Epidemiology and Management of
BRD in Dairy Heifer Replacements
Alex Bach,1,2
1IRTA-Department of Ruminant Production
2ICR...
Examine the operation holistically
Identify bottle necks and remove them
Introduction
Reducing AFC (w/o compromising BW at...
For every 100 g ADG during the first 2
months of life, one could expect additional
300 l of milk in the first lactation.
B...
ZONE 1 ZONE 2
BRD Incidence
n=2,771 0 1 2 3 > 4 P-value
Final BW, kg 624 618 624 625 598 0.21
Final age, d 661 665 671 666...
Immune status of the animal (colostrum)
Vaccination program
Medication
Management
BRD Incidence
Immune Status
n=204 Low Hi...
The risk of having respiratory problems was only 8% lower
in the animals with a high serum protein level compared to
calve...
General recommendations for calf rearing advocate for
keeping the animals individually housed and feeding milk
replacer (o...
Experiment 1. To evaluate whether allowing calves to remain
for an additional 6 d individually-housed after weaning was
be...
Materials and Methods (Exp. 2)
Two hundred and forty female Holstein calves were assigned
to two different treatments in t...
Results (Exp. 2)
Grouped at 49 d
Grouped at 56 d
15 18 21 24 27
25.8
25.2
Proportion of calves affected, %
0 0.325 0.65 0....
0
13.75
27.50
41.25
55.00
Cases/hutch Calves affected, % Time to 1st case, d
11
52
9
11
38
5
23
24
4
0-8 2-6 3-5
Ratio
No ...
120.00
125.50
131.00
136.50
142.00
Final BW, kg
136
141
0-8 8-8
Ratio
No previous case-Previous case
1.12
1.15
1.17
1.20
1...
0
0.3
0.6
0.9
1.2
BRD Incidence Cases/calf
0.74
0.452
1.16
0.449
Control Zactran
BRD
P = 0.18
There were no differences (P...
Combining the results from Experiments 1 and 2 the overall
response to Zactran could be assessed with a bit more
precision...
Thank you
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6.epidemiology and management of brd in dairy heifer replacements

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6.epidemiology and management of brd in dairy heifer replacements

  1. 1. Epidemiology and Management of BRD in Dairy Heifer Replacements Alex Bach,1,2 1IRTA-Department of Ruminant Production 2ICREA, Institut de Recerca i Estudis Avancats Veterinarians represent a major piece in the sustainability chain: Provide management advice Care for the environment Ensure economical performance of the herd Foster data collection and use records to make management decisions THE SUSTAINABLE VET Introduction 0 15 30 45 60 Feed Labor Replacement Fixed costs Maintenance Misc. Energy 3.9 4.95.0 7.6 8.7 16.8 53.1 % Introduction
  2. 2. Examine the operation holistically Identify bottle necks and remove them Introduction Reducing AFC (w/o compromising BW at calving) implies: 1) the number of animals needed 2) the number of days on feed 100 x .30 x ((1-.03)x(1-.01)) x 2x(24/24) = 58 -> 46,000 € 100 x .30 x ((1-.03)x(1-.01)) x 2x(28/24) = 67 -> 53,000 € 100 x .30 x ((1-.03)x(1-.01)) x 2x(22/24) = 52 -> 41,000 € Number of cows x replacement rate x ((1-mortality) x (1-heifer culling rate)) x 2x(Age first calving/24) Introduction For every kg of BW at calving, one could expect 14.5 l more milk in the first lactation (70 Kg of BW mean 1,000 l of milk). Bach et al., 2008 Introduction
  3. 3. For every 100 g ADG during the first 2 months of life, one could expect additional 300 l of milk in the first lactation. Bach et al., 2008 Introduction Item 1 2 3 4 5 6 7 8 9 10 11 Age range, d 1-65 66-110 111-158 159-229 230-307 308-336 337-415 416-483 484-546 547-639 640-660 Target BW, kg 80 125 175 250 325 530 390 454 510 590 610 Introduction Item 1 2 3 4 5 6 7 8 9 10 11 Age range, d 1-65 66-110 111-158 159-229 230-307 308-336 337-415 416-483 484-546 547-639 640-660 Target BW, kg 80 125 175 250 325 530 390 454 510 590 610 Introduction
  4. 4. ZONE 1 ZONE 2 BRD Incidence n=2,771 0 1 2 3 > 4 P-value Final BW, kg 624 618 624 625 598 0.21 Final age, d 661 665 671 666 670 0.03 BRD 700 750 800 850 900 0 1 2 3 ≥4 Accumulated DIM Number BRD Bach, 2010 BRD Incidence Heifers with 4 or more BRD cases had 1.87 greater odds of not finishing first lactation than heifers with no BRD history.
