Algorithms for Detecting Cattle Diseases at Early Stages and for Making Diagnoses and Related Recommendations

Analytical and theoretical studies were conducted in working cattle facilities in order to identify infectious, parasitic, and nervous diseases in large horned cattle. Our analytical study was based on the analysis of available scientific research papers. The theoretical research was based on processing the measurement results with existing hardware and software. Both environmental and physiological parameters were obtained from five farms for at least 30 days. The studied cows were divided into two groups. One group consisted of 37 dairy cows of the Holstein breed aged 2–3 years having no clinical signs of disease. All cows in this group were fed the same diet, kept in the same conditions, and had the same lactation period (from 3 to 5 months). Their average weight was 517 (±2.03) kg. For inclusion into the second group, we selected 23 dairy cows with parameters similar to those of the cows in the first group but with some clinical signs of diseases such as encephalomyelitis, infectious enteritis, and hypodermatosis. The data obtained from the animals in the first group were considered as the parameters’ standardized boundary values for the estimation of a cow’s conditions, i.e., as the norm (the setpoint). As for the data obtained for the second group, they were considered to be deviations from the threshold values of the parameters (deviations from the setpoint, which required a pre-planned action). The analysis was carried out using the program code implemented in the software package “Matlab R2019b”. We analyzed the correlations between the cows’ rumen temperature and pH, their locomotive activity, and environmental parameters such as air temperature and relative humidity in the cowsheds. We then constructed graphs of inter-correlating functions. As a result of the study, for the first time, algorithms were compiled enabling the detection of infectious, parasitic, and nervous diseases.

Estrus Prediction Models for Dairy Gyr Heifers

Technological devices are increasingly present in livestock activities, such as identifying the reproductive status of cows. For this, predictive models must be accurate and usable in the productive context. The aims of this study were to evaluate estrus-associated changes in reticulo-rumen temperature (RRT) and activity (ACT) in Dairy Gyr heifers provided by reticulo-rumen boluses and to test the ability of different models for estrus prediction. The RRT and ACT of 45 heifers submitted to estrus synchronization were recorded using reticulo-rumen boluses. The means of RRT and ACT at different time intervals were compared between the day before and the day of estrus manifestation. An analysis of variance of RRT and ACT was performed using mixed models. A second approach employed logistic regression, random forest, and linear discriminant analysis models using RRT, ACT, time of day, and the temperature-humidity index (THI) as predictors. There was an increase in RRT and ACT at estrus (p < 0.05) compared to the same period on the day before and on the day after estrus. The random forest model provided the best performance values with a sensitivity of 51.69% and specificity of 93.1%. The present results suggest that RRT and ACT contribute to the identification of estrus in Dairy Gyr heifers.

PSVIII-18 Effect of rumen temperature on the average daily gain of growing-finishing calf-fed Holstein steers in the feedlot

Objectives were to evaluate the relationship between ruminal temperature and average daily gain of calf-fed Holstein steers during the extreme summer months characteristic of the Southern California desert region. Thirty-eight calf-fed Holstein steers (395 ±25 kg) were utilized in the 84-d experiment (June 30 – September 20, 2020). Steers were blocked by initial shrunk weight (168 d before the initiation of the experiment) and randomly assigned to 38 pens with 4 other steers (5 steers per pen). Pens were 62 m2 with 25 m2 overhead shade, automatic waterers and 2.4 m fence-line feed bunks. All steers were fed a steam-flaked corn-based growing-finishing diet. A bolus measuring temperature and activity at ten-minute intervals (smaXtec Basic, SmaXtec Animal Care GmbH, Austria) was placed in the rumen of each steer 112 d before the initiation of the experiment (March 10, 2020). Air temperature for the trial averaged 34.90 ± 3.03°C (maximum = 43.8 ± 2.97° C; minimum 24.72 ± 4.00°C). Average temperature-humidity-index (THI) was 80.1 ±5.4. Maximum THI during the 84-d period averaged 89.29 ± 7.85 (steers experience “emergency” THI category for all 84 days of the trial). Maximum (RTmax) and mean (RTm) daily ruminal temperature averaged 40.93 ±0.24 and 40.21 ±0.23°C, respectively. Average daily gain (mean = 1.18 kg/d; maximum = 1.54 kg/d; minimum = 0.88 kg/d) increased (P &lt; 0.01) as RTm decreased (ADG, kg = 19.13 – 0.45 RTm; r2 = 0.28). There was a close association between RTmax and RTm (RTm = 4.57 + 0.87 RTmax; r2 = 0.84). While there are numerous factors that influence ADG of feedlot cattle, differences in ruminal temperature during periods of elevated ambient conditions (ie. temperature, humidity, ration) accounts for an important portion of that variation.

