Posts by Rob Costello, Dairy Technical/Business Support Manager, Milk Specialties Global

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Thursday, November 15, 2012

Calf Starter -- big impact on calf growth

Milk replacer feeding rates have received much attention over the past several years. Many calves these days grow bigger in a shorter period of time mainly due to consumption of more milk or milk replacer. At high intake levels, the role of starter feed in supporting this early growth is often markedly reduced, or at least altered. The quality of calf starter and the structure of the milk replacer feeding program are both major factors in determining the impact of starter in preweaning calf growth.

In general, we expect to see starter intake delayed as milk replacer intake increases. But that's not a hard, fast rule. The table below shows feed consumption results for a research trial comparing two milk replacer formulas and feeding schedules. Calves on the 20-20 (20% protein, 20% fat) all milk protein formula received 16 oz of milk replacer powder in one gallon of water each day, while calves on the 25-15 formula received 24 oz of powder in one gallon of water each day. Calves were fed milk replacer twice daily, had access to free choice water and starter, and were weaned at the end of Week 6.

By the end of week 6, calves on the 20-20 treatment consumed a total of 42 pounds of milk replacer powder, and had eaten 49 pounds of starter feed for a total feed intake of 91 pounds. Calves on the 25-15 treatment consumed 63 pounds of milk replacer powder and also ate 49 pounds of starter feed for a total feed intake of 112 pounds by the end of week 6. During weeks 7 and 8, calves received only starter feed and free-choice water. Feed values in the table are cumulative from the beginning of the trial and are reported on an as-fed basis.

Milk Replacer Research Data

In spite of the different formulas and feed rates, calves on both treatments ate the same amount of starter by weaning. After weaning, calves on the 25-15 treatment consumed more starter than 20-20 calves. The following graph shows the energy intake from the different feed sources during the trial.

Milk Replacer Research Data

Daily energy provided by the two milk replacers are shown by the blue and red horizontal lines. Energy provided by the amount of starter each day is shown by the green line. For calves on the 20-20 program, energy from starter intakes surpassed that provided by the milk replacer at about 4 weeks. This transition point was a couple days later for calves on the 25-15 program. Now consider what happens when starter quality is changed.

Effect of Starter Quality

The treatment results described above are for calves that received Starter A, pictured below on the left. Starter B was fed to two other treatment groups of 20-20 and 25-15 calves in this trial instead of Starter A. Both starters were commercially available and had similar nutrient analyses. Starter B is obviously a drier feed, with little molasses, more pellets, less grain and more small, broken particles (fines).

Starter A                                      Starter B

Calf response to Starter B is shown in the graph below. The transition point where energy from starter intake surpassed that of milk replacer was delayed more than a week for the 20-20 calves and was pushed back to weaning time for the 25-15 calves. By week 8, Starter B calves were eating 3 pounds per day less starter than calves on Starter A. As a result of starter quality differences, 20-20 and 25-15 calves on Starter A averaged 18 and 20 pounds heavier, respectively, than their counterparts on Starter B by the end of week 8.

Milk Replacer Research Data

Effect of Milk Replacer Program

Another reason for starter intake depression is the design of the milk replacer feeding program. The following table shows the results of a trial comparing milk replacer and starter intakes for calves on a 25-15 program to calves on a 28-20 program. Calves on the 25-15 treatment were fed 1.5 pounds of milk replacer powder per day whereas the 28-20 calves received 1.88 pounds of powder per day during the first week. The feeding rate for 28-20 calves was increased to 2.6 pounds per day during weeks 2 through 6, and dropped to 1.3 pounds per day during week 7. Calves were fed milk replacer twice daily and had access to free choice water and starter. Calves on the 25-15 treatment were weaned at the end of week 6, and 28-20 calves were weaned at the end of week 7.

Milk Replacer Research Data

By the end of week 6, the 25-15 calves had consumed 41 pounds less milk replacer powder and 25 pounds more starter than the 28-20 calves -- that's nearly double the starter intake. By the end of the trial, the 25-15 calves had consumed 50 pounds less milk replacer powder and 45 pounds more starter than the 28-20 calves -- that's one bag less milk replacer and one bag more starter. Although not reported in the table, the 28-20 calves were significantly heavier (p<0.05) at the end of weeks 2 and 3, were only 4 pounds heavier at the end of week 6, and were the same weight as the 25-15 calves by the end of week 8.

