Push Metabolizable Protein in Close-up Cows

We spend so much time fine-tuning transitional management in our quest to achieve optimal performance.  The performance of an athlete, a sprinter, is highly dependent on how they start; if they stubble out of the blocks, they have already lost the race and some may never finish.  The same is true for the cow in relation to the starting point of the lactation period.  We are constantly seeking the perfect dry cow ration, the ration that will solve all of your transition problems.  In this article, we will focus on the importance of protein, particularly metabolizable protein (MP), in the close-up period.

Metabolizable protein (MP) is a better predictor of protein availability for the cow’s use compared to crude protein (CP).  MP passes from the rumen as rumenal undegraded protein (RUP), rumen microbial protein (yes, rumen bugs are an excellent source of protein), and endogenous protein, digested in the abomasum, and absorbed as amino acids in the small intestine.  Therefore, the goal of nutritional program is to maximize rumen microbial protein, in essence, “Feed the Bugs!”  If the rumen microbial protein can not be enhanced further, more RUP, rumen bypass protein, needs to be fed.  

Why is metabolizable protein important for the dry cow?  In all ruminants, the rumen microbes need readily available protein and energy sources in order to survive and grow.  In return, the rumen microbes ferment fiber and rapidly multiply providing more MP.  The cow has important maintenance requirements.  A protein called albumin transports calcium, sodium, potassium, etc  and helps to maintain fluid balance throughout tissues.  Protein is needed for proper liver and immune system function.  Higher protein levels improve sensitivity to insulin as well.  So, it seems reasonable to assume that if MP is low, more metabolic problems ensue.  The growing fetus increases protein demands.  Sixty percent of the calf’s total body weight occurs in the last 2 months of gestation.  The 2001 NRC (National Research Council, Nutrient Requirements of Dairy Cattle) fails to account for the protein demand needed for mammary growth and colostrum production.  Heifers have an additional protein requirement for growth.  Finally, a higher pre-calving protein level is needed so requirements are met in the face of dry matter intake declines.  Individuals with lower dry matter intakes, such as heifers, cows with BCS>3.75, cows with twins, lame cows, etc, need to consume a ration with a higher protein level.

Controlled energy dry cow diets minimize the intake decline pre-calving and are excellent one group dry cow rations.  However, when problems arise we typically find particle length >2” which promotes sorting, low starch, and/or low MP.  Starch is needed to feed rumen microbes, from which the cow derives protein.  Therefore, when starch is limited, more rumen undegradable protein (bypass protein) is needed to maintain adequate MP levels.  Close-up rations higher in Non-Fiber Carbohydrates (NFC) or starch have higher levels of MP as long as the starch and rumen degradable protein fractions are adequate. 

Meeting a dry cow’s metabolizable protein requirement is extremely important.  Meet and exceed a Close-up dry cow requirement of 1200g MP per day.  Due to lower intakes and declining rumenal volume due to the growing calf, a close-up cows require a higher level of rumen undegradable protein in order to meet MP requirements.  If commingling all dry cows in a single group, the close-up ration should address the nutritional needs of the groups with lowest dry matter intakes, i.e. your heifers, fat cows, cows with twins, lame cows, etc. 

Eliminate the stumbling blocks that will prevent your cows from achieving a productive lactation.  Critically analyze your close-up dry cow diets.  Feeding appropriate levels of metabolizable protein to your close-up cows will enhance performance and improve health.   

Identifying Stillbirth Risk Factors

A veterinarian in the Mid-Atlantic region has an opportunity to work with dairies of all shapes and sizes.  Therefore, we have a true opportunity to compare and contrast varying dairy management styles from clear opposite spectrums.  In this article, we will discuss one of those “aha” moments where a concept proven on a small grazing farm was applied to a larger commercial dairy herd.

