Top-dressing of the different feed additives is effective to prevent lameness and to increase feedlot cattle performance during a short-term period

Abstract

In order to compare three feed additives on occurrence of lameness and their effects on performance, 200 Holstein bull calves were used in a completely randomised design. Calves were group fed a similar basal diet for a 42-day experimental period. The treatments used in the study included: (1) basal diet without feed additive (BD), (2) basal diet plus 50 g/d bicarbonate sodium (SB), (3) basal diet plus 7 g/d organic micro-mineral complex including amino acid complex of Cu, Zn, Mn and glucoheptonate Co (MM) and (4) basal diet plus 3 g/d ZnSO4 (ZS). All of feed additives were delivered as a top-dressing. Feed intake, average daily gain (ADG), gain:feed (G:F) ratio and blood metabolites were evaluated in this research. Experimental treatments did not affect dry matter intake (DMI). ADG during total period was affected (P<0.05) by treatments and was more in ZS, SB and MM, respectively. Similar pattern was observed for G:F ratio (P<0.002). The prevalence of lameness was higher in BD group than in the experimental groups, with highest effect in SB treatments (odds ratio=3.24, P=0.05) and with relatively high effect in MM and ZS (odds ratio=2.54, P=0.1). Generally, our results show that feeding feed additives as top-dressing, such as those were used in the current study, can have an efficient role in reducing lameness occurrence and increasing profitability in feedlot farms.