Accuracy of Image Analysis for Linear Zoometric Measurements in Dromedary Camels

Abstract

The present study consisted in verifying the effectiveness of the image analysis method for body measurement in dromedary camel compared to manual measurements as a reference method. To do this, twenty-one linear body measurements were estimated on 59 adult Sahraoui dromedary camels (22 males and 37 females) with normal clinical condition by the standard method using a measuring stick or vernier caliper. Image analysis on profile, front or behind photographs were processed using Axiovision Software. Overall; mean comparison, relative error, variance, Pearson's correlation coefficient and coefficient of variance showed that the image analysis method is accurate in relation to the manual measurement. Furthermore, image analysis results indicated relevant accuracy (bias correction factor, Cb ≈1) and precision (Pearson ρ ≈ 1) which were significantly correlated with the results of the reference method (Lin's concordance correlation coefficients rccc ≈ 1). According to Blant Altman upper and lower limits of agreement, the concordance was estimated between 93.22 and 98.3%. Passing-Bablok regression showed good relationship between results of the two methods displaying no significant systematic and proportional bias. The image analysis method for linear body measurements in dromedary camel yielded results that are in agreement with the manual measuring method. This method is a valid tool for studies on camel conformation traits.

Exploiting morphobiometric and genomic variability of African indigenous camel populations-A review

“…However, measurements done manually have some disadvantages such as stress of camels, less accuracy and livestock aggressiveness (leading to the attack of the individuals taking the measurements). In order to address these constraints, the use of geometric morphometrics to effectively capture the overall size and shape of camels has been proposed (Rahagiyanto et al, 2019;Gherissi et al, 2022). The many advantages of geometric morphometrics (threedimensional) over the traditional method (one-dimensional) include proper account for size differences, provision of a more realistic image, easiness, less workload, and impersonal impartiality (Zelditch et al, 2012;Alhaddad and Alhajeri, 2019;Sénèque et al, 2019;Çağlı and Yılmaz, 2021;Gherissi et al, 2022).…”