• Nutritional Management of Bulls

    Breeding bulls are large capital investments. However, the bull is often the nutritionally forgotten or most marginalized component of the beef cattle enterprize. This article explains some basic concepts in Breeding Bull Nutrition.


    This is unfortunate because proper bull management, particularly nutrition, is vital to ensure the long-term viability of the beef cattle enterprise. The bull contributes one-half of the genetics to each calf crop; without a functional bull the breeding season success and subsequent calf crop could be jeopardized. Therefore, proper and adequate nutritional management of herd bulls is paramount to the breeding season success and economic viability of the beef enterprise. Nutritional management of the herd bull necessitates planning to ensure success. In light of the tightening of feed supplies, adequate planning is both nutritionally and financially imperative.

    Nutritional Management of Beef Bulls

    There are a number of well defined nutritional periods during a bull's life.

    1. Pre-pubertal – pre-weaning

    2. Pre-pubertal – post-weaning to 30-60 days pre-breeding

    3. Conditioning prior to the breeding season

    4. Management during the breeding season

    5. Management after the breeding season


    During this period the bull is at the dam's side and nutrition during this period is generally adequate to ensure normal growth and development. Exceptions would be indicated when the dam's nutritional environment limits milk production. Creep feeding of potential herd sire bulls is utilized in some instances. Currently, there is little or no data that have evaluated the long-term effects of creep feeding on bull performance.


    This period of nutritional development should allow the bull to grow at nearly full genetic potential. The nutritional design of many growing programs or bull test station diets is a concentrate-based, low-roughage, high energy diet. The goal of this period is to grow the bulls rapidly, but avoid excessive fat development. The nutritional program should also be designed to avoid digestive upsets or affect soundness. The high-energy, high-plane of nutrition also stimulates the onset of puberty particularly in later maturing breeds. Adequate research indicates that either under- or over-nutrition during this period can have detrimental effects on bull development, attainment of puberty, and semen quality. Well-designed bull test diets or purebred bull breeders with sound development programs should allow bulls to express their growth potential without any deleterious effects on future performance.

    Conditioning prior to the breeding season

    This period is the most important next to the development phase, but that could be debated. Not only do growing bulls need this conditioning period, but mature bulls also need to be conditioned before entering service during the breeding season. Growing bulls generally have just gone through the development phase which consisted of a high-energy concentrate-based diet. As such, these bulls need to be cycled down from that high plane of nutrition. That means there needs to be a transition from the test diet or development diet to a conditioning or maintenance diet that is often forage-based. The transition to a forage-based diet often occurs when the bulls are losing their teeth (at approximately three years of age), compounding the stress of the diet transition. The conditioning period should be around 60 days. This time frame should allow adequate time for the bulls to adjust to a new diet. For well-conditioned bulls this time frame will allow bulls to moderate their fat cover and “harden up”, likewise thin bulls will have adequate time to increase their body condition if required. Additionally, the 60-day time frame provides adequate time for the sperm population to turnover and quality sperm to develop prior to the bull entering breeding service. The bull should enter the breeding season with a body condition score of 5.5 to 6.5 (9 point scale). This body condition provides the bull adequate body reserves to draw upon during the defined breeding season.

    Nutrition during the breeding season

    The nutritional environment during this period is almost always the same as the cow herd. Therefore special nutritional attention for bulls is nearly impossible. As a result, the conditioning period prior to initiation of the breeding season becomes all the more important. During the breeding season, bulls can lose from 100-400 lbs of bodyweight which equates to a loss of 1 to 4 units of body condition score. The amount of bodyweight and body condition loss will be influenced by the age of the bull, prior body condition, length of the breeding season, level of activity experienced by the bull, and breed type of the bull. Young bulls and terminal sire type bulls in the Gulf Coast environment will generally lose more body weight and condition during the breeding season compared to older or maternal type bulls in the Gulf Coast environment.

