Understanding the willingness of farms to utilize lung scanning in their cattle operations

Results Summary

I was able to lung scan calves on three different farms from July 2020 to December 2021 to evaluate the effect of respiratory disease on cattle weight and performance. Below are a portion of results from each farm that participated in the study. Neither dairy farm tracked animal weights or incidence of respiratory disease on their farm before this project. The beef backgrounding farm tracked these aspects but did not analyze them in relation to each other. Therefore, this project has already provided valuable insight for farms to aid in understanding how their management practices affect animal performance. 

Lindauer Dairy Farm:

Total Number of Individual animals Lung Scanned: 232

• 159 animals scanned for growth data
• 74 animals scanned over multiple weeks for lung damage observation over time

Birthweight

• # of calves with Birthweight: 122
• Average birthweight: 98 pounds
• Minimum birthweight: 65 pounds
• Maximum birthweight: 126 pounds
• No effect of birthweight on the calves’ chance to obtain lung damage

Respiratory Disease

• 75 of 232 calves treated for respiratory = 32%
• Average age of treatment: 73 days
• Calves treated 0-60 d old (only antibiotic treatment with resflor)
  • 40% of the calves who were treated
  • Average age of calves treated in this period: 40 days
• Calves treated 61 days and older
  • 60% of the calves who were treated
  • Average age of calves treated in this period: 94 days
• Percentage of calves with lung damage at or after 60 d old (132 heifers)
  • No lung damage: 67%
  • Single side lung damage: 13%
  • Double side lung damage: 20%
  • 15% of heifers had a 5 or 6 on one or both sides of lungs

Growth Measurements

• ~3 Week Lung Scoring Results (104 heifers)

• ADG of calves at or after 60 d old (132 heifers) broken into individual scores

• Heifers at Hunley Creek
  • 50 heifer’s lungs scanned after arriving at Hunley Creek
    • 3 heifers had lung damage (6%)
    • Lung damage can heal over time
      • Lung damage is not always a set score but a continuum that progresses to higher scores and goes to lower scores over time
      • What are the affects left behind after lung damage heals?
    • Thoughts on heifer growth
      • When heifers were scanned on arrival there was a difference in ADG and ~70-pound reduction in weight
      • However, as animals grew, the inverse occurred and there was an increase in weight and ADG of animals who had lung damage at weaning.
        • This could be the case for several reason
          1. Animals were on a different diet which basically allowed ad libitum consumption once arriving
          2. Not enough number strength to support the findings

Heifers Lung Scanned Over Time

• The first scan was within the first week of entering group housing
• All calves included were scanned at least 3 times (56 heifers)
  • 3 were treated prior to entering the first group pen
  • 8 were treated after leaving the first group pen
    • 5 did not have lung damage prior to leaving the first group pen
    • 3 had at least one scan with lung damage prior to leaving the first pen
  • 11 were treated during the first group pen
    • Average age of treatment in this group was 11 days after calves entered group housing
  • The highest amount of lung damage was seen at the 2^nd lung scan after entering the group housing system
  • 10 Heifers scanned over time (producer was advised to monitored calves with lung damage after 2^nd scan and treat with antibiotics)
    • 8/10 lung damage 2^nd scan
    • 3/10 lung damage 4^th scan

Survival to first breeding

• 13 calves died out of 232 calves scanned
  • 6% death rate

Heifer Breeding

• 74 who went through the lung scanning program had been bred as of January 2022
• Breeding Age
  • 62 heifers had weaning lung scans and their first breeding date

• Pregnancy to First Service
  • 47 heifers had weaning lung scans and were confirmed pregnant/not pregnant at first service
  • 36% total pregnancy to first service

Conception Age

• 29 heifers had weaning lung scans and were confirmed pregnant
  • Age of conception was calculated based on days pregnant at pregnancy check
  • If you compare animals treated for respiratory disease with antibiotics to their age at conception
    • Not Treated: 482 days
    • Treated: 481 days

