Estimation of genetic parameters for calving ease for Simmental cattle in Croatia

The objective of this study was to estimate the genetic parameters for calving ease of Simmental eau le in Croatia. Data consisted of 135,S92 calves. and pedigree included 639.999 animals. Calving ease was scored from I to 5 (I = unassisted, 2 to 5 =various levels or assistance). Calving ease at first calving. and second or later parities where treated as different traits. Variance components were estimated by REML as implemented in VCE-5 package. Statistical model included age at calving. sex, region-year interaction as fixed effects and owner and direct additive genetic effect as random effects. The estimated heritabilities were 0.1 05±0.005 for calving ease at first calving and 0.07S±0.005 for calving ease at second and later parities. These results suggest that model tested can be used for call le evaluation for calving case of Simmental catle in Croatia

Preliminary study of average milking speed for the first calving cows in Simmental and Holstein breed

Mastitis is a significant disease in cattle production In order to reduce mastitis, special attention in Cattle Breeding program in Croatia has given to average milking speed (AMS). It is necessarily to achieve maximum milking speed as soon as possible and to keep it during longer period. This gives opportunity to select the animals with no extreme values of milking speed, i.e. animals with average milking speed. The objective of this study was to determine the average milking speed for first calving cows of Simmental and Holstein cattle in Croatia, and to define the environmental effects affecting this trait as well. Data consisted of 7155 test-day records of 4341 cows. Similar values of AMS mean was found for Simmental (1.56 kg/min) and Holstein breed (1.57 kg/min). The following fixed effects were tested in the model for AMS: year of calving, month of test-day control and stage of lactation, and did not show statistically significant effect. Correlations between AMS and milk traits were low