Effect of health status upon arrival at a single milk-fed veal facility on breakeven purchase price of calves

Male calves are purchased from the dairy industry in North America to produce red meat. The price paid for male calves varies widely, and it is unclear which variables influence the price paid for each calf. The objective of this study was to assess how the health traits of calves at the time of arrival and demographic variables affect the breakeven purchase price of a male calf entering the veal industry. A financial model was constructed using the prevalence of health abnormalities, weight at arrival, source of the calf, number of days in the barn, base carcass price, days to mortality, feed costs, season at arrival, interest rate, housing location, carcass dressing percentage, and costs associated with housing, labor, utilities, trucking, and health to calculate the breakeven purchase price and an estimate of profit. Sensitivity analysis was conducted using health variables measured at arrival and demographic variables, including season at arrival and housing location, to identify the factors with the largest impact on the predicted average daily gain, early and late mortality risk, breakeven purchase price, and profit. At the baseline inputs, the average calculated profit was ?$5.36 per calf and it was most sensitive to the location of housing where calves were fed and the body weight of the arriving calf. The mortality risk in the first 21 d after arrival (early) was calculated to be 2.2%, whereas the risk of mortality after 21 d (late) was 3.7%. The risks of early and late mortality were most sensitive to the level of dehydration measured at arrival and the season at arrival for the purchased calves, respectively. The calculated average daily gain was 1.12 kg/d and it was most sensitive to housing location. The breakeven purchase price was calculated to be $242.49 per calf, which was most sensitive to the housing location where the calves were fed. The results of this analysis demonstrate that veal producers need to consider many variables before purchasing calves. In addition to overall market conditions, veal producers should factor health characteristics and the expected performance of the calves they purchase into what they are willing to pay for them.     

Validation of an automated cell counter to determine leukocyte differential counts in neonatal Holstein calves

Recent advances in the understanding of risk factors and biomarkers in calves entering rearing facilities show promise for identifying high-risk calves on arrival at veal and dairy beef operations. Rapid automated leukocyte differential cell counts may be a good addition for augmenting or refining calf risk identification on-farm. The objective of this study was to validate an automated leukocyte cell counter, the QScout BLD test (Advanced Animal Diagnostics, Morrisville, NC), for its ability to determine leukocyte differential cell counts in neonatal Holstein calves. From June to July 2018, blood samples collected in EDTA anticoagulant from 235 calves upon arrival at an independent veal research facility in Ontario, Canada, were evaluated using the QScout BLD test and manually by microscopy. We compared these leukocyte differential counts using Lin's concordance correlation coefficient (ρ) and found very good agreement between tests for neutrophil counts (ρ = 0.83); fair agreement for lymphocyte counts (ρ = 0.32); fair agreement for the ratio of neutrophils to lymphocytes (ρ = 0.36); slight agreement for monocyte counts (ρ = 0.14); and slight agreement for eosinophil counts (ρ = 0.20). We further examined test results to determine if they differed in their classification of samples as being above, within, or below reported 95% reference intervals for neonatal Holstein calves. Classification between tests resulted in very good agreement for neutrophils and lymphocytes, with only 4.2% and 5.8% disagreement in classification, respectively. We observed moderate agreement for monocytes, with 23.3% classified differently, and poor agreement for eosinophils, with 70.3% classified differently. Further study is required to determine the role of leukocyte profiling in the risk assessment of calves arriving at calf-rearing facilities.     

Short communication: Validation of a test-day milk test for β-hydroxybutyrate for identifying cows with hyperketonemia