    Nutrition after the breeding season

    After the breeding, season bulls generally will need some attention to restore their bodyweight and body condition. The amount of bodyweight and body condition that needs to be replaced can be considerable depending upon how much bodyweight and body condition the bull mobilized. A 2,000 lb bull that loses 200 lbs could require up to 1,200 lb of 65% TDN feed to fully regain all of the bodyweight that was lost. As mentioned previously, young bulls and terminal sire type bulls generally lose more bodyweight. The length of the breeding season and length of the resulting recovery period will dictate the intensity of feeding to recover the lost bodyweight. Maternal sire type bulls are likely to be expected to regain bodyweight on pasture alone or with minimal supplemental feed. Terminal sire type bulls may require supplemental feeds to regain lost bodyweight because pasture quality may not support the needed performance. Likewise the use of young bulls that still have growth requirements will generally result in greater feed input requirements after the breeding season.

    Transition Time-frame Considerations

    As mentioned previously, the transition of a purchased bull from a high-growth diet to a normal production type diet is critical. An assessment of the bull's previous level of nutrition, and its characteristics on his current and future performance, needs to be made. Often bulls come off of test diets rather well-conditioned (i.e. fat, with a body condition score of 7+). While that conditioning may have been appealing in the sale ring, it is not an asset for breeding cows. How much fat needs to be shed and replaced by lean muscle is the issue. Excessive condition can be detrimental to semen quality because fat deposition decreases the effective cooling of the testes. Likewise excessive condition going into the breeding season can set the bull up for failure as the increased activity level and reduced feed intake cause him to “melt” as the breeding season progresses. Therefore, the goal of the transition period should be to “let down” the new bull from a high-energy concentrate diet to a low- to moderate-energy, roughage-based or grazing diet over time, continue the growth pattern as needed, and adapt the bull to an elevated activity level.

    The transition between diets should occur over several weeks to provide adequate time for the bull to adapt to the new diet. In that regard, the bull will need to receive a diet similar to the test diet when he arrives at the ranch. A supply of similar concentrate feedstuffs will need to be on hand for the bull upon arrival. The transition at the ranch could begin with a diet that contains 60-70% of the previous concentrate intake and then be decreased gradually over a number of weeks until the final diet formulation is reached. Therefore, it is imperative that planning go into the purchase, nutrition, and overall management of a bull prior to his use during the breeding season. The concentrated portion of the ration can be replaced by bulky, fibrous feedstuffs (soybean hulls, citrus pulp) or with moderate quality hay or silage. Remember, young bulls still have a growth requirement and likely still need to gain 2.0 to 2.5 lbs/day of bodyweight during the transition. Therefore, depending upon the quality of the forage base utilized, complete removal of the concentrated portion of the diet may not be feasible. The concentrated portion of the ration generally supplies the energy and most of the protein to meet the bull's growth requirement.

    Bull bodyweight gain during the transition period is dependent upon a number of factors that include previous bodyweight gain, current bodyweight, current body condition, and desired bodyweight at the initiation of the breeding season. Subsequent gain is then determined by dry matter intake and diet energy and protein density. Bulls that are undersized for their desired breeding season bodyweight will need to be developed during the transition period at a greater rate of bodyweight gain compared to more fully developed bulls. In contrast, bulls that are overly conditioned but are not fully mature still require a positive plane of nutrition, albeit one that emphasizes lean bodyweight gain rather than fat deposition. To that end, desirable rations are high in roughage content or utilize quality pasture, moderate the readily available carbohydrate concentration, and provide adequate protein.

    Another important consideration during the transition period is exercise. Bull test animals generally come out of confined spaces and are not acclimated to open space. Provide the bull with adequate space and let it become accustomed to getting exercise. Water, feed, and mineral can be spread aroundto encourage a level of activity prior to the breeding season, if the pasture size is adequate. An increased level of activity may also increase the bull's nutrient requirements by 5-10%, so appropriate consideration should be given to nutrition levels.