In the middle of a herd check with one of our seasonal grazing herds, I asked the dairyman a random question.  “So how many calves were stillborn this past spring during calving season?”  The client replied proudly, “Forty-eight calvings.  Forty-eight live calves.”  Doesn’t that send chills up your spine?  Ask yourself how many stillbirths your herd experienced over the past year.  Truly, the above statistic is one I would be very proud of.  Look at national statistics.  An estimated 7-10% of all births are stillborn.  Close to 15% of first-calf heifers and 7-8% of mature cows calve with stillborns.  These numbers reveal a potential animal welfare issue that needs to be addressed in addition to a lost profit opportunity from replacement loss.  Case in point; I work with a large commercial herd that was experiencing a higher level of stillbirths of around 10%.  We recognized a potential profit opportunity lost as a result of this high level of stillbirths.  We made a goal of lowering stillbirths below 8%.  I brought up the grazer data.  So we asked ourselves what could be learned from the grazer. 

           

The first concept that came to mind was “wide open spaces;” a picturesque wide open, lush green and clean spring-time pasture on which to calve.  Overcrowding stress was not an issue.  Consequently, cows were able to exhibit their natural calving behavior of stress-free isolation.  In the larger commercial herd, stillbirths averaged 17% in January 2008 and 24% in January 2009 when the largest calving slug of the year occurred.  The obvious problem was overcrowding stress associated with pen size that did not accommodate the larger group.  To compound matters, commingling first-calf heifers in an overcrowded pen resulted in more social stress and anxiety and a higher level of stillbirths, 31% in January 2009.  Furthermore, the overcrowded pens were a nightmare to keep clean, meaning that the cows and calves were exposed to a higher bacterial level.  Construction of a new barn for milk cows allowed the larger dairy to provide a larger pen for close-up cows.   In addition, we now had two close-up pens which enabled us to split mature close-up cows from first-calf heifers with both pens providing in excess of 150ft2 per head and greater than 30” bunkspace per head.

           

Second, the grazing herd had very little transitional problems.  He treated one milk fever during the calving season.  Metritis, retained placenta, ketosis, DA’s, and even lameness were non-existent.  How does metabolic disease result in a higher level of stillbirths?  Cows with metabolic disease at the time of calving have a slower calving process creating more stress for the calf.  In addition, failure of passive transfer of IgG from colostrum is more common which affects calf health.  As you might imagine, with close-up pen overcrowding, transitional problems in the larger dairy were a greater issue.  To make matters worse, the close-up ration had obvious problems and needed adjustment.  After the ration changes were implemented, the LDA rate dropped from 5% down to <2.5% along with a reduction in stillbirth risk.

           

Third, the grazer had a tighter A.I. breeding window in order to maintain seasonal calvings.  Due to an adequate number of replacements, cows that did not fit the window were culled.  Cows experiencing lower conception rates and longer calving intervals are at greater risk for developing transitional problems.  As a result of the need to maintain a tight calving window, the grazer eliminated cows that would likely be at greater risk for stillbirth.  Because the larger dairy was experiencing a high fresh cow cull rate, potential cull cows were kept in the herd in order to maintain numbers.   Consequently, he held onto cows with a higher risk for stillbirths.  Dairies need to evaluate culling strategies and management areas that impact culling risk. 

Finally, the grazing dairyman practices cross-breeding and uses calving-ease sires for first-calf heifers.  Certainly, hybrid vigor affects calf survivability and the smaller dairy breeds typically do not have large calves.  The larger dairy began using sexed semen for first service in heifers and in 35% of cow first service. 

Both dairies have an excellent heifer rearing program.  Heifers calve between 22-24 months of age with adequate size and scale and body condition ~3.0.  On many dairies inadequate heifer rearing management leads to higher stillbirth incidence.  Both dairies have solid vaccination protocols and forage quality reducing stillbirth risk from infectious disease and mycotoxins. 

Earlier studies have shown that 50% of all calf deaths are a result of dystocia or calving problems.  Speak with your veterinarian about  proper calving management and calf resuscitation techniques. Too often, lack of patience on the part of the dairyman or employee creates calving problems and a paralyzed or dead cow and a dead calf.  Intervention should occur after 1 hour of active labor in mature cows and 2 hours of active labor in first calf heifers. 

