I. Varlyakov, V. Radev, Т. Slavov, N. Grigorova

Abstract. Milking behaviour of 102 dairy, cows (Brown cattle breed – imported from Austria) was studied by computer monitoring system in 3 periods: Period 1(P1) – 60 days after the group formation, Period 2 (P2) – 120 days after P1 and Period 3 (P3) – 120 days after P2. An entrance order in the milking parlour was established, that is preserved over the lactation. Kendall coefficients ranged between 0.373–0.421 (P<0.001), increasing with time after forming the group. The entrance order for milking was mostly influenced by the stage of lactation (r=+0.330, P<0.001) and at the least extent – by the daily milk production (r=0.398, P<0.001). A preference towards the milking side was observed in more than half of cows (50.2%). Their share increase as followed: 40.5% P1, 42.1% P2, and 68.1% – P3. In a herd of 100 cows, three groups are formed with respect to the entrance order for milking: 16% that tended to enter first, 18-25% that are always the last, and the largest, ‘tolerant” group of 50-66%. Highly productive cows are never the majority among those that are first or last to enter for milking.