Osteochondrosis in bull beef cattle following lack of dietary mineral and vitamin supplementation

Thermographic Screening of Beef Cattle Metatarsal Growth Plate Lesions

Simple Summary

Young beef bulls are predisposed to develop diseases of the growing skeleton, especially growth plate lesions. These lesions jeopardize both welfare and production, often leading to anticipated culling and diminished weight gain. However, beef cattle are prey animals and do not exhibit signs of pain and lameness until the disease becomes extensive and severe. Fast methods to screen for growth plate lesions presence could therefore lead to prompt treatment of the affected animals, enhancing recovery and diminishing losses. The aim of the present study was to examine the potential of infrared thermography as a non-invasive tool for rapidly screening beef bulls for the presence of growth plate lesions. Here, 20 Charolais and Limousine beef bulls affected by growth plate lesions were screened using infrared thermography. A difference in maximum, mean, and minimum temperatures was detected between healthy and affected growth plate areas, and a difference in mean and maximum temperatures was detected globally in the affected limbs against healthy ones. Infrared thermography could therefore serve as a reliable tool for screening growth plate lesions in beef bulls, permitting rapid detection at pen level and aiding fast and targeted treatment, thus improving animal welfare and production.

Abstract

Lameness represents one of the main causes of decreased productive performance and impaired animal welfare in the bovine industry. Young beef bulls are predisposed to develop diseases of the growing skeleton, especially growth plate lesions. Early diagnosis is indispensable for ensuring correct treatment, fast recovery and reduction losses. However, when dealing with beef cattle, this is not always possible. Fast and reliable diagnostic imaging techniques are necessary to improve dealing with lameness in beef animals. The aim of the present study was to examine the potential of thermographic imaging as a non-invasive tool for rapidly screening beef bulls for the presence of growth plate lesions. Here, 20 Charolais and Limousine beef bulls affected by growth plate lesions in one of the rear limbs were selected. IRT was performed on both hind limbs using a digital infrared camera (ThermaCam T420 Model, Flir Systems, Boston, MA, USA), prior to radiographic imaging and clinical examination. The temperature of healthy and affected limbs was measured in two regions: the area correspondent to the growth plate (AR01) and the whole area of the metatarsus (AR02). Growth plate lesions were found to increase the maximum, mean, and minimum temperatures in AR01; and the mean and maximum temperatures in AR02, therefore, indicating the potential of IRT as a reliable, practical tool for screening growth plate lesions in beef bulls.

Radiographic diagnosis and surgical management for successful outcomes for osteochondrosis in Japanese Black calves

Osteochondrosis (OC) is not well recognized in cattle. Japanese Black (JB) cattle are valued for their beef and studies regarding OC are scarce. Hence, the aim of this study was to retrospectively discuss clinical and radiographical findings, diagnosis and treatment options for OC in JB cattle for successful outcomes. Medical records of 11 calves affected with OC were reviewed, retrospectively. Clinical and radiographic findings, treatment and outcomes and postmortem examination findings were analyzed. All calves had lameness. Stifle (4/14) and tarsal (4/14) were the most affected joints. Subchondral bone lucencies were observed in all joints (14/14) and accompanied with sclerosis (10/14). Radiographic grading was performed in calves. Calves were treated surgically (8/11) or conservatively (1/11). Surgically treated calves were auctioned (5/8). Postmortem examination was performed (2/11). Gross findings revealed ulcerative lesion at articular surface. Histopathologically, cartilage layer was defected at lesion. Inflammation (2/2) and granulation tissue (1/2) was also observed. In conclusion, OC in JB cattle can be diagnosed on the basis of radiography with history and clinical signs in clinical setting. Surgery should be performed in mild cases for successful outcomes. A modified radiographic grading criteria for clinical cases may hold potential in evaluating prognosis and outcomes.

An assessment of dairy herd bulls in southern Australia: 2. Analysis of bull- and herd-level risk factors and their associations with pre- and postmating breeding soundness results

In pasture-based, seasonally calving dairy herds of southern Australia, the mating period usually consists of an initial artificial insemination period followed by a period of natural service using herd bulls. The primary objective of this study was to identify associations between individual bull- and herd-level management factors and bull fertility as measured by a pre- and postmating bull breeding soundness evaluation (BBSE). Multivariable mixed effects logistic regression models were used to identify factors associated with bulls being classified as high risk of reduced fertility at the premating and postmating BBSE. Bulls older than 4 yr of age at the premating BBSE were more likely to be classified high risk compared with bulls less than 4 yr of age. Bulls that were in herds in which concentrates were fed before mating were more likely to be classified as high risk at the postmating BBSE compared with bulls that were in herds where concentrates were not fed. Univariable analyses also identified areas in need of further research, including breed differences between dairy bulls, leg conformation and joint abnormalities, preventative hoof blocking for bulls, and mating ratios.

