Comparing growth performance, carcass characteristics and economic profits between Holstein-Belgian Blue cross and pure Holstein calves

The aim of this study was to compare growth performance, carcass characteristics , and economic profits between Holstein -Belgian Blue cross and pure Holstein calves .

This study was carried out in the Mahdasht Milk and Meat farm , Dasht -e Naz Agriculture Company (Sari - Mazandaran ) , affiliated to Mostazafan Foundation of the Islamic Revolution , Iran . Beef crosses were produced by crossing Holstein (H) cows with Belgian Blue (BB ) bull’s semen . The performance of 25 calves of each breed ( 50 calves in total ) was compared in a fattening period of 7 months . Feed intake was measured daily for each group using a residual feed intake ( RFI ) system. Total Mixed Ration ( TMR ) diet was delivered to the animals at 8 o'clock in the morning and at 4 o'clock in the afternoon . Animals weighted monthly in order to obtain average daily gain. Statistical analyses were performed using SAS programs ( GLM and MIXED procedures ) .

The results indicated that average daily gain was significantly higher in Holstein - Belgian Blue cross calves than in pure Holstein calves (1.43 vs 1.33 kg ) . The pure Holstein calves had significantly lower dry matter intake than Belgian Blue crossbred . However, feed conversion ratio in the BB×H calves was remarkably more favorable than Holstein group (6.74 vs 7.04) . Dressing percentage for BB×H crossbred was higher than for pure Holstein . Effect of genetic groups on fat thickness through the front hindquarter, thickness of the fat covering over the back and thickness of the fat through the front hindquarter was not significant. Hovewer, thickness of the fat covering over the loin was significantly different among genetic groups (p < 0.05) . The comparisons of the least square means across genetic groups showed that smaller internal organs (e.g. liver) in Belgian Blue crossbred and largest in pure Holstein . Also, fat depots weight (subcutaneous and visceral) was significantly highest in pure Holstein and lowest in Belgian Blue crossbred (p < 0.05) .

Economic calculations demonstrated that the respective highest profit for the whole fattening period belonged to crossbred of BB×H (38543843 Rials ) , and pure Holsteins (24826300 Rials ) . Therefore, the hypothesis that the calves from Holstein - beef crosses have higher economic productivity than pure Holstein calves is confirmed .