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Abstract
This study was aimed to look at the effectiveness of a carried out beef crossbreeding program under recurrent selection in Germany. For this, single trait animal model restricted maximum likelihood (REML) and best linear unbiased prediction (BLUP)' methodologies were used respectively for variance component and breeding value estimation. Estimated breeding values were regressed on year of birth to obtain estimates of genetic trend for each trait. Estimated annual genetic trends were: in beef cows, -0.38, 0.24, 0.50, 0.32, -0.35, 1.10 and 0.82 kg respectively for body weights at 6,12,15,18 months, first, second and third calving; in beef bulls, ranged from -0.003 to 0.12 cm for nine body measurement traits; 3.69 g and -4.94 NE (net energy) respectively for test period average daily gain and energy efficiency, for birth difficulty -0.002; in fattening hybrids, for body weight at the end of test period (WT-T) 1.18, 0.59,1.52 and 0.96 kg respectively in overall, industrial farms, breeding farms and testing stations; in beef x dairy animals, -0.0002 for birth difficulty and 0.025 kg for birth weight. All estimated trends except back width of beef bulls were significant, generally in the expected direction, low and were of 0.02 to 0.18, 0.07 to 0.33, 0.01 to 0.11 % of the 'population mean per year respectively for reproduction, production and body measurement traits. These results show that recurrent selection can also be successful for cattle breeding under sspecialised situations.