Keep in mind that the stillbirth risk factors discussed in this article impact the profitability of the cow.  According to a Cornell 2007 study, cows that had a stillbirth had a 41% greater risk of dying or being culled during the lactation compared to cows that had live calves.  Furthermore, median days open increased 88 days which increases culling risk compared to cows that had live calves.

As you can see, there is much that we can learn from each other.  The case outlined in this article demonstrates how interdependent each dairy management segment is to each other.  Management problems that diminish the health of fresh cows lead to greater stillbirth risk.  

Time for a Transition Cow Intervention

Why do we focus so much attention on the transition period?  The return on investment for the first 100 DIM is 3:1.  A problem in the transition period results in greater health-related costs and lower productive and reproductive performance.  We plan to take the discussion a little further and provide you with real-life scenarios and problem-solving skills.  In this article on transition management, we will show you information and analysis from 2 herds, one that made a transition management error and another that corrected a problem.  The herds in this review are between 400-600 cows.  However, the concepts gleamed from this article can be applied to smaller herds.  From this discussion, we hope you take the time to critically review transition cow management on your farm. 

           

Herd A was performing well in 2009, with production in the high 80’s and lower 90’s, zero displaced abomasums, and 60-DIM cull rate < 6%.  Then, by early December, we begin to see a deviation from the transitional norm with a higher incidence of retained placentas, metritis, ketosis, and DA’s.  DairyComp305 dairy records analysis showed a graphically dramatic first-test butterfat spike for cows calving at the end of November. 

First-Test Butterfat

Herds with first-test butterfat over 1 percentage point higher than the herd average butterfat are at greater risk for ketosis.  First-test milk and Week 4 Milk in the same cows began to decline.   

First-Test Milk

Week 4 Milk

What management change occurred to create this transition problem?  Prior to November, Far-off dry cows were separated from pre-fresh cows giving pre-fresh cows sufficient feedbunk space at more than 30” per head and adequate bedpack space exceeding 150ft2.  Far-off cows were receiving a controlled energy ration (0.64 NeL) and the pre-fresh were being fed a higher energy steam up ration (0.69-0.72 NeL).  Due to a lack of shelter, the far-off cows were grouped with the pre-fresh cows and fed the prefresh ration when wintry weather developed in the middle of November.  By commingling the groups, feedbunk and bedpack space became limiting factors, and the energy level in the ration was too high for far-off dry cows resulting in the transition problems experienced by this herd.  Higher energy far-off diets predispose cows to health problems particularly if intakes are interrupted.  Furthermore, the far-off ration influences the response to close-up management.  We are fortunate that we only saw 6 LDA’s.  Today, the far-off dry cows are again segregated from pre-fresh cows giving pre-fresh adequate feedbunk and bedpack space.  Additionally, both groups are currently being fed a controlled energy TMR.  We have not seen a DA since the management changes were made.   The herd is currently averaging 98 pounds.   

Herd B appeared to be doing everything right.  The cows had adequate feedbunk and bedpack space.  In fact, mature cows and heifers were grouped separately and both groups were held to 80% populated to prevent overcrowding.  After calving, the fresh cows were moved to an equally comfortable fresh cow group that was also held to 80% populated.  However, fresh cows were not transitioning in well.  We saw too many down cows unresponsive to treatment, retained placentas, metritis, ketosis, stillbirths, 5% DA’s, and the cull rate (sold and died) <60DIM was too high at 8%.  Pre-fresh metabolic profiles revealed that NEFA levels were too high (too much early body fat metabolism) and albumin (protein) levels were too low.  With high NEFA’s and low albumin concurrently, dry matter intakes were a concern.  Additionally, close-up energy levels exceeded 0.72 NeL and protein levels were borderline too low. 

