Livestock

Why cows sort feed

Written by Dr. Jim White on .

Nearly all cows sort their feed to some degree. That is why the leftover feed is the larger and unpalatable portions of the feed. Depending on conditions, the amount of sorting varies widely.

The degree and overall effect of sorting on cow performance is worth your attention. To evaluate the level of sorting, look for certain symptoms that indicate feed sorting is a problem.

Watching the cows eat is informative, especially just after feed delivery. In a well-mixed and palatable ration, cows will eat aggressively from the top of the feed pile as soon as it is delivered.

The cow’s head often stays in one spot or moves slightly. Spilling from the cow’s mouth is relatively low, and consumption is rapid. As she progresses, you may see feed falling from her mouth, and eventually, the tell-tale hole burrowed into the feed all the way to the feeding surface. She is nibbling the fines or goodies as they fall into the funnel while leaving the less desirable feeds behind. This also occurs if the cow burrows through the feed, shifting feed concentrates into the hole. When this occurs, the feed in the bunk changes in appearance.

It is easiest to notice if the feed has been in front of the cows for some time and they have selected what they want. Given that cows have a pecking order, the result of feed sorting means different cows get different diets and intake.

Common contributors to ration sorting

  • Particles are too long. The rule of thumb is that if the particles are longer than the width of the cow’s muzzle, she can sort it. Sorting is prevalent with “shredlage” for corn silage and longer chop lengths. Sorting can be more common if the feed left behind is not the favorite part of her diet (lower parts of Sudan stalks or corn cobs). The opposite of this effect is when the cow selects the free-choice long alfalfa hay because she likes it to the exclusion of other feeds in the partial-mixed ration. Both behaviors promote a diet different than intended by the producer. Processing long-stemmed baled hay before putting it in the mixer helps. Understand that using the mixer for this is time-consuming, reduces particle length of other feeds and puts excess wear on it.
  • Lack of initial palatability. Dry diets are less palatable to begin with, and in dry diets, concentrates do not adhere together with the forage base. Cows prefer eating a mixed ration that is 50-66 percent dry matter. Wetter diets in the summer tend to be preferred over drier rations. Rations that are dry hay and dry concentrates (say 90 percent dry matter) respond well to adding moisture such as molasses, syrup or water. Having adequate moisture in the mixed ration will reduce feed sorting.
  • Worn out mixers. Mixers get plenty of hard use, and as they wear, they become less efficient at mixing correctly. Further, some operations will overload their mixer to gain batch size, but they lose the benefits of proper mixing. Highly worn mixers require more mix time, causing particle reduction and less effective mixing action. Check the kick plate on the bottom of vertical augers for wear, and inspect feeds as they discharge from the mixer. Clumps of concentrates or forages in the mixed ration (often seen at the beginning or very end of feed unloading) indicate either too short of mix time or a mixer that isn’t operating correctly. Overloading always reduces mixer efficiency and promotes sortable diets. Overloading is the cause of the majority of improperly mixed rations. Mixers require routine maintenance and should be on a service schedule.

Sorting may become a health and financial issue. Cows that aggressively sort feed do not get a balanced diet. Mostly they get too much concentrate and not enough fiber. This is accompanied by shifts in manure consistency. The cow sorting for grains today is often slightly off feed the next day and sorting for fiber to correct her unhealthy rumen pH. The result is lower milk or components or acute digestive issues.

In a crowded pen, where bunk space may be limited, the aggressive cows sort out the goodies, and the passive cows eat the already-sorted feed. Neither animal meets her target feed requirements.

So you have a new horse...

Written by Dr. Jim White on .

Congratulations! It’s your birthday. Or it’s your wife’s birthday. Or you won the auction bidding. And now you own a new horse. Everyone is excited. But the question comes up: “What is the best way to get the new horse on the farm with minimum upsets—hopefully, no upsets at all?”

Many of us have seen horse colic when their feed changes. Thus the first consideration is keeping the horse on the same grain ration. If you intend to change the ration, do it over time. Take 14 days to make the switch after the horse settles into its new accommodations. If the horse has been eating grass hay and MFA Easykeeper 11%, you’ve inherited a good ration. If you don’t know what the horse was consuming, try using MFA Easykeeper as the concentrate.

