Effect of pre-weaning concentrate supplementation on peripheral distribution of leukocytes, functional activity of neutrophils, acute phase protein and behavioural responses of abruptly weaned and housed beef calves

摘要

Background The effect of pre-weaning concentrate supplementation on peripheral distribution of leukocytes, functional activity of neutrophils, acute phase protein response, metabolic and behavioural response, and performance of abruptly weaned and housed beef calves was investigated. Calves were grazed with their dams until the end of the grazing season when they were weaned and housed (day (d) 0) in a concrete slatted floor shed, and offered grass silage ad libitum plus supplementary concentrates. Twenty-six days prior to weaning and housing, 20 singled suckled, pure-bred Simmental male (non-castrated), (n = 10, m) and female (n = 10, f) calves were assigned to one of two treatments (i) concentrate supplement (CS: n = 10 (5 m and 5 f), mean age (s.d.) 201 (12.8) d, mean weight (s.d.) 258 (20.2) kg) or (ii) no concentrate supplement (controls) (NCS: n = 10, (5 m and 5 f), mean age (s.d.) 201 (13.4) d, mean weight (s.d.) 257 (19.6) kg) pre-weaning. Results There was a treatment × sampling time interaction ( P + and WC1+ (γδ T cells) lymphocytes and concentration of plasma globulin. On d 2, percentage CD4+ lymphocytes decreased ( P + lymphocytes increased ( P + lymphocytes in NCS did not differ ( P > 0.05) from d 0. On d 2, WC1+ lymphocytes decreased ( P 0.05) from pre-weaning baseline. On d 2, the increase in concentration of globulin was greater ( P Conclusions Calves supplemented with concentrate prior to weaning had a lesser reduction in WC1+ lymphocytes, increased percentage CD4+ lymphocytes and concentration of total protein, and spent more time lying post-weaning, compared with non-supplemented calves.