    Several nutritional time frames exist in the lifespan of the bull in the beef herd. The appropriate nutritional management of growing bulls is a key component of the long-term reproductive success of the beef cow herd. As with most management of beef cattle, the transition periods are management situations that can have significant effects on the success of the bull management program. During these periods, the prior nutritional status, current body condition, and bodyweight growth goals of the bull all need to be considered when designing a nutrition management program. The take home message is to know your bull. A correct assessment of the current and targeted bodyweight, body condition score along, and breed type are important factors to consider when designing nutritional programs to address any production scenario



  • Low Stress Handling

    With Fall on the horizon it is time to look at how we handle cattle. It is important to remember that low stress handling of cattle will reduce injuries to both cattle and the people working them. There are many other benefits to low stress handling such as improved weight gain and are less likely to have dark cutting meat.

    Even the best designed system -- if used wrong -- will be stressful for cattle. The basic principle for low stress handling is to work with cattle's natural behavior to get the desired effect instead of against it.

    Key points in reducing stress while handling cattle

    - No Yelling or loud whistling. When cattle become frightened from loud yelling or other poor

    methods, it takes 20 to 30 minutes for them to calm back down.

    - Reduce or no use of Cattle Prods. The only time one might be needed is at the entrance to a

    squeeze chute. If needed it should only be used on the stubborn cow and then put away. Not

    used on every animal.

    - Remove Distractions. Loose chain hanging down in alley’s, clothing hung on fences, hoses or

    other high contrast objects on ground are just a few examples.

    - Learn Behavioral Principles. Know and understand flight zone and point of balance

    - Only Fill crowd pen half full.

    - Finally measure your handling. Are there any cattle running, how many? Is there a lot of

    bellowing, don’t count separated cows and calves, times such as branding or tagging. How

    many fell, and finally how many did you HAVE TO use the hot shot on.

    Just a few ideas to help keep your operation safe and profitable.



  • Heat Stress

    Its finally warm, time to get the boats out and go fishing. The kids want to go and spend time out at the water park and eat ice cream; but with the rise in temperatures we need to be aware that it can be detrimental to our cattle.

    Heat stress in cattle is one of the biggest culprits of lost profits. Heat stress reduces feed intake, production, health and reproduction. Decreased performance is a result of the cattle’s inability to dissipate enough of its own body heat during periods of high environmental temperature and humidity. In addition, the cattle are prone to losing valuable electrolytes, mineral and buffering agents during hot weather due to increased sweating and respiration.

    The combination of decreased feed intake and increased nutrient losses by cattle requires additional

    supplementation of key nutrients to compensate for these losses.

    To help with combating heat stress consider adding ThermoCAD. ThermoCAD supplies a source of electrolytes, mineral and buffering agents to help restore electrolyte imbalances associated with heat stress.

    In addition, ThermoCAD provides ingredients that have been demonstrated to help cattle dissipate heat and lower body temperature during periods of heat stress.

    Also be sure to use proper management practices on your operation to help diminish the effects of heat stress.



  • Dealing with Dystocia

    Dealing with Dystocia (Calving difficulty)

    You can’t sell a calf that didn’t survive calving. To that end, we advise cattle producers to not be shy about calling their veterinarian when dealing with dystocia, or a difficult calving.

    According to Dale Grotelueschen, a DVM and director of the University of Nebraska-Lincoln’s Great Plains Veterinary Educational Center at Clay Center, Neb., the calving process is divided into three stages.

    • In the first stage, the cow or heifer becomes restless. “She may get up and lie down more often and move around,” he says, and often will isolate herself from the herd.

    • Stage 2 begins when the water bag appears, and it includes the delivery process.

    • Stage 3 is expulsion of fetal membranes and involution of the uterus, he says.

    Stage 1 can last 12 hours or it can be two hours. The challenge is not that every animal is different, but that we need to see progression. If they’ve quit straining, then we need to intervene.

    In fact, you can sum up the entire philosophy of when to help deliver a calf with one word: progression. We need to see progression from the time calving starts.