Preliminary report on osteochondrosis in cattle in the north-western parts of South Africa

The north-western part of South Africa, in particular, is well known for mineral imbalances. Aphosphorosis, resulting in rickets and osteomalacia, received a lot of attention at the turn of the nineteenth century (1882–1912). This was followed in 1997 by research on Vryburg hepatosis, another area-specific mineral imbalance–related disease in young calves reared on manganese-rich soil derived from the weathering of dolomitic (carbonate) rock formations. In 1982, a totally new syndrome (osteochondrosis) manifested in, amongst others, areas in South Africa where aphosphorosis was rife. Osteochondrosis was also identified in the south-western parts of Namibia as well as southern Botswana and other areas in South Africa. Osteochondrosis has a multifactorial aetiology and this study focused on the role of minerals, particularly phosphorus, in the development of the disease. A significant improvement in the clinical signs in experimental animals and a reduction of osteochondrosis occurred on farms where animals received bioavailable trace minerals and phosphorus as part of a balanced lick. An increase in the occurrence of the disease on farms during severe drought conditions in 2012–2013 prompted researchers to investigate the possible role of chronic metabolic acidosis in the pathogenesis of the disease.

Osteoarthritic cartilage lesions in the bovine patellar groove: a macroscopic, histological and immunohistological analysis

A high percentage of osteoarthritis (OA)-like patellar groove lesions in the stifle joint in calcium-deficient bulls has been recently reported. The prevalence of these lesions in bulls deficient in or supplemented with calcium was compared to findings in culled and healthy bulls to determine whether they represent normal anatomical variations, developmental anomalies or OA. It was hypothesized that the patellar groove lesions may represent OA. Distal cartilage samples from 160 femurs were analysed using a macroscopic Société Française d'Arthroscopie (SFA) OA grading system. Samples representing different SFA grades were subjected to Osteoarthritis Research Society International (OARSI) histological and high-mobility group box 1 (HMGB1) immunohistological OA grading. For a qualitative analysis three OA samples were immunostained for interleukin (IL)-1β, matrix metalloproteinase (MMP)-13 and collagenase-produced COL2-3/4M neoepitopes. Patellar groove lesions were found in 48% of the femurs and were highest in calcium-deficient animals (71%, P<0.001). All three different grading systems disclosed OA in culled bulls, but no focal areas of cartilage necrosis. OARSI and HMGB1 grades were fairly concordant (Spearman's ρ=0.95, P<0.001; Cohen's κ=0.23, P<0.005), both with a slight disparity with the SFA grade (ρ=0.80 and 0.87, P<0.01; κ=0.36 and 0.46, P<0.001). IL-1β, MMP-13 and COL2-3/4M staining patterns were compatible with OA. The study showed that patellar groove lesions are common in bulls. In all SFA, OARSI and HMGB1 graded samples the lesions clearly demonstrated OA and showed OA-typical pathophysiology. Arthroscopic SFA grading showed similar changes in calcium-deficient and calcium-supplemented bulls, but in the absence of a time course study and histological data the primary nature of these lesions could not be established with certainty.

Role of slaughtering in Salmonella spreading and control in pork production

Salmonella is one of the major foodborne pathogens worldwide. Pork products are among the main sources of Salmonella infection in humans, and several countries have established Salmonella surveillance and control programs. The role of slaughtering in carcass contamination has been indicated by studies focused on the slaughterhouse environment. In this review, we examine and discuss the information available regarding the influence that farm status, pig transport, and lairage have on the carriage of Salmonella by pigs entering the slaughter line. The evolution of carcass contamination throughout the slaughtering process, the main sources of contamination in the dirty and clean zones of the slaughter line, and previously reported prevalence of Salmonella on carcasses and factors affecting this prevalence also are discussed. The importance of implementing interventions at the slaughter level is discussed briefly. Consistent with the information available, pigs from infected farms and newly acquired or recrudescent infections in pigs at the subsequent stages of transport and lairage are important sources of Salmonella at the slaughtering plant. The continuous introduction of Salmonella into the slaughterhouse and the potential for resident flora constitute a risk for carcass contamination. At the slaughterhouse, some dressing activities can reduce carcass contamination, but others are critical control points that jeopardize carcass hygiene. This information indicates the importance of considering slaughter and previous stages in the pork production chain for controlling Salmonella in swine production.

