Comparing the performance of Holstine and Montbeliarde male calves Using a Complete Feed Blocks.

The present study was aimed to evaluate the effect of the Blocked mixed shape ration on performance and carcass characteristics of feedlot Holstein and Montbeliarde calves. For this purpose, in overall, 24 calves (12 for each cattle breed) was proceeding for initial weighting and distributed within 8 semi-opened house units within manure. The experimental design was according to Random Block Complete Design (RCBD) including two Blocks of Holstein and Montbeliarde cattle breed and also a whole feedlot period of the experiment was fixed in 5 months. Initially, the experimental feed ration was mixed and using particular machines and pressed and formed into block shape with approximately 15 (kg) and then served to feed and the available in the ad libitum manner of feeding of experimental calves. Finally, daily feed intake, average daily gain for each month and feed conversion ratio and efficiency was calculated for each group of treatments. To avoid any covariant negative effect on final outputs, initial weight of Holstein and Montbeliarde calves were calculated and showed 337.71 and 332.48 respectively. While, in the final period of experiment those mean weights reached at 458.09 and 475.20 which indicated a higher rate of growth for Montbeliarde at a same feeding time.Total daily gain of calves for treatment 1 and 2 was 120.38 and 142.72 (kg) respectively which show high rate of increasing belong to treatment 2 (p0.01). The mean of feed consumption in the whole period of experiment about treatment 1 and 2 was 9.77 and 9.56 and didn t meet any significant level of differentiation is statistical viewpoint.The feedconversion ratio for treatment 1 was variable between 9.37 to 10.27 with an overall mean of 9.95 in Holstein calves and this value also indicated range of 7.17 to 9.32 and total mean of 8.18 in Montbeliarde which can conclude significant different (p0.05). The mean of live body weight in slaughtering time for Holstein and Montbeliarde after 5 months feedlot period was significantly(p0.01) different (512 versus 542.75).The overall mean of hot and cold carcass in Holstein and Montbeliarde after 5 months feedlot period was significantly(p0.01) different (54.89 vs. 51.70 and 56.24 versus 54.84). The average rate of lean in Holstein and Montbeliarde after 5 months feedlot period was significantly (p0.01) different (75.70 versus 76.96).The mean of bone percentage of Holstein and Montbeliarde after 5 months feedlot period was significantly (p0.01) different (20.56 versus 17.66). Keywords: Feedlot period, Montbeliarde breed, Holstein calves, Performance, Carcass quality