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Seventy two Holstein heifers (initial BW 138.0 ± 2.4 kg) were randomly assigned to a 3 × 3 complete block design to study the effect of the number of feeding places per pen on performance, blood metabolites and haptoglobin. Heifers were blocked by BW and treatments consisted of 1 (T1), 2 (T2) or 4 (T4) feeding places/pen (8 heifers/pen). Pelleted concentrate (3 Mcal/kg ME, 16.4% CP, 20.3% NDF, DM basis) and barley straw, both fed daily at 0800, and water were offered ad libitum and in different containers. After five weeks of adaptation, DMI and ADG were recorded at 28-d intervals during 6 periods. Blood samples were taken at 1600 of d 23, 24 and 25 of each period, for high, medium and low block of BW, respectively. Data were analyzed with a mixed model considering the fixed main effects, and their possible interactions, of treatment, block and week, which was the repeated measure subjected to pen nested within the block by treatment interaction. Total DMI (6.76 ± 1.15 kg/d), ADG (1.24 ± 0.10 kg/d), gain to feed ratio (0.188 ± 0.031 kg/kg) and final BW (389.47 ± 3.85 kg) were not affected by treatments. Blood haptoglobin was affected by treatments (P = 0.02; 0.178, 0.170 and 0.157 ± 0.005 mg/mL for T1, T2 and T4, respectively). Plasma non-esterified fatty acid concentrations (0.097 ± 0.002 mM) were not affected by treatments, whereas β-hydroxybutyrate (P = 0.05; mM) was greater for T1 (0.281) than T4 (0.251) but similar to T2 (0.276 ± 0.009). Low feeding places per pen did not affect performance, but blood haptoglobin and β-hydroxybutyrate levels were increased. [ABSTRACT FROM AUTHOR]

Seventy two Holstein female calves (104.7 ± 1.25 d of age; initial BW 110.36 ± 2.54 kg) were randomly assigned to a 3 × 3 complete block design to study the effect of the number of feeding places per pen on performance and blood profile during the first month after arrival at the feedlot. Calves were blocked by BW and treatments consisted of 1 (T1), 2 (T2) or 4 (T4) feeding places/pen (8 calves/pen). Concentrate (3 Mcal/kg ME, 16.4% CP, 20.3% NDF, DM basis) and barley straw, both fed once a day, and water were offered ad libitum and in different containers. The DMI and ADG were recorded, and blood samples were taken weekly during the first 4 weeks after arrival at the feedlot. Data were analyzed with a mixed model considering the fixed main effects, and their possible interactions, of treatment, block and week, which was the repeated measure subjected to pen nested within block by treatment interaction. Treatments affected total DMI (P < 0.01) and ADG (P = 0.03). The T1 calves ate less DM and gained less (P < 0.05) than T2 and T4 (3.72, 4.05 and 4.00 ± 0.07 kg DMI/d; 0.86, 1.05 and 1.05 ± 0.05 kg ADG/d, respectively). However, the gain to feed ratio was similar among treatments (0.25 ± 0.07 kg/kg). Blood haptoglobin (0.30 ± 0.08 mg/mL) and β-hydroxybutyrate (0.180 ± 0.004 mM) were not affected by the number of feeding places per pen. Non-esterified fatty acids (mM) were affected (P = 0.006), being lowest for T4 (0.176) compared to T2 (0.226) and T1 (0.233, SEM ± 0.01). Total blood leucocytes (10.00 ± 0.17 × 103 cells/mL) and the neutrophile to lymphocyte ratio (0.58 ± 0.02) were not affected by treatments. The lowest number of feeding places (T1) resulted in a lower performance compared with T2 and T4. However, immune status and haptoglobin levels were not affected by increases in the number of feeding places. [ABSTRACT FROM AUTHOR]