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.

Investigation of a Standardized Qualitative Behaviour Assessment and Exploration of Potential Influencing Factors on the Emotional State of Dairy Calves

“…Pairwise housing and group housing of calves are mandatory in organic farms, which lead to decreased fear levels [26,27]. Furthermore, enhancement in social interactions is aiding calves during the feed uptake in the transition period at weaning [28,29].…”

Early weaning: new insights on an ever-persistent problem in the dairy industry

“…Groups can be small (3–8) or large (9–30), and to avoid health issues, calves grouped together should be approximately of the same age, entering the group at the same time (Pedersen et al ., 2009). Due to increasing farm animal welfare concerns in the general public as well as among dairy farmers and other stakeholders involved in the dairy industry (Ventura et al ., 2013), group housing of calves has become more prevalent in recent years (Cobb et al ., 2014b). These housing systems are interesting to the industry as they provide easier management for the farmer (Hötzel et al ., 2014), bring benefit to the social development of calves and increase productivity (Costa et al ., 2016).…”

Space allowance influences individually housed Holstein bull calf innate immune measures and standing behaviors after castration at 3 weeks of age

“…In fact, neutrophil oxidative burst intensity was decreased in all calves after castration compared with baseline, which was decreased further 12 d after castration. The further decrease in neutrophil oxidative burst may have been associated with increasing age of the calf and not related to castration because neutrophil oxidative burst is commonly reported to decrease over the preweaned period in dairy calves (Cobb et al, 2014).…”

“…The CONV calves may have had more microbial exposure from their hutch environment, resulting in their immune systems being "primed" for tissue damage from the castration procedure. Cobb et al (2014) reported that group-housed calves had more active neutrophil responses when compared with individually housed calves, and they suggested that increased social interaction among the calves exposed them to a greater degree of microbial exposure. More research with calf housing needs to determine how the microbial environment is altered and if that has an effect on the leukocyte responses of calves.…”