Plane of nutrition influences the performance, innate leukocyte responses, and resistance to an oral Salmonella enterica serotype Typhimurium challenge in Jersey calves.

Two experiments investigated how plane of nutrition influences performance, leukocyte responses, and resistance to an oral Salmonella enterica serotype Typhimurium challenge. In experiment 1, 46 (2±1 d of age) calves were randomly assigned to 2 diets: a low (LPN; n=23) and high plane of nutrition (HPN; n=23). The LPN calves were fed 409 g/d of dry matter (DM) of a 20% crude protein and 20% fat milk replacer, whereas HPN calves were fed 610 and 735 g/d of DM of a 28% crude protein and 25% fat milk replacer during wk 1 and 2 to 6, respectively. In experiment 2, 20 bull calves (LPN; n=11 and HPN; n=9) were orally challenged on d 80 with 1.5×10(7) cfu of Salmonella Typhimurium (ATCC #14028). The HPN calves had a greater incidence (87.5 vs. 45.5%) and duration of days with high fecal scores (5.5 vs. 3.5 d). The LPN calves had greater neutrophil surface expression of L-selectin on d 7, 21, and 42. Following the Salmonella Typhimurium challenge, calf starter DM intake was greater among the HPN calves. The percentage of neutrophils producing an oxidative burst was also greater among HPN calves on d 1 to 5 after the challenge. Similarly, the intensity of the oxidative burst tended to be greater among the HPN calves on d 2 and 3 postchallenge. The secretion of tumor necrosis factor-α from whole-blood cultures stimulated with lipopolysaccharide tended to be greater on d 1 and was greater on d 5 and 6 among HPN calves. The median ranks of haptoglobin concentrations were greater and plasma zinc concentrations tended to be decreased among LPN calves. These data indicate that feeding a HPN to Jersey calves improved average daily gain and feed efficiency, but increased the incidence of high fecal scores during the first few weeks of life; however, the HPN Jersey calves may be more resistant to Salmonella Typhimurium after weaning.

Group housing of Holstein calves in a poor indoor environment increases respiratory disease but does not influence performance or leukocyte responses.

The objective of the current study was to determine if group-housing Holstein heifer calves in indoor pens with poor ventilation and drainage influences performance, health, leukocytes, and behavioral responses compared with individually housed calves. Ninety colostrum-fed calves (2 ± 1 d of age) were randomly assigned to 3 treatments: individually housed (G1; n=30 calves), 2 calves per pen (G2; n=30 calves), or 3 calves per pen (G3; n=30 calves). The space allowance per calf was 2.5m(2) for all treatment groups. All calves were fed 747 and 1,010 g/d of dry matter of a 28% CP and 20% fat milk replacer during the first 2 wk and wk 3 to 6, respectively. Weaning was initiated on d 46 by removing the evening feeding, and calves were completely weaned when they consumed 800 g/d of dry matter calf starter for 2 consecutive days after d 54. Calves were randomly commingled at d 90 in groups of 5 calves per pen in outdoors pens with an attached hutch. Peripheral blood was collected during the neonatal (3, 10, 21 d), weaning (46, 48, 54 d), and commingling periods (90, 93, 98 d) and was analyzed for neutrophil oxidative burst capacity when cocultured with an Escherichia coli, neutrophil surface L-selectin protein concentration, and whole blood secretion of tumor necrosis factor-α when cocultured with lipopolysaccharide. Behavior of each calf was assessed using 2 independent tests: an approach response to a human subject and the response of the calf when placed in an isolated cage. Calf starter intake was greater for G2 and G3 during wk 8 and 9, and also at wk 11 for G3 compared with G1. No treatment × time interaction or treatment effect for average daily gain was observed. Additionally, no treatment × time or treatment effect was noted for any leukocyte or biochemical variable of biological significance throughout the entire study. Individually housed calves tended to have a reduced incidence of respiratory disease during the first 90 d of life. No other treatment differences for the other health outcomes were observed. Group-housed calves also relied more on calf-to-calf interactions than calf-to-human interactions, as evident by their reduced approach of the human observer and more frequent movement when placed in an isolated pen. Group housing in an environment with poor ventilation and drainage may increase the risk of respiratory disease.

