Effects of replacing steam-flaked corn with shredded sugar beet pulp on feed sorting, behavior, blood metabolites, and growth performance of dairy calves

This experiment was conducted to investigate the effects of partial replacement of steam-flaked corn (SFC) with shredded sugar beet pulp (SBP) in the starter diet on selective intake (sorting), feeding and chewing behavior, blood biochemical parameters, and growth in newborn female Holstein dairy calves. A total of 48 calves (3 d old; 40.1 ± 0.84 kg body weight; mean ± SE) were randomly assigned to 1 of 2 feeding treatments containing 0 or 25% SBP (percentage of dry matter [DM]) in the starter diet. Calves were weaned on d 61 and remained in the study until d 81. Intake of starter feed and total intake of DM (milk DM + starter feed DM), crude protein, and neutral detergent fiber were increased (P < 0.05) by feeding SBP; however, intake of starch (P < 0.01) and total intake of ether extract (P = 0.03) were decreased with no apparent effect on total intake of ME. Average daily gain, feed efficiency, final weight, and skeletal growth also showed no significant changes. Circulating concentrations of glucose, total protein, and albumin were not affected by partial replacement of SBP with SFC; however, higher concentrations of blood urea-N (P = 0.01) and a lower albumin-to-globulin ratio (P = 0.03) were observed in SBP- vs. SFC-fed calves. Calves fed SBP sorted more for particles retained on the 4.75-mm sieve (P = 0.02) and against particles retained on the 0.6-mm sieve and bottom pan (P < 0.01). Intake of neutral detergent fibers and starch from particles retained on all sieve fractions was increased and decreased (P < 0.01), respectively, by replacing SFC with SBP. Replacement of SBP with SFC was associated with increased meal length and meal size and increased rumination frequency and length, but decreased intervals between rumination (P ≤ 0.01). Calves fed SBP spent more time eating, rumination, and standing and less time lying and non-nutritive oral behaviors (P < 0.01). In general, 25% replacement of SFC with SBP did not affect calf performance but increased time spent rumination and eating and decreased non-nutritive oral behaviors.