effect of amount alfalfa hay and replacing corn grain by other grains in starter on performance of pre and post-weaning holstein calves- a meta-analysis

this study was carried out to assess the effects of alfalfa hay level and replacing corn grain by other grains in starter on daily feed intake, average daily gain (adg) and feed efficiency (fe) of pre and post-weaning dairy calves during the pre and post-weaning periods. for this purpose, a database meta-analysis used in the present study. statistical analyses were performed using proc mixed in sas software. starter intake and adg were not affected by alfalfa hay feeding level during the pre-weaning period. however, alfalfa hay feeding tended to increase starter intake during the post-weaning and entire periods (p = 0.07 and p = 0.09, respectively). further, adg increased during the post-weaning and entire periods with alfalfa hay supplementation. starter intake and adg quadratically affected by the level of alfalfa hay supplementation. at pre-weaning period, feed efficiency tended to decrease (p = 0.06) with alfalfa hay supplementation, but was not different with control group during the post-weaning and entire periods. in addition, partial replacement of corn with other grains increased (p < 0.01) starter intake of dairy calves, but feed efficiency decreased (p < 0.01). based upon the findings of the present research, alfalfa hay supplementation up to 7.5 % of the total diet could improve starter intake and adg in dairy calves at post-weaning period. further, it is possible to replace corn with other grains, up to 50 %, without any negative effect on neonatal dairy calves performance.