In general terms, you will want to keep the horse in quarantine for 30 days. It is a common practice for the owner to house the new horse across a sturdy fence from the existing herd. Once the animals acclimate to each other over the fence, add one horse at a time in with the new horse to allow them time to adjust. In time, all of the horses will slowly be introduced, and hopefully, you have no major issues. As far as I know, there is no standard as to how long this acclimation period should be. The time it takes for horses to adapt depends on attitude and disposition to exert dominance.

Consider biosecurity whenever you are traveling to horse shows, auctions or shopping around for a new member of the herd.
I like the USDA definition of biosecurity: “Doing everything you can to reduce the chances of an infectious disease being carried onto your farm by people, animals, equipment or vehicles, either accidentally or on purpose.”

USDA publishes some common-sense recommendations for biosecurity; I highlight some here because I think we can all use an occasional reminder about farm hygiene.

  • If you show horses, don’t share trailers. And if your horse ends up in someone else’s trailer, only allow it if the trailer has been cleaned and disinfected. If you can “smell horse” in the empty trailer, it has not been cleaned and sanitized properly.
  • When at events or rides, don’t let your horse touch other horses, especially nose to nose.
  • Don’t share equipment (e.g., water, feed buckets, brushes or sponges).
  • Wash your hands, especially after helping other people with their horses.
  • Don’t let strangers pet your horse, especially those with animals at home or people who have been out of the country in the past two weeks.
  • Before leaving the show grounds, clean and disinfect tack, boots, equipment and grooming supplies. Brush off dirt or manure; then disinfect (spray or wipes are easy to take with you).
  • When you get home, shower, blow your nose and put on clean clothes and shoes before going near other horses.
  • If you’re going to a horse auction, have a pair of shoes or boots that you save for visiting and don’t wear around your horse.
  • Wear plastic shoe covers. Plastic bags from newspapers work well.
  • If you are going to be working with horses on another farm, wear coveralls or plan to change clothes before returning to your horse.
  • If there are farms you visit all the time and you can’t change clothes and shoes, be sure their vaccination program and biosecurity practices are as good as your own.

All of the above is good advice. Keep in mind that bringing new horses onto the farm is the most likely way to introduce diseases. During that 30-day quarantine, don’t mingle feeding buckets, pitchforks or grooming tools between existing horses and the new arrival. You need to work with the new horse daily to acclimate it but consider having a pair of coveralls to either change into or out of before going between pens. Wear a different pair of boots and launder your clothes before wearing them back to the pens.

Just like after shaking hands at church, it’s a good idea to wash your hands before you move between pens.

You can find more detail on biosecurity and horse hygiene at: http://mfa.ag/2cHYMzW.

From the field

Written by David Yarnell on .

We have seen good results on beef and dairy operations in my area, but a success story I ran across near Seymour, Mo., is worth a note.

After an information meeting last fall, one of my customers—a rabbit producer—began feeding his does Rabbit 16% Shield pellets from MFA. It was a full switch in feeding programs for him, and he has been happy with the results.

Since the switch, he has noticed a 10 to 15 percent boost in pregnancy percentages overall. The producer pulled a group of a dozen does to run a comparison of MFA’s Rabbit 16% Shield pellets to his previous ration.

Here’s what he told me:

  • Does on Rabbit 16% Shield pellets averaged one to two more kits per litter.
  • Kits can be weaned at five weeks of age on Rabbit 16% Shield pellets compared to six weeks on the previous ration.
  • Does on Rabbit 16% produce a litter every six weeks compared to seven weeks on the previous ration.

This producer’s goal has traditionally been to have a fryer ready to sell at 12 weeks of age and weighing 5 pounds. Feeding Rabbit 16% Shield, he has adjusted expectations with the goal of reaching 5 pounds at 10 to 11 weeks. Looking over his weight tickets, I was able to do some quick math.

He gave me several weight tickets where he sold fryers and here are the numbers:

  • On these tickets he sold 347 fryers weighing 1808 pounds, which is an average of 5.21 pounds per fryer at market.
  • With the new price per pound, that 5.21-pound rabbit is worth $8.08.

