353 Neonatal Holstein Calves fed a Pelleted Calf Starter Containing a Botanical Extract and Direct-fed Microbial (DFM) Alone or in Combination without or with Milk Replacer DFM

Abstract

Abstract Botanical extracts (BE; Adisseo North America, Altanta, GA) are known to enhance dry matter intake (DMI) and gut health, while direct-fed microbials (DFM), such as a actobacillus acidophilus fermentation product (RC: RumaCell DF 5G; Pacer Technology, Inc., Murtaugh, ID), had shown improved gut health and growth performance of growing Holstein calves. The hypothesis was this combination may be synergistic to neonatal calf growth performance. Eighty 2- to 5-d old Holstein bull calves were blocked by body weight (BW) and randomly assigned to one of 8 treatments arranged in a 2 x 4 factorial using a randomized complete block design. Main factors were 2 milk replacers (MR) without (Control) and with RC added at 5 g/d fed with calf starter (CS) main effect of 4 experimental CS being: 1) Control: no additives; or 2) BE added at 496 mg/kg to the calf starter (CS); 3) RC added to the CS at 2.50 g/kg; and 4) BE&RC: same BE and RC rates to CS. The CS was a 25% crude protein dry matter basis with the MR being a 22:20 (CP:fat) fed 2x/day at 0630 and 1800 h along with free choice water. Weaning occurred after d 42 for the 56-d experiment. No significant (P > 0.10) MR by CS interactions were detected for BW, BW gain, CS intake, total DMI, or feed conversion parameters. The BW gain (38.0 and 39.3 kg for Control and RC, respectively) for MR main effect was similar (P > 0.10) for calves fed both MR, while CS main effect (38.7, 39.7, 39.2, and 37.2 kg for Control, BE, RC, and BE&RC, respectively) were similar (P > 0.10) among all CS. This study demonstrated little calf growth performance and health benefits when feeding an BE and/or RC alone or in combination compared with calves fed Control.