A579
Nutrition for Dry Cows

stages of the dry period | the far-off dry period | the transition dry period | feeding the far-off dry cow | feeding the transition dry cow | balancing DCAD using diet acidifiers (anionic salts) | products used to create a negative DCAD | supplementing calcium orally | fatty liver and ketosis | milk fever | retained placenta and metritis | displaced abomasum | udder edema | rumen acidosis and laminitis

Introduction: Why talk about dry cow nutrition?

The dry period of a dairy cow’s lactation cycle is often viewed as only a rest period to enable the cow to respond well at freshening and produce the maximum amount of milk the next lactation. Because these cattle are not contributing to the milk check and do not have the energy demands and stress of milking, they are often given the lowest quality feed on the dairy. They are not as intensively managed, and little attention is given to their well-being until they approach calving.

The time right around calving, however, is the period where cattle experience the most susceptibility to metabolic and infectious disease. The large growing fetus, the stress of calving, the drop in dry matter intake, and the change to new more energy dense feeds of the milking ration can all lead to familiar problems on dairies. These problems include milk fever, dystocia, displaced abomasum, mastitis, retained placenta, fatty liver, ketosis, acidosis, laminitis, udder edema, and uterine infections.

These problems are not only costly in and of themselves, but they lead to other drains on the dairy producer’s cash flow. Loss of milk production is the biggest one. When a cow experiences any of the above conditions related to calving, her milk production for the following lactation is severely lowered. In addition to that, her ability to get pregnant again is compromised. Her overall health and longevity is diminished, and she is at greater risk of becoming a cull. Recent studies have shown that the majority of cows culled from a dairy herd are culled within the first 30 days of calving. The majority of these are culled for reasons directly related to calving.

With good nutrition in the dry period, there is potential to prevent or minimize the metabolic and infectious problems associated with calving. Goals of the dry period should be the following:

1. Prepare the mammary gland for colostrum production and lactation.
2. Allow for fetal growth while maintaining the cow’s body condition.
3. Allow time for the cow’s digestive system to adapt or transition to the higher energy, more energy dense lactating ration.
4. Help the body respond to the calcium demand during and following calving.
5. Help maintain a healthy and responsive immune system.
6. Meet the energy, protein, mineral, and vitamin requirements of the cow.

Meeting these goals is mainly accomplished through management and nutrition. Although this discussion deals mainly with the concept of nutrition, some of the most important management strategies will be mentioned. When these goals are achieved, each cow will come closer to reaching her full potential of milk production. She will not be limited in her ability to get pregnant, and she will maintain good health and longevity.

 

Ideally, the dry period should be around 60 days. This number has been studied a great deal and seems to be the length of time that gives the maximum return on performance the next lactation. Cows that get less than 45 days in the dry period have significant reductions in production. Cows with over 60 days dry will show greater production the longer they are dry, but will bring diminishing returns because of the length of time the cow is out of the milking herd. Sixty days seems to be the ideal length for the dry period. The importance of the length of the dry period suggests one important management item. Accurate pregnancy diagnosis is critical to ensuring adequate time in the dry period. Only with a regular pregnancy check, usually performed by a veterinarian, will the herd manager be able calculate a dry-off date to provide a consistent 60-day dry period for each cow.

The dry period is divided into two stages. The first stage, or far-off period, begins at dry off and extends up until 3 weeks before calving. The second stage is called the close-up (sometimes called transition, steam-up, or lead-feed) period and encompasses the 21 days before calving.

1. The Far-off Dry Period: The main goal of the far-off dry period is to be a period of rest from lactation and allow the mammary gland to involute or shrink. The ration of the cow is changed from the energy dense lactation ration to a dry, high-forage, low-energy ration that will greatly limit milk production. This is necessary to prevent engorgement of the mammary gland which may lead to mastitis. The ration is also balanced to meet the energy, protein, carbohydrate, mineral, and vitamin needs of the cow, as well as the developing fetus. The cow at this time is well into her third trimester of pregnancy. Ideally, the cattle in the far-off dry period are divided into three groups.
    
   1. Springing heifers 60 days from calving.
   2. First-calf heifers (ready to have their second calf) and thin cows.
   3. Fat cows.
       
   It may not be possible, especially on smaller dairies, to have 3 pens of far-off dry cows, but there are advantages to having these 3 groups. Springing heifers are young and timid and will often have limited time at the feed bunk and watering trough if penned with larger adult cows. This can be very detrimental to the heifer. Penning the fat cows separate from the rest of the adult cows is an important management tool that may help prevent serious health problems in the over-conditioned cows. The benefit of keeping heavier, fat cows separated from thin cows and first calf heifers will be discussed in more detail in the section on Feeding to Prevent Metabolic Disease-Fatty Liver and Ketosis below.
    