That means he is getting one or two more kits per litter. For the sake of this argument, let’s say just one. With the previous ration, his does had a litter every seven weeks, which would be 7.45 litters per year. On Rabbit 16% Shield pellets, his does produce a litter every six weeks, which equals 8.69 litters a year. How many more fryers will be available for market? Well, 8.69 litters a year x 1 extra kit per litter = 8.69 x 60 does = 521 more fryers. At the market price of $8.08 as I wrote this, the additional kits would mean an additional $4,210 per year in income.

Shield Technology does require more expensive ingredients and is priced accordingly. However, if you carry the math out, it’s probably worth the investment. This producer buys between 4 and 5 tons of Rabbit 16% Shield pellets a month. It costs about $16 per ton more than MFA 16% without Shield ($768 to $960 per year). So take that extra $4,210 in income and extract $960. That is $3,250 per year in cash or to invest back into the operation.

I continue to look for other Shield Technology success stories. If you want to contact me, write: This email address is being protected from spambots. You need JavaScript enabled to view it..

A nutritional defense against stress

Written by Dr. Jim White on .

Cattle suffer various levels of stress depending on what stage of production they are in. Mitigating stress through management and feeding can pay dividends.

At weaning, calves experience a tremendous amount of stress and for a prolonged period. Proper nutrition can help alleviate some of the negative issues related to stress. It is important to understand how stress impacts the animal and how nutrition can help.

Animals subjected to stress have increased blood concentrations of the hormone cortisol. Cortisol can compromise the immune system. Specifically, cortisol will decrease T-lymphocyte cells, which are involved in cell-mediated immunity. Cell-mediated immunity is the portion of the immune system responsible for destruction of pathogens. Prolonged stress can reduce the animal’s ability to fight infection.

In order to mount an immune response, energy, protein and certain trace minerals are used, which increases nutrient requirements of the animal. Unfortunately, when calves are under stress, dietary intake is reduced. Research shows that fasting or feed deprivation can increase cortisol release. Therefore, the calf now has two problems: stress has compromised the immune system, and calves are not eating enough to meet the increased nutrient demands of an immune response.

Reduction in dietary intake is well documented in newly received feedlot calves. Upon arrival to the feedlot, intake can be as low as 60 percent of the consumption observed a week later. The National Academies of Sciences 2016 publication, “Nutrient Requirements for Beef Cattle,” suggests mineral concentrations in stressed calves be increased. Essential trace minerals hold an integral role in the immune system, with copper, zinc and selenium being of particular importance.

Copper is involved in the production of antioxidants and serves a role in neutrophil function, which is involved in the killing of pathogens. Although reports on the benefit of additional copper for improving immune function vary, the mere fact that it is necessary for proper function of the immune system warrants consideration when developing mineral programs. Studies show that when dietary copper supply and bodily reserves are low, there is a reduction in the ability of the immune system to kill pathogens. The publication states a non-stressed calf requires a diet that contains 10 parts per million copper. In a stressed calf, copper requirements increase up to 15 ppm.

Copper can be a challenging trace mineral to balance in a diet because of its relationship with iron, molybdenum and sulfur. If these minerals are too high, they can interact with copper and reduce its availability to the animal. For example, when total dietary sulfur intake increases above 0.2 percent, the amount of copper available for the animal decreases by approximately 25 percent. In some parts of the U.S., water sulfur concentration alone can be high enough to cause this reduction.

Zinc is involved in signals that initiate activity of certain cells in the immune system. Zinc requirements for non-stressed calves is 40 ppm and for stressed calves is up to 100 milligrams per kilogram. Some reports demonstrate a benefit from supplemental zinc, and some do not. In most cases, animals suffering from zinc deficiency exhibit positive responses to supplemental zinc. Therefore, calves not consuming adequate amounts of zinc are at a greater risk of becoming sick during periods of stress.

