Dairy Grist - Spring 2023

Dairy Grist

CENTRAL & ATLANTIC EDITION A PERIODIC NEWSLETTER PRODUCED

BY GRAND VALLEY FORTIFIERS VOLUME 25, ISSUE 1 | SPRING 2023

Dear Friends, With the unseasonably warm weather and the field dryness that we have experienced in the past few weeks, many producers have already been on the land, moving manure and even planting for the 2023 growing season. The return of a cool and wet week or two provided some additional needed moisture to fields. Whatever weather we actually receive this year, we wish Canadian dairy farmers a very productive and high quality yield. As Henry Verhoog explains in the SNF ratio article below, having high quality, well stored forages is fundamental to a dairy’s success in milk production, hitting the target SNF ratio and simply making the dairyman’s life in the barn much more pleasant. Henry has authored many great articles for the Grand Valley Dairy Grist over the years he has been with us. We recently celebrated the completion of Henry’s 35th year with the company. It has been an honour to have Henry Verhoog on our dairy team at Grand Valley Fortifiers and a privilege to witness his passion and on-going work and consulting with so many dairies and so many cows across Ontario.

It seems that no matter where milk, meat and eggs are produced in the world, there are growing challenges with animal diseases that have significant impacts on herd health and productivity. Whether ASF, PED or Strep Zoo in swine, High path AI in poultry, or foot and mouth in numerous species, including ruminants as well as Mannheimia haemolytica, producers of all types will need to continue to work closely with their veterinarians on prevention with vaccine protocols as well as both traditional and novel treatments. Additionally, producers will need to consider heightening bio-security and hygiene protocols in their operations while taking a very good “second look” at the cleanliness and quality of the water they provide their animals each day. Animals consume 2-3x the amount of water that they do feedstuffs but water is often the most overlooked nutrient. With the recent addition of six water and hygiene experts at Farmers Depot, across Canada, consider having one of them visit your operation to see how they can assist in improving herd health, performance and feed efficiency together with your dairy feed specialist.

Sincerely, Ian Ross, President & CEO, GVF group of companies

PNEUMONIA IN DAIRY COWS: WHAT IS OLD IS NEW AGAIN

by: ROBYN ELGIE, DVM Kirkton Veterinary Clinic

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ver the past few years, there is a growing incidence of severe pneumonia outbreaks in dairy herds across Ontario and other parts of Canada. From a veterinarian’s perspective, the most troubling aspect of these outbreaks has been the speed and unpredictability with which it begins. During these sudden outbreaks it is possible to lose up to 5% of the herd and have 30% or more of the animals treated, all within the span of 1 week. Surprisingly, the implicating pathogen found in these herd outbreaks is not new. In fact, it can be found in almost all healthy cattle and is a well-known pathogen associated with pneumonia in feedlot cattle (1). The pathogen is known as Mannheimia haemolytica. Over the past three years, our practice has encountered 10 presumed and 7 confirmed cases of Mannheimia haemolytica herd outbreaks. This article is based on the collective clinical experiences of our veterinarians as well as discussions with veterinarians from other parts of Ontario and Canada.

What is Mannheimia haemolytica?

Mannheimia haemolytica is a bacterial pathogen that can be found in the nasal passages and larynx of clinically health cattle. Mannheimia,

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along with a few other bacterial pathogens, commonly live in the upper respiratory tract in low numbers. However, once a stressful event occurs it is able to rapidly reproduce into a large population and travel to the lower part of the respiratory tract (1). In the lungs, Mannheimia bacteria release a substance called leukotoxin which is designed to kill white blood cells (2). Under normal conditions white blood cells are able to consume and destroy bacterial cells like Mannheimia. When Mannheimia increases in number suddenly, the leukotoxin it releases can quickly eliminate the white blood cell supply, overwhelming the immune system (2). Once this occurs, Mannheimia bacteria can cause severe irreversible lung damage. Mannheimia haemolytica is one of the main bacterial pathogens in the Bovine Respiratory disease complex which is commonly associated with calves shortly after transport and arrival to a feedlot. Until recently, Mannheimia has not been associated as a common cause of pneumonia in dairy cattle.

There are 4 things that make Mannheimia 1960 “outbreaks” in particularly devastating in dairy herds: 1. The apparent unpredictability of when an outbreak will occur.