Efficacy of statistical process control procedures to identify deviations in continuously measured physiologic and behavioral variables in beef heifers resulting from an experimental combined viral-bacterial challenge

The objective of this experiment was to determine if statistical process control (SPC) procedures coupled with remote continuous data collection could accurately differentiate between animals experimentally inoculated with a viral-bacterial (VB) challenge or phosphate buffer solution (PBS). Crossbred heifers (N = 38; BW = 230 ± 16.4 kg) were randomly assigned to treatments by initial weight, ADG, BHV-1 and MH serum titers. Feeding behavior, DMI, animal activity and rumen temperature were continuously monitored remotely prior to and following VB challenge. VB-challenged heifers exhibited decreased (P &lt; 0.01) ADG and DMI, as well as increased (P &lt; 0.01) neutrophils and rumen temperature consistent with a bovine respiratory disease (BRD) infection. However, none of the heifers displayed overt clinical signs of disease. Shewhart and cumulative summation (CUSUM) charts were evaluated, with sensitivity and specificity computed on the VB-challenged heifers (n = 19), and PBS-challenged heifers (n = 19) respectively, accuracy was determined as the average of sensitivity and specificity. To address the diurnal nature of rumen temperature responses, summary statistics (Mean, minimum, maximum) were computed for daily quartiles (6-h intervals), and these quartile temperature models were evaluated separately. In the Shewhart analysis, DMI was the most accurate (95%) at deciphering between PBS- or VB-challenged heifers, followed by rumen temperature (94%) collected in the 2 nd and 3 rd quartiles. Rest was most the accurate accelerometer-based traits (89%), and meal duration (87%) and bunk visit (BV) frequency (82%) were the most accurate feeding behavior traits. Rumen temperature collected in the 3 rd quartile signaled the earliest (2.5 d) of all the variables monitored with the Shewhart, followed by BV frequency (2.8 d), meal duration (2.8 d), DMI (3.0 d) and rest (4.0 d). Rumen temperature and DMI and remained the most accurate variables in the CUSUM at 80 and 79%, respectively. Meal duration (58%), BV frequency (71%) and rest (74%) were less accurate when monitored with the CUSUM analysis. Furthermore, signal day was greater for DMI, rumen temperature and meal duration (4.4, 5.0 and 3.7 d, respectively) in the CUSUM compared to Shewhart analysis. These results indicate that Shewhart and CUSUM charts can effectively identify deviations in feeding behavior, activity and rumen temperature patterns for the purpose of detecting sub-clinical BRD in beef cattle.

Differential haptoglobin responsiveness to a Mannheimia haemolytica challenge altered immunologic, physiologic, and behavior responses in beef steers

Indicator traits associated with disease resiliency would be useful to improve the health and welfare of feedlot cattle. A post-hoc analysis of data collected previously (Kayser et al., 2019a) was conducted to investigate differences in immunologic, physiologic, and behavioral responses of steers (N = 36, initial BW = 386 ± 24 kg) that had differential haptoglobin (HPT) responses to an experimentally-induced challenge with Mannheimia haemolytica (MH). Rumen temperature, DMI and feeding behavior data were collected continuously, and serial blood samples were collected following the MH challenge. Retrospectively, it was determined that 9 of the 18 MH-challenged steers mounted a minimal HPT response, despite having similar leukocyte and temperature responses to other MH-challenged steers with a greater HPT response. Our objective was to examine differences in behavioral and physiological responses between MH-challenged HPT responsive (RES; n = 9), MH-challenged HPT non-responsive (NON; n = 9), and phosphate-buffered saline (PBS)-inoculated controls (CON; n=18). Additionally, 1H NMR analysis was conducted to determine if the HPT responsive phenotype affected serum metabolite profiles. The RES steers had lesser (P &lt; 0.05) cortisol concentrations than NON and CON steers. The magnitude of the increases in neutrophil concentrations and rumen temperature, and the reduction in DMI following the MH challenge were greatest (P &lt; 0.05) in RES steers. Univariate analysis of serum metabolites indicated differences between RES, NON and CON steers following the MH challenge, however, multivariate analysis revealed no difference between HPT responsive phenotypes. Prior to the MH challenge, RES steers had longer (P &lt; 0.05) head down and bunk visit durations, slower eating rates (P &lt; 0.01) and greater (P &lt; 0.05) daily variances in bunk visit frequency and head down duration compared to NON steers, suggesting that feeding behavior patterns were associated with the HPT responsive phenotype. During the 28-d post-challenge period, RES steers had decreased (P &lt; 0.05) final BW, tended (P = 0.06) to have lesser DMI, and had greater (P &lt; 0.05) daily variances in head down and bunk visit durations compared to NON steers, which may have been attributed to their greater acute-phase protein response to the MH challenge. These results indicate that the HPT responsive phenotype affected feeding behavior patterns and may be associated with disease-resiliency in beef cattle.

