Checking Passive Transfer of Immunity

One of my clients routinely checks on passive transfer of immunity once a month.

Industry goals are:

90 percent at or above 5.0g/dl, and

75 percent at or above 5.5g/dl.

The May report just came to my desk.

These are the 2016 results: (bold shows failure to meet industry goals)

                                                     January  March    April     May  

Percent at or above 5.0g/dl             82%       92%     88%      82%

Percent at or above 5.5g/dl             82%       92%     88%      55%

(N)                                                  11           12          8          11

The May values look like this: (in order by calf ID number)

5.5

6.2

4.3

4.8

5.8

6.1

5.9

5.4

6.1

5.3

5.2

Notice that the lowest BSTP values are grouped. Additional information would be needed to pick out the most reasonable reason for these low values.

Here are several examples:

1. Low quality colostrum from one cow fed to two calves in a row? [a breakdown of the farm protocol to check all colostrum before feeding].

2. Possible delay in feeding colostrum - were these calves born at a time when labor was not available to promptly feed colostrum - calves had to wait to the end of the milking shift to receive their first feeding of colostrum?

3. Person assigned to feed colostrum did not have the skills needed to use a tube feeder - maybe the calves received less than the prescribed four quarts of colostrum?

4. The colostrum fed to these two sets of calves had a high bacteria count? For example, the warm colostrum sat in the  utility room for several hours before being bottled and chilled. 

Bottom line - The potential for improvement depends on routine checking for passive transfer success. 

Surges in Calvings: Responding Positively Rather than 

"Muddling Through"

This is the title of a new Calf Facts resource sheet just added to the Calf Facts section of the www.atticacows.com web site. Click 

A summary of the content is:

• Breeding records allow us to accurately predict sustained surges in calvings.

• These sustained surges in calvings can overload the calf care system creating sub-standard care.

• It is better to manage overloads rather than just “muddle through” and have compromised calf care.

• Choose between decreasing the calf population, increasing resources or some combination of the two.

Colostrum: Feeding Strategies

This is the title of a new Calf Facts resource sheet just added to the Calf Facts section of the www.atticacows.com web site. Click HERE to go to the resource sheet.

A summary of the content is:

• When testing colostrum quality it is recommended to take a sample from the milker bucket to use with a Colostrometer or Brix refractometer.

• However, if hand-milked colostrum (first three or four quarts) must be used, for practical purposes it will have an antibody concentration relatively close to colostrum coming from a cow that is milked out entirely.

• Fully forty to fifty percent of calves will voluntarily consume three or more quarts in the first feeding.

• Always have a person available who is trained to use an esophageal tube feeder. It is common to have as many as three out of ten calves that will not voluntarily drink even two quarts of colostrum.

• Follow best management practices when using an esophageal tube feeder for colostrum feeding. For a review of these practices go to http://www.atticacows.com/documentView.asp?docID=6030.

Colostrum: Quantity and Quality Variation

This is the title of a new Calf Facts resource sheet just added to the Calf Facts section of the www.atticacows.com web site. Click Here to go to the resource sheet. 

A summary of the content is:

• Findings from two studies are summarized, one from Pennsylvania and the other was US national including twelve states.

• Later lactation cows had higher levels of antibody concentration.

• Poor quality colostrum was present for all lactations - better to check before feeding.

• Average quantity was in the range of 6.4 to 7.2 quarts (6-6.8l).

• There was a very wide variation in antibody (IgG) concentration at every interval of colostrum quantity. Volume was an unpredictable guide for sorting out the lowest quality colostrum. 

• Better to measure than guess - both Colostrometer or Brix refractometer are practical on-farm means of estimating antibody concentration.

Ventilation - Managing Calf Barns

This is the title of a new Calf Facts resource sheet just added to the Calf Facts section of the www.atticacows.com web site.

A summary of the content is:

• Setting air quality goals

• Measuring air quality – what to do

• Managing housing – if you are already meeting your goals right now

• Managing housing - when threshold values are not met

Enjoy.

Treating Sick Calves and Biosecurity

I was just reviewing a study of US calf ranches (that is, places that raise either only heifer calves or both bull and heifer calves). W. L Walker and Others, "Characteristics of dairy calf ranches: morbidity, mortality, antibiotic use practices, and biosecurity and biocontainment practices." Journal of Dairy Science 95:2204-2214.

Two practices caught my attention.

1. "When sick preweaned calves were treated or examined, the person treating or examining them usually entered their pen or individual housing area."

2. "Personnel were required to wear disposable gloves while working with preweaned calves."

What did I do while working with my calves twenty years ago?

Yes, if I checked out a calf that might be sick I got right in and up close.

No, I did not wear disposable gloves. And, maybe even worse, I did not in any way clean off my rubber boots after checking out a sick calf! I have no idea why more of my calves did not get sick! 

One of my clients has a bio-security routine that I have been admiring. The calves are housed outdoors in individual hutches far enough apart that the calf care person has to take several steps between hutches. All the calves that need to be examined or treated have a white plastic clip attached to the wire pen in front of the hutch. The examining and treating is done separately from any feeding activity.