Thoughts based on the year of lung scanning

1. Lung Scanning Timepoints
   • 3-week lung scan
     • Not many calves were being diagnosed with respiratory disease while calves were in the hutches
     • If calves were sick, they showed more visible signs of respiratory disease
     • Weight and ADG were not impacted by the lung scores during this phase
   •  Weaning/Post-weaning
     • There was a difference in weight and ADG at weaning of calves specifically with lung scores of 5 or 6 or lung damage on both sides of their lugs
       • First group pens around old milk parlor
         1. Calves are getting lung damage during this time period especially during large temperature changes but they are not showing visible symptoms
         2. The majority of lung damage is seen on the 2 weeks after entering this group housing
         3. 40% of calves treated up to 61 days of age
   • Second group pens, old barn with dry cows etc.
     • • Some calves leaving with residual lung damage from first group pens and visual symptoms are showing up later in age
         1. 60% of calves are treated after 61 days old with an average of 94 days old

1.  
2. The most ideal time period to lung scan calves to most accurately diagnose disease during these timepoints would be 2 weeks after entering the first group housing system.
   • • Catch those subclinical calves with lung damage early and have fewer animals entering the next phases with lung damage
   • Areas of improvement to reduce lung damage in the group housing phase
     • Consider intranasal vaccination prior or at grouping (talk with veterinarian) to help with viral spread of respiratory disease. Calves in hutches are in their own individual biome, so when they are grouped together, they are sharing germs even if from one hutch down.
     • Consider monitoring ventilation especially during the times of year with large weather changes
       • Lung scans of calves increased when curtains were down in the group pens by old milk parlor, consider starting a group with the curtains up to see how calves adjust
       • Calves in old barn by dry cows during the summer months have increase amount of lung damage.
3. Thoughts on heifer growth
   • When heifers were scanned on arrival there was a difference in ADG and ~70-pound reduction in weight
   • However, as animals grew, the inverse occurred and there was an increase in weight and ADG of animals who had lung damage at weaning.
     • This could be the case for several reasons
       • Animals were on a different diet which basically allowed ad libitum consumption once arriving
       • Heifers who have lung damage focus their energy on weight gain instead of reproductive purposes
       • Not enough number strength to support the findings
     • Summary of Heifer Breeding
       • There was not a major difference in heifer age at first breeding
       • 1^st service conception rate shows how many heifers are getting pregnant off the first AI
         1. All scenarios showed that heifers who were treated for respiratory or had a large amount of lung damage had a lower 1^st service conception percentage
         2. If heifers had lung damage on a single side or scored a 4 they had a higher first service conception rate
            1. 9 heifers in analysis
            2. Single sided lung damage and score of 4 does not affect future heifer productivity
         3. When analyzing age at conception and calves with lung damage on a single side versus both sides had a 6-day increased age of conception. When looking at individual scores, calves who score a 5 or 6 on one or both sides of their lungs had up to 33-day differences in age at conception. Therefore, focus on those animals who have lung score of 5 or 6.
4. What is the most ideal time to lung scan calves and cull animals based on lung score?
   • Neither 3 weeks or weaning should be the time in which animals are identified for culling. Because lung damage can change over time (proved by the calves scanned over time and pictures) the farm may not accurately identify the correct animals to cull.
     • Suggestion: lung scan calves when you are vaccinating to identify those who should be kept for replacement heifers and those who should be culled
     • Because lung damage can heal over time and the animals will adapt and grow efficiently but not reproduce efficiently you could consider putting those heifers with a 5 or 6 score in a feed lot scenario instead breeding them as a replacement heifer.

Lueken Dairy Farm

Animals Scanned

• # scanned between 53 and 85 days of age (average 65 d old): 274
• # scanned between 133 and 222 days of age (average 167): 258

Birthweight

• # of calves with Birthweight: 189
• Average birthweight: 93 pounds
• Minimum birthweight: 50 pounds
• Maximum birthweight: 132 pounds
• No effect of birthweight on the calves’ chance to obtain lung damage

Death Rate

• 124 calves died from ID 9938 to 431 (birthdates: 4/28/2020 to 12/27/2020)
  • Between these dates 429 heifer calves and 124 died
    • 29% death rate
  • % of animals died before 30 days old
    • 56%
  • % of animals died between 30-60 days old
    • 4%
  • % of animals died between 60-100 days old
    • 9%
  • % of animals died between 100-200 days old
    • 22%
  • % of animals died between 200-400 days old
    • 10%