PSXI-16 Inclusion of automated sensor data as a predictor of feed intake increases the variance explained by a random forest model

Prediction of feed intake from indicators would benefit the dairy industry since on-farm feed intake data are rare. The objective of this study was to examine the ability of sensor data to improve predictions of feed intake. Dry matter intake (DMI), milk yield (MY) and components, metabolic body weight (MBW; body weight0.75), and veterinary health records were collected from two cow groups (n1=47, n2=60). Automated sensors (ear tags, rumen bolus, environmental) captured measurements of cow activity, temperature, rumination and rumen pH, and barn temperature and humidity which were used to calculate THI. Random forest (RF) models were trained in R (Caret package) by 10-fold cross validation, with DMI as the response variable. Training data originated from the full study with the exception of the final day, for which DMI was then predicted. Predictive ability was evaluated against a base model excluding automated sensor data to determine changes in accuracy and the percent of variance explained (VAR). The base model included MY and components, MBW, THI, health status and parity. Base model mean square error (MSE) was 9.86, 13.25 and 12.50 kg of DMI and VAR 44.71, 42.9 and 44.85% (n = 92, 56 and 41, respectively). The correlation between actual and predicted final day DMI (CORR) was 0.05, 0.03 and 0.02 (n = 92, 56 and 41, respectively). Adding activity and temperature (first ear tag; n = 92) reduced MSE to 9.70 kg and VAR increased to 45.62% (CORR=0.20). Independently adding bolus activity, rumen temperature and pH (n = 56) to the base model also decreased MSE to 12.53 kg (VAR=46.24% and CORR=0.26). Lastly, adding activity and rumination from the second ear tag (n = 41) to the base model decreased MSE to 12.32 kg (VAR=45.63%, CORR=0.18). Automated sensors appear to explain additional variation in DMI that is not captured in the typical energy sink variables utilized when predicting intake.

64 Immunological, physiological, and behavioral responses to an experimentally-induced respiratory disease challenge in growing steers

Immunologic, physiologic, and behavioral responses to a combined viral-bacterial respiratory challenge were explored in beef steers (initial BW 293 kg). Steers (n = 24) were inoculated intranasally with bovine herpes virus-1 (2×108 PFU) and intratracheally with Mannheimia haemolytica (MH, 2.15×1010 CFU) on days -3 and 0, respectively, (n = 16; VB), or similarly inoculated with phosphate-buffered saline (n = 8; PBS). Venous and arterial blood were collected on -3, -1, 0, 2, 3, 5, 7, 10, and 14 relative to MH challenge for CBC, haptoglobin, and arterial blood oxygen saturation analysis. Continuously recorded variables included rumen temperature, activity, rumination, DMI, and feeding behavior. Data were analyzed with a repeated-measures mixed model (SAS 9.4) with fixed effects of day, inoculation, and the interaction. Bunk visit frequency and DMI were reduced (P &lt; 0.01) in VB steers throughout the 14 d post-MH period compared to PBS steers. Rumination (days 1, 7) and activity (days 1, 2, 4–8, and 11–13) were reduced (P &lt; 0.03) in VB steers vs PBS steers. Rumen temperature was elevated (P &lt; 0.04) in VB steers until day 6 post MH inoculation. Neutrophil concentrations (days 2 and 3), platelets (days 7–14), fibrinogen (days 2–10), and haptoglobin (days 2–7) were elevated (P &lt; 0.05) in VB vs PBS steers. Hematocrit was depressed (P &lt; 0.05) in VB steers on days 3–10. The VB steers had decreased (P &lt; 0.05) arterial SO2% and pO2 than PBS steers; however, the inoculation × day interaction was not significant. Results indicate that the experimental VB challenge substantially altered rumen temperature, DMI, feeding behavior, rumination and immunological response as expected. Arterial sO2% and pO2 concentrations were reduced minimally by VB challenge, indicating challenges in using blood gas to detect BRD in beef cattle.