  5. 5. Immune status of the animal (colostrum) Vaccination program Medication Management BRD Incidence Immune Status n=204 Low High P-value BW at exit of Z1, kg 80.4 80.4 0.98 ADG in Z1, kg/d 0.7 0.7 0.91 BW at exit of Z2, kg 126.7 125.8 0.65 ADG in Z2, kg/d 1.0 1.0 0.52 BW at exit of Z3, kg 167.5 167.5 0.97 ADG in Z3, kg/d 0.8 0.9 0.63 Immune Status
  6. 6. The risk of having respiratory problems was only 8% lower in the animals with a high serum protein level compared to calves with a low protein serum level (P = 0.61). Similarly, there were no differences in the incidence of diarrhea between the two groups. Under the conditions of RLN, the use of serum protein levels provided no indication of risk of future pathologies or impaired performance. Good management and environmental conditions may overcome immune deficiencies. Immune Status 5 calves per hutch: 3 m2 and 7 m3 per calf 6 calves per hutch: 2.5 m2 and 5.7 m3 per calf 7 calves per hutch: 2.1 m2 and 5 m3 per calf - 16.6% - 28.5% BRD 7 6 5 0 15 30 45 60 22 38 58 Respiratory afflictions, % Numberofcalves/pen Item 5 6 7 n 50 60 70 BW entrance, kg 80 79 79 BW exit, kg 114 117 113 ADG, g/d 830 899 867 BRD
  7. 7. General recommendations for calf rearing advocate for keeping the animals individually housed and feeding milk replacer (or waste milk) twice daily. The main purpose of keeping calves individually is to minimize the spread of infectious diseases (mainly diarrhea and pneumonia). A recent survey (Fulwider et al., 2008) indicated that 50% of the producers send their calves to contract heifer operations. BRD The implementation of management schemes that reduce the spread of calf diseases is even more important in contract heifer operations (where animals from different origins are commingled). Weaning time has been traditionally considered as a stressful moment for calves. A common recommendation extensively implemented in the field is to keep calves individually-housed for at least one additional week after weaning (Quigley, 2001). To our knowledge, there is no scientific evidence of the advantages or consequences of such a practice. BRD Several studies have evaluated the impact of weaning calves in groups or individually on performance (Terre et al., 2006), behavior (Warnick et al., 1977; Keil and Langhans, 2001), and health (Svensson and Liberg, 2006; Terré et al., 2006). These studies have kept the animals either individually- or group-housed throughout the study. An alternative weaning strategy would consist on keeping calves individually-housed for a period of time and, then form groups of calves for another period of time, and finally wean them while in groups. BRD
  8. 8. Experiment 1. To evaluate whether allowing calves to remain for an additional 6 d individually-housed after weaning was beneficial in terms of performance and respiratory problems. Experiment 2. To evaluate the effect on performance and incidence of disease of moving calves in groups before weaning. BRD Materials and Methods (Exp. 1) Three hundred and twenty female Holstein calves were assigned to two different treatments: Allowing the calf to remain individually housed for an additional 6 d after weaning Move the calf immediately after weaning to a different pen forming groups of 8 contemporaneous calves. Individually Housed Group HousedIndividually Housed Starter..4 L of MR 2 L of MR Dry TMR Starter..4 L of MR 2 L of MR 49 d 56 d 62 d Group Housed Dry TMR 98 d 104 d Results (Exp. 1) 0 17.5 35 52.5 70 Grouped 6 d after weaning Grouped at weaning 41.4 61.2 1.691.72 Before Grouping After Grouping Proportionofcalvesaffected,% a b Incidence of Respiratory Problems Bach et al., 2010
  9. 9. Materials and Methods (Exp. 2) Two hundred and forty female Holstein calves were assigned to two different treatments in three different periods: Remained until the age of 56 d individually housed Moved to groups of 8 calves in super-hutches at 49 d of age Group HousedIndividually Group HousedIndividually Housed ..4 L of MR ..4 L of MR 49 d 56 d 63 d 112 d70 d Starter Starter Dry TMR Dry TMR 2 L of MR 2 L of MR Materials and Methods (Exp. 2) Results (Exp. 2) 1.2 1.8 2.4 3 3.6 49-56 57-63 63-70 71-77 3.36 2.73 2.3 1.57 3.42 2.81 2.41 1.79 Grouped at 49 d Grouped at 56 d Solidfeedintake,kg/d Age, d P < 0.05 * Grouped calves consumed more solid feed than those individually housed.