Interactive effects of bulk density of steam-flaked corn and concentration of Sweet Bran on feedlot cattle performance, carcass characteristics, and apparent total tract nutrient digestibility.

Two hundred twenty-four steers (initial BW = 363 ± 1.57 kg) were used in a 2 × 3 + 1 factorial arrangement of treatments to evaluate the interactive effects of concentration of wet corn gluten feed (WCGF) and bulk density (BD) of steam-flaked corn (SFC) on feedlot performance, carcass characteristics, and apparent total tract digestibility. Diets consisted of 0, 15, or 30% WCGF (DM basis) with a BD of SFC at 283 or 360 g/L. The additional treatment consisted of 15% WCGF, SFC at 283 g/L, and a 6% inclusion of alfalfa hay vs. 9% for all other treatments. Steers were fed once daily for an average of 163 d. During a 5-d digestion period, DMI was measured, and fecal samples were collected for measurement of nutrient digestibility using dietary acid insoluble ash as a marker. There were few WCGF × BD interactions for feedlot performance, carcass characteristics, and digestibility. Similarly, contrasts between the treatment containing 15% WCGF/360 g/L SFC and 15% WCGF/360 g/L with 6% hay yielded few differences for performance and carcass data. Final BW responded quadratically (P ≤ 0.02) to WCGF inclusion and showed increased (P ≤ 0.007) BW for greater BD. As WCGF inclusion increased, G:F and calculated NE values (P ≤ 0.03) decreased quadratically. Steers consuming 360 g/L SFC had greater (P < 0.05) G:F than those fed 283 g/L SFC. Marbling score, HCW, 12th-rib fat thickness, and calculated yield grade increased quadratically (P ≤ 0.04) with increased inclusion of WCGF. Percentage of cattle grading premium Choice or greater responded quadratically (P = 0.04) to WCGF concentration. Increasing BD increased (P ≤ 0.01) HCW, dressing percent, marbling score, and 12th-rib fat thickness and decreased calculated yield grade and percentage of cattle grading Select; however, lower BD tended (P = 0.09) to increase LM area. Intake of DM, OM, CP, and NDF and fecal output during the digestibility period increased linearly (P ≤ 0.01) with increasing WCGF, and greater BD increased (P ≤ 0.04) intake of DM, OM, starch, and CP. Starch digestibility decreased quadratically (P = 0.008) as WCGF increased; however, digestibility of CP and NDF increased (P ≤ 0.02) linearly as WCGF increased. The 283 g/L BD increased (P ≤ 0.02) starch and CP digestibility compared with 360 g/L. These data suggest that increasing WCGF in feedlot diets with a greater BD of SFC can increase performance and carcass characteristic, but it might not be ideal for starch digestibility.

Improved performance and heightened neutrophil responses during the neonatal and weaning periods among outdoor group-housed Holstein calves.

