Tuesday, September 19, 2017

Measuring Colostrum Quality

Measuring colostrum quality is a best management practice. It's not difficult to do and the equipment is inexpensive. Guidelines for using a Brix refractometer are found HERE.

A recent report on a survey of dairy farms in Michigan and Ohio included information from 449 farms (56% <100 cows, 39% between 100-499 cows and 5% 500 cows and greater). 

They were asked if they measured colostrum quality before feeding it to newborn calves. 

Results? The percent measuring were:

>500 cow herds      = 25%
100-499 cow herds = 18%
<100 cow herds      = 3%

These same producers were asked this question:
"Measuring colostrum quality is useful to make decisions on feeding calves colostrum: (responses were Strongly agree, somewhat agree, neither agree or disagreee, somewhat disagree, strongly disagree).

Of the 43 producers that regularly measure quality 41 agreed with this statement - their attitude and behavior matched. 

Of considerable interest to me was that finding that 39% of the farms NOT measuring colostrum quality agreed that measuring quality is useful in making decisions on feeding calves colostrum. 

Of those of the opinion that measuring colostrum quality is not useful, 53% also felt that the process of measuring quality was time consuming. That makes me wonder if they had actually observed the use of a Brix refractometer for colostrum quality measurement.

Reference: Pempek, J.A. and Others, "Dairy calf management - a comparison of practices and producer attitudes among conventional and organic herds." Journal of Dairy Science 100:8310-8321.

Friday, September 15, 2017

Every Time I Try Feeding My Calves More 
They have Scours

This past week I talked with some calf care folks. One of the practices I recommended was feeding calves more than the out-of-date four quarts a day of 20-20 milk replacer. 

The reaction of some folks was captured in the words of one calf care person, "Every time I try what you suggest of feeding more, my calves have scours."

So, I spend about half an hour explaining that we control the conditions that either increase or decrease the chances of calves having diarrhea when fed more that 4 quarts of milk/milk replacer a day. The greater the number of best management practices we follow the lower the opportunity for calves to have diarrhea.

You may want to review this list of 10 factors that I think probably are most likely to make a difference in how calves respond to increased feeding rates. Click HERE for the list (2 pages) or if the link does not work for you try pasting this link in your browser:
http://www.atticacows.com/library/newsletters/FeedingMoreMilkwithoutScoursR1745.pdf 




Thursday, September 14, 2017

How Often Do I Need to Check My 
Colostrum Bacteria Count?

It depends. Well, that is not a very helpful answer.

The national Dairy Calf and Heifer Association Gold Standards thresholds for bacteria counts in colostrum are <5,000cfu/ml coliforms and <50,000cfu/ml total plate count. For an expanded discussion of bacteria in colostrum click HERE

If the farm has not sampled and cultured "as-fed" colostrum for bacteria you can find a sample collection protocol HERE (or in Spanish HERE). I like to see a minimum of 5 samples each time. If the dairy is large enough to have different shifts of workers handling and feeding colostrum then 2 samples from each shift is a good idea.

When the results come back compare them to the standards above. By the way, when ordering the culturing from a lab you often have to specify that you want both speciation (which bacteria are present) and quantification (how many of each species). I usually tell the lab I do not want them to use techniques to get exact counts when the number of colonies on the plate are too numerous to count (often abbreviated as TNTC).

If the farm sample results look good (below standards) I recommend extending the sampling interval to every 3 months. This quarterly interval follows the seasons of the year along with changes in labor availability that go with cropping cycles. 

If the farm sample results contain one or more high count samples I recommend taking corrective action and resampling each month until the results come back in below the farm's goals. If coliform counts are high you may want to review my checklist for reducing these counts (click HERE).

Monday, September 11, 2017

Passive Transfer Failure: It's Hard to Hit Zero!

In research study Holstein heifer calves received their first colostrum feeding at 4 or less hours after birth. They were fed 4.2 quarts of colostrum in one feeding that averaged 58g/l quality - so on the average they received around 240g of Ig's. 

In spite of this exemplary care they still had 2 percent passive transfer failure. The average efficiency of absorption (percent of antibodies fed that end up in the calf's blood) was around 23 percent. However, the range of efficiency was from less than 10 to over 50 percent. 

Another part of the study included calves fed 4 quarts as first feeding (less than 4 hours old) and another 2 quarts before they were 12 hours old. This colostrum averaged nearly 70g/l. With the combination of two feedings of excellent quality  colostrum (added up to 390g of Ig's) a higher level of passive transfer was  achieved.   

Bottom line? If you have a calf now and then that has passive transfer failure don't beat yourself up over it. Genetics always will play a role when you roll the dice and once in a while you will lose. 

Despite the wide range in apparent absorption efficiency demonstrated in this study it was clear that feeding 4 quarts (10% body weight) of good quality colostrum within 4 hours of birth will result in an excellent program for calf immunity. Other research has shown that at this volume similar results will be achieved with either one or two feedings and feeding either by bottle or tube feeder. 
[Click HERE for more on this.]  

Reference: Halleran, J. and Others, " Apparent efficiency of colostral immunoglobulin G absorption in Holstein heifer." Journal of Dairy Science 100;3282-3286. Osaka, J. and Others, "Effect of mass of immunoglobulin intake and age at first colostrum feeding on serum IgG concentration in Holstein calves." Journal of Dairy Science 97:6608-6612.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

Wednesday, September 6, 2017

Guidelines for Storing Colostrum

The September 2017 issue of the calf management newsletter offers guidelines for doing a good job of storing colostrum. Whether refrigerated or frozen, having a backup to fresh colostrum is a best management practice.