  10. 10. Results (Exp. 2) Grouped at 49 d Grouped at 56 d 15 18 21 24 27 25.8 25.2 Proportion of calves affected, % 0 0.325 0.65 0.975 1.3 1.23 0.87 Cases/calf P < 0.05 Incidence of Respiratory Problems Bach et al., 2010 Can we use records to cope with BRD? BRD Materials and Methods (Exp. 1) Two hundred and forty female Holstein calves were raised in individual hutches and were checked for respiratory afflictions once daily starting at 5 d of age. At weaning time calves were allocated into different groups of 8 calves based on their previous BRD history. Within each period, 2 superhutches housed: 8 calves with no previous record of BRD 6 animals with no previous BRD record and 2 calves with previous episode of BRD 5 calves without a history of BRD and 3 calves with previous
  11. 11. 0 13.75 27.50 41.25 55.00 Cases/hutch Calves affected, % Time to 1st case, d 11 52 9 11 38 5 23 24 4 0-8 2-6 3-5 Ratio No previous case-Previous case Bach et al., 2010 BRD Materials and Methods (Exp. 2) Two hundred and forty female Holstein calves were raised in individual hutches. Calves with no previous record of BRD were randomly allocated to 3 superhutches containing 8 calves Calves with a previous case of BRD were randomly allocated to 3 different superhutches (RRR). 0 13.75 27.50 41.25 55.00 Cases/hutch Calves affected, % Time to 1st case, d 9 99 11 19 38 4 0-8 8-8 Ratio No previous case-Previous case Bach et al., 2010 BRD
  12. 12. 120.00 125.50 131.00 136.50 142.00 Final BW, kg 136 141 0-8 8-8 Ratio No previous case-Previous case 1.12 1.15 1.17 1.20 1.22 ADG, kg/d 1.13 1.21 Bach et al., 2010 BRD 0.9 1.025 1.15 1.275 1.4 0 1 2 3 ≥4 ADG, kg/d Bach et al., 2010 120 127.5 135 142.5 150 0 1 2 3 ≥4 BW, kg BRD Materials and Methods 140 Holstein calves were housed in individual hutches until 49 d of age and moved to super-hutches in groups of 8-10 animals. The Control group did not receive any antibiotic treatment I.M. unless needed. Calves in the Zactran group were treated with gamithromycin at 6 mg/kg (1 mL/25kg BE) one week after being moved from individual to group housing (at the age of 56 d).
  13. 13. 0 0.3 0.6 0.9 1.2 BRD Incidence Cases/calf 0.74 0.452 1.16 0.449 Control Zactran BRD P = 0.18 There were no differences (P = 0.81) in growth rate Materials and Methods 157 Holstein calves were housed in individual hutches until 52 d of age. At weaning they were moved to super-hutches in groups of 8-10 The Control group did not receive any antibiotic treatment unless needed. The calves in the other group were treated with gamithromycin at 6 mg/kg (1 mL Zactran/25 kg BW) at the time of movement from individual to group housing at the age of 56 d. 0 0.225 0.45 0.675 0.9 BRD Incidence Cases/calf 0.44 0.301 0.81 0.516 Control Zactran BRD P < 0.05 There were no differences (P = 0.62) in growth rate
  14. 14. Combining the results from Experiments 1 and 2 the overall response to Zactran could be assessed with a bit more precision (more than 300 animals). Overall, there were no differences (P = 0.38) in animal performance between the Control (1.2±0.04 kg/d) and Zactran (1.2±0.04 kg/d) calves. The incidence of respiratory problems was greater (P < 0.05) in Control (49.5±0.04 %) than in Zactran (37.0±0.04 %) calves. The number of respiratory cases per calf was also greater (P < 0.05) in Control (1.0±0.18 cases/calf) than in Zactran (0.60±0.18 cases/calf) calves. BRD Conclusions Monitoring health aspects is crucial BRD incidence my compromise overall productive life of dairy cows Action must be taken rapidly Start with symptomatic treatment and move to antibiotic if no response is seen Use an adequate vaccination program Calves that are moved to groups immediately after weaning grow better and have less BRD incidence than those that are kept isolated for one additional week. Calves that are grouped at pre-weaning time and continue to receive MR in groups improve ADG, solid feed intake, and suffer less BRD relapses. Offering milk in groups does not affect CV of BW or ADG. Conclusions
  15. 15. Thank you

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