title: Improved performance and heightened neutrophil responses during the neonatal and weaning periods among outdoor group-housed Holstein calves.
abstract: 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.
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409.
authors.forename: C J
authors.initials: CJ
authors.lastname: Cobb
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409; Department of Animal Production, Faculty of Agriculture, Jordan University of Science and Technology, Irbid 22110, Jordan.
authors.forename: B S
authors.initials: BS
authors.lastname: Obeidat
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409.
authors.forename: M D
authors.initials: MD
authors.lastname: Sellers
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409.
authors.forename: A R
authors.initials: AR
authors.lastname: Pepper-Yowell
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409.
authors.forename: D L
authors.initials: DL
authors.lastname: Hanson
authors.affiliation: Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409. Electronic address: michael.ballou@ttu.edu.
authors.forename: M A
authors.initials: MA
authors.lastname: Ballou
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000831:Animals, Newborn; D002417:Cattle / Q000502:physiology*; D005260:Female; D006799:Housing, Animal; D019041:L-Selectin / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology*; D009752:Nutritional Status; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014886:Weaning
chemical_list: D014409:Tumor Necrosis Factor-alpha; D019041:L-Selectin
keywords: calf; housing; immune