The Gross Energy Intake graph provides insight into what's going on with the two treatments. Energy intake with the 25-15 and 28-20 programs is shown by the red and blue lines, respectively. Energy from starter intake of the 25-15 calves, the purple line, shows that starter became the major energy source for those calves just prior to the end of week 4. Energy from starter intake of the 28-20 calves didn't cross that point until weaning at 7 weeks.

Milk Replacer Research Data

By week 4, the difference in total daily energy consumption between the two groups had narrowed substantially, and by week 6, daily energy intakes were virtually the same. During weeks 7 and 8, the 25-15 calves consumed more energy than 28-20 calves.

These intake and growth results show that 28-20 calves lag behind as they approach weaning, and strongly suggest that calves could benefit from modifications to this milk replacer feeding approach. These calves certainly can't afford any intake lag due to starter quality and composition issues. Increasing the number of milk feedings per day might be one way to help improve starter intake -- perhaps for both groups, and adjustments to the 28-20 feeding rates may help reduce the growth lag and need for these calves to catch up. With total feed costs about 60% higher with this 28-20 program, the only time you'd expect calf weights to be the same is on day 1.

Wednesday, May 23, 2012

Calf Feeding - Milk Extenders & Fortifiers

Most operations that feed waste milk to calves need to extend or supplement their supply of whole milk, at least periodically. They may have a variable or limited supply of waste milk or they may be looking to ensure a minimum solids level with each feeding. Consequently, they still have a need for a milk replacer type of product.

Formulations of these products vary depending on the farm's objectives. An old standard is a 20% protein, 20% fat milk replacer that can be blended with waste milk and water to extend the supply, or it can be fed directly to calves when the waste milk is used up. Variations on this approach include 22-22 and 24-24, each with a slightly different effect on the protein and fat levels of the final mixture when added to waste milk.

Another approach is to measure or estimate the protein and fat in the farm's waste milk and have a custom formula made to approximate that analysis. This approach attempts to minimize variability in protein and fat from one feeding to the next. Alternatively, a 25-15 is used to match the protein level of waste milk while lowering the fat level in the final mix. An objective here would be to enhance the intake of starter feed.

Extenders and fortifiers provide a special opportunity to take advantage of non-milk proteins. The use of certain non-milk proteins in milk replacer formulas has long been a way of reducing cost while maintaining growth and performance. In this application, since the extender is not the complete diet and is mixed with another milk source, the percentages of non milk proteins such as egg, plasma or wheat can be increased above the normal milk replacer limits, further reducing cost. These specially formulated products should not, however, be fed directly to calves as their only source of nutrition. The level of non-milk proteins may be too high for them to be fed as regular milk replacers.

Regardless of the formula, there is an inherent source of variability when using these products, namely how much water is added along with them. To minimize this variability, many operations use a refractometer to measure total solids in the waste milk and then add the correct combination of water and milk extender to achieve a specific solids level in the final mix.

milk refractometer
A refractometer tends to underestimate the solids in non-homogenized whole milk such as waste milk or milk from the bulk tank. A common practice when measuring these fluids is to simply add "2" to the refractometer results. 

Whole Milk Extender & Fortifier Calculator                                                
Managing daily variation in total solids of waste milk is much simpler than trying to manage fluctuations in protein and fat. In many situations, the amount of waste milk available and the number of calves that need to be fed change frequently. Figuring out how much powder and how much water need to be added to today's supply of waste milk to adjust total solids for today's number of calves takes a bit of calculating. With a few pieces of information you can do this by hand... or you can use a calculator like the one below, where the formulas are already plugged in and ready to go.

All you do is enter the required values in the red cells and the calculator does the rest. The right arrow points to the results of the calculation, showing how many gallons of water and much powder must be added to the available waste milk to feed those calves for one feeding.. The down arrow points to those results in a chart which is more of a quick reference that shows what to do at various calf numbers and various amounts of waste milk.

AdditivesThe calculator also lets you choose to include two additives. ClariFly to help with fly control during the summer months, and 7-60 fat, a supplemental energy source for winter months. The inclusion levels of these additives are based on the manufacturers' recommended feeding rates.

Note: negative numbers may show up in the table. In this case, there is excess waste milk for the number of calves and you can't adjust solids appropriately unless you reduce the amount of waste milk being fed. 

Using a calculator like this makes the job of calculating daily mix ratios a simple task. You can take the chart out to the mix area for quick reference or work with it in the office to explore different scenarios and determine your future needs.

