An animal model using a combination of reproductive and milk productive traits and somatic cellcount in fleckvieh cattle

A total number of 19755 first lactation records of Austrian Fleckvieh cows collected from the Swiss Simmental and Red and White Cattle Breeding Association, Zollikofen, Switzerland during the period from 1994 to 2000 were used in-the present study. Genetic and phenotypic parameters of milk and reproductive traits were estimated by MTDFREML using an multi-trait animal model (MTAM). The model included individual, and error terms as random effects, month and year of calving as fixed effects and age at first calving and days open as a covariate. Traits studied were 305-day milk yield (MY 305, kg) 305-day fat yield (FY 305, kg), 305-day protein yield (PY 305, kg), lactation Somatic cell Score (LSCS), age at first calving (AFC, month) and days open (DO, days). Unadjusted means for MY 305, FY 305, PY 305, LSCS, AFC and DO were 6257 kg, 248.5 kg, 209.5 kg, 2.631, 26.5 month and 162 days, respectively. Estimates of heritability were 40� 0.02, 0.55:1:0.40, 0.48:1:0.08, 0.0~0.02,0.18:1:0.01 and 0.05:i:O.01 for the above-mentioned traits, respectively. Genetic correlations among MY 305, FY 305, PY30S, AFC and DO were positive and ranged from 0.52:%:0.14 (between MY305 and PY3OS) to 1.00:%:0.02 (between FY 305 and PY 305). The correlations with LSCS were negative and ranged from -0.08:%:0.02 (between DO and LSCS) to -0.25:%:014 (between AFC and LSCS). The phenotypic correlations between milk traits and reproductive traits were positive for all the studied traits and ranged from 0.02:%:0.15 (between AFC and DO) to 0.98:1:0.01 (between MY 305 and PY 305)' The correlations with LSCS were negative and ranged from -0.01:%:0.10 (between FY3O5 and LSCS) to -0.12:1:0.08 (between DO and LSCS). Predicted breeding values of cows (pBV C) ranged from -2807.1 to 2502.8 kg for MY 305, -126.5 to 1.19 kg for FY 305, -102.4 to 81.7 kg for PY 305, -1.4 to 1.2 for, LSCS, -1.06 to 3.57 mo for AFC and -19.35 to 17.93 d for DO. Also, predicted breeding values of sire (pBV S) ranged between -3181.2 and 3496.9 kg, -128.4 and 127.3 kg, -67.5 and 87.3 kg, -.69 to .62, -6.65 and 4.39 mo and -20.54 and 41.19 d for the same traits, respectively. Similarly, predicted breeding values of dams (pBV D) ranged form -992.6 and 1970.9 kg, -49.7 and 81.9 kg, -41.8 and 85.8 kg, -.12 and .07, -0.64 and 0.73 mo and -4.54 and 10.64 for the above mentioned traits, respectively, The present results will help the farmers to select the best dairy cows based on a combination of production, reproduction and somatic cell count in early lactation.