Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57, 19-26
Published online 2014-10-10

Evaluation of milkfat and milkprotein production in inbred and outbred Holstein cows

Jiří Bezdíček1, Jan Šubrt2, Radek Filipčík2, Jan Říha3

1Agrovýzkum Rapotín, s. r. o., Výzkumníků 267, 788 13 Vikýřovice, Česká republika
2Ústav chovu a šlechtění zvířat, Mendelova zemědělská a lesnická univerzita v Brně, Zemědělská 1665/1, 613 00 Brno, Česká republika
3Agrovýzkum Rapotín, s. r. o., Výzkumníků 267, 788 13 Vikýřovice

The aim of this study was to explore the depression effects of level of inbreeding on kg of fat and protein presented in the form of breeding values. The data included cows calved in the years 1990–2006 at farms in the Czech Republic. Inbred cows were grouped according to Fx coefficients (Fx = 1.25%, Fx = 2.0–3.125%, Fx = 4.0–12.5% and Fx = total). The breeding values for inbred cows were compared with their outbred equals (2689 equals in sum) – half–sisters, sharing the same sire, dam reaching the same breeding value (± 5%) and their first calving occurring at the same farm, at the same time (±2 month). The PROC GLM of SAS® with fixed effects (age at first calving, year of calving, number of lactations, first calving interval and relative breeding value of sire and dam were applied to all data).
In the groups with Fx coefficients (Fx= 1.25 %, Fx = 2.0–3.125 %, Fx = 4.0–12.5 % and Fx = total) we found a decrease in the breeding values of kg fat in inbred cows of −1.48; 0.17; −8.26 and −0.51 kg. In the case of protein content the depressed production in inbred cows was: −0.58; −0.48; −3.21 and −0.94 kg. These differences were significant (p ≤ 0.01) in the group with the highest Fx value (Fx = 4.0–12.5%). The inbred animals showed higher variability within the range of observed corrected breeding values (Yijklmno) for kg of fat and protein.
The results also show that increasing the level of parents (as RBV) caused a very significant increase in production both in inbred and outbred daughters but greater increase in fat and protein was evident in the non–inbred cows.


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