The key points are:
·       Start with clean colostrum
·       Reduce growth of bacteria
·       Monitor effectiveness of storage methods

Enjoy.

Friday, September 1, 2017

More on Transition Milk
"Transition Milk is Too Valuable to Sell"

This article [click HERE to go to it online] by Maureen Hanson quotes Dr. Jeremy Schefers from the University of Minnesota Veterinary Diagnostic Laboratory, If the link does not work, try this URL
http://www.dairyherd.com/advice-and-tips/calf-and-heifer/transition-milk-too-valuable-sell 

He is quoted as saying that transition milk is easily worth $30/gallon or $300/cwt because of its value in  promoting good gut health. 

This blog reinforces my transition message in my June 15th Blog on the value of second milkings - about half of the samples tested 50g/L (that is the national threshold for acceptable first feeding colostrum). 

Monday, August 28, 2017

My Ruminations about Rumen pH Among Weaned Calves

By using intensive data collection methods a research team was able to monitor rumen pH in  calves before, during and after weaning. Because of practical limitations (equipment, rumen canulas) the number of calves was limited to six.

"Pre-weaning the average daily pH was low (5.6 ) implying rumen acidosis. The pH reached its lowest levels during the week after weaning (wk 7) with a mean of 5.5 and did not increase before wk 11. Furthermore, ruminal pH was below 5.5 and 5.2 for approximately 745 and 220 minutes daily during wk 7 and 8, respectively. The pH increased significantly in wk 11 and 12 with a mean pH of 6.1."

Even when calves were not eating very much calf starter grain the pH levels were low. I did not expect that finding. In addition to 900g of milk replacer powder daily these calves had free-choice access to chopped straw - supposedly that ration should modify the rumen environment to achieve more favorable pH conditions. Among these few calves clearly the addition of straw did not improve pH conditions pre-weaning.

I noted that rumen pH dropped to 5.2 during weeks 7 and 8 for 220 minutes a day. Those prolonged low pH times suggest a depression of the favorable rumen microbial populations. The article did not mention whether or not  fresh concentrate was provided  before these periods of low pH. If calf "slug fed" on concentrate (usually due to not having a consistent supply 24/7) I would expect depressed pH conditions post feeding.

When feeding my own calves I thought that feeding a big handful of palatable alfalfa hay daily to my older calves would lead to more favorable rumen conditions - the fiber would form a stabilizing mat in the rumen, the calve would be encouraged to spend more time chewing a cud thus delivering more pH neutralizing fluid for the rumen. 

Now ,I wonder about feeding the hay. How well did this dietary rumen adaptation post-weaning work to manage rumen pH? My intent was to start building the appropriate rumen microbial population for fiber digestion (alfalfa hay). I didn't even think about rumen pH.

 I do know that I tried to be sure that after the calves had a milk step-down as part of weaning they always had access to plenty of clean water and palatable calf starter grain - never let either of those run out. At the time I thought that this was a best management practice. I wanted to prevent "slug" feeding (that is, eating an excessively large volume of grain at one time).

I recall that a few of my calves would cycle in their grain intake during weeks six and seven - up and down, up and down over a period of three to five days.  Maybe these were the ones where the rumen pH was very low for prolonged periods of time - perhaps they "went off-feed" because of this - then after recovering they dug into the grain, often eating six or more pounds of grain for the next several days. Then, off-feed again.

Perhaps the take-home message from this research is that we need to pay closer attention to the dietary transitions from weeks 5 through 12 to gradually ease the rumen into the most favorable pH conditions. 

Reference:
J.K. van Niekerk and Others, "Ruminal pH in Holstein dairy bull calves from pre-weaning to post-weaning." Journal of Dairy Science, 100:178 July 2017

Wednesday, August 23, 2017

Pair Housing of Preweaned Dairy Calves

There is a growing body of evidence that housing preweaned calves in small groups (for example, pairs) results in higher rates of gain and more positive social behavior when placed in larger groups. They tend to have less stress when weaned and moved into larger pens. These paired-housing studies have been done in barns.

But, if the farm is raising calves in hutches that will not work. Right?

Well, maybe no so impossible.

Research compared (only a small number, however) raising calves individually in hutches and along side them placing 2 hutches next to each other with a common run. Same farm, same calf care procedures, just that some  hutches were paired.

Now, these findings are from a small number of calves (14 individual housed, 16 calves housed as 8 pairs). So, the results should be considered more exploratory rather than conclusive.

The dairy fed milk twice daily. Calves started out at 6L per day and worked up to 10L per day (until 35 days) and then back down to 6L per day (until 56 days). 

Starter intake:
Up to 35 days (period of high milk intake) no difference in calf starter grain intake between individual and paired calves. Figures below are averages for each type of housing.

Between 35 and 56 days (milk cut back to 6L a day)
     Individual-housed calves = 2.2 lbs daily (1.02kg)
     Pair-housed calves = 3.8 lbs daily (1.72kg)

That is 68 percent more starter intake!

