Thursday, July 1, 2004

What is Pre-conditioning?

The Bovine Respiratory Disease Complex (BRDC) results from a complex series of steps: (1.) stress, (2.) viral infection, and (3.) bacterial infection.

Stress can be caused by routine procedures such as castration, dehorning, nutrition, weather (change of environment), congregation (co-mingling) and transportation. Stress causes the entire body to be more prone to infection. This occurs by allowing disease causing organisms easier route of entry and by disarming some of the body’s important defense mechanisms against disease.

Viruses that commonly take advantage of the situation usually include IBR and BVD. Other viruses such as BRSV and PI3 sometimes can cause problems. Although viruses may cause death, the major role they play in the BRDC is to allow the third factor-bacteria-to gain a foothold and possibly lead to death.

Mannhemia haemolytica, Pasteurella multocida, and Haemophilus somnus account for
the majority of bacterial infections of the BRDC.

This complex series of steps causing the BRDC with large economic losses with high morbidity and mortality resulted in the development of pre-conditioning.

Pre-conditioning programs vary considerably, but generally include weaning, training to eat and drink from troughs, vaccination, and treatment for internal and external parasites, castration, and dehorning. Pre-conditioning is a general term used in the beef industry to basically describe the time period and management of calves which takes place at the farm/ranch before arrival into the feedyard. Therefore, pre-conditioning can be defined as the preparation of feeder calves for the marketing and shipment to the feedyard. Pre-conditioning is intended to give the calf time to return to normal behaviors, improve feed intake, and allow time for the immune system to rebound from weaning stress and immunization. (Bartle, Steve ADM Alliance Nutrition) Don’t confuse or compare the term pre-conditioning towards backgrounding. Backgrounding is a similar approach; however, the vaccinations and other management procedures take place at a separate facility-not at the farm/ranch.

American Association of Bovine Practitioners (AABP 1968) defined the following areas in pre-conditioning:
  • Weaned at least three weeks before sale.
  • Trained to eat from a feed bunk and to drink from a trough
  • Treated for parasites.
  • Vaccinated for blackleg, malignant edema, PI3, IBR, Pasteurella, and sometimes BVD and Haemophilus.
  • Castrated and dehorned.
  • Identified with an ear tag.
  • Sold through special auctions
Historically, most pre-conditioning programs supported a 21-30 day weaning period; however, more recent efforts have been directed toward increasing the number of days weaned before shipment and improving management procedures on the ranch. The Texas Ranch to Rail data shows it take at least 45 days for calves to develop independent behaviors, achieve consistent intake targets, and to develop immunity from vaccination. Therefore today, most programs require a 45-day weaning period. Several pre-conditioning programs have also been replaced by individual programs developed at the producer level and by commercial programs promoted by biological firms. (Radostits, Otto Third Edition)

The vaccination requirements also vary but most include modified live vaccines such as IBR, BVD, PI3, BRSV, Mannheimia haemolytica leukotoxoid, and clostridial bacterins. In any pre-conditioning program, it’s important to meet beef quality assurance standards and all label directions should be followed regarding injection location, dosage, needle size, and timing of vaccination including boosters.

Different alliances of which this author works with have different requirements but a general outline includes:
  • Ownership-cows or calves originate from pre-conditioned facility
  • Bulls must be castrated and healed before shipment
  • Calves dehorned or tipped and healed before shipment
  • Calves must be weaned for 45 days or longer
  • Treated for internal and external parasite
  •  Vaccination program:
    At branding or six weeks prior to weaning:
    A vaccine containing chemically altered modified-live IBR and PI3, modified-    live BRSV and inactivated BVD.
    Seven-way clostridial bacterin
    Mannheimia haemolytica leukotoxoid or Mannheimia haemolytica and Pasteruella multocidia combination
  • Radio frequency identification ear tag
  • At weaning:
    Revaccinate with modified-live IBR, PI3, BRSV and BVD
  • Heifers will need to be palpated and determined open or an abortion program   must be implemented at point of origin.
 The nutrition and management during the pre-conditioning period is dependent upon the producer’s objective. Oklahoma State University (extension publication F-3031) list several possible objectives:
·        Optimize condition and health for the pre-condition phase
·        Produce added weight at low cost
·        Market calves through a program requiring pre-conditioning for best market potential
·        Minimize the risk of digestive upsets and disease
·        Achieve a specific target weight.

Suggested Nutrient Recommendations for Stressed Calves

(Adapted from 1996 Nutrient Requirements for Beef Cattle)
     Dry Matter,%-------------------       80-85
     Concentrate,%------------------       50-75
     NEm, Mcal/lb-------------------      0.82-0.90
     NEg, Mcal/lb--------------------      0.46-0.56
     Crude Protein,%-----------------     12.5-14.5
     Calcium,%-----------------------      0.60-0.80
     Phosphorus,%-------------------      0.40-0.50
     Potassiun,%----------------------     0.80-1.40
     Magnesium,%--------------------    0.20-0.30
     Sodium,%-------------------------    0.20-0.30
     Copper,ppm------------------------- 10-15
     Iron,ppm----------------------------- 100-200
     Manganese,ppm--------------------  20-40    
     Zinc,ppm----------------------------  75-100
     Cobalt,ppm-------------------------- 0.10-0.20
     Selnium,ppm------------------------ 0.10-0.20
     Iodine,ppm--------------------------  0.30-0.60
     Vitamin A, IU/lb-------------------  2500
     Vitamin E, IU/lb-------------------  50-100

Management practices that minimize weaning and arrival stress will result in fewer calves requiring health treatments. The importance about prevention of disease, particularly the BRDC, does not only affects the morbidity (health treatments) and mortality (deathloss) but data also shows the impact on average daily gain, feed efficiency and carcass merit.

Health and Performance Effects of Preweaning Management

(Reprinted from Cattle Health Tech)
How does preweaning management influence disease resistance, average daily gain, feed efficiency, quality grade, and yield grade of carcasses? This question has been addressed in various research projects over the course of several years.
1. Compared to fresh, unweaned calves, calves that were preweaned and fed for 30-45 days at the ranch had:
  • 20 % less sickness and death loss
  • Similar average daily gain
  • 2%-to 7% poorer feed conversion
2. Compared to fresh, unweaned calves, calves that were limit creep fed (1-3 lb/head/day) for the last 60 days had:
  • 20 % less sickness
  • 25 % less death loss
  • 0%-3% better feed conversion
3. Compared to polled steers, calves that must be castrated and/or dehorned/tipped at the feedyard generally had:
  • 3 % poorer average daily gain
  • 3 % poorer feed conversion
  • Lower quality grade at slaughter (castration only)
4. Compared to nonvaccinated calves, calves that were vaccinated for IBR, BVD, PI3, BRSV and Pasteurella on the ranch had:
  • 20 % to 30 % less sickness
  • 40 % less death loss
  • Similar feedyard performance.
 The Texas A & M Ranch to Rail program has consistently shown an impact of health on the ability of steers to express their genetic potential and the costs associated with sick cattle beyond the cost of medicine. Healthy steers had an average of $93.20 more favorable return than sick steers in the 20003 program and an average net return over a five-year period has been $37.54 per head.

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