2. The Transition Dry Period: The main goal of the transition dry period is to prepare the cow for parturition (calving) and lactation. This is accomplished in 4 ways:
    
   1. The first is to provide a half-way step in transition between the feed of the far-off dry cow ration and the feed of the lactating ration. The digestive system of the cow is complex. The main stomach of the cow is a large fermentation vat with a sensitive and adaptive population of bacteria, yeast, and protozoa that will respond to changes in feed. It takes 2-3 weeks for adaptive changes to occur, and the transition dry period provides an ideal opportunity to adapt the rumen to the feed and increased energy of the lactating ration.
       
   2. The second is to prepare the body for the huge demand of calcium that will occur at parturition and early lactation. It is estimated that a moderate to heavy producing cow will draw more calcium from the bloodstream than what is typically present. If the mechanism which the body uses to stabilize calcium in the blood is not in place or prepared to respond to this calcium demand at calving, calcium is rapidly depleted from the blood and the effects of hypocalcemia will be seen. Hypocalcemia (low blood calcium) is directly related to the conditions of milk fever, dystocia (difficult calving), displaced abomasum, and retained placenta.
       
   3. The third way is to maximize dry matter intakes of the close-up cows right up until the time of calving. The dry matter intakes of cattle decline sharply 24-48 hours prior to calving. The day they calve they actually eat very little. This puts these high-producing, lactating animals in a negative energy balance. This means that they do not take in enough nutrients to meet their energy needs. The faster cows can begin eating after calving, the faster they can get to a point where they meet their energy needs. This will mean a stronger immune system, a stronger ability to conceive, and less chances of developing an infectious or metabolic disease.
       
   4. The fourth and final way is to prepare the cow for the stress and trauma of calving. This can be done by making sure all nutrient requirements are being met in the diet. Adequate energy and protein are vital to a healthy immune system. Vitamins and minerals are involved as co-factors in many of the body’s important functions. There are also many management factors that are critical at this important stage in the cow’s lactation cycle. Cleanliness in the calving area, appropriate vaccinations, appropriate stocking density, comfortable pen and stall design, and the way animals are grouped all will play a big part in the health of this pre-fresh cow.
      
       

The following table, taken from Nutrient Requirements of Dairy Cattle, National Research Council (NRC 2001), outlines the nutrient requirements for the far-off and the transition dry cow:

1. Far-off dry cows should be fed to meet the requirements in order to maintain their own body and to allow for growth of the developing fetus. It is not healthy or desirable to feed cattle in this period of their lactation in a way to gain or lose weight. The majority of the ration should be made up of one or more rough forages. The sudden change of diet from the milking ration, which is high in energy and protein, to the dry cow ration which is low in energy and protein, but high in fiber, will enable the cow to dry up. For the remainder of the cow’s time in this period this ration should help the cow neither gain or lose, but maintain body condition.
    
2. Cows in the far-off dry pen should be monitored on a regular basis for body condition, signs of making up (preparing for calving and lactation), and cow comfort. Many dairy producers like to feed push-out or weigh-back (the feed picked over and left uneaten) from the lactating cows to the far-off dry cows. Often all that remains from the diet of the lactating cows is stems and fibrous sorted material. However, the stems and fibers from the good quality hay or silage in the milking cow ration may still provide more than enough nutrition for the far-off dry cow and may lead her to gain weight. This should be monitored very closely when push-out or weigh-back is fed.
   
    

1. Fatty Liver and Ketosis (see also page F420): Fatty liver and ketosis are conditions that can occur shortly after freshening. They are especially common in obese cows and cows that have become fat because of extended periods of time in the dry pen. It is generally excessive body condition that predisposes cows to this condition. At calving, all cows experience a suppression of feed intake, but over-conditioned cows have a much greater response. If they do not get on feed right away, the body begins to mobilize fat and send it to the liver to be processed into usable energy. The cow’s liver is inefficient at metabolizing fat, and if the cow is overweight and has many fat stores, the liver can easily become overwhelmed. Fat plugs the liver, and the liver becomes enlarged and has a pale appearance. Once it is plugged with mobilized fat, the liver is then unable to function in its many other capacities. The cow becomes toxic, recumbent, and will eventually die if no intervention occurs.
   
