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Inclusion of anti-phospholipase A2 antibody to backgrounding diets on performance , feed efficiency , in vitro fermentation , and the acute-phase response of growing beef calves . In Exp . 1 , individual performance and daily DMI was measured on 70 crossbred weaned calves during a 70-d period using a GrowSafe system ( GrowSafe Systems Ltd. , Airdrie , AB , Canada ) at the University of Florida North Florida Research and Education Center Feed Efficiency Facility ( FEF ) . Calves were fed a low-concentrate ( LC ) growing diet , blocked by weight and sex , and then randomly assigned to pens to receive either no additional supplement ( CON ; n = 35 ) or receive a supplement of anti-phospholipase A2 antibody ( aPLA2 ) at an inclusion rate of 0.6 % of the diet DM ( n = 35 ) . After the 70-d feed efficiency ( FE ) trial ( Phase 1 ) , calves were loaded into a commercial livestock trailer and were driven for approximately 1,600 km during 24 h. Upon return to the FEF ( Phase 2 ) , calves were relocated to the same pens and groups and received the same diets and treatments for 28 d. Blood samples from each calf were collected on d 0 , 1 , 3 , 5 , 7 , 14 , 21 , and 28 relative to initiation of transportation and were analyzed for determination of concentrations of plasma ceruloplasmin and haptoglobin . In Phase 1 , initial BW ( 242.0 ± 3.7 kg ; P = 0.92 ) , BW at d 70 ( 313.0 ± 4.1 kg ; P = 0.79 ) , and ADG ( 1.01 ± 0.02 kg ; P = 0.95 ) were similar between treatments . However , daily DMI was greater ( P = 0.01 ) for CON ( 9.18 ± 0.15 kg ) than aPLA2 ( 8.53 ± 0.15 kg ) . In addition , residual feed intake was greater ( P = 0.002 ) for CON ( 0.389 ± 0.110 kg/d ) than aPLA2 calves ( -0.272 ± 0.110 kg/d ) . In Phase 2 , after transportation , there were no differences between treatments on BW loss due to transportation shrink ( 26.0 ± 0.6 kg ; P = 0.86 ) , BW at d 28 ( 339.0 ± 4.1 kg ; P = 0.72 ) , ADG ( 1.28 ± 0.03 kg/d ; P = 0.72 ) , G : F ( 0.164 ± 0.004 ; P = 0.83 ) , and concentrations of plasma haptoglobin ( 0.08 ± 0.02 mg/mL ; P = 0.41 ) . However , concentrations of plasma ceruloplasmin were greater ( P < 0.001 ) for CON calves ( 14.3 ± 0.3 mg/dL ) compared to aPLA2 calves ( 13.0 ± 0.3 mg/dL ) . In Exp . 2 , the effects of aPLA2 inclusion on LC and high-concentrate ( HC ) substrates on in vitro fermentation parameters were assessed . Addition of aPLA2 had no effects on in vitro fermentation parameters of LC and HC substrates . In conclusion , supplementation of aPLA2 improved FE of growing beef calves when fed LC diets in Phase 1 and addition of aPLA2 had no effect on fermentation parameters of LC and HC substrates . In addition , calves supplemented with aPLA2 had reduced concentrations of plasma ceruloplasmin after 24 h of transportation .
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Intervention_Pharmacological
anti-phospholipase A2 antibody
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Intervention_Pharmacological
low-concentrate ( LC ) growing diet
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Intervention_Control
either no additional supplement
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Intervention_Pharmacological
receive a supplement of anti-phospholipase A2 antibody ( aPLA2
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Outcome_Other
performance , feed efficiency , in vitro fermentation , and the acute-phase response of growing beef calves .
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Outcome_Physical
concentrations of plasma ceruloplasmin and haptoglobin .
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Outcome_Physical
BW
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Participant_Condition
anti-phospholipase A2 antibody
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Participant_Age
growing
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Participant_Age
calves
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Participant_Sample-size
70