Download a working copy of the  Whole Milk Extender & Fortifier Calculator

If you are interested in tools for economic evaluations of on-farm pasteurization and feeding options you might want to check out  Penn State Calf Milk Pasteurizer Evaluator

 (updated Jan 15, 2015)

Thursday, April 5, 2012

On The Fly: fly control for calves

This is a seasonal reminder about the importance of effective fly control in calf management. Actually, with the warm weather many of us have experienced so early this year, flies may already be a nuisance. When it comes to calves and their environment, we're primarily talking about two types of flies: house flies and stable flies.

House flies can carry or transmit disease, such as pinkeye and mastitis, and they are a primary nuisance for people. Female house flies lay their eggs in manure, wet organic material, spilled feed, compost piles and other decaying organic matter. Adults have sponging-type mouthparts, so they don't bite.

Stable flies, on the other hand, have piercing-type mouthparts, and they do bite. They pierce the skin to obtain blood meals and can cause quite a bit of stress, leading to decreased productivity. As with house flies, females lay eggs in manure, wet hay and other decaying organic matter.

The first time I wrote about flies was more than twenty years ago. And one thing that has certainly remained constant is that routine sanitation and clean-up are at the core of effective fly control. A good fly control program is built around that theme (which should be obvious when you consider where these flies lay their eggs). Clean up decaying silage and piles of spilled feed. Pay attention to starter feed that may accumulate under each calf's feed and water buckets. Don't let it build up. And of course, clean and sanitize all feeding and feed handling equipment.

The choice of bedding material can also have an impact on fly populations. Materials such as straw and wood shavings absorb more liquid and provide more organic substrates than sawdust or sand, for example. This doesn't mean they can't be used - they need to be managed in a way that minimizes their potential impact. The decision about appropriate bedding material for an operation should be based on farm-specific factors, one of which is fly control. 

You can do a lot to take care of stable flies by mowing around the calf area. These flies live in nearby grassy areas, come in to feed and then fly back out. Mow at least 30-50 feet around where calves are housed to remove the living environment for stable flies. This may work to some degree for horn flies, too. These biting flies are about half the size of stable flies and congregate on the animal's back where they spend most of their time. Each horn fly can take 20-40 blood meals each day. Their scientific name fits them well, Haematobia irritans. These irritating flies lay their eggs in freshly deposited cow manure, so their relationship to the calf environment is somewhat different from house and stable flies.

There may be times when you decide to use a pesticide to knock down the adult fly population .You could have an unknown or unsuspected breeding ground or flies may migrate in. Using an adulticide on the adult fly population can temporarily reduce fly numbers, but it won't address the countless fly larvae getting ready to repopulate the airways.

There are a couple ways to reduce fly larvae populations. One is a biological approach which involves fly parasites that target house and stable fly larvae. These fly parasites are released on the premises and lay their eggs in fly pupae. The fly parasite larvae consume the pest fly larvae as they grow. Once they become adults, they can repeat the process, thereby reducing the fly population. 

Another approach is to use a larvicide feed supplement. When added to feed, these larvicides pass through the digestive tract and into the manure where they deliver their effect. Organophosphates, such as Rabon®, have been around for a while and provide a toxic effect which disrupts the nervous system of larvae. A newer larvicide, ClariFly®, contains diflubenzuron which provides a very specific effect by inhibiting the formation of the fly's exoskeleton, preventing it from ever reaching adulthood. 

Pre-weaned calves pose a particular challenge when using larvicides. Young calves don't consume a lot of dry feed and therefore require more larvicide per pound of feed than a more mature animal. For example, the necessary dose of diflubenzuron is 0.1 mg. per kg. of body weight. To achieve this dose, the amount of ClariFly® added to starter feed needs to reflect a calf's feed intake level. In other words, it's important to provide young calves with a starter feed that's properly formulated to achieve a larvicidal effect.

With good management under normal circumstances, calves begin consuming an appreciable amount of starter by the end of their second week of age, and by 3-4 weeks they are consuming enough ClariFly® to stop the development of fly larvae. If you remove the old bedding and start each calf off with new bedding, it will take a while for the calf's manure, urine, dropped feed, bedding etc. to build itself into a sustainable breeding ground for flies. This approach minimizes the amount of time a calf's manure does not contain ClariFly®, while at the same time providing the calf with ClariFly® protection that is already established from those calves around it. 