In the post-weaning period (days 56 through 67)
    Individual-housed calves = 3.8 lbs. daily (1.71lg)
    Pair-housed calves = 7.7 lbs. daily (3.51kg)

That is 105 percent more starter intake!

Interesting outcomes from a very small sample.

Reference:
L. Whalen and Others, "Pair housing of dairy calves in modified individual calf hutches." Journal of Dairy Science 100:227 July 2017


Friday, August 18, 2017

Take Time to Care for the Dystocia Calf

The August 2017 calf management newsletter is now posted at www.atticacows.com or click HERE to directly to the letter. 

The key points:
·  Calving difficulty, often called dystocia, affects between 13 to 15 % of Holstein calves.
·   Treatment rates are higher for dystocia calves (scours 17%, pneumonia 70%) compared to calves experiencing unassisted births.
·      Providing special care, both in the first few hours and first two weeks, can cut both death losses and treatments for scours and/or pneumonia.
·        Give lots of stimulation during first few hours.
·        Be sure to follow up for the next two weeks.

Thursday, August 17, 2017

Pneumonia Among Preweaned Calves Cuts
1st Lactation Production 1,155#

These were the findings of a research project completed involving 215 animals from 3 southwestern Ontario herds.

Calves were assessed using thoracic ultrasonagraphy weekly for the first 8 weeks of life. At least one diagnosis of lung consolidation was found in 57 percent of the animals. They were followed through their first lactation.

"The presence of lung consolidation [evidence of bovine respiratory disease] at least once in the first 8 weeks of life was associated with a 525kg (1,155 lbs) decrease in first lactation."

Given this study population, preventing pneumonia (bovine respiratory disease) was an important factor in allowing the animals to express their genetic potential for milk production. 

Reference:
T.R. Dunn and Others, " The effect of lung consolidation, as determined by ultrasonography, on first lactation milk production in Holstein dairy calves." Journal of Dairy Science 100:194 July 2017.


Monday, August 14, 2017

Yes, Air Quality Can Make a Difference!
Increased BRD Among Group-Housed Calves

Seventeen dairy farms in southern Ontario, Canada, using automatic feeders for preweaned calves were visited 4 times over a year.

Sharing air with cattle 5 to 8 months of age was a significant risk factor for bovine respiratory disease (BRD) (p<.01) 

The range of BRD among the 17 farms was from 0 to 28 percent (median 17%). 

Air quality can make a difference for group-housed calves on automatic feeders. Once weaned, the calves belong in another barn - not mucking up the air for the younger ones. 

The authors also found that frequently cleaning of the feeder and pen helped reduce both scours and BRD.

Reference: Medrano-Galarza, C. and Others, "Association of Management practices and calf health on dairy farms using automatic milk feeders in southern Ontario." Journal of Dairy Science 100:340 July 2017

Thursday, August 10, 2017

How Long Does it Take for Antibodies from Colostrum to Reach their Maximum Concentration in Calf Blood?

Using blood drawn from 20 calves received one feeding of 3 liters of colostrum at or less than 2 hours after birth they found this: (this delivered at least 200g of antibodies)

Average time to maxiumum concentration:

Colostrum fed with nursing bottle = 786 minutes (13.1 hours)
Colostrum fed with tube feeder     = 966 minutes (16.1 hours)

The variation was from an estimated low of 625 and estimated high of 1127 (18.8 hours).

Given the small number of calves in the study the difference in these times was not statistically reliable and could have been due to chance variation among calves.

Practical conclusion if we want to estimate maximum antibody blood level?

Wait to draw blood to assess effectiveness of passive transfer of antibodies until at least 18 hours after the last feeding of colostrum.

Reference: Desjardins-Morrissette, M. and Others, "The effect of nipple bottle vs. esophageal tube feeding of colostrum on absorption of IgG and plasma glucagon-like peptide-2 concentrations." Journal of Dairy Science 100:215 July 2017


Tuesday, August 8, 2017

Timing of Colostrum Feeding Makes a Difference

A study reported efficiency of absorption of colostral antibodies. The research team claimed that all 20 calves were fed colostrum at 2 hours after birth.

They reported efficiency of absorption of 54%. Most of the literature reports values around 30 to 35%.

Why so high in this study compared to the other reported data? In my opinion it was due to the timing of feeding. None of the calves went more than 2 hours before the first feeding of colostrum of 200 grams of antibodies (IgG). 

The much lower efficiency of absorption values reported in the literature includes data from calves receiving their first feeding of colostrum anytime before 24 hours.

I really like the protocol followed at the Cornell University Ruminant Research Center in Dryden, NY. They have a collect and feed protocol. The cow is milked as soon as practical right in the calving pen. After the colostrum is tested to be sure it meets the minimum antibody concentration the calf care person feeds the calf. Collect and Feed. No delay.

Timing of colostrum feeding makes a difference. Sooner is better.

As a side note, the research objective was to compare bottle and tube feeding of colostrum. They fed 3 L of adequate quality to provide at least 200g of antibodies. No differences were found in blood serum total protein, time to maximum concentration of BSTP, and efficiency of absorption.

Reference:
Desjardins-Morrisssette, M. and Others, "The effect of nipple bottle vs. esophageal tube feeding of colostrum on absorption of IgG and plasma glucagon-like peptide-2 concentrations." Journal of Dairy Science 100:215 July 2017.

