Comparison of three refractometers in colostrum quality estimation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00027162%3A_____%2F18%3AN0000195" target="_blank" >RIV/00027162:_____/18:N0000195 - isvavai.cz</a>

Alternative codes found

RIV/00027014:_____/18:N0000020

Result on the web

<a href="https://www.bcva.eu/" target="_blank" >https://www.bcva.eu/</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Comparison of three refractometers in colostrum quality estimation

Original language description

Cattle Practice OCTOBER 2018 Volume 26 Part 2 BCVA Congress 2018 Additional posters, Jurys Inn Hinckley Island Hotel, Watling Street, Hinckley, LE10 3JA, Anglie, 18.–20. října 2018 - poster. Less than 50% of Czech dairy farmers use devices for colostrum quality estimation. They use them mostly irregularly, at least in periods of higher calf morbidity.. About half of them stopped using colostrometers and started to use different Brix refractometers (with questionable accuracy) which can also be used for estimation of total protein in calf serum. The Brix refractometer is a suitable tool - it is rapid, user-friendly and functions independently of colostrum temperature. Previous studies recommended cut-off levels for the determination of good quality Holstein colostrum between 20% and 23% Brix. The objectives of this study were to determine the IgG concentration of colostrum in Czech dairy herds, compare refractometer results with results achieved by radial immunodiffusion (RID) – reference method, evaluate the reliability of three different types of refractometers and recommend the best solution for the evaluation of colostrum quality for routine use on farms. Colostrum samples (n = 1522) were collected from 38 common dairy cattle herds (Holstein 44.2%; Czech Fleckvieh 55.8% of colostrum samples) between autumn 2015 and spring 2017. The immunological quality of colostrum was estimated by Brix refractometry: 1) optical refractometer with a scale from 0 to 32% Brix (type RBR32-ATC; made in China); (2) simple digital refractometer (without a cover) with a scale from 0 to 85% Brix (type RDBR85-ATC; 128 detector elements, resolution 400 pixels per inch – PPI; made in China); (3) digital refractometer Misco (with a cover) with a scale range from 0 to 85% Brix (type Misco DD-3 Digital DairyTM; 1024 detector elements; resolution 3256 PPI; made in USA) and compared with the IgG concentration assessed by RID. The results were statistically evaluated and 7 cut-off levels (17-23% Brix) were tested for the detection of poor quality colostrum (IgG <50 g/L) – the best cut-off level was defined as the highest summation of sensitivity and specificity. Statistical analyses were performed using MedCalc for Windows, version 18.6 (MedCalc Software, Ostend, Belgium). We found high variability in the quality of colostrum. The minimum, maximum and median of individual measurements were the following: RID IgG – 5.2, 199.1, 76.9 g/L; optical refractometer – 9.5, 32.0, 23.1% Brix; simple digital refractometer – 5.4, 35.0, 19.1% Brix; digital refractometer Misco – 9.8, 37.4, 23.2% Brix. On the basis of IgG concentration assessed by RID, 20.9% of colostrum samples were of low quality. The Spearmann correlation coefficients between RID–measured IgG concentrations and the Brix scores from the optical, simple digital and digital Misco refractometers were 0.67, 0.62 and 0.67, respectively (p<0.001). The cut-off evaluation of the readings from optical refractometer and digital refractometer Misco showed similarly as the best cut-off level 20% Brix; with sensitivity 89.4% and 88.2%, specificity 73.2% and 74.5%, accuracy 86.0% and 85.4%, respectively. The best cut-off level for the simple digital refractometer out of those tested was only 17% Brix (or even less in reality) with the sensitivity 77.5%, specificity 80.4% and insufficient accuracy 78.1%. For both, optical and digital Misco refractometers, we recommend using 2 cut-off levels for the evaluation of colostrum (preconditions: sensitivity for the higher cut-off level and specificity for the lower cut-off level ≥90%): 23% Brix for the selection of good quality colostrum suitable for the first meal or freezing and 19% Brix to discard poor quality colostrum. Different best cut-off levels obtained by measuring with different types of refractometers indicated the need to check the technical quality of the instruments (e.g. cover, number of detector elements and pixels per inch), especially in digital refractometers prior to their use on farms and, where appropriate, to determine their own cut-off levels on the basis of comparison of results with the reference method.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

40301 - Veterinary science

Project

<a href="/en/project/QJ1510219" target="_blank" >QJ1510219: Complex colostrum management and its improving as a natural tool for support of calf health, contagion control and reduction of need for antibiotics</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů