Principal Component Analysis of Biometric Traits in Guilan Native Cattle of Iran

In this study, 230 heads of Guilan native cows were phenotypically evaluated for 29 traits. Descriptive statistics were obtained per each level of sex (male and female), two levels of the genetic group (straight bred native and crossbred of the native by Holstein), and four levels of genetic groups x sex interaction. The results showed that the crossbred cows had dairy conformation while the type of Guilan native cows was meat-oriented. A distinctive feature of native cattle compared to cross and other breeds are the presence of withers, which is often seen in males and rarely in females. The phenotypic correlation coefficients of 25 attributes were calculated. There were 270 positive and 30 negative coefficients. Correlation coefficients ranged from -0.5 (thigh girth and fore teat length) to 0.95 (thigh girth and front leg length). The principal component analysis was performed to find the variables explaining the maximum variance in the main set of variables. The first and second components accounted for 57.17 and 11.53 percent of the total variance, respectively. Seven components accounted near to 90 percent of the total variance. Traits consist of width and environment of the chest, height in the hip area (rump), head length and hip to pin distance, height in stature area, depth and girth of abdominal, hip-width (hip to hip distance), front leg length, body length, and neck girth were more important for the first component, which is important in terms of bulk, size, length, width, height, and body growth as a result of meat production.