Thursday, August 3, 2017

Pelleted compared to Textured
Calf Starter Grain
[Yet, another chapter]

A research project run between August and October 2016 in Minnesota had the objective of comparing starch levels in calf grains to see if there would be differences in rates of gain and feed conversion efficiency. Calves were fed 20-20 milk replacer at the rate of 1.25# of powder daily.

The comparison grain was a textured calf grain with 30 percent starch. The pelleted grains had starch levels of 18, 24 and 30 percent.

Gain findings
1. There were no significant differences in gains among calves fed the three pelleted feeds that contained different levels of starch.

2. The textured starter gains among calves were 1.5 #/day compared to 1.3 #/day for the pelleted feeds. That is a 17.5% difference when comparing textured to pelleted feeds.

Feed conversion findings
1. There were no significant differences in feed efficiency among calves fed the three pelleted feeds that contained different levels of starch. 

2. The gain-to-feed ratio (measure of feed conversion efficiency) was 0.57 for textured-starter fed calves compared to 0.52 for calves receiving the pelleted feed. That is a 9% reduction in feed efficiency when pelleted is compared to textured feed.

Other observations: No differences in health costs and daily fecal scores among the four feeds.

Conclusion by authors:

"Under the conditions of this study, calf performance was reduced with a complete pelleted starter regardless of starch level compared with the textured starter with 30 percent starch." (p116)

They continued, "Cost savings with a complete pelleted starter may still provide economical gains over a textured starter with 30 percent starch." (p116)

Sam's observations:

I checked our local mill (in July 2017) for prices. For a 20% protein product, the textured feed delivered to our vet clinic cost was $351 per ton bulk [minimum 3 T) compared to $327 for the pelleted product. 

The choice of product may have more to do with the on-farm facilities for storage and feeding rather than either the rate of gain and/or price of feed. 

When caring for my own calves I chose to feed the textured product until calves were about seven weeks old, fed a 50:50 blend of textured:pelleted for a week, then grower pelleted feed from then on. Recall that I was feeding milk replacer at a maximum of 2.2#/day from weeks 2-5 so getting calves to eat starter before 5 weeks was challenging.

Reference: Zeigler, D. and Others, "Pre- and post-weaning performance and health of dairy calves fed complete pelleted calf starters formulated for three different starch levels." Journal of Dairy Science 100:116 July 2017.


Tuesday, August 1, 2017

Greater Feed Conversion Efficiency with More Gradual Weaning of Intensively-Fed Calves

More evidence that gradual weaning is preferred for calves on an intensive-feeding program is reported by the Nurture Research Center run by Provimi North America. 

Calves in the study were fed selected levels of milk replacer varying from a low of 1.4 lbs/day to a high of 2.2 lbs/day. They had weaning programs as short as 7 days and as long as 18 days. 

Feed efficiency (gain per pound of dry matter intake) was highest for the high feeding rate calves weaned over the longest (18 days) period of time.

As I look back at my own weaning practices for intensively-fed calves there were two trends that were significant for me:

1. Although my goal was to complete my step-down weaning in one week nearly all my calves took two weeks to arrive at my goal of calf starter grain intake. Thus, rather than calves completing weaning between 42 and 49 days, most of them were completely weaned between 42 and 56 days - thus the weaning took two weeks. 

2. I participated in a feeding trial involving these intensively-fed calves. We had rates of gain for each week up to when they were completely weaned. The majority of these calves taking two weeks to wean gained over two pounds a day between 42 and 56 days. It seems to me that we were getting very acceptable rates of feed conversion among these calves even though I admit I did not have dry matter intakes for them.

Reference:
Dennis, T.S. and Others, "Effects of milk replacer feeding rate and age at weaning on calf performance and digestion through 8 weeks of age." Journal of Dairy Science, Supplement 2, 100:301 July 2017.

Monday, July 31, 2017

What to do When the Train Falls off the Rails?

We did a routine check on effectiveness of cleaning procedures on colostrum handling equipment. The previous check results were really good.

Oops! The train fell off the rails.

I use the Hygiena SystemSure Plus unit (luminometer) to do adenosine triphosphate (ATP) monitoring. The ATP test is a process of rapidly measuring actively growing microorganisms through the detection of adenosine triphosphate. An ATP monitoring system can detect the amount of microbial contamination that remains after cleaning a surface (for example, calf feeding equipment). 

Here is where the train fell off the rails: (this farm set their standard for an acceptable clean surface is 100rlu)

Sample site                                                                    Previous          Current
                                                                                       Reading          Reading
Milker bucket used to collect colostrum                             5                    46
Plastic lid for milker bucket                                                0                5298

Tube feeder inside the bottle                                               0                    10
Tube feeder inside tube at top where screws on bottle       0                 1404
Tube feeder inside tube at ball end                                    12                3458

These tests were run on-farm with the maternity pen supervisor at my elbow. He was not a happy camper. 

We checked out the sink where the milker bucket and lid were washed. Chlorinated detergent supply was okay, brushes were there. The plastic lid reading appeared to be a breakdown in protocol compliance. He was going to review cleaning procedures with the two employees that had responsibility for that cleaning job. 

We checked out the sink where the tube feeder was washed. Supply of hot water was okay, chlorinated detergent supply was okay, brush for tube feeder bottle was there but the one for cleaning the inside of the tube itself was missing - just gone. A phone conversation with the guy that feeds and cleans this equipment turned up the fact that the brush had been missing for a week. [Note that the employee did not tell the maternity pen supervisor about the brush for a whole week!] I supplied a new brush from my truck.