Effect of a microencapsulated feed additive of lactic and formic acid on the prevalence of Salmonella in pigs arriving at the abattoir

The main objective of this work was to investigate the potential of a microencapsulated mixture of organic acids (formic and lactic acid) added to the feed of fattening pigs to reduce the prevalence and shedding of Salmonella when arriving to the abattoir. Two trials were performed. In Trial 1, 24 fattening pigs received one of three diets: a control diet, the same diet including lactic and formic acid (0.4% each) (non-protected blend; NPB), or a lipid microencapsulated blend (0.14% each acid) (protected blend; PB). After 10 days, digesta samples from various parts of gastrointestinal tract were taken. No changes were detected either in pH, total short chain fatty acids (SCFA), lactic/formic acid concentrations in any of the sections studied or in caecal lactic acid bacteria or enterobacteria. In Trial 2, 261 pigs from a commercial farm were distributed between the three previous diets in the five weeks before slaughtering. At the abattoir, no change was detected in caecal pH, but increased concentrations (p < 0.05) of formic and lactic acid were found with the NPB and PB treatments. The total SCFA concentration was higher with the PB compared to the control diet (p = 0.002) with a lower percentage of branched chain fatty acids. Both acidified diets decreased enterobacteria in the caecum but did not modify lactobacilli. NPB treatment decreased Salmonella seroprevalence (p < 0.001). A significant (p < 0.05) increase in Salmonella faecal shedding was found related to the stress previous to slaughter with the control group and PB, but not in the NPB group. More studies will be needed to confirm the usefulness of protected acids to prevent Salmonella prevalence and shedding at the abattoir.

Quantitative examination of Salmonella spp. in the lairage environment of a pig abattoir

One of the initial sources of Salmonella spp. and other bacterial pathogens at the abattoir is the carrier pig. In the absence of effective cleaning and disinfection measures, such animals may contaminate the lairage environment, which may act as a significant source of infection for incoming non-infected animals. The objectives of this study were to quantify the levels of Salmonella spp. in the lairage of a large pig abattoir and to compare the effect on environmental contamination levels with Salmonella spp. of the cleaning procedures carried out daily to those undertaken weekly. A total of 359 swabs were collected from lairage pen floors at three timepoints throughout the course of two slaughter days. All samples were analyzed quantitatively. On day 1, Monday, following weekly cleaning and disinfection, 6% of the 179 floor swabs taken were positive for Salmonella spp. On day 2, Thursday, at the end of the slaughter week, when lairage pens were subjected to high-pressure cold water washing between batches of pigs, 44% of the 180 floor swabs taken were positive for Salmonella spp. Quantitative analysis revealed that the median numbers of salmonellae detected following weekly cleaning and disinfection were approximately 1.8 organisms/100 cm(2). The numbers of salmonellae detected on day 2 were approximately 8 organisms/100 cm(2). The most prevalent serotype isolated in this study was S. Typhimurium (42%). Phage types DT12, DT104b, and U302 comprised the majority of phage types identified. These results highlight the need to develop effective intervention measures to control the spread of Salmonella spp. in the preslaughter environment.

Rapid infection of pigs following exposure to environments contaminated with different levels of Salmonella typhimurium

Pigs reared in an environment free of Salmonella species or on farms with low levels of infection may acquire infection during transport to the abattoir or while held in lairage. We designed a study to determine if pigs could become infected with S. Typhimurium when placed in a contaminated environment similar to that observed in commercial lairage. In addition, quantitative examination of salmonellae in all environmental and animal samples was undertaken. In order to simulate a naturally contaminated environment, animals experimentally infected with a challenge strain of S. Typhimurium (PT12) were used to seed the trial pen environment with salmonellae. In trial 1, pigs were exposed to a highly contaminated environment (5.4 log(10) CFU/100 cm(2)) for 2, 3, or 24 hours. Following these exposure periods, pigs were euthanized and samples including gastrointestinal and associated lymphoid tissue were analyzed for the challenge strain. S. Typhimuirum PT12 was detected in at least one sample type analyzed from each pig after exposure for > or =2 hours. The most frequently contaminated samples were tonsils (100% positive), followed by segments of the ileocecal junction (94.4% positive) and cecal contents (89% positive). Quantitative analysis conducted on cecal contents and ilocaecal junction segments revealed that similar numbers of organisms (1.1-2 log (10) /g) were isolated at all timepoints. In trial 2, pigs were exposed to a less contaminated environment (2.65 log (10) CFU/100 cm(2)) for periods of 1, 3, 6, or 24 hours. S. Typhimuirum PT12 was not detected in any sample from pigs euthanized after exposure of 1 hour. The challenge strain was recovered from the cecal contents of pigs after exposures of 3, 6, and 24 hours, and from the tonsil of one pig after exposure for 6 hours. These results highlight the need to reduce the environmental load of Salmonella spp. in lairage holding pens in order to reduce the numbers of infected pigs entering the slaughter process.