    Since calving difficulty is more often a problem in heifers, Spare suggests this timeline for progression: “When I see them off by themselves starting heavy labor, I want to see that water bag in about 30 to 45 minutes. Then in another 30 minutes, see the feet inside the water bag. Then in another 30 minutes, see the nose; and 30 minutes after that, we need to have a calf.”

    There is a definite timetable and unfortunately sometimes cattle don’t pay attention to timetables, so it will vary. But the point is this: things need to keep moving at a reasonable clip. But we’d rather have people err on the side of caution, so at any time when progression stops, intervene.

    Beyond watching the clock, there are some signs to look for that a cow and calf need some assistance, Grotelueschen says. If the legs present normally and the calf’s nose is there, and the calf’s tongue or nose starts to swell, that’s an indication of delayed progress.

    What do you need to do? You get that animal up and restrained properly in a clean area where we can safely assist her. By safe, we mean the safety of the cow as well as the safety of the people.

    That doesn’t mean a rope around her horns and snubbed up tight to a fence post. A squeeze chute will work, as will any sort of safe head catch with gates that open, in an area that’s cleanable. It can be a dirt floor that we wipe clean and throw lime on, or it can be concrete that we wash down between animals. But you need to have access to that animal to properly examine her.

    Dealing with a bad presentation

    In the examination, you’re looking for a normal presentation, with the calf’s two front feet visible with the tips of the hooves pointing up, followed by the calf’s nose a few inches behind. If a hoof or the head is back, or it’s a breech, the calf can be manipulated to get everything lined up. But a hoof or head out of position might be a symptom of another problem.

    In a normal presentation, the calf’s front hooves are facing forward with the tips up, and the calf’s nose is an inch or two behind. A breech presentation can be a challenging dystocia presentation. But with training, producers can learn how to manipulate the fetus to make delivery easier. A calf can be delivered when in a posterior presentation, but may require assistance. If you see hooves but no head, don’t assume the calf is coming backward. The head may be back. An examination will help determine the problem. All illustrations courtesy of Oklahoma State University.

    Many times, with an abnormal presentation, particularly with a heifer, it means the birth canal isn’t big enough for the calf. Using a calf puller in that situation only makes things worse.

    That’s a situation where having a good relationship with your vet is helpful. Large animal vets are always willing to help their clients learn what they can do in the field. Your vet knows you and your abilities. It can save time and calves when assistance is needed.



  • Controlling Flies on Pasture Cattle

    Controlling Flies on Pastured Cattle

    There are three primary fly species in South Dakota that economically impact pastured cattle: horn fly, face fly and stable fly. Control of these flies can be economically beneficial to cow-calf and stocker/yearling operations.

    Horn Fly

    The horn fly is one on the most important blood feeding pests of pastured cattle in the United States. Losses in the United States have been estimated at about $800 million annually.

    When horn fly numbers are high, cattle experience annoyance and blood loss (see image at right, click on image for larger view). The result may be decreased milk production, reduced weight gains, changes in grazing patterns and bunching of animals. Significant reduction in calf weaning weights is well documented. Nebraska studies demonstrated calf weaning weights were 10 to 20 pound higher when horn flies were controlled on cows. In addition, horn flies have been implicated in the spread of mastitis.

    The economic injury level (EIL) for horn flies is 200 per animal and population numbers of several thousand of flies can often be observed during the summer.

    The horn fly is a blood feeding fly that is located on the shoulders, back and belly region of cattle, they take some 20 to 30 blood meals per day and the only time they leave an animal is when the female deposits eggs in fresh cow manure. The complete life cycle, egg to adult, can be completed in 10 to 20 days during warm conditions. In Nebraska, where we typically have several generations during the summer, horn fly populations can reach very high levels.


    Horn fly control for pastured cattle involves different insecticide use strategies. These include dust bags, back-rubbers (oilers), animal sprays, oral larvicides (Rabon and Altocid IGR,available in Stockmaster® Minerals and Crystalyx® barrels), pour-ons, and insecticide impregnated ear tags.

    Force-use, self-treatment devices, such as dust bags and back-rubbers (oilers), provide effective and economical fly control. Studies have shown that horn fly control is 25-50 percent less using free-choice methods.