Now we had a better idea why the calf care person had been using so much electrolyte solution for scouring calves the past couple of weeks.

Friday, July 28, 2017

How Long are Calves Left with Dams after Birth?


How about leaving the calf with the dam for 2 hours? Six hours? Twelve hours or more?

A study of dairy farms in Ohio and Michigan included both conventional and organic producers. They reported their practice of separating calves from dams.

"The majority of conventional (64%, 279/439) producers reported separating the calf from the dam 30 minutes to 6 hours after birth. 

More organic (34%, 56/166) than conventional (18%, 80/439) producers reported separation 6 to 12 hours after birth, and organic producers were more likely to agree that time before separation is beneficial." (p292)

If we do a little adding we conclude that among conventional dairies with 279 separating less than 6 hours and another 80 separation between 6 and 12 hours we have a total of 359 separating at 12 hours or less. 

That means among the 439 conventional dairies there 80 farms (18%) remaining that routinely left calves with the dam for more than 12 hours.

On one hand, the advantage of early separation is reduced exposure to pathogens (for example, coliform bacteria, cryptosporidia parasites) being shed in high numbers by the dam. 

On the other hand, folk knowledge suggests that the presence of the calf during the first 24 hours promotes lower rates of retained placenta and metritis.

In a review of scientific literature Dr. Leslie (University of Guelph) pointed out that the process of uterine recovery from birth is closely related to frequency of udder stimulation (either nursing or being milked). 

Beef cows being suckled by their calves or dairy cows being milked 4 times daily have more rapid uterine recovery than dairy cows milked twice daily. Thus, the biological evidence shows that frequent oxytocin release in the days after calving is key to the processes of uterine health. Unless leaving the calf with the dam is connected to frequent suckling there appears to be no advantage to leaving the calf for an extended time with the dam (and maybe other adult animals).

What do I recommend to my clients? Do whatever you can to reduce pathogen exposure for newborn calves. On some dairies this means physically removing the calf from the dam's environment as soon as the calf is able to stand.

On other dairies dam access to the calf is given priority. Good calf health can still be accomplished without high pathogen exposure. 

This means placing the calf in an environment where she cannot fall face-first into dirty bedding or lick the dam's dirty hair coat BUT the dam can still reach her to continue licking and stimulating respiration and healthful behaviors. Some farms put the calves a water tub in the calving pen while others use some kind of low gating to confine the calf while allowing access by the dam.

In my consulting practice, especially in Australia and Europe where it is a common practice to leave calve with dams for 24 hours or more, I have seen significant improvements in calf health associated with reducing cow:calf contact hours.

References:
Pempek, J. and Others, "Dairy calf management - A Comparison of practices and producer attitudes among conventional and organic herds." Journal of Dairy Science, Supplement 2, 100:292. July 2017

Leslie, K., "The Events of Normal and Abnormal Postpartum Reproductive Endocrinology and Uterine Involution in Dairy Cows: A Review." Canadian Veterinary Journal 24:67-71


Monday, July 24, 2017

Pain Relief Among Calves Dehorned with Chemical Paste

In a report published in the American Journal of Dairy Science (August, 2017) the authors assessed pain response to dehorning with chemical paste. They also evaluate methods of pain relief.

In summary, they reported

1. Calves dehorned with chemical paste with no pain relief showed symptoms of strong pain at 60 minutes that continued somewhat diminished out to three hours. 

2. Calves dehorned with chemical paste with a cornual nerve block (similar to that used for thermal dehorning) showed much, much lower symptoms of pain over the 3-hour observation period post treatment.

3. The authors recommended using the same pain relief procedures for caustic paste dehorning as for thermal burning.

As always consult your dairy veterinarian for the procedures best for your farm. 

Reference:
Winder, C.B. and Others, "Clinical trial of local anesthetic protocols for acute pain associated with caustic paste disbudding in dairy calves." Journal of Dairy Science 100:6429-6441 #8 August 2017

Thursday, July 20, 2017

Vaccinating Calves 
Thoughts from Dr. Woolums

I was reviewing a file in vaccinating calves. I found Dr. Woolums' talk at the 2013 NY Calf Congress, "Calf Immunity: Expectations and Reality."

Dr. Woolums is an internationally recognized authority on bovine immunity. She had these thoughts:

1. When vaccinating calves, plan to boost once or twice before disease is expected to occur. 

2, When vaccinating calves under 6 months of age, try to give a least 2 doses one month apart.

3. Try to administer vaccines so that the final boost is given one month before expected disease. 

4. Reliability of response [to vaccines] is inversely correlated with age. 

5. Consult with your veterinarian regarding vaccine choice and timing. 

All good ideas. 

Tuesday, July 18, 2017

Protecting Calves from Stress

Some stresses seem to be unavoidable. We have to wean all of the calves eventually. Their ration will change. Their housing will change.

We know that the changes in the calf's body caused by stress can have negative consequences. What, then, can we do to reduce these "bad" effects?

In a recent consultation we (owner, me) talked about improving the overall well-being of the calves as a means of compensating for these stresses. Calves were "flat-lining" (no growth) for a month after weaning, many requiring treatment for  pneumonia.

