عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In order to survey the inclusion effects of different levels of barley and/or corn grain in diet on growth and performance of Holstein calves 40 newborn calves were taken in 5 experimental groups with 4 female and 4 male calves in each group for a duration of105 days. The experimental group was comprised of: group 1; no barley (only consisting of corn grain) and other experimental groups 2, 3, 4 and 5 which contained 5, 10, 15 and 20 percent respectively of barley grain in total diet. The values of dry matter intake (DMI), body weight changes and feed efficiency ratio were evaluated periodically. The obtained data were statistically analyzed using repeated measurements of mixed procedures. The least square means of final weight, gain, total DMI and feed conversion ratio of calves, fed diets with no barley grain, were respectively, 138.5, 97.3 and 125.3 kg and 1.29. Increasing barley grain ratio in the diet resulted in reduction of DMI (P<0.05). Body weights in calves which consumed diets containing barley were lower as compared with the control (P<0.05), but there were no differences observed between the groups consuming diets containing barley. Increasing the barley content in the diets had no effect on feed efficiency ratio. DMI was improved with increasing calves age (P<0.05), but was not affected by the sex. Body weight, weight gain during the period as well as feed conversion ratio in male calves was more pronounced than those in females. All in all, replacement of barley up to 20 percent in Holstein calves, diets is possible with no arisal of any negative effect on their feed efficiency ratios.