A Statistical Analysis of the Structure of Bleats From Sheep of Four Different Breeds

Abstract

[Bleats from groups of ewes from Clun Forest, Dalesbred, Jacob and Border Leicester breeds of sheep were analysed on a sonograph and the results from four measurements were analysed statistically using a Canonical Variate analysis and a Variance component analysis. The measurements used were length, fundamental frequency and the position of the 1st and 2nd formant. The mean value of the 'Mahalanobis D' distances calculated from the canonical variate analysis were Clun Forest bleats 10.5, Dalesbred bleats 7.94, Jacob bleats 4.83 and 6.1 for the Border Leicester bleats. The Clun Forest bleats were the most heterogeneous and the Jacob bleats most homogeneous. The variance components (σ2b + σ2) for all breeds was large for the fundamental frequency and greatest for the Clun Forest bleats. This was confirmed by high 'F' values for the fundamental frequency showing that this variable is important in discriminating between bleats of ewes., Bleats from groups of ewes from Clun Forest, Dalesbred, Jacob and Border Leicester breeds of sheep were analysed on a sonograph and the results from four measurements were analysed statistically using a Canonical Variate analysis and a Variance component analysis. The measurements used were length, fundamental frequency and the position of the 1st and 2nd formant. The mean value of the 'Mahalanobis D' distances calculated from the canonical variate analysis were Clun Forest bleats 10.5, Dalesbred bleats 7.94, Jacob bleats 4.83 and 6.1 for the Border Leicester bleats. The Clun Forest bleats were the most heterogeneous and the Jacob bleats most homogeneous. The variance components (σ2b + σ2) for all breeds was large for the fundamental frequency and greatest for the Clun Forest bleats. This was confirmed by high 'F' values for the fundamental frequency showing that this variable is important in discriminating between bleats of ewes.]