Lung Scanning Statistics

• 21% of calves did not have lung damage at weaning but had lung damage at 5.5 months
  • Calves are getting lung damage during the post-weaning phase when calves are grouped together
• 10% of calves with lung damage at weaning did not have lung damage at 5.5 months
  • Lung damage can heal over time
  • 15 of the 18 calves who didn’t have lung damage at 5.5 months only had lung damage on 1 side of their body

Body Weight Growth

• Weaning

• Average 167 d old (5.5 months)

Heifer Breeding Data

• Age of conception (41 heifers with 5-month lung score records and were diagnosed pregnant)
  • No lung damage: 449 days (30 calves)
  • Lung Damage: 463 days (11 calves)
• Age of conception (41 heifers with 5-month lung score records and were diagnosed pregnant)
  • Lung score 1-3: 449 days (30 calves)
  • Lung Score 4: 449 days (8 calves)
  • Lung Score 5-6: 499 days (3 calves)

*This is a trend and there are not enough calves to prove this data. Upon observation, 60% of the calves with lung damage (>4 on one or both sides of lungs) who were of age to be pregnant and were open or not bred yet had 5 or 6 lung score and 40% of calves had a score of 4. This suggests that calves with scores of 4 were not as severely affected by respiratory disease as those with a 4 or 5*

Thoughts based on the year of lung scanning

1. Death Rate
   • 2019 (Mortality-Culling Rates of Dairy Calves and Replacement Heifers and Its Risk Factors in Holstein Cattle)
     • 3 to 60 days: 5.5%
     • 61-365: 7.4%
   • Lueken Dairy
     • 0-60 days: 17%
     • 61-365: 11%

• • The highest periods of death are from 0-30 days and 100-200 days of age

• • Areas to look into for death rate decrease in calves 0-30 days old
    • Newborn care/colostrum management
      • Good quality and amount of colostrum
      • Timely colostrum consumption
    • Antibiotic treatment of calves
      • 73% of weaned calved treated with Excede at an average of 6 days old
        1. Use another antibiotic (resflor or draxxin)
        2. Consider using banamine (resflor or draxxinkp have banamine in the drug) to help with fever
    • Look into the milk being fed to calves
      • Waste milk/milk replacer/bulk tank milk
      • If waste milk then bacteria count should be checked
  • Areas to look into for death rate decrease in calves 100-200 days old
    • Calves are getting respiratory disease during the grouping period
    • Organize groups of calves in an all in and all out system
      • Place calves in a pen and don’t add or take out calves
      • Consider administering intranasal vaccination (talk with veterinarian) before grouping or at group to deal with viral respiratory
    • When bringing back to the big barn at calf hutches consider grouping by weight instead of one big group

2. Lung Scanning

• • Calves with lung scores of 4 on either or both sides should be reconsidered before culling
  • Lung scores are not always final. Respiratory disease is like a bell curve. Lung score can increase and disease as the respiratory disease evolve
  • When is the best time to lung scan for increased accuracy of treatment diagnoses that will help with death rates?
    • 2-3 weeks after entering into group housing
    • Increase accuracy of diagnosing lung damage and allow animals to heal efficiently if treated in a timely manner
  • When is the best time to lung scan calves and cull animals?
    • Before leaving for heifer raiser
      • Slower growing and higher conception age
      • Other data has shown that in the proper conditions calves with lung damage will continue to grow and, in some cases, even catch up to other healthy calves later in life
        1. Instead of using animals for reproductive purposes put them in a fat lot to grow and become protein for others instead of selling as a young cull cow after freshening

Hunley Creek Heifer Farm

100 calves brought in on 9/28/2020 and 50 calves were lung scanned and weights were recorded

Average weight: 437 pounds

Initial Lung Scores:

• No lung damage (Score 1, 2, or 3): 76%
• Lung damage (Score 4, 5, or 6): 24%

Vaccination Weight (10/15/2020)

• Average Weight: 423 pounds
• ADG (9/28/2020 to 10/15/2020)
  • No lung damage: -0.37 pounds/day
  • Lung damage: -1.1 pounds/day
• 16 of the 38 calves without initial lung damage gained lung damage during this time period
  • Total percentage with lung damage as of 10/15/2020: 56%

Castration Weight (11/18/2020)