2. The high number of affected animals within the herd.

3. The speed at which the animals become clinically sick and die.

4. Affected animals do not always look like a cow with pneumonia.

Risk Factors Our clinic gathered farm level treatment records and Dairy Comp herd level data from 3 herds that had recent outbreaks of Mannheimia

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haemolytica within a 21-day period of one another. While outbreaks do appear to be unpredictable and likely multi-factorial (3), there were some commonalities among these herds that may be considered risk factors.

1) Vaccine Protocol and Compliance Classically, Mannheimia haemolytica is an opportunistic pathogen that will increase in number soon after a stressful event such as viral pneumonia (1). A well designed and executed modified-live vaccine (MLV) protocol can reduce the risk of viral pneumonia and abortion. In dairy herds this has been the main focus of vaccine programs. Until recently, Mannheimia haemolytica pneumonia was not identified as a major pathogen in Ontario dairy herds. As a result, most veterinarians recommended viral only vaccines. The theory was prevention of viral pneumonia would reduce the risk of a less likely bacterial pneumonia outbreak.

The effectiveness of a well-designed vaccine program is limited by compliance to the protocol. To achieve adequate protection using a 5-way Modified-Live vaccine, every animal needs to receive a proper primary series as a calf/heifer and a booster dose every 12 months after the primary series is completed. There are killed vaccines available that will provide immunity for the same viruses however they require more frequent booster doses.

Protocol compliance is dependent on accuracy. Every time an animal receives a dose there are 4 areas where error can occur. The correct cow, the correct product at the correct dose and the correct timing of administration are all variables where compliance can suffer. For example, a cow is bred and confirmed pregnant late in lactation so her calving interval will be greater than 12 months. This means the recommended time between her previous dose and the next dose of vaccine will exceed 12 months. Therefore, her previous dose may not be effective and theoretically she would need a primary series again to be 100% protected.

It is also important to note that vaccine handling, storage and proper administration route are also very important factors to achieve effective protection.

2) Ventilation In lactating animals, we often think of ventilation primarily as cow cooling. However, ventilation is actually defined as bringing fresh air in and removing stale air at an adequate rate. Naturally ventilated barns are designed to achieve 4 air exchanges an hour during the winter when the side curtains are almost closed. This is achieved by the differences in air temperature between the outside and inside air.

Natural ventilation does not work in the same way when the outside temperature is more moderate. During these times we rely on open curtains and fans to move air. When there is extreme humidity with low natural air movement, less fresh air will come into the barn. Therefore, the fans can only push or move stale air.

During warmer weather, the curtains may be raised to reduce sunlight into the barn leaving less space for stale air to exit and for fresh air to enter the building. The type of fan can also make a difference. High volume, low speed fans create “dead spots” of air between fans. This type of fan moves air in a multi-directional manner, therefore it does not move stale air away from the cows.

3) Herd Health Status (Closed or Open) The risk of bringing in a novel disease is significantly increased if animals are brought in from multiple other sources or, from somewhere where they would have been exposed to animals from other herds. Even if the vaccine protocol is well designed and the compliance is excellent, there is still opportunity for novel diseases to enter the herd. Even diseases that cause only mild sickness can be enough of a stressor to trigger Mannheimia haemolytica proliferation (3).

Taking animals off farm and then re-entering is also a risk but can be controlled by isolation, quarantine and booster vaccination of those animals.

It is very important to point out that although the above 3 factors increase the risk of a Mannheimia haemolytica outbreak, limiting or controlling all three does not guarantee immunity from a Mannheimia outbreak.

We hypothesize that the unpredictable nature of the outbreaks we have encountered is likely due to a “perfect storm” of factors that coincide to cause an abnormal physiologic stress on the herd.

These coinciding factors can be difficult to prove in retrospect. In many cases, a proportion of these inciting factors may be invisible to our observation but may include sudden feed and weather changes, bedding type, season or other herd level health stressors. We have also seen cases where the herd was struggling with pink eye or mild viral exposure such as coronavirus which can cause dysentery or mild respiratory infection which is often evidenced by tearing around the eyes.

With regards to seasonality, our clinic has experienced a herd outbreak in every season on the calendar. There is a tendency to see more cases during the classic pneumonia season of the fall, however, there have been clusters of herd outbreaks in the winter and summer months as well.