For those operations using a feeding system where each calf consumes a large daily volume of milk/milk replacer, starter intake is usually reduced and delayed until much closer to the weaning process. This further increases the time calves remain unprotected when using a larvicide feed additive. The good news is that Central Life Sciences, the manufacturer of Clarifly® hopes to have a version of ClariFly® available this summer that can be added on-farm to milk and milk replacer. 

Whatever fly control options you choose, the time to get going is about 30 days before you think flies will appear. Flies generally remain a concern until about 30 days after the first hard freeze. And if you live where is doesn't freeze, you don't really get a break.

Here's a link if you want more information about ClariFly®.

Thursday, March 1, 2012

Newborn Calf With Rapid, Shallow Breathing

On a recent trip to Torreon, Mexico I came across a two day old calf whose breathing was rapid and shallow. It was still early in the day so environmental temperature wasn't a factor. As it turns out, the calf had a difficult birth. The calf manager didn't have details, but said the calf was breathing this way because it had fluid in its lungs. Although the calf could have aspirated some amniotic fluid during birth, I wasn't sold on that diagnosis and felt there was some other reason for the calf's breathing pattern.

I was curious about what was going on with this calf but didn't have the opportunity to explore it further. I took out my cell phone and recorded this short video so that I could review it later:

After watching, if you want to reset the video to the beginning without replaying it, double click the replay button in the lower left corner of the video player after the clip has finished running.

Back home,  I sent the video clip to Dr. Sheila McGuirk at the University of Wisconsin-Madison, School of Veterinary Medicine, to see what she thought about the calf's condition, and possible reasons for its breathing pattern. Assuming the calf had a difficult birth that required assistance, Dr. McGuirk suggested several reasons for the calf's respiratory effort, resulting from a hard pull.
  1. fractured rib
  2. pneumothorax (air around lung) caused by rib fracture/punctured lung - can lead to collapsed lung
  3. blood in the thorax
  4. diaphragm injury - rupture or tear

These conditions result from trauma in the chest and lungs. The pain associated with major chest trauma can make breathing difficult and may compromise ventilation.

Timing can also be a factor. Dr. David Wolfgang at the Penn State University, Department of Veterinary and Biomedical Sciences, points out that if the calf is pulled too quickly it may miss out on important physical and hormonal stimulation. Uterine contractions and hormones associated with birth help prepare the lungs and get them ready for a life outside the uterus, centered on breathing air. If the lungs are not activated properly, this can result in reduced lung capacity at birth, making it difficult for the calf to fully inflate its lungs.

Patience during the birth process and judicious assistance according to the cow's schedule -- not the clock -- can help reduce the likelihood or severity of trauma and injury. This also applies to that critical time right after the calf is born. If there is concern about fluids in the calf's airways, it's best to lay the calf on its side on an elevated surface such as a bale, bag or elevated platform so you can drape the head and neck into a lower position for gravitational draining. Suspending or hanging the calf for drainage pushes all the abdominal organs against the diaphragm and compresses the chest. This puts a lot of unnecessary stress on the calf, especially if it has an injury, and increases blood cortisol -- or stress hormone.

Other possible causes of this breathing behavior include

aspiration pneumonia
  • The first type is meconium aspiration which can occur during birth. Meconium is the first feces passed by a newborn and can be excreted into the amniotic fluid during birth, often during stress. The calf may aspirate some of this mixture during birth or while still covered with amniotic fluid after birth. Meconium aspiration can cause breathing difficulties due to swelling (inflammation) in the lungs and may lead to pneumothorax. It is unclear how meconium triggers this inflammatory response; however, bile and liver enzymes have been suggested as possible causes.
  • A second type of aspiration pneumonia is from colostrum administration, typically from improper placement of an esophageal feeding tube.

vitamin E/Se deficiency
  • Dr. McGuirk also noted that every now and then, calves with a deficiency of vitamin E/Se can show a nutritional myopathy, or muscle disorder, which can affect the diaphragm, resulting in a rapid, shallow breathing effort.

Treating the calf. Perhaps the most important thing you can do for this calf is to treat it with a lot of tender loving care, TLC. That may not sound very interesting or innovative, but it can go a long way to helping the calf get through the first few days of life. Even nursing can be a challenge. Trying to take deep breaths or hold its breath while suckling and swallowing can be painful and quickly discouraging. Gently helping the calf to its feet and hand feeding with a bottle and nipple as many as six times/day may be needed to ensure adequate nutrient intake. Providing a heat lamp or calf blanket to keep the calf warm and comfortable can also help reduce stress. If things go as planned, the calf should be ready to be on its own in about 3-5 days.