Selenium plays a role in immune function as it contributes to the production of antioxidants in the body and reduces oxidative tissue damage. Dietary selenium inclusion in diets of non-stressed calves is 0.1 ppm and up to 0.2 ppm for stressed calves. There are reports that demonstrate additional benefit of supplemental selenium even above 0.2 ppm. But federal regulations say that the selenium content of a complete feed cannot exceed 0.3 ppm or 3 milligrams per head per day. In animals fed diets deficient in selenium, selenium supplementation improves the immune system’s ability to combat pathogens.

Mineral supplementation programs generally focus on the cow; a good mineral program can positively impact cow and calf performance. In fact, calves generally consume mineral at the same time as the cow. However, their supplemental mineral consumption, as a percent of bodyweight, is approximately 50 percent of that of the cow. Thus, mineral status of calves as they go into the weaning season could be marginal. The associated stress could lower intake, which may exacerbate any mineral deficiencies and increase the risk of illness.

Beat heat stress

Written by Dr. Jim White on .

This won’t come as a news flash: it is important to have enough water and shade for cattle. Cattle can tolerate summer temperatures and remain productive when properly managed and allowed access to adequate fresh water and shade.

But what you might not realize is that cattle are most productive when temperatures are between 41ºF and 77ºF. Temperatures above that put cattle at a greater chance for heat stress: decreased reproductive performance, decreased calf performance, lower milk production, and the rest.

There are many environmental factors that affect cattle and their potential for heat stress, including relative humidity, wind speed, solar radiation, ground cover, access to water, diet, shade and temperature. Animal characteristics can also contribute to heat stress, including color, breed, health, adaptation, hair length and disposition.

Heat stress occurs when these factors and ambient temperature cause an animal’s heat load to exceed its ability to dissipate that heat.

Available water and adequate shade are effective at reducing the effects of heat stress. The amount of shade required is 30 to 40 square feet for mature cattle, 20 to 25 square feet for feeder cattle and 15 to 20 square feet for stockers. Heat stress is compounded by animals crowding together, which happens when shade is limited. If natural shade is inadequate, construct permanent or portable shade structures.

Permanent structures are more suitable for feeding pens and but are frequently placed in pastures as well. Portable structures are more expensive to construct but can be moved with the cattle. The advantages to portable structures include: more uniform grazing, less pasture damage in the shaded areas and better manure distribution. Locate shade structures in areas to take advantage of prevailing winds during the summer. Select areas with minimal slope to prevent erosion that can result from concentrated animal traffic.

All shade structures should allow adequate airflow. Permanent structures will require manure removal in some situations. Inexpensive UV-resistant shade cloths that block at least 80-90 percent of light, or two offset layers of snow fence provide adequate shade and allow for proper airflow. Solid coverings are more expensive and last longer but are more susceptible to wind damage. If a solid cover is used, then the structure will need to be taller.

You can affect heat stress through feeding, too. One way is to reduce forage to minimum effective fiber levels. Practically speaking, this is a difficult task, in that many beef cattle are eating principally forage diets. That said, the tactics would be to feed the best forage available and use additives that help alleviate heat stress. From our perspective, the product of choice is MFA Ricochet FesQ Max products.

Additionally, feeding a yeast culture helps for heat. The feeding rate depends on the product but ranges from 10 grams per head per day to 10 ounces per head per day. All MFA Gold Minerals and dairy feeds have yeast cultures, as do Trendsetter, Cattle Charge and Full Throttle. The same goes for Aspergillus oryzae, which is usually fed at 3 grams per head per day. Some products/brands suggest as high as 15 grams per day.

Potassium is a consideration as well. Usually, beef animals on forage diets are high in potassium, but when more concentrate is fed, potassium content declines. Thus, under heat stress, you can add potassium to equal 1.5 percent of the entire diet intake. The source that works the best is potassium carbonate, but since this is a costly mineral, most of us use potassium chloride.

Feeding fat increases energy, reduces package size, reduces fiber content and load without increasing acidosis risk. For beef, I feed up to a pound of fat. For dairy animals, I feed a pound of fat as a vegetable (roasted soybeans), 1 pound as animal (Taltec) and 1 pound as a “bypass” fat (megalac etc.). But that is where I stop—overfeeding fat, especially vegetable fat, will reduce fiber digestion and intake, which is exactly what we don’t want for milk production in heat-stressed cows.

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