged 4 to 6 mo and weighing 297 to 392 kg were randomly assigned to receive either 1) 0.5 mg/kg lactose monohydrate placebo (PLBO; n = 6), 2) 0.5 mg/kg MEL (n = 6), or 3) 0.5 mg/kg MEL combined with 15 mg/kg GABA (MEL-GABA; n = 6) once daily for 4 d. The first treatment was administered 4 h after a chemical synovitis/arthritis was induced with injection of 15 mg amphotericin B into the left hind lateral distal interphalangeal joint. Changes in activity were evaluated continuously with pedometers. Contact force, contact area, contact pressure, impulse, and stride length were recorded once daily with a pressure mat and visual lameness scores were determined by a masked observer using a 5-point scale. Cortisol and drug concentrations were determined daily by immunoassay and HPLC-mass spectrometry, respectively. Outcomes were compared statistically using a random effects mixed model and analysis of covariance. There was a positive association between lameness scores and serum cortisol concentrations (P = 0.02) and a negative association between lameness score and step count (P < 0.0001), total force (P = 0.001), force applied to the lateral claw (P = 0.02), contact pressure (P = 0.005), and impulse of the lateral claw (P = 0.01). Step count was greater in MEL calves compared with PLBO (P = 0.008) and MEL-GABA (P = 0.04) calves. Impulse was greater in the MEL-GABA calves compared with the PLBO calves (P = 0.03). There was an inverse relationship between plasma MEL concentrations and lameness score (P = 0.02) and a positive association between MEL concentrations and force applied to the lateral claw (P = 0.03), total contact pressure (P = 0.03), and impulse on the lateral claw (P = 0.02). There was a tendency towards a positive association between GABA concentrations, total impulse, and impulse on the lateral claw (P = 0.08) and a negative associate between GABA concentrations and step count (P = 0.08). The results of this study suggest that MEL administered alone or in combination with GABA reduced the severity of lameness in calves following induction of lameness with amphotericin B. These findings have implications for developing analgesic protocols in lame calves that address both production and welfare concerns.