At the cow level, our practice has not seen a stage of lactation or lactation number represented more than another overall. There does appear to be an increased risk in high production herds. We have seen it in both lactating and dry cows, with lactating cows being the most common. Other clinics in Ontario have experienced higher representation in fresh cows.

Rarely are heifers younger than those found in the close up group affected. In multiple cases, groups of differing pregnancy status or lactation were housed within nose to nose contact of the pen experiencing an outbreak and did not demonstrate any clinical signs consistent with Mannheimia haemolytica. This demonstrates that Mannheimia haemolytica is not contagious from animal to animal but requires a stressor within the animal, or a group of animals, to trigger the disease process.

Prevention and Control In Ontario dairy herds, many calf vaccine protocols have incorporated intranasal vaccines which include Mannheimia haemolytica however, it has not been common to include it in the vaccine protocols for the lactating herd. Fortunately, there are a number of options that include Mannheimia haemolytica as part of a combination or on its own in both injectable and intranasal forms. Our current clinic principle outlines each animal should receive at least 2 doses annually of a vaccine with Mannheimia haemolytica as one of the components. The selection of vaccine and timing of administration is herd specific depending on management and facilities as well as known risk factors. It is best to consult with your herd veterinarian to tailor the protocol to your herd.

What to do in the Face of an Outbreak 1) Take Samples for Confirmation – Post Mortem animals that have died In our experience, a farm will lose an animal unexpectedly proceeding the outbreak. This often occurs around 1 week before the majority of the cases appear. This does not mean that every animal that dies unexpectedly may be the beginning of an outbreak, but it is important to discuss with your herd veterinarian to determine whether a post mortem would be beneficial for any sudden deaths. Certainly, if morbidity and mortality have increased in adult animals in a short period of time this would be warranted.

2) Intranasal Vaccination Due to the speed in which animals transition from clinically healthy to very sick, action needs to be taken immediately to reduce mortality and morbidity. This is almost always before results from the lab are available.

Administration of intranasal vaccines in the affected group and any other groups that may be potentially affected are the most effective and quickest way to boost immunity in the face of an outbreak. Injectable options are also available but have a slower immune response. They can be used as an alternative when restraint for intranasal administration is unsafe.

Herd level supportive measures can also include increasing the amount of chopped straw in the ration temporarily and bicarbonate freely available.

3) Treat Animals Immediately When Detected Mannheimia haemolytica pneumonia often presents with very subtle clinical signs in the early stages. Producers who have experienced these outbreaks report a change in attitude is the first sign a cow will typically demonstrate. Clinically affected animals do not always have apparent increased expiratory effort or audible increase in lung sounds. Using tools like milk temperature, milk yield and rumination as well as walking the pens and observing the animals every 4-6 hours can help detect animals in the early stage of disease.

Mannheimia haemolytica progresses clinically very quickly. Antibiotics and anti-inflammatories can have successful cure rates but must be given early in the disease process to reduce morbidity and mortality. It is not uncommon to have up to a third of the affected group treated over the course of 1-2 weeks.

Depending on antibiotic selection and the number of animals treated within the lactating herd there should be clear communication with the client about the possibility of antibiotic residues and appropriate testing and withdrawals.

Take Home Messages 1. Mannheimia haemolytica is a normal upper respiratory bacterial inhabitant of cattle that can cause sudden and severe pneumonia.

2. An outbreak is often triggered by undetected stressful event(s) in a group of animals, up to one third of the herd can be affected.

3. Herd level intranasal vaccination as well as early detection and treatment of affected individuals will significantly reduce morbidity and mortality during an outbreak.

4. Reducing known risk factors as well as effective implementation of a regular vaccine protocol can considerably reduce the risk of an outbreak.

References 1. Radostits, O., Gay, C., Hinchcliff, K., Constable, P. (2007). Veterinary Medicine (10th Ed). Saunders Ltd. 2. Campbell, J. (2022). Merck Veterinary Manual. Merck & Co., Inc. Rahway, NJ, USA. 3. Caswell, J. and Gordon, J. (2020, November). Mannheimia in Dairy Cows, [Conference presentation] OABP Annual Fall Meeting Online Webinar.