This is the protocol:

1. Positively identify the calf to be examined/treated. All the calves have easy to read ear tags, calves to be examined/treated have large white clips on the wire pen outside the hutch.

2. Set a small footbath down from the back of the 4-wheeler.

3. Pull on disposable gloves.

4. Step into footbath, using a small garden-type pressure sprayer containing a disinfectant solution to spray off boots.

5. Enter wire pen and examine/treat calf.

6. Exit pen, step into footbath and spray off boots, stomping up and down to rinse bottom of boots. 

7. Dump footbath, put in back of Gator, discard gloves and drive on to next calf to examine/treat.

Back in 1991 I never even thought about this level of biosecurity.

Maybe all of us need to think more seriously about how we spread pathogens from calf to calf as we provide care?

Colostrum for 10-Year Old's

Imagine this! You have a group of 20 ten-year old's for 30 minutes. They are 4-H dairy club members from all around New York State.

Your goal is to have them learn something useful about colostrum. So, what to do?

I had three such groups in Morrison Hall on the Cornell campus on Saturday (May 7th, 2016).

I thought you might be interested in the two pages I prepared for this event;

1. Summary of facts about colostrum.

2. Places to find out more about colostrum. 

I pasted them below. Enjoy.

Colostrum Facts

By Sam Leadley, Attica Veterinary Associates, P.C.

1. First milking after a cow calves.

2. Compared to whole milk, colostrum has 91% greater solids (24% solids vs. 13% for milk).

3. Compared to whole milk, colostrum has 88% greater fat (6.8% fat vs. 3.6% for milk)

4. Compared to whole milk, colostrum has 6,500% greater antibodies (6% antibodies vs. 0.09% for milk).

5. Primary source of immunity for newborn calves (cows cannot pass antibodies to their babies before they are born like human mothers do).

6. Excellent place to grow bacteria – E. coli bacteria can double every 20 minutes in warm colostrum. Remember 30-minute rule: After collecting colostrum either feed or chill within 30 minutes.

7. Antibody content varies very widely among cows.

WHERE CAN I FIND OUT MORE ABOUT COLOSTRUM?

1. Try www.calffacts.com – there are 25 fact sheets written for calf care person dealing with many practical day-to-day aspects of colostrum management.

2. Try www.calfnotes.com – there are 50 facts sheets written for dairy farm managers dealing with many scientific aspects of colostrum.

3. Try http://www.vetmed.wisc.edu/dms/fapm/fapmtools/calves.htm - there are three useful resources especially one for collection, labeling, storage and administration of colostrum.

4. Try

http://www.extension.umn.edu/agriculture/dairy/calves-and-heifers/colostrum-management.pdf - this is a general 30-slide power point presentation about colostrum and best management practices.

5. Try

http://afsdairy.ca.uky.edu/extension/nutrition/calves/colostrummanagement - this is a more scientific article with plenty of facts about colostrum and best management practices.

Using a Brix Refractometer to Evaluate Colostrum Quality

On May 8, 2016 Dr. Jim Quigley published Calf Note #187 on this topic. To go to that note click HERE. 

Jim summarizes the finding of three studies done in 2013, 14 and 15 in one very handy table (Table 1.)

Using these data he worked out another table showing the estimated connection between BRIX readings and serum IgG values (g/L). Table 2 shows that a BRIX reading of 8.0% is about equal to the standard we have been using for minimum passive transfer of 10g/L IgG.

Using total serum protein values (from a clinical refractometer) I have been recommending these performance standards:

1. 90% calves testing at 5.0g/dl or greater

2. 75% calves testing at 5.5g/dl or greater

If we make the conversion from these values to those from a BRIX refractometer then my recommended performance standards are:

1. 90% calves testing at 8.0% or greater

2. 75% calves testing at 8.5% or greater

It should be uncommon to get readings as high as 9.5-10.0. While high readings may indicate superior passive transfer more often these very high readings suggest significant dehydration in the calf. 

What Percentage of Colostrum Antibodies end up in the Blood?

Given a few facts it is possible to estimate the efficiency of absorption of antibodies by calves. Need to know the calf's weight and the volume of antibodies fed.

Quigley notes in his Calf Notes #81 that observed variation in this efficiency varies from 20 to 35 percent. That's right. Feed 100 units of antibodies and only 20 to 35 end up in the blood. Don't be surprised. It is a rough trip for antibodies from mouth to small intestine where they are transported from the intestinal wall into the blood - think of all those abomasal acids!

A recent report at the University of New Hampshire collected data from 28 calves. They found efficiency of absorption averaged 26 percent.

A study done in Florida looked at the question of heat stress on the dam precalving might effect the efficiency of absorption of antibodies by their calves.

 Ten dry cows had luxury apartments - their free stall area had fans and soakers. Ten dry cows had the standard housing - no fans, no soakers. The temperature-humidity index in both stall areas averaged 78. (Referring to the standard THI graph, 78 is in the upper end of the "moderate-heat-stress" range. That puts it relatively close to being classified as "severe heat stress.")