By late August, we chose to implement a one-group controlled energy TMR using hay and straw chopped to a consistent 2” length, with energy levels ~ 0.64NeL (15-16 Mcal/day) and metabolizable protein levels exceeding 1200g.  A well-designed controlled energy ration improves rumen fill which is maintained during the post-calving period.  Additionally, dry matter intakes immediately pre-calving experience a less significant drop prior to calving than higher energy diets.  Also, we eliminated wet haylage which was high in butyric acid from the prefresh ration and lowered it in the post-fresh ration.  Wet, high butyric acid haylage reduces DMI, suppresses the immune system, and increases the incidence of ketosis.  Since the ration change occurred in August 2009, DA incidence rate is <2%.  RP and metritis are below 3%.  Clinical milk fevers are non-existent.  Stillbirths went from 10% to 6%. 

DA Count

And with transitional health improving, we are starting to see a significant improvement in 21-day Pregnancy rate.  Over the last 6 months, preg rate is averaging 28%!

21-Day Pregnancy Rate

Both herds experienced common transitional management problems that we typically see.  Data analysis helped to pinpoint problems and support and monitor implementation of specific management changes.  In our example, eliminating overcrowding and utilizing controlled energy TMR’s enhanced transition performance.  

Preventing Dairy Cow Injuries

As a practice, there is one thing we can agree upon.  We all hate to see down, injured cows.  Treatment is usually unrewarding and we typically leave the farm feeling defeated knowing that euthanasia was the only solution.  If treatment is unrewarding, we need to focus on prevention. 

How prevalent is mortality associated with injury/lameness?  The 2007 National Animal Health Monitoring System (NAHMS) reported that 5.7% of all cows die on the farm.  Many of the deaths in the U.S. dairy herd could be prevented.  Of the producers surveyed, injury and lameness were mentioned as the leading causes of death on the farm.  A staggering 20% of all cow deaths are associated with injury or lameness and 16.5% and 15.2% of all deaths are secondary to mastitis and dystocia (calving problems) respectively; all potentially preventable problems.  Lameness and injury account for 16.0% of all cows sold, behind Reproduction (26.3%), Udder/Mastitis (23.0%), and Production (16.1%).  A 2006 paper by Hadley et al analyzing 1993-1999 DHIA culling data for Upper Midwest and Northeast herds revealed that the primary reason for culling (sold and dead) was injury for both large and small dairy herds.  Colorado State University researchers showed in a 2008 paper that herds experiencing a high incidence of lameness (>16.1%) experienced mortality rates 2.89 times higher than herds with a low incidence of lameness (<3.3%). 

At what management period do we see greater mortality rates?  In the Hadley et al study, the majority of cows that died (42%) did so during the first 60 days in milk.  A similar statistic was found in another study analyzing mortality and culling patterns in Pennsylvania dairy herds by Dechow et al.  In that study, 44.6% of all cows culled during the transition period died on the farm.  Another 27.4% of cows culled during the transition period were coded injury/other.  Calving paralysis and metabolic disease lead to greater morbidity and mortality.  Transition cows are weaker and more prone to injury.  Additionally, when cyclicity begins, standing heats increase the risk of injury.  Mortality rates typically increase during the summer months.    

What are injuries costing a herd?  The value of a cow as compost is minuscule compared to her value as a productive member of the lactating herd.  Let’s use an example.  Over the past year, our example herd has euthanized 31 cows due to injury out of 68 total on-farm deaths (46% of dead cows were injured).  If the average cow in the herd is worth ~$1000, injuries cost the dairy ~$31,000.  Additionally, 39 cows out of 185 cows (21%) were sold due to injuries.  If those injured, broken cull cows averaged ~$300-500 dollars, $500-700 less than the value of an average cow in the herd sold for dairy, then the herd lost an additional $19,500-27,300.  If a replacement is not immediately available to take her place, the cost in lost production and replacement cost adds to the loss. 

What steps can be taken to prevent injuries?  With the majority of injury cases and injury-related culling occurring during the transition period, dairymen need to focus on the transition management.

