Evaluation Relation between Traits of Milk Production and Calving Interval in Breeding Herds of Slovak Simmental Dairy Cows

Slovak Simmental cattle are a dual-purpose breed with a good milk and meat production, which belongs to the Simmental type of cattle. The aim this work was evaluated relation between traits of milk production and calving interval in breeding herds of Slovak Simmental dairy cows (S0). Data were analysed using the Statistical Analysis System (SAS) version 9.3 (TS1M2) Enterprise Guide 5.1. and linear model with fixed effects of herd-year-season of calving (HYS), sire, number of lactation, and code of milk production by average of milk production. The average of milk production 5 866.4 ± 2 066.6 kg, average of fat production 233.5 ± 83.6 kg, average of protein production 200.4 ± 72.5 kg and average of lactose production 280.8 ± 98.2 kg, average of calving interval (CI) was 408.6 ± 83.9 days. The linear model to represent coefficient determination R2 = 0.2481 % (P 0.001) for calving interval with all fixed effects. The analyses by the effect was the highest effect of HYS of calving R^2 = 0.1962 %, than effect of sire R^2 = 0.0417 %. These effects were statistically high significant (P 0.001). Correlation between milk, fat, protein, lactose in kg with calving interval (r=0.0130-, r=0.0214^+++, r=-0.0028^+++, r=0.0115^++) were statistically high significant. The results confirm the lower positive relation between traits of milk production (milk in kg, fat in kg, protein in kg and lactose in kg) and calving interval in breeding herds of Slovak Simmental dairy cows.