The heat-stress cows had higher rectal temperatures compared to cooled cows. Cooled cows had a respiration rate of 49 breaths/minute compared to 67 br/min for heat-stressed cows. Lots of huff and puff for the heat-stressed cows.

What happened to their heifer calves? They were all fed the same volume of the same quality of colostrum at about the same time after birth. The calves from heat stressed cows had an apparent efficiency  of absorption of 19 percent. In contrast the calves from cooled cows had an absorption rate of 33.6 percent. 

What do I conclude?

1. If we want high levels of circulating antibodies from colostrum in our calves we need to feed enough antibodies to allow for a high level of losses.

2. Given large variations from calf-to-calf in efficiency of absorption (mostly unpredictable) our best management strategy is to feed enough high quality colostrum shortly after birth to all our calves to get adequate immunity even among the calves with low efficiency.

On a side note, feeding a greater volume of colostrum to newborn calves can be a poor policy if the colostrum is badly contaminated with bacteria. The greater number of bacteria fed the greater the chances that the calf will either get quite sick or die. Please do not increase the volume you feed to calves (for example, increase from 2 quarts to 4 quarts) until you have confirmed that your colostrum is clean.

References: S. Tao and Others, "Effect of late-gestation maternal heat stress on growth and immune function of dairy calves." Journal of Dairy Science 95:7128-7136. K.M. Aragona and Others, "Prepartum supplementation of nicotinic acid: Effects on health of the dam, colostrum quality and acquisition of immunity in calf." Journal of Dairy Science 99:3529-3538.

Cooling Dry Cows?

In a small study done in Florida (n=20) it was demonstrated that heat stress among dry cows may play a role in the growth and development of heifer calves.

Ten dry cows had luxury apartments - their free stall area had fans and soakers. Ten dry cows had the standard housing - no fans, no soakers. The temperature-humidity index in both stall areas averaged 78. (Referring to the standard THI graph, 78 is in the upper end of the "moderate-heat-stress" range. That puts it relatively close to being classified as "severe heat stress.")

The heat-stress cows had higher rectal temperatures compared to cooled cows. Cooled cows had a respiration rate of 49 breaths/minute compared to 67 br/min for heat-stressed cows. Lots of huff and puff for the heat-stressed cows.

What happened to the heifer calves? Although they all started out about similar birth weights by the time they reached 56 days the calves from cooled dams were heavier (157 pounds from cooled dams, 135 pounds from heat-stress dams). 

An analysis of feed intake showed that most of this difference was dry matter intake from calf starter grain. At the end of the 56-day trial cooled-dam calves were eating about 4.4 pounds of grain daily compared with the 3.0 pound-a-day consumption of the heat-stress-dam calves.

Only a small study - but the differences were pretty large. Just one more reason to keep our expectant mothers comfortable.

Reference: A.P.A Monteiro and Others, "Effect of maternal heat stress during the dry period on growth and metabolism of calves." Journal of Dairy Science 99:3896-3907 May 2016.

How Accurately Does Colostrum Volume Predict Quality?

In a study involving 507 Holstein cows the study team collected colostrum measuring both the volume at first milking and the antibody concentration.

There was a very wide variation in antibody (IgG) concentration at every interval of colostrum volume. For example, at the 4-quart volume the lowest IgG concentration was approximately 15 mg/mL and the highest was 200 mg/mL. Or, at the 12-quart (3 gallons) volume the lowest value was about 40 mg/mL and highest value was 220 mg/mL.

There was a measurable decrease in IgG concentration as volume increased only among cows 3^rd lactation and greater. However, this relationship between volume and IgG level was dwarfed by the variation among mature cows at every level of colostrum yield. 

No connection was found between volume and concentration among 1^st and 2^nd lactation samples. Since in the US on average dairy herds are composed of 50 percent in lactations 1 and 2 there are a lot of dams where there is little or no connection between volume and quality

In my opinion, knowing the volume is an unreliable guide to sorting out the lowest quality colostrum. Better to measure than guess.

References: Kehoe, S. I., A.J. Heinrichs, M.L. Moody, C.M. Jones, and M.R. Long, “Comparison of immunoglobulin G concentrations in primiparous and multiparous bovine colostrum.” Professional Animal Scientist 27 (2011): 176-180. E. Hare and Others, "Survival rates and productive life of dairy cattle in US." Journal of Dairy Science 89:3713-3720.

Getting the most bang for your vaccination dollar

This is the title of a webinar given by Dr. Amelia Woolums, DVM at Mississippi State University in February, 2016.

I was impressed by her straight forward presentation of basic immunology concepts and how they apply to young calves.

The archived copy of the webinar is available at 

http://www.hoards.com/webinararchives_16-feb 

or just click HERE.

May Calf Management Newsletter

"Do I Need a Calf Vaccination Protocol?"

·        Why do we vaccinate?

·        What is a calf/heifer vaccination protocol?

•   What are the costs and benefits of a calf/heifer vaccination protocol?
•    If I don’t have a protocol, what are the steps to get one?

Click HERE to go to the May 2016 issue of Calving Ease.