• Reduce metabolic disease by addressing nutritional and housing/grouping management areas.  Cows with metabolic disease are at greater risk for injury because they are physically weaker and more likely to be injured by more aggressive cows.   Ensure that the dry cow ration is correctly formulated.  However, a well-balanced mixed ration is only as good as the dry cow pen management.   Limit pen moves and limit populations in order to promote intakes.  Furthermore, with populations limited, aggressive social interactions are decreased.  Remember, Close-up and post-fresh pens should be 80% populated with 30” feedbunk space per head.  Additionally, freestalls for large-framed pre-fresh Holsteins should be 52-54” wide, 72” long from the curb to the brisket board with deep-bedded sand or provide 150ft2 if a bedpack is used for housing.
• Decrease Calving Problems.  Decreasing metabolic disease, ensuring that heifers achieve adequate growth, and maintaining body condition scores that are not on the extremes (i.e. <2.75 and >4.0) will reduce calving problems.  Additionally, strive to reduce social stress and anxiety in the close-up pen through proper pen management by limiting pen moves, monitoring pen stocking density,  and by providing adequate stall and bedpack dimensions and allocating a clean, dry, deeply bedded maternity pen.  Train employees in proper maternity pen management and obstetrical techniques.  Finally, consider the use of calving ease sires or gender-selected semen. 
• Limit Feedbunk and Group Overcrowding.  With overcrowding cows jostle for feedbunk and freestall space leading to more aggressive social interactions which can increase the risk of injury.  Overcrowding leads to greater manure build-up which will create footing limitations.  Additionally, keeping feed on the bunk for 24-hours a day and providing fresh feed while the cows are in the parlor will help to decrease confrontations.  Feedbunk length is compromised in a 3-or 6-row barn compared to a 2-or 4-row barn and at 20% overcrowding based on freestalls, feedbunk overpopulation becomes very real.  Some herds have added feedbunk extensions to address this issue. 
• Keep the Cows Off Their Feet by Addressing Freestall Limitations.  If the cows are lying comfortably in a freestall, they are less likely to be injured.  Leg lesions (particularly on the hock), sores over the back (particularly around the thoraco-lumbar region), hoof-related disorders, and lack of cleanliness around the feet and legs likely indicate a serious problem with freestall design and dimensions and lack of freestall bedding. All of the lesions mentioned will increase the risk of injury.   Is this a good time to discuss deep-bedded sand?  Herds utilizing sand have a lower cull rate and a decreased incidence of lameness.  Furthermore, lame cows which are more prone to sustaining an injury can more comfortably utilize a freestall with deeply bedded sand decreasing the risk for injury.  The goal is to keep >14 pounds of bedding in each freestall in order to provide adequate comfort.        
• Address barn and alley design.  Narrow alley design including cross-overs, lack of crossovers, and dead ends lead to more aggressive social interactions and stress. Additionally, footing issues need to be addressed particularly in breeding groups.  Analyze grooving depth and width.  Sand also enhances footing.  Rubber flooring is preferred by cows.  The beneficial effects of proper concrete grooving and rubber flooring are negated when manure slurry builds up leading to poor footing and poorer foot health.  Alley width should be 12-14ft wide.  In the winter months, provide extra footing, i.e. sand, etc, when concrete surfaces are slick.          
• Make Employee Training a Priority.  As herds become larger, identifying and treating cows early in the course of a disease becomes an issue.  Therefore, focus must be placed in training employees to identify the early signs of disease.  Provide animal husbandry and handling techniques that will limit animal and employee stress and decrease aggressive handling that may lead to injuries. 
• Have we addressed lameness yet?  Identify cases of lameness early.  Have a maintenance foot trimming schedule in place.  Ensure adequate heat abatement during the summer months.  The frequency of manure removal must be increased due to sprinkler use in order to reduce foot exposure to manure.  By addressing the management areas mentioned earlier, the incidence of lameness should decrease. 

The incidence of injuries on today’s dairy farms is too significant to ignore.  Injuries are the leading cause of mortality on the dairy resulting in significant economic loss.  The majority of injuries occur during the first 60 days of lactation.  Therefore, by correcting transition management problems and cow comfort limitations, the incidence of injuries can be lowered.  As an animal welfare issue and source of economic loss, make management decisions now to decrease injuries on your farm. 