Consequences of hazardous dietary calcium deficiency for fattening bulls

Background

Deficient mineral supplementation on a feedlot farm resulted in severe clinical manifestations in fattening bulls. Animals mistakenly received only 60–70% of the recommended calcium intake, while simultaneously receiving twice the amount of phosphorus recommended. Thus, the dietary Ca/P ratio was severely distorted. After approximately six months on such a diet, four fattening bulls were euthanized because of severe lameness and 15% of other animals on the farm were having clinical leg problems. Veterinary consultation revealed the mistake in mineral supplementation.

Methods

Fattening bulls were divided into three groups depending on the time of their arrival to the farm. This enabled the effect of mineral imbalance at different growth phases to be examined. After slaughtering, the bones of both front and hind limbs were macroscopically evaluated.

Results

Over 80% of the animals with a calcium-deficient diet had at least one severe osteoarthritic lesion. The economic impact of the calcium deficiency was statistically significant.

Conclusion

Calcium deficiency with distorted Ca/P ratio yielded a severe outbreak of osteoarthritis in fattening bulls. Calcium deficiency caused a more serious lesions in age group 5–12 months than age group 12–18 months. Besides causing obvious economic losses osteoarthritis is also a welfare issue for feedlot animals.

National survey for Salmonella in pigs, cattle and sheep at slaughter in Great Britain (1999-2000)

AIMS

The objective of these surveys was to estimate the prevalence of faecal carriage of Salmonella in healthy pigs, cattle and sheep at slaughter, and of pig carcase contamination with Salmonella. These data can be used as a baseline against which future change in Salmonella prevalence in these species at slaughter can be monitored.

METHODS AND RESULTS

In this first randomized National Survey for faecal carriage of Salmonella in slaughter pigs, cattle and sheep in Great Britain, 2509 pigs, 891 cattle and 973 sheep were sampled in 34 pig abattoirs and 117 red meat abattoirs in England, Scotland and Wales. Carriage of Salmonella in 25 g caecal contents was identified in 578 (23.0% pigs) but in only 134 (5.3%) of carcase swabs. The predominant Salmonella serovars found in both types of sample were S. Typhimurium (11.1% caeca, 2.1% carcases) and S. Derby (6.3% caeca, 1.6% carcases). The main definitive phage types (DT) of S. Typhimurium found were DT104 (21.9% of caecal S. Typhimurium isolates), DT193 (18.7%), untypable strains (17.6%), DT208 (13.3%) and U302 (13.3%). Three isolates of S. Enteritidis (PTs 13A and 4) and one enrofloxacin-resistant S. Choleraesuis were also isolated. A positive 'meat-juice ELISA' was obtained from 15.2% of pigs at 40% optical density (O.D.) cut-off level and 35.7% at 10% cut-off. There was poor correlation between positive ELISA results or carcase contamination and the caecal carriage of Salmonella. The ratio of carcase contamination to caecal carriage rates was highest in abattoirs from the midland region of England and in smaller abattoirs. In cattle and sheep 1 g samples of rectal faeces were tested. Two isolates (i.e. 0.2%) were recovered from cattle, one each of S. Typhimurium, DT193 and DT12. One sheep sample (0.1%) contained a Salmonella, S. Typhimurium DT41. In a small subsidiary validation exercise using 25 g of rectal faeces from 174 cattle samples, three (1.7%) isolates of Salmonella (S. Typhimurium DT104, S. Agama, S. Derby) were found.

CONCLUSIONS

The carriage rate of Salmonella in prime slaughter cattle and sheep in Great Britain was very low compared with pigs. This suggests that future control measures should be focused on reduction of Salmonella infection on pig farms and minimizing contamination of carcases at slaughter.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work has set baseline figures for Salmonella carriage in these species slaughtered for human consumption in Great Britain. These figures were collected in a representative way, which enables them to be used for monitoring trends and setting control targets.