You may be tempted to treat this calf with a product like Banamine (flunixin meglumine) in an attempt to make the calf more comfortable. This medication is a nonsteroidal anti-inflammatory drug (NSAID) and is mostly used to reduce fever and inflammation. In this instance, though, you may want to steer clear. NSAIDs have been associated with inhibition of platelet aggregation, or blood clotting, which is not something you want to happen to an animal that may have an internal bleeding problem.

If you are uncertain about what to do or you feel the calf has a serious injury that may require veterinary assistance, it's better to act sooner rather than later. This can increase the calf's chance of survival.

Contact Information
University of Wisconsin-Madison, School of Veterinary Medicine:
Veterinary and Biomedical Sciences, Penn State University:

Thursday, February 2, 2012

Feeding Electrolytes - How much does a calf need?

If I were to pick the one conversation I have most often with calf raisers, it would be how much and how often to feed oral electrolytes to scouring calves. Confusion seems to arise when trying to apply package instructions, which are limited and typically describe a narrow set of applications. They often read like cookbook instructions which simply don't - and can't - describe all situations.

Instructions may run counter to personal intentions. Some say to use the product in place of milk feedings, others say to feed in addition to normal milk feedings. Add to milk; don't feed in milk. Feed two quarts twice a day, once a day, feed for three days -- what if the calf still has diarrhea?

To begin with, it helps to have a good idea or a sense of what a scouring calf needs. It's safe to assume that a calf with diarrhea and no other visible signs of dehydration is about 4-5% dehydrated. If, for example, this calf weighs 100 lbs, then it needs about 4-5 lbs of water to get back to normal.

100 lb calf  x 0.04 = 4 lb; 100 lb calf  x 0.05 = 5 lb
easy to calculate for a calf of any weight

Since a gallon of water weighs about 8 lbs, a quart of water weighs 2 lbs. To rehydrate our 100 lb calf, we need to feed 4-5 lbs of water, or about 2 quarts of electrolyte solution. This is the amount of electrolyte solution that would be administered each day to this calf until it improves.

Keep in mind that this calf became 4-5% dehydrated while it was drinking its regular milk/milk replacer feedings. This means the calf needs the 2 quarts of electrolyte solution in addition to the liquid nutrition it normally receives, not instead of.

If the calf shows additional signs, such as sunken eyes, depression, tight skin (skin tents when pinched), or water-like diarrhea, it may be 7-8% dehydrated and in need of additional electrolyte feeding. The table below summarizes daily electrolyte requirements for 100, 80 and 60 lb calves.

Another way to look at this is that a calf with diarrhea and no signs of advanced dehydration requires treatment at the 5% dehydration level. Calves with water-like diarrhea or other clinical signs of advanced dehydration are likely losing water at a higher rate and would benefit more from treatment at the 8% dehydration level. Calves that are 10% dehydrated may not be good candidates for oral rehydration therapy, and usually require other methods of administering supportive fluids such as intravenous administration.

Note: some organisms damage intestinal villi while other cause hypersecretion of water into the digestive tract. These situations can lead to decreased absorption of fluids. If, for example, only 70% of the electrolyte solution is absorbed, the other 30% will pass through the calf, increasing fecal water loss. This makes the diarrhea appear to be worsening even though treatment is effective. In these situations, the frequency of treatment should be increased. Based on the table, you treat calves with water-like diarrhea at the 8% dehydration level.

Also, keep an eye on the front end of calf. If the calf is alert, active and wanting to eat, you are on the right track. Balance what's happening at this end of the calf with what you see at the other end.


Once you have a good idea of what the calf needs, you can administer oral electrolytes accordingly. Be sure to read the product label to understand what the product is and to understand how to mix the product and how the manufacturer intends/suggests that it should be used.

That won't necessarily end all conflicts, but at least now you'll be able to decide how to use the product or whether you should choose another one. If the label tells you to mix with water and feed in place of regular milk/milk replacer feedings or to add directly to the milk or milk replacer, you may choose to do that, but what are you going to do to correct the calf's water loss? Correcting dehydration is what electrolyte therapy is all about.