Subclinical ketosis is a common metabolic disorder affecting dairy cattle that results in a greater risk for the development of subsequent metabolic and infectious disease. Canwest Dairy Herd Improvement (DHI; Guelph, ON, Canada) has begun to use an infrared test (MilkoScan FT600, Foss Analytical A/S, Hillerød, Denmark) applied to metered composite milk samples to detect β-hydroxybutyrate (BHB) levels as a herd surveillance test for hyperketonemia. However, the test has not been compared with the gold standard, serum BHB as determined in a reference diagnostic laboratory. The objective of this cross-sectional diagnostic accuracy study was to validate the DHI milk BHB test to identify cows with hyperketonemia as determined by quantification of BHB in serum. A total of 316 cows from 17 dairy herds in southwestern Ontario had a milk and blood sample taken. Milk was collected at a routine DHI test, and blood from the same cow was sampled within 24 h of the milk test. The BHB concentration in milk was determined using the DHI milk BHB test, and serum was sent to the Animal Health Laboratory at the University of Guelph (Guelph, ON, Canada). A nonparametric receiver operating characteristic curve was generated to compare DHI milk BHB concentrations with serum BHB concentrations. Overall, a total of 34 cows (11%) had a level of serum BHB ≥1.2 mmol/L. The concentration of DHI milk BHB was moderately correlated with the concentration of serum BHB, yielding a coefficient of determination value of 0.61. The optimal cut point for determining hyperketonemia (≥1.2 mmol/L) on the DHI milk BHB test was ≥0.14 mmol/L, yielding a sensitivity of 81% and specificity of 92%. The performance of the DHI milk BHB test varied depending on the days in milk (DIM) of the cows tested, with a higher specificity being found in cows that were ≤25 DIM compared with cows tested >25 DIM. If the herd-level prevalence of hyperketonemia was ≥14%, the DHI milk BHB test had an improved sensitivity when compared with a herd-level prevalence of <14%. This study demonstrates that the DHI milk BHB test is a reliable measure for evaluating hyperketonemia using routine DHI milk samples and could be used as a herd-level monitoring tool for ketosis when evaluating nutritional management or preventative medicine strategies.     

A matheuristic approach for optimizing mineral value chains under uncertainty

Optimization and Engineering - Mineral value chains, also known as mining complexes, involve mining, processing, stockpiling, waste management and transportation activities. Their optimization is...     

Probing photonic and optoelectronic structures by apertureless scanning near-field optical microscopy

This report presents the Apertureless Scanning Optical Near-Field Microscope as a powerful tool for the characterization of modern optoelectronic and photonic components with sub-wavelength resolution. We present an overview of the results we obtained in our laboratory over the past few years. By significant examples, it is shown that this specific probe microscopy allows for in situ local quantitative study of semiconductor lasers in operation, integrated optical waveguides produced by ion exchange (single channel or Y junction), and photonic structures.     

Ka and Q band propagation experiments in Toulouse using ASTRA 3B and ALPHASAT satellites

From January 2008 to March 2011, ONERA operated in Toulouse, France, a beacon receiver able to collect the 19.7‐GHz beacon signal of the HotBird 6 satellite. In March 2011, the radio frequency chain was modified to be able to receive the 20.2‐GHz ASTRA 3B beacon to benefit from a higher Equivalent Isotropically Radiated Power of the satellite. Since June 2015, a second beacon receiver has been installed and is able to record the 39.4‐GHz beacon signal of the Alphasat satellite. The objective of this paper is to present the results of the first 2 years of measurements (June 2015 to May 2017) of the Q‐band Alphasat propagation experiment in Toulouse, as well as concurrent measurements collected at Ka‐band with ASTRA 3B. First of all, the propagation experiments are briefly described. Second, the results of the statistical analysis are highlighted. Finally, a deep analysis of the performances of the 2 frequency scaling prediction methods recommended in ITU‐R P.618‐13 is performed.     

Power‐Law Fluid Flow Over a Sphere: Average Shear Rate and Drag Coefficient

Based on the consideration of the rate of mechanical energy dissipation, an expression for the average shear rate for a sphere falling in a power‐law fluid in the creeping flow regime has been deduced. The average shear rate in a power‐law fluid (n<1) appears to be higher than that in an equivalent Newtonian fluid. This in turn has been combined with the numerical predictions of drag coefficient (up to Reynolds number of 100) of a sphere to develop a generalized drag correlation for power‐law liquids encompassing both n > 1 and n < 1 which appears to apply up to much higher values of the Reynolds number. The available experimental data have been used to demonstrate the reliability and accuracy of the new correlation for shearthinning liquids. Also, in the limit of n = 1, this expression reproduces the standard drag curve with a very high accuracy.