• Average Weight: 479 pounds
• ADG

Overall Summary

• From the first weight (9/28/20) to the last weight (11/18/20) ADG
  • No lung damage: 0.90 pounds/day
  • Lung damage (score 4, 5, 6): 0.78 pounds/day
• Comparing ADG (first to last weight) of calves with a score 5 or 6 to other lung scores
  • No Lung damage: 0.99 pounds/day
  • Lung damage of 5 or 6: 0.31 pounds/day
• Calves who arrived with lung damage had a larger reduction in ADG after arrival compared to calves without lung damage; however, these calves adapted better to their new environment and ended with the same ADG as calves without lung damage. Calves who developed lung damage due to the transition period had lower ADG throughout the recorded time period.
  • From the analysis, calves who adapted lung damage after arrival were on average smaller on arrival (418 pounds compared to 444-pound average of calves without lung damage)
• Final Lung Scores
  • No Lung Damage: 40%
  • Lung Damage: 48%
  • Died: 12%

26 calves arrived on 12/2/2021 and were lung scanned on arrival with a 0% lung damage rate

• All 26 calves were housed in the same pen after arrival
• Upon the second scan, 7 of the 26 calves increased their lung score by 2 points (to at least a 3 in score)
  • When looking at the average weight of calves who had increased lung scans at the second scan versus not
    • Score 1 and 2 average weight at arrival: 569 pounds; 1.34 lb./day
    • Score of 3, 4, 5, 6: 460 pounds; 0.49 lb./day
  • This set of data again shows that calves who are smaller upon arrival are more susceptible to lung damage

Should background calves be scanned on arrival?

• The average weight of background calves arriving on the farm was 509 pounds. The calf weights ranged from 300 pounds to 900 pounds, but the majority was in that 500 pound range. When the groups that were brought in were averaged separately, I noticed a trend on if they had lung damage or not. Smaller calves tended to have more lung damage upon arrival than the larger averaging groups, and to my surprise there were several groups that did not have any lung damage on arrival.
  • Due to this finding, lung scanning most groups of calves on arrival is not efficient or cost effective for the farm. Lung scanning also increases the amount of time each calf is in the chute, and lung scanning on arrival increases the stress level of calves.
  • The more effective and less time consuming/stressful way to sort animals on arrival would be by weight and not lung score unless the producer is bringing in a smaller weight averaging group of calves.
    • If calves’ average weight at purchasing is below 500 then calves should be scanned and those who have lung damage on arrival should be treated.

Should lung scanning be incorporated into the beef backgrounding system at all?

• At Hunley Creek, calves are put through the chute system 2 to 3 times depending on if they are heifers or bulls at arrival (3 times if calves are bulls and need to be castrated).
• Would it be more beneficial to lung scan calves on the 2^nd time through the chute instead of the first?
  • 50 calves arrived and scanned on 9/28/2020
    • 24% had lung damage at arrival
    • 58% of calves had lung damage when they were scanned for the second time, and lung damage increased by 34%
  • 26 calves arrive on 12/2/21
    • 0% had lung damage at arrival
    • 15% of calves had lung damage (>4) after the second lung scan with another 11.5% whose lung scored increase 2 points (lung score of 3)
  • 10 calves arrived on 12/10/2020
    • 0% had lung damage at arrival
    • 20% had lung damage after the second lung scan with another 20% whose lung score increased by 2 points.

       *Lung damage does increase as calves arrive at Hunley Creek Heifer Farm; therefore, lung scanning at the 2^nd time through the chute would be worth allocating the extra time to lung scan the calves. These calves will be treated with antibiotics decrease the lung damage and allow the animal to feel good enough to eat*

• Through lung scanning at Lindauer Dairy Farm, I have confirmed that lung damage can be healed over time if treated with antibiotics in a timely manner.
• How many weeks after should background calves be put through the chute to lung scan for the 2^nd time?
  • I did not have the opportunity to scan enough calves to pinpoint the exact week the majority of lung damage would show on the ultrasound machine. Based on my research with the dairy farms, I believe the most optimum time for this would be two weeks after arrival.
    • Calves were scanned anywhere from 5 to 1 week after arrival. The second scan was based on how the calves were eating, looking, and if we were having a lot of sick ones. Because we put them through the chute and vaccinate during this second scan, we waited to put them through until the majority were doing well and when we had time on the farm.