    Animal sprays can be an effective way on reducing horn fly numbers. Drawbacks with animal sprays are increased cattle handling, cost, and added stress to the cattle during the fly-season.

    Oral larvicides and insect growth regulators (IGR) prevent horn fly larvae from developing into adults. These can be delivered to cattle as loose mineral, or through Crystalyx® Barrels and have been very effective when implemented early in the season and fed continuously through the season.

    Pour-on insecticides are ready-to-use formulations applied along the back line of cattle. Although pour-ons will control flies for short periods, the stress in cattle in using this method may offset the benefits of the fly control.

    Insecticide impregnated ear tags contain one or more insecticides embedded in a plastic matrix. To achieve the maximum performance from an insecticide ear tag, two tags per animal are required, and delaying ear tagging until June 1st will provide a producer with the greatest degree of horn fly control. A livestock producer in South Dakota can expect 8 to 12 weeks of horn fly control if the aforementioned methods are utilized.

    Face Flies

    The face fly is a robust fly that superficially resembles the house fly. It is a nonbiting fly that feeds on animal secretions, nectar, and dung liquids. Adult female face flies typically cluster around the animals' eyes, mouth, and muzzle, causing extreme annoyance.

    In addition to being very annoying to cattle, face flies vector Moraxella bovis, the principal causal agent of bovine pinkeye or infectious bovine keratoconjunctivitis. Pinkeye is a highly contagious inflammation of the cornea and conjunctiva of cattle. If coupled with the infectious bovine rhinotracheitis (IBR) virus, M. bovis can cause a much more severe inflammatory condition.


    Controlling face fly numbers is a key to reducing pink-eye problems. Because face flies are on animals for only short time periods they are difficult to control.

    Fly control methods described in the discussion of the horn fly can be used against the face fly. Insecticide ear tags, if used according to label recommendations, provide a higher degree of face fly control. Both cows and calves must be treated if control is to be achieved.

    This year we are featuring a Barrel from Crystalyx called Rolyx Max. It is a high quality mineral program that contains Rabon® Oral Larvacide. Rabon is the only feed through option that is indicated for Horn, Face, Stable flies and house flies.

    Stable Flies on Pastured Cattle

    Stable flies are pests of cattle on pastures in the Midwest. Stable flies mainly feed on the legs of cattle. To avoid being bitten, animals stomp their feet and switch their tails. Other avoidance behaviors include standing in water, lying with legs tucked underneath and bunching at the corners of pastures.

    The effect of stable flies on weight gain performance of pastured cattle is similar to that of livestock in confined operations. Research conducted at the University of Nebraska, West Central Research & Extension Center recorded a reduction in average daily gain of 0.44 lb per head per day in 84-day trials compared to cattle that received an insecticide application. The economic threshold of five flies per leg is easily exceeded in South Dakota pasture conditions.

    The female fly deposits eggs in spoiled or fermenting organic matter mixed with animal manure, moisture and dirt. The most common breeding sites are in feedlots or dairy lots, usually around feed bunks, along the edges of feeding aprons, under fences and along stacks of hay, alfalfa and straw. Grass clippings and poorly managed compost piles also may be stable fly breeding areas. Winter hay feeding sites where hay rings are used can often be a source for stable fly development through the summer if the proper amount of moisture is present.


    The only adult management option available for control of stable flies on range cattle is use of animal sprays or by controlling populations utilizing a Rabon Oral Larvacide in a Stockmaster Mineral, or Crystalyx program. However, the implementation of either procdure may not reduce the economic impact of stable fly feeding.

    Stop in to Agritech today to discuss a fly management program that will minimize losses from flies on your pasture cattle this summer. We have Stockmaster® minerals, and Crystalyx® programs that contain either Altocid (IGR) or Rabon. We also carry cattle insecticides, Fly tags and Dust bags, and Cattle oilers. Most importantly, we have the knowledge on how to implement an effective fly control strategy for your individual needs.



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