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Dairy Grist

ne thing that we need to remember is that while whole milk/milk replacer is the biggest source of nutrition to the calf and the amount fed will primarily determine their growth rate until weaning. However, we also need to get them onto calf starter as soon as possible to develop the rumen. In the beginning, calves only receive liquid nutrients which bypass the reticulum and the rumen through the closed esophageal groove, sending the liquid nutrients to the omasum and abomasum where they are quickly digested. By feeding only liquid feeds we are not allowing for the growth of the rumen or the reticulum which is needed for when they start to consume forages. Therefore, it is very important that within the first week of a calf’s life we introduce dry feeds whether that be a prepared calf starter or an on farm calf TMR mix. The dry feeds are moving through the esophagus into the rumen where digestion begins and rumen papillae growth results from volatile fatty acids produced from the starch and sugars in the calf starter/ TMR. Remember to always have clean fresh free choice water available to your calves. Research shows a 45% increase in calf starter consumption when water is available. Selecting the right species and implementing good agronomy practices are critical to successfully producing winter cereal forage.

We want to ensure the calf starter is of high quality, has no dust or mold and is palatable to the calves, anything less will decrease their intakes.

Ideally, we want the calves to be consuming 1 kg per day of calf starter by 8 weeks of age or approximately 3.5kg of TMR. It is important to keep the dry feed fresh, it should be a daily routine to give the leftover/old dry feed to the older calves and provide fresh dry feed to the young calves.

If we were to stop the liquid nutrients before the rumen is completely developed the calves will not grow and may even lose body weight for a couple of weeks until the rumen has been developed. This is key as you want your calves to have a fully developed rumen to continue growing.

Research shows that keeping calves on milk/milk replacers for 10 weeks provides better growth of the calf, and this would be recommended for all calves to achieve superior growth.

OUR ON-FARM HYGIENE SPECIALISTS have been trained to help support livestock producers in reaching hygiene and water sanitation goals that result in improved animal health and reduce the use of antibiotics.

Dave DeGraaf

Mark Reynolds

STEPHANIE MURPHY Dairy Specialist, Grand Valley Fortifiers

CALF MANAGEMENT/GROWTH

Book an appointment with one of our specialists at 1-866-527-6229.

It is important to make sure that the amount of grain/TMR your calves are being fed is known. With the help of your nutritionist weigh how much grain/TMR each age group of calves is eating and ensure that it is adequate to reach their maximum growth potential. Consistency for calves is so important, consistent in amount being fed, time being fed, and quality of feeds for example.

While feed is very important to achieve adequate growth, the housing environment of the calf is just as much so. Keeping calves out of drafts and wet environments is important to maintain a healthy calf and prevent sickness. Calves should have a deep bed to be able to make a nest and stay warm. A good way to check if the bedding is dry is to do a knee test, simply kneel down for 20 seconds and if your knees are damp or cold, there needs to be more fresh bedding added. In group housing environments,

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group calves according to size will allow for optimum growth and less competition at the feed bunk. If calves can be moved through the heifer program as a group to eliminate a stressor of introducing new calves to one another, that will help to keep them performing well.

In closing keeping the calf program consistent with high quality milk/ milk replacer, good quality dry feeds and a dry, draft free environment calves will perform well.

with HENRY VERHOOG Dairy Specialist, Grand Valley Fortifiers

ADJUSTING TO THE NEW SNF RATIO THAT BEGAN FEB 1ST 2023

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s many of you are now aware, the DFO has recently dropped this SNF ratio down from 2.25 to 2.20 which in essence, better represents the current market status toward minimizing the amount of structural protein and skim milk surplus in our supply managed system.

In simple layman terms, at present we have a good strong demand for butter and butterfat products but due to recent trade regulations we do not have a good market for this extra protein. It is also important to point out that this may be a temporary dilemma. For those of us who have been around long enough, we remember adjusting feed rations to lower butterfat as much as possible to efficiently fill quota 20 years ago.

With these new rules in place each producer needs to assess their own situation to determine what gameplan makes the most sense.

Without going into too many different scenarios I do want to discuss the options that I see on some very well managed herds.

Scenario 1: You have a well managed herd that is averaging 40 to 45 liters with an average 4.0%bf in the winter and 3.7%bf in the summer.

