Least Squares, Simple Linear Regression, and Pearson Correlation Analysis between the Lactation Milk Yield of Norduz Ewes and Their Lambs’ Live Weight

Abstract

This study aimed to determine the lactation milk yield of Norduz ewes and to determine the effects of milk yield on their lambs’ growth and development characteristics. Additionally, the correlations between the sheep’s milk yield, lambs’ live weight, and affecting factors were determined. The study was conducted at the Van University of Yüzüncü Yıl Agricultural Research Center. In the study, 61 Norduz ewes and 66 male and female lambs they bore were included. The sheep were milked at 30-day intervals until the 180th day. Similarly, the lambs were weighed at 30-day intervals from birth to 180th day. The means and standard errors of the milk yields were obtained on the 30, 60, 90, 120, 150th, and 180th days of milking. The live weight means and standard errors of the lambs on the 30th, 60th, 90th, 120th, 150th, and 180th days are given. According to the GLM analysis results, sex significantly influenced lactation length (p<0.05), and there was a difference in favor of female lambs. The impact of dam age was notably significant on live weight at days 60 and 90 (p<0.05). Additionally, birth type significantly affected live weight at day 30 and 60 (p<0.001), as well as at day 90 (p<0.01). Regarding the linear relationship between dam weight and live weight, a significant effect was observed at day 30 (p<0.001), day 60 (p<0.01), and day 90 (p<0.05). Notably, the linear effects of lamb birth weight on live weight remained significant across all control periods (p<0.001).