Dairy Cow Culling Decisions

The goal of a production medicine veterinarian is to help clients maximize profitability per slot, which is equivalent to one freestall or defined bed-pack space.  Maximizing profit per slot means that first, the slots must be full, and second, they must be filled with the most profitable animals.  Maximizing profitability per slot encompasses both replacement and cow management including making intelligent and timely culling decisions. 

Culling Introduction...

A dairy has an optimal stocking density.  Within the defined space, economic decisions must be made to fill each slot with the most profitable cows.  Those economic culling decisions are very farm and cow specific.  Most dairies are missing an opportunity to make more intelligent culling decisions. 

The goal of dairy management should be to avoid damaging cows which lowers cow value and increases culling risk.  Factors affecting cow value are milk production level, fertility status, age, health status, and stage of lactation.  A cow’s income is derived from milk volume, milk composition (components and quality), calves/embryos, and carcus value.  Disease decreases cow value through drug and veterinary costs and death.  More importantly, disease reduces production efficiency, reproductive performance, milk quality, and life expectancy which increase culling risk.

Culling Rate Defined... 

A herd analysis of culling should begin with cull rate.  So, what is your herd’s culling risk or rate?  How do you define your Cull Rate?  Unfortunately, the experts disagree on the true definition of cull rate.  To clear the muddle, Fetrow et al 2006 recommended changing the term cull rate to “Herd Turnover Rate.”  So now we need to ask, “What’s your herd turnover rate?” 

Herd Turnover Rate is defined as [the number culled over a specified time (Year)] / [ mean cow inventory for the same time period].  Using this definition, you should be able to gain an appreciation for your herd turnover rate. 

Defining the optimal herd turnover rate is dependent upon the current dairy herd dynamics.  As stated earlier, economic culling decisions are very farm specific with dependency on the business need to push return on assets.  The herd needs to find the balance between the need to maintain optimal stocking density, preferably grow considering the Internal Herd Growth Model, while maximizing profit per freestall.  The Internal Herd Growth Model is dependent on Replacement management, reproductive management and herd turnover rate.  Herds with excellent heifer management (low mortality and morbidity rates and age at first calving ~23 months) and reproductive management (21-24% preg rates) can withstand a high cull rate and maintain herd size. 

Let’s consider this scenario. The national cull rate is ~40%.  Depending on heifer completion rate and calving interval, an average herd would achieve a 34-36% lactating herd entrance rate for first calf heifers.  Therefore, a herd with a 40% herd turnover rate with a reasonable 34-36% entrance rate would have a need to purchase lactating cows simply to maintain herd size (to keep the slots full).  Considering the average heifer entrance rate, a 34-36% herd turnover rate would seem reasonable if you want to maintain herd size.  However, agriculture economists prefer to see lower target levels between 23-28%.  Why?  Cows are considered capital, a depreciable asset.  The longer the asset remains in the herd, replacement costs are spread over more years which frees up more capital to invest in other areas of the business.  At current milk and feed prices, a cow takes almost 2 lactations to cover her rearing or replacement cost. 

But keep this in mind.  Herd turnover rates are poor monitors of the quality of culling decisions.  You could have an incredibly low turnover rate with excellent internal herd growth.  However, you could be holding on to more unprofitable cows – two-quartered cows with average milk production comes to mind.  You must continually strive for greater returns on your assets by replacing current genetics with better genetics. 

Herd Turnover Rate Cohorts or Subgroups

Herds should have an understanding of several herd subsets that may point to specific problem areas.  The most important cohorts to analyze are Cull Rate Less Than 60 DIM and Cull Rate Less Than 30 DIM, measurements providing an assessment of transition cow management.  To accurately calculate Transitional Cull Rates divide the number culled (30 or 60 DIM) by the number fresh during a defined period (Year, past 6 months, etc).  Benchmark cull rates should be less than 6% and 4% respectively.  Also, analyze and compare the early culling rates for each lactation group in order to pinpoint problem areas with particular focus on first calf heifers and mature cows. 

Cohorts based on calving date also present fresh insight into the herd’s culling pattern.  Seasonal differences are typically observed.  Particularly focusing on summer calving cohorts, the seasonal differences will show the value of heat abatement strategies for both fresh cows and dry cows.     