Metabolism and Endocrinology of Cattle in High Environmental Temperatures

Close-to-market weight grain fed cattle experience high heat loads during summer. There are health, welfare and production impacts on these high value animals. Two cohorts of 600 kg Black Angus steers (n = 12) were subjected to heatwave conditions during a thermal challenge in climate chambers. Frequent blood sampling enabled a detailed description of the metabolic and endocrine trajectories during high heat load and recovery in feedlot cattle. In high heat load ruminants, blood flow is diverted from the major organs impacting metabolic rate and cellular functions. The metabolic rate will slow with falls in the thyroid hormone plasma concentrations. Insulin and the adipokines gave an indifferent response. The high heat load cattle were hypoglycaemic and oxidising fatty acids. Liver involvement was evidenced by the build-up of bilirubin in plasma, and reduced release of cholesterol and ALP. Thermal challenge saw markedly increased plasma creatinine and urea implicating reduced glomerular filtration; although the kidneys were working to retain chloride ions to balance the loss of bicarbonate from the increased respiration rate. As heat load reduced during recovery, rumen temperature and respiration rate normalised and feed intake gradually returned. Plasma glucose levels increased also. With increased blood supply to the organs, there was a rise in liver enzymes into the blood, although liver function had not fully restored during the recovery period; plasma bilirubin concentrations were still high, and ALP and cholesterol levels low. Twelve days after the thermal challenge, most blood parameters had returned to normal and the steers had gained weight.

Efficacy of statistical process control procedures to identify deviations in continuously measured physiologic and behavioral variables in beef steers experimentally challenged with Mannheimia haemolytica

The objective of this experiment was to determine if statistical process control (SPC) procedures coupled with the remote continuous collection of feeding behavior patterns, accelerometer-based behaviors, and rumen temperature can accurately differentiate between animals experimentally inoculated with Mannheimia haemolytica (MH) or PBS. Thirty-six crossbred steers (BW = 352 ± 23 kg) seronegative for MH were randomly assigned to bronchoselective endoscopic inoculation with MH (n = 18) or PBS (n = 18). Electronic feed bunks were used to measure DMI and feeding behavior traits, accelerometer-based neck collars measured feeding- and activity-behavior traits, and ruminal thermo-boluses measured rumen temperature. Data were collected for 28 d prior to and following inoculation. Steers inoculated with MH exhibited elevated (P &lt; 0.02) levels of neutrophils and rumen temperature indicating that MH challenge effectively stimulated immunologic responses. However, only nine of the MH steers exhibited increased serum haptoglobin concentrations indicative of an acute-phase protein response and one displayed clinical signs of disease. Shewhart charts (SPC procedure) were used for two analyses, and sensitivity was computed using all MH-challenged steers (n = 18), and a subset that included only MH-challenged haptoglobin-responsive steers (n = 9). Specificity was calculated using all PBS steers in both analyses. In the haptoglobin-responsive only analysis, DMI and bunk visit (BV) duration had the greatest accuracy (89%), with accuracies for head-down (HD) duration, BV frequency, time to bunk, and eating rate being less (83%, 69%, 53%, and 61%, respectively). To address the diurnal nature of rumen temperature, data were averaged over 6-h intervals, and quarterly temperature models were evaluated separately. Accuracy for the fourth quarter rumen temperature was higher (78%) than the other quarterly temperature periods (first = 56%, second = 50%, and third = 67%). In general, the accelerometer-based behavior traits were highly specific ranging from 82% for ingestion to 100% for rest, rumination, and standing. However, the sensitivity of these traits was low (0% to 50%), such that the accuracies were moderate compared with feeding behavior and rumen temperature response variables. These results indicate that Shewhart procedures can effectively identify deviations in feeding behavior and rumen temperature patterns to enable subclinical detection of BRD in beef cattle.