Changes that were considered to improve the overall well being of the  included these:

1. Strengthen the colostrum management program - increase the volume fed from the current one 2-quart feeding; try to get more calves fed sooner after being born, start checking colostrum quality so the best quality can be fed for first feedings. The vet will take blood samples to check on passive transfer effectiveness. Try to get readings for 10 to 12 calves total. 

2. Feed more milk to preweaned calves - feed more than the current 2 quarts twice a day of 20-20 milk replacer (currently mixed 8oz. makes two quarts).

3. Change calf starter grain feeding program - currently fills bucket when calf is a week old and leaves it until it gets empty - talked about keeping only enough starter grain in buckets close to consumption rate and dumping them at least once a week.

4. Check on how well these efforts to improve overall well-being are working. Using a heart girth weight tape get some birth:weaning weights to get actual growth rates [industry standard is now to double weight in 56 days]. As they are weaned, try to get 10 calves.

We also talked about the weaning procedures and weaning pen management but that is a discussion for another day. 

Monday, July 10, 2017

We Quit Testing Our Colostrum!

This is the conversation last week on a dairy.

Me: How is your colostrum quality this past month?
Dairy: Oh, we don't have enough colostrum. We have to feed all of it. So, we quit testing our colostrum.

Me: Well, if you don't have any good quality colostrum for first feeding, can't you feed a colostrum replacer?
Dairy: No, we don't have replacer. It costs too much. We just feed whatever we have.

End of conversation.

They have a written colostrum-feeding protocol that is followed very well. They collect blood from all the two - three day-old calves. Their average blood serum total protein level for the past six months has been around 6.2mg/dl. (Industry standards are 90% at 5.2 or above, 80 % at 5.5 and above.)

But, when I scan the list of blood serum total protein values really low values keep popping up. Most often there are two or three together. This in contrast of isolated low values. 

What do I conclude? Batches of really low quality colostrum are being fed to two or more calves in a row.

Here is the critical question.

Are the health and growth disadvantages associated with feeding this poor quality colostrum worth more than feeding a good quality colostrum replacer? My answer is "YES."

My recommendations:

1. Start testing colostrum again. Use the Brix refractometer to identify the low IgG stuff. 

2. For first feeding, if no good quality (Brix >22 solids) colostrum is available. use a good quality colostrum replacer that will provide 200 g of IgG (we have to be careful here because there are many products on the market that are packaged to provide only 150 g IgG). 

3. For the second feeding, use whatever quality colostrum that is available. Fresh maternal colostrum has a lot of other stuff in addition to antibodies that will benefit the calves. (All the calves receive 6 quarts of colostrum during the first 24 hours.) When practical use the lower quality colostrum for feeding calves on the second day, too. It is a great energy source especially during cold weather months. 

Bottom line: Continue to test colostrum quality. We can make better management decisions knowing quality than just blindly feeding "whatever we have."

Friday, July 7, 2017

Test, Don't Guess: Monitoring Bacteria Counts in "as-fed" Milk

The July, 2017, issue of the calf management newsletter focuses on a quality-control issue important for reducing the rate of scours treatments among preweaned calves. Click HERE for this issue. If the link does not work on your computer, then enter this in your browser window:
http://www.atticacows.com/library/newsletters/CEJuly2017.pdf 

The key points:
  • Milk residues provide an excellent place for bacteria to grow and form biofilms.
  • Biofilms on equipment are a common source of bacteria in the milk/milk replacer we feed to our calves.
  • Contaminated milk (bacteria) can pose a significant health challenge for young dairy calves resulting in diarrhea and secondary respiratory infections.
  • It is cost effective to regularly sample and culture “as-fed” milk in order to monitor the effectiveness of our sanitation practices.
  • Practical sampling procedures for group and individually-housed calves.
Enjoy.

Monday, July 3, 2017

Revised 7/3/2017
Colostrum Bacteria Control: 8 Practical Steps to Reduce  Bacteria Counts

This resource is in the Metric version of the Calf Facts Resource Library at www.atticacows.com.

The eight steps that are detailed in this resource are: 
·         Step 1. Clean teats in the parlor.
·         Step 2. Clean dump buckets including lids, valves and gaskets.
·         Step 3. Clean buckets to collect colostrum as it is harvested.
·         Step 4. If buckets or pails are in the parlor, clean covers are used for every bucket before, during and after use.
·         Step 5. Prompt feeding of fresh colostrum
·         Step 6. Prompt cooling of colostrum if it is to be stored
·         Step 7. Clean containers for feeding and storing colostrum.
·         Step 8. Prompt feeding of warmed up colostrum

    The resource is HERE or type this into your browser
     http://www.atticacows.com/library/newsletters/ColostrumBacteriaControlUK162R17.pdf




     Enjoy.

Thursday, June 29, 2017

Gradual compared to Abrupt Weaning

I was reading a report involving 18 dairy farms in western Canada. Among the data were facts about weaning practices followed by these farms. Thirty-nine percent of them abruptly weaned calves with the remaining 61 percent following "gradual" weaning procedures. Why do so many farms continue to abruptly wean dairy calves?

Then I recalled work done in 2010 that compared different weaning strategies (abrupt, 4 days, 10 days and 22 days). They found that the 10-day weaning period resulted in the minimum growth check post-weaning. That is, the calves weaned this way had the lowest decrease in their rate of gain. In sharp contrast, abruptly weaned calves lost weight initially post-weaning.