Develop a consistent system for recording the culling reason for every cow or heifer sold or died.  Record accuracy and consistency is very important in order to avoid confusion and to make analysis easier.  Fifty reasons for culling create confusion.  Initially, categorize culls based on destination:  dairy sales, slaughter, death.  Use simple and broader categories, like Digestive, Lame/Injured, Reproductive, etc.  Herds with high cull rates and/or mortality rates must use the data, the accurate and easily interpreted reason, to identify and correct management problems. 

Heifer Culling Strategies

High heifer raising costs mean that culling decisions should be made <12-13 months of age.  Again, we are trying to fill the barn with the most profitable cows and heifers.  Therefore, we should raise our most valuable replacements with the greatest potential for future profit.  Greater heifer culling options and flexibility are achieved with low heifer mortality rates, high heifer completion rates at an age of first calving between 22-24 months, low cow cull rates, high pregnancy rates, and use of gender select semen.  With greater culling flexibility several culling strategies can be utilized.  New developing genomic testing will continue to improve and provide a tool for improving your herd.  Heifers experiencing pneumonia and coccidiosis have been shown to produce less than their herdmates and should be considered for culling.  Heifers from the lower 25% of your herd and from Johnes positive cows would fit into a herd culling strategy as well.

     

Cow Culling Strategies

A cow culling strategy, with greater emphasis on economic culling (replacing a cow with a more profitable individual) is useless if biological or forced culling threatens the viability of your herd.  How many times have we heard, “I can’t sell that chronic mastitis cow because too many cows are leaving on the trailer.”  Therefore, the first step to developing an intelligent culling strategy is to initially address and reduce biological or forced culling by working with your herd management team. 

We are striving to define what is breaking or damaging cows.  Significant opportunities exist in many herds to quickly address forced culling by correcting cow comfort problems which create higher levels of lameness and injuries.  Exceeding a facilities optimal stocking density will impact culling.  Transition cow management, reproductive management, and milk quality are noteworthy segments that significantly impact forced culling.

Use herd testing programs to identify potential biological cull cows.  Infectious disease herd testing programs can be utilized to identify carriers of  Johnes, BVDV, etc.  Utilize DHIA records, mastitis treatment records, and milk culturing programs to identify chronic mastitis cows and individuals infected with contagious mastitis pathogens.   

Work with your veterinarian to devise and use treatment decision trees to help determine whether there is economic justification to either treat or cull the cow.  The fifth lactation cow with a high SCC and LDA may be a better candidate for culling rather than a surgery.  Use pharmaceutical treatment strategies, particularly for groups at greater risk to be culled, that provide greater culling flexibility by using drugs with low and clearly defined withhold periods.

The financial penalty for forced culling is huge.  First, you are selling a cow prematurely before a replacement is available to take her place.  Second, you are selling a broken cow at a loss compared to selling the average valued cow for dairy purposes.  Third, you lose the entire value of a dead cow, and unfortunately compost will not breakeven with her value. 

After making corrections in the management areas of cow comfort, transition, forage quality and feeding management, replacements, milk quality, and reproduction, the herd begins to grow because conception rates improve, heifers flood the herd, and forced culling declines.  As a result, the dairy can begin to focus more on herd goals and economic culling.  Can a cow be replaced by a more profitable animal?  Options are now available to sell heifers and cows for dairy purposes.  DHIA production records can be analyzed after 60 DIM to closely compare a cow’s average production to a first-calf heifer.  As long as data inputs are accurate, DC305 COWVAL and PREGVAL provide reasonable culling decision tools.  Genomic testing is another potential tool that can be used for economic culling decisions.

Culling Conclusion

A dairy has an optimal stocking density.  Within the defined space, economic decisions must be made to fill each slot with the most profitable cows and heifers.  Most dairies are missing an opportunity to make more intelligent culling decisions.  By focusing the dairy management team on opportunities to decrease forced culling, dairies can increase economic culling strategies.