Bile salt inclusion rates in milk replacer fed to neonatal calves

Objective

The objective was to evaluate bile salts (BS) at increasing inclusion rates to determine the opti- mal inclusion rate for increasing neonatal calf fat digestion and absorption for improved growth performance.

Materials and Methods

Eighty 2-to-5-d-old Holstein bull calves were blocked by BW and randomly assigned to one of 4 treatments using a randomized complete block design. Treatments of (1) BS0: control, no BS added to milk replacer (MR); (2) BS1/2: BS (poultry bile, Runeon, LaChance, China) fed at 0.175 g/d; (3) BS1: BS fed at 0.35 g/d; and (4) BS2: BS fed at 0.70 g/d. Calves were fed 2×/d a 22:20 (CP:fat) milk replacer at 0630 and 1800 h at 0.55 kg/d for d 1 to 14, then increased to 0.82 kg/d for d 15 to 35 reduced to 1×/d for d 36 to 42 with wean- ing after d 42 along with free choice water and a 22% CP mini-pellet calf starter for the 56-d study.

Results and Discussion

Linear, quadratic, and cu- bic exponential polynomial responses to BS inclusion rates were nonsignificant for BW, BW gains, and ADG. Feed conversion demonstrated a negative quadratic response with calves fed BS0 having greater feed conversions (0.52, 0.45, 0.49, and 0.50 kg BW gain/kg DMI; SEM = 0.02) compared with calves fed BS1/2, with calves fed BS1 and BS2 being intermediated and similar.

Implications and Applications

Supplementation of BS to a MR fed to neonatal calves did not enhance growth performance, rejecting the hypothesis.