The objective was to determine if outdoor group housing of Holstein calves influences metabolic status, leukocyte responses, and behavior compared with individually housed calves. Forty-nine Holstein heifer calves (2 ± 1 d of age) were randomly assigned to 1 of 2 treatments: individually housed (G1; n = 22) or group housed [3 calves per pen (G3); n = 27]. The space allowances per calf were 4.8 and 7.0m(2) for G1 and G3, respectively. All calves were offered an identical plane of milk replacer nutrition (747 and 1,010 g of DM/d of a 28% CP:20% fat milk replacer from wk 1 to 2 and wk 3 to 6, respectively). Weaning was initiated during wk 7 by removing the p.m. feeding and calves were completely weaned when they consumed 900 g of calf starter/d (as fed) for 2 consecutive days after d 54. At d 90, calves were commingled into random outdoor groups of 5 calves per pen. Peripheral blood was collected during the neonatal (d 3, 10, and 21), weaning (d 46, 48, and 54), and commingling periods (d 90, 93, and 98) and was analyzed for neutrophil oxidative burst (OB) capacity when cocultured with Escherichia coli, neutrophil surface L-selectin protein expression, and whole-blood secretion of tumor necrosis factor-α when cocultured with lipopolysaccharide. Starter intake was greater for G3 during the postweaning period (wk 8 to 12). Average daily gain was greater for G3 than G1 from d 54 to 68 and tended to be greater after commingling from d 113 to 133. During the neonatal period, G3 calves had more activated neutrophils, as evidenced by increased neutrophil L-selectin protein expression and a tendency for increased percentage of neutrophils producing an OB than G1 calves. During weaning, G3 calves continued to have more activated neutrophils with increased L-selectin expression on d 46 and 48 and a greater OB intensity throughout the period. No differences were observed among leukocyte responses between treatments at d 93 and 98. Outdoor group-housed Holstein calves had improved performance and heightened neutrophil responses compared with individually housed calves.

Plane of nutrition during the preweaning period but not the grower phase influences the neutrophil activity of Holstein calves.

Two experiments were conducted to determine the influence of plane of nutrition during (1) the pre- and immediate postweaning periods and (2) the grower phase on the performance and leukocyte responses of Holstein calves. In experiment 1, 39 (2 ± 1 d old) colostrum-fed heifer calves were randomly assigned to 2 planes of nutrition, a low (LPN; n = 19) and a high plane of nutrition (HPN; n = 20). Calves in the LPN treatment were offered 418 g/d of dry matter (DM) of a 20% crude protein (CP)/20% fat milk replacer, whereas calves in the HPN treatment were offered 747 and 1,010 g/d of DM of a 28% CP/20% fat milk replacer during wk 1 and wk 2 to 6, respectively. Calves were offered ad libitum access to a calf starter until the end of the study. Peripheral blood samples were collected on d 3, 10, 21, 45, 47, 53, and 91 for many ex vivo leukocyte responses and biochemical analyses. A nutrition × time interaction was present for average daily gain and feed efficiency (feed:gain ratio). A nutrition × time interaction existed for plasma glucose concentration. Neutrophil L-selectin expression was greater in calves fed the LPN than HPN on d 3 and 21. The percentage of neutrophils producing an oxidative burst (OB) when cocultured with Escherichia coli tended to be greater and was greater in calves fed the LPN than HPN on d 10 and 21, respectively. In addition, neutrophils from calves fed the LPN had greater OB intensity throughout the neonatal period (0 to 21 d). However, plasma haptoglobin was not different between the 2 planes of nutrition throughout the study. In experiment 2, 50 heifer calves that were all previously fed a HPN similar to that described for experiment 1 were randomly assigned to 2 planes of nutrition (HPN and LPN) during the grower phase (5 pens/treatment; 5 calves/pen). Calves fed the HPN during the grower phase were fed 4.1 kg of concentrate DM (pellets; 22.4% CP, DM basis) per head per day, whereas calves on the LPN during the grower phase were fed 1.6 kg of DM of the same concentrate per head per day. All calves were fed alfalfa hay (16.2% CP; DM basis) ad libitum. Overall, average daily gain was greater in HPN calves than LPN calves. No differences were noticed for concentrations of plasma urea nitrogen, glucose, neutrophil L-selectin expression, percentage of neutrophils producing OB, and plasma haptoglobin concentration between the 2 planes of nutrition. In summary, intake and performance were improved in calves fed the HPN than calves fed the LPN in both experiments. The neutrophil responses of calves fed an LPN were more active during the preweaning period than calves fed an HPN; however, this response was not observed during the immediate postweaning period or the grower phase.