This herd is probably milking 3x or have robotics. They have bred for years toward top production and want to keep challenging their cows. If I am helping to manage this herd, we are going to keep doing the same things they are doing now with a couple of consistent changes. We will look closely at those top 2yr olds that calved in recently and those with a lower than average bf will be sold to a reputable cattle dealer who will gladly buy them and sell them south of the border. You will also keep making top quality forages and restrict feeding too much starch in summertime to try and move the bf up gradually. We will also continue to use protected palm fats because we know by now that these help the herd reach its repro goals and help keep the bf up as needed. This formula for success also applies to producers who choose to milk 2x and are aiming for the same top production. The main difference is that any cow that milks 2x will always have a little higher bf % than when we milk her 3x or put into robot system to get milked 3 or 4 times in early lactation.

Scenario 2: You have a well managed herd with good genetic potential, but you are much more focused on trying to produce this high bf milk. If you are milking Jerseys today, you are already where you need to be! I would argue that some Jersey herds I have seen numbers on could actually breed for a bit more milk and sacrifice a bit on that 5.5 bf milk – personal opinion only. I am also aware of some Holstein herds that are now maintaining 4.5 to 4.8% bf year round. Most of these herds have bred for higher components for many years and are now reaping the full benefits from this.

Another common thread on many of these herds is the desire to feed more kgs of forage year round and not worry about getting that last litre of milk. These farms usually have a very good land base so growing extra

forage and feeding home grown feeds is part of their way of life. And since most of this land was purchased long before prices hit 30 or 35k per acre this model still works fine. One key factor that remains the same in both scenarios above is that cows that naturally produce higher amounts of bf will be the easiest ones to work if this SNF game is your main focus.

When producers give us a chance to feed cows that have been well bred, and put up top quality forages and well stored grains (no heating and no mold) obtaining this end goal of that ideal 2.20snf ratio becomes much easier.

With warm summer days coming, the main challenge of keeping these nice high bf tests is to keep bunks or silos nice and cool and minimize any pockets of moldy feeds. Well fermented feedstuffs go a long way to keep healthy rumens producing good quality milk. With high temperatures in summer time, adding extra rumen buffers or stabilizers like bicarb and yeast culture along with protected fats will pay back quickly with this new pricing model. Those who have made some top quality corn silage with loads of starch in it this past year, may be well worth looking at the option of adding a kg of dry alfalfa hay to the ration over the summer time.

In closing, I encourage producers to take a closer look at your recent milk cheques to get a good handle on what I call the 4 prices of milk.

1. Within quota is highest and best priced milk. This will represent all the milk you shipped in category below 2.0snf ration. (this encompasses all Jersey herds and really high Holstein herds above 4.5%bf ).

2. The next line is the market ratio where you get paid about 40 cents a litre. This will be the milk that falls between 2.0 and 2.2snf.

Having some of your milk fall into this category is not terrible as it at least covers your production costs. Do keep in mind that having some milk fall into this category actually do maximize out your returns on a kg of butterfat quota which is a whole article in of itself. Suffice to say, no harm in having 5 or 10% of production fall into this category.

3. The third category is call SNF ratio Cap. This will be milk over the 2.2snf ratio and even though producers aren’t paid for this milk, having some milk hit this category usually means that the kgs of butterfat quota were most economically filled.

4. The fourth category is over quota and that comes with a big penalty of 25 cents per litre. This is where you definitely do not want to ship any milk in no matter what your butterfat level is.

I am hoping by now that I have not completely confused everyone.

What I would encourage producers to do is to spend a bit of time going over their recent milk cheques to compare all prices this past year and get a good handle on understanding where this pricing is all coming from.

Thought for the Day

Fear and Refuge

Psalm 31:19 - NIV “How abundant are the good things that you have stored up for those who fear you, that you bestow in the sight of all, on those who take refuge in you.”

Consider two important truths shared by the Psalmist: 1. The goodness of the Lord.

2. The Fear of the Lord.

Initially these two truths seem to be opposites – fear seems to drive away and taking refuge seems to draw in. But when we understand this fear as a healthy, respectful fear; a fear of straying from him – then they work together. So, cherish the goodness of the Lord. Fear straying from him. Flee from sin and take refuge in him.

- Adapted from April 20, 2023 devotion by John Piper.