Identification of beef cattle categories (cows and calves) and sex based on the near infrared reflectance spectroscopy of their tail hair

Near infrared (NIR) reflectance spectroscopy combined with chemometrics was used to classify tail hair samples from animals of the same breed of cattle (Brahman) into cow or calf and into male or female animals. Tail hair samples (n = 74) were scanned in the NIR region (680-2500 nm) using a fibre optic probe attached to an instrument operating in reflectance mode. Principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA) were then used to classify the samples according to their origin or sex. Full cross validation (leave-one-out) was used as the validation method when classification models were developed. Correct classification rates of 92% for cow and 100% for calf samples were obtained using PLS-DA. These results demonstrated the ability of NIR spectroscopy to discriminate between the animal categories and sex of animals. Further studies will be carried out to validate the methodology in various categories of beef cattle.