My consulting experience with health problems among "just-weaned" calves include many farms experiencing high respiratory treatment rates among these abruptly weaned calves. What else would we expect among calves that are experiencing high levels of stress?

That transferred my attention to a June 2017 Journal of Dairy Science article, "Abrupt weaning reduces postweaning growth and is associated with alterations in gastrointestinal markers of development in dairy calve fed an elevated plane of nutrition during the preweaning period." [underline added by me]. They compared 0 step-down with a 12 day gradual weaning protocol.

If one uses only average daily gain as measure of successful weaning their data show that both groups of calves had about the same rate of gain at the end of the full 54 days of the study.

BUT, during the post-weaning period (days 49 - 54) the gradually-weaned calves consumed 2.9 pounds (1.32kg) of starter grain daily compared to the abruptly-weaned calves considerably lower consumption rate of 2.2 lbs. (0.991kg).

Further, the average daily gain among the abruptly-weaned calves dropped from 2.2 pounds daily pre-weaning to 0.5 during the week post-weaning - a huge growth check. These are the high-risk calves for respiratory illness.

As an aside, I recommend that farms feeding milk/milk replacer at an intensive level (that is, 8 or more quarts per day) not depend on calf starter grain intake for coccidiosis control. In my experience calves that I started to wean around 35 days (5 weeks) were eating far to little starter to provide coccidosis control. With my step-down program (eliminate one full feeding a day when the calf is regularly eating one full pound of starter daily for three days in a row) I depended on amprolium in the milk for coccidiosis control. Most of my calves increased their daily starter intake by 56 days to roughly 4.5-5.0 pounds (about 2kg). At that age they were moved into small group pens (N=5) and continued to be offered ad lib a 16%cp heifer pellet. Coccidiosis breaks were few and far between.

References: Sweeney, B. C. "Duration of weaning, starter intake, and weight gain of dairy calves fed large amounts of milk." Journal of Dairy Science 93:148-1525 2010. Atkinson, D. J., and Others, "Benchmarking passive transfer of immunity and growth in dairy calves." Journal of Dairy Science 100:3773-3782 April 2017. Steele, M.A. and Others, as above Journal of Dairy Science 100:5390-5399 June 2017. 


Thursday, June 22, 2017

Automatic Calf Feeders - Bacteria Control Challenges

During a study including 38 farms over 18 months the research team assessed the bacteria contamination levels of milk consumed from automatic calf feeders. Each farm was sampled from both the automated feeder mixing tank (mixing tank) and the point of connection between the flexible dispensing tube and the nipple (tube end). 

Bacteria counts reported:


Source of Sample           Value                         Standard Plate Count      Coliform Count
                                                                                   (cfu/ml)                         (cfu/ml)
1. Mixer tank                  Median                              166,916                             336
                                        Range - lowest                         125                                 0
                                                   - highest              59,396,100               25,621,330

2. Tube end                     Median                            2,566,867                       10,430 
                                        Range - lowest                       6,668                              45
                                                   - highest              82,825,000               28,517,000

Using the thresholds of 10,000 cfu/ml coliforms and 100,000cfu/ml standard plate count (SPC) they reported:

Source of Sample                 SPC>100,000            Coliform Count >10,000
                                         (% farms above)            (% farms above)
1. Mixer tank                          32                                   15
2. Tube end                             68                                   28

What are the messages for me?

First, RANGE values for both SPC and coliforms demonstrate that while it is possible to deliver clean food to autofeeder calves it clearly is possible to screw up badly - very, very badly - 82,000,000 plus cfu/ml!

Second, when I culture "as-fed" milk samples for my clients we use these upper thresholds to determine if on-farm cleaning and handling procedures are being met (usually fed in bottles or buckets manually):
                              SPC     <10,000cfu/ml
                       Coliforms   <1,000cfu/ml

If my clients' samples came back looking like those from theses 38 farms I would be all over their cases - all cleaning procedures would be examined closely for protocol compliance slip-ups. Weekly samples would be taken all along the handling stream to isolate possible points of inoculation and growth.

Third, in terms of calf care and calf health, I consider feeding milk with these levels of bacteria contamination irresponsible and perhaps bordering on animal abuse.

As an aside, one time when we were monitoring bacteria levels with automatic feeders for a client we discovered that the warm-water holding reservoir was serving as a bacterial incubator because the feeders were being used most of the time for whole milk. Contaminated water was leaking into each batch of milk as it was heated. By changing the settings to use 10g of powder in every mixer bowl the reservoir problem was eliminated. So, I have to admit that issues beyond cleaning can sometimes contribute to high bacteria counts. 

References:
Jorgensen, M.W. and Others, "Factors associated with dairy calf health in automated feeding systems in the Upper Midwest United States." Journal of Dairy Science 100:5675-5686 June 2017. Dietrich, M. and Others, " Factors associated with aerobic plate count, coliform count, and log reduction of bacteria in automated calf feeders." Journal of Dairy Science, 93, Suppl. 2, p214 #86.

Monday, June 19, 2017

Variation in Colostrum Yields

In response to a recent question about variations in colostrum yields I pulled together data from two studies published in the Journal of Dairy Science in 2016 and 2017. All cows were second lactation and greater.

