Growth Analysis of Brown Swiss and Holstein Heifers under Harsh Climatic Conditions

Authors: ÖMER AKBULUT

Abstract: Monthly live weights and heights at withers of Brown Swiss and Holstein heifers were compared in the period from birth to 18 months of age between 1991 and 1994. This study was carried out under harsh climatic conditions of Erzurum, situated in North-Eastern Anatolia with an altitude of 1950 m. During the experimental period annual mean temperature was 4.3 °C and minimum and maximum average monthly temperatures being -17 °C and 19.5 °C respectively. Total annual rainfall was 389 mm, and average humidity was 68.4 %. Feeding systems were based on medium quality roughage consisted of dry hay (grass, alfalfa and sainfoin) grazing in a medium quality pasture. A commercial feed concentrate of 16 % crude protein was fed with an including calf starter initially according to age and live weight. The number of live weight records used for Brown Swiss and Holstein was 1628 and 725 respectively. Mean live weights at birth, 6,12, and 18 months were 35.5, 111.1, 202.7 and 314.2 kg for Brown Swiss, and 36.2,122.7, 215.3 and 323.9 kg for Holstein whereas height at withers were 66, 86, 102 ve 113 cm for Brown Swiss and 65, 89, 104 ve 114 cm for Holstein respectively. Live weight were regressed on age with third-order regression separately for each breed. Linear effects of age were significant but not quadratic and cubic effects. According to tentative model analysis linear regression functions of Brown Swiss and Holstein were different, although linear regression coefficients were similar for both breeds.

Keywords: Brown Swiss, Holstein, Growth Pattern, Growth Function, Live Weight

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