The aim of the present research was to work out equations of multiple regression for the estimation of body weight of cows on the basis of body measurements and evaluation of the animals’ condition. The studies involved 318 lactating cows (from the first up to the fourth lactation). The following equation was derived for the estimation of the cows’ body weight on the basis of their body measurements and evaluation of their condition: Y = 6.043X₁ + 3.129X₄ + 20.876X₈ – 882.756. The mean error of evaluation reached + 1.8 kg for primiparous cows and – 2.6 kg for multiparous cows. Independent variables included: X₁ – chest girth; X₄ – width of pelvis measured in the hips; X₈ – value of the condition’s evaluation. The highest accuracy of the body weight estimation based on the body measurements and condition, irrespective of the age of cows and equation used, was reported for the cows with 25-75% genes of the Holstein-Friesian breed. Small mean differences between real and estimated body weight indicate that the suggested equations can be put into practice when estimating the body weight of cows.

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