The first study was with Holstein breed cows from 9 farms with a total of 111 first milkings. They averaged 17 pounds of colostrum at first milking. However, the overall variation was from 1 pound to 87 pounds! Two-thirds of the samples (N=74) fell between 2 and 33 pounds.

The second study was with Jersey breed cows from one 3,500 cow dairy in California. They collected data on 134 first milkings. The average yield was 9 pounds. The overall variation was from less than 1 pound to 30 pounds. Two-thirds of the samples (N=90) fell between 3 and 15 pounds.

The answer to the question "How much variation in volume of colostrum production is 'normal'?" is:

1. Widely varying amounts among cows for any given lactation, length of dry period, dry-cow ration and season of the year are "normal." Further, predicting this variation based on production in previous lactation is not very reliable.

2. If we plan on feeding about 17 pounds (4 quarts) of colostrum for newborn calves during the first 4 hours of life (Jersey calves = 13 pounds or 3 quarts) then we need to be prepared to supplement the dam's yield for many of our calves.

3. Having a provision to store excess colostrum while minimizing bacteria contamination is a best management practice. Remember rapid chilling to 60F (16C) after collection is a cost effective way to maintain high colostrum cleanliness.




References: Cabral, R. G. and Others, " Predicting colostrum quality from performance in the previous lactation and environmental changes." Journal of Dairy Science 99:4048-4055 2016 Silva-del-Rio, N. and Others, "Colostrum immunoglobulin G concentration of multiparous Jersey cows at first and second milking is associated with parity, colostrum yield, and time of first milking, and can be estimated with Brix refractometry." Journal of Dairy Science 100:5774-5781.

Thursday, June 15, 2017

Second Milking - A Colostrum Resource?

Colostrum in short supply? Try collecting and testing second milking from fresh cows.

In a study involving second lactation and greater Jersey cows the investigators collected both first and second milking (N=68 cows).

This is what they found from the second milkings:

                                                                  Average(Mean)   Minimum    Maximum
Amount of colostrum collected (lbs.)            9.5                       0.9               25.3
Brix value (percent)                                     18.7                     13.4               29.3
Antibodies (IgG) in lab test                         46.9                       6.2              100

Nearly one-half of the second milkings (43 percent) had the industry standard of 50g/l minimum for colostrum acceptable for first-feeding newborn calves. 

TEST, DON'T GUESS.  That's the message - your second milking from cows may be a "hidden" colostrum resource on the dairy. 

Reference: Silva-del-Rio, N. and Others, " Colostrum immunglobulin G concentration of multiparous Jersey cows at first and second milking is associated with parity, colostrum yield and time of first milking, and be estimated with Brix refractometery." Journal of Dairy Science 100:5774-5781. July 2017.

Tuesday, June 13, 2017

The Value of Being Raised on a Farm

Right away you need to know that this post has nothing to do directly with animal science for managing calves.

A mom wrote this about her son, a recent college graduate, and his experiences on his first job. Click HERE to access or paste in your browser this URL
http://whminer.org/pdfs/06-17.pdf   Scroll down to the article on page 9.

For those of us who grew up working on farms it will resonate soundly with our life experiences.

By the way, it is in a really interesting  monthly report from the Miner Institute, a research and educational institution in northern New York State. It's easy to subscribe and receive it monthly. Just send an e-mail to dutil@whminer.com and tell her to sign you up for their monthly publication notice.

Enjoy. 


Monday, June 12, 2017

More on Group-Housed Calves
on Automatic Feeders

"A study of farms using automatic feeders and group housing revealed some practices that point to success in these calf rearing systems." This is the lead for an article by Dr. Marcia Endres (University of Minnesota, St. Paul) that summarized factors that can be important for the successful use of automated calf feeder systems.

She listed these nine factors:

"1. Reduced time to reach peak milk allowance.
2. Milk or milk replacer with low bacteria counts (cleanliness of equipment is key).
3. Positive pressure ventilation tubes.
4. Sufficient amount of space per calf in the resting area.
5. Small number of calves per group.
6. Adequate farm serum total  protein concentration averages (an indicator of passive immune transfer.
7. Drinking speed used as a warning signal to identify sick calves.
8. Consistent navel dipping and disinfecting.
9. Narrow age range within calf groups." (p349)

You may want to read the entire article including her nine "Rules of Thumb" or specific recommendations for automated calf feeder systems.

Reference: Endres, Marcia "Lessons learned from group-housed calves." Hoard's Dairyman May 25, 2017, page 349.


Friday, June 9, 2017

Hay for Preweaned Calves

"Hay for Preweaned Calves" is the subject for the June, 2017 issue of the calf management newsletter. In summary you will find:

  • Calf-care persons have widely different opinions about feeding hay to preweaned calves.
  • Discussions about feeding hay to preweaned calves need to to specify (1) the physical form of hay, (2) volume hay fed, (3) nutrient profile, (4) species present, and (5) calf age at which hay is introduced to the ration.
  • Discussions about feeding hay to preweaned calves may focus on papillae development and health and lack emphasis on the microbial population essential for forage digestion.
  • Recent research is leading me to conclude that limited hay intake has a variety of positive outcomes for preweaned calves.
  •  Practical aspects of feeding hay to preweaned calves.
If you have any stories to share dealing with feeding hay to calves please feel free to forward them to me at smleadley@yahoo.com. I would enjoy hearing from you. 

Sam