|SHARON, KATE - Texas Tech University|
|LIANG, YU - Texas Tech University|
|Carroll, Jeffery - Jeff Carroll|
|BALLOU, MICHAEL - Texas Tech University|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/22/2015
Publication Date: 7/1/2015
Citation: Sharon, K.P., Liang, Y.L., Sanchez, N.C., Carroll, J.A., Broadway, P.R., Ballou, M.A. 2015. Plane of nutrition during the preweaned period and Mannheimia haemolytica dose influences inflammatory responses to a combined bovine herpesvirus-1 and Mannheimia haemolytica challenge in post-weaned Holstein calves. Journal of Animal Science Supplement. 93 (E-Supplement 3):193, Abstract#27.
Technical Abstract: To determine whether previous plane of milk replacer nutrition (PON) and M. haemolytica (MH) dose influences inflammatory responses to a combined viral-bacterial respiratory challenge, Holstein calves (1 day of age; n=30) were assigned to treatments in a 2 x 3 factorial with preweaned PON and dose of MH as main effects (n=5/treatment). Calves were fed either a low (LPN; n=15) or a high PON (HPN; n=15) from birth through weaning. Calves fed the LPN were fed 445g dry matter/day of milk replacer until weaning, and HPN calves were fed 830g dry matter/d of milk replacer from 1 to 10 days and 1080g from 11 days until weaning. Calf starter and water were offered ad libitum. Calves were step-down weaned beginning at 54 days and moved into an enclosed barn at 70 days. Indwelling rectal temperature (RT) devices and jugular catheters were inserted at 80 days. Calves were challenged with 1.5x10^8 plaque forming units/mL/nostril of bovine herpesvirus-1 (BHV-1) at 81 days and with 10^6, 10^7, or 10^8 colony formng units of MH at 84 days. Blood samples were collected at varying intervals respective to BHV-1 and MH challenges. There was a PON x MH interaction (P<0.01) on RT, where calves receiving 10^8 MH had the greatest increase among HPN calves, but the least among LPN calves. Haptoglobin (Hp) concentrations were greater (P=0.04) in LPN vs HPN calves after BHV-1 challenge. There was a time x MH interaction (P<0.01) for Hp concentrations after the MH challenge, where calves receiving 10^7 MH had the greatest Hp concentrations at 24 hours, and calves receiving 10^8 MH the greatest at 144 hours. During the BHV-1 challenge, neutrophil concentrations (PMN) and change in total leukocytes were greater (P<0.01) among LPN vs HPN calves. After the MH challenge PMN were greatest (P=0.05) in calves receiving 10^8 MH at 5 and 24 hours. During the MH challenge calves receiving 10^8 MH had the greatest (P<0.05) IL-6 and TNF-alpha concentrations. These data demonstrate that LPN calves responded more severely to a combined viral-bacterial respiratory challenge and greater doses of MH increase the acute inflammatory response and prolong inflammation.