   Ketosis occurs when the liver attempts to metabolize the fat from body fat stores into glucose. By-products or intermediate metabolites from this process are ketones. Again, the liver is inefficient at processing fat, and if the influx is too great, many ketone bodies will build up and enter the bloodstream before being further metabolized. Ketone bodies affect the brain of the cow and cause depression, loss of appetite, staggering, incoordination and recumbency. Treatment of fatty liver and ketosis include supplementing the cow with energy, such as dextrose and propylene glycol, to stop further mobilization of fat. Corticosteroids such as dexamethasone and insulin injections have also been shown to be helpful in treating these conditions. Despite best efforts to treat these cows, there are some that just do not respond. The best scenario is to prevent these conditions. The following are a few suggestions on how to prevent this problem:
   1. Have proper and balanced energy nutrition for cows just prior to calving to compensate for the drop in feed intake.
   2. Implement aggressive reproduction programs that prevent cows from getting overweight because of a long number of days milking before getting pregnant.
   3. Feed dry cows that are over-conditioned or are dried up early so that they do not gain any more weight in the dry period.
   4. Avoid silages that are put up too wet. These silages may have fermentations that produce butyric acid. This acid is directly converted to ketones in the cow’s stomach and may cause or worsen a case of ketosis.
   5. Fresh cow drenches provide a way to prevent ketosis and fatty liver, stimulate appetite, and get the fresh cow started after calving. Many fresh cow drench formulas, which may contain energy, electrolytes, vitamins and probiotics (bacterial products that enhance fermentation in the cow’s stomach), are available and are often mixed with 5-10 gallons of water and then pumped into the cow’s stomach by a stomach tube.
   6. Ensure adequate time in the close-up dry cow period by having accurate pregnancy diagnosis, drying-off cows at the right time, and then moving animals into the close-up pen 3 weeks before calving. Adequate time in the transition pen will prevent many of the digestive problems that may occur to animals that do not have time to transition.
   7. Feed excellent quality, highly palatable feed to the transition dry cows. Beware of anything that may be unpalatable or may cause a decrease in dry matter intake, even anionic salts.
       
2. Milk Fever (see also page F510): Milk fever is a term used to describe clinical hypocalcemia (low blood calcium). It is generally characterized by weakness, inability to rise, cold extremities and a generalized loss of muscle function. Cows that experience milk fever will produce approximately 14% less milk during their lactation. They are 8 times more likely to develop a case of mastitis, and 24 times more likely to develop ketosis. Milk fever cows are also more likely to have a retained placenta, uterine infection, uterine prolapse, and displaced abomasum. One study estimated that a case of milk fever may reduce the cow’s productive life by 3.4 years. Therefore, it is much better to prevent milk fever than to treat milk fever. Following are some suggestions on how to prevent this condition:
   1. Balance dry cow transition rations to help the cow’s system prepare for the calcium demand at calving using one of the three methods that were discussed earlier. These include the following:
      1. Calcium restriction prior to calving.
      2. Dietary acidification by balancing the DCAD (dietary cation:anion difference).
      3. Oral calcium supplementation at calving.
   2. Beware of feeds, especially forages, with high levels of potassium. Potassium is a strong cation and feeds high in this mineral have been implicated in many outbreaks of milk fever.
   3. Feed adequate calcium in the transition dry period. More calcium may be needed if feeding anionic products.
   4. Supplement with adequate vitamin D. Vitamin D helps the body absorb calcium from the gut and mobilize it from the bone. Vitamin D injections are notorious for causing reactions, and so feed supplementation is usually the best.
   5. Maximize dry matter intakes by feeding high quality, palatable feed. Again, beware of unpalatable products such as anionic salts.
       
3. Retained Placenta and Metritis (see also page F710): Retained placenta is a failure of the cow to finish the third stage of labor, the delivery of the placenta. There are many conditions and events leading up to calving that can affect whether or not a cow develops a retained placenta. The majority of these factors are nutritional and immunological. Non-nutritional factors include shortened gestational length, twinning, infectious diseases, or improper assistance during calving. Nutritional factors include hypocalcemia (low blood calcium), energy deficiency, and protein deficiency. Phosphorus, vitamin E, vitamin A, selenium, and iodine deficiencies have also been implicated in causing retained placenta.
   
   The detachment of the placenta is actually a partly immunological event. The cow’s immune system mounts an immune-mediated response to the placenta which helps lead to detachment of the placenta. Any feeding or management practice, therefore, which does not lend itself to a healthy and strong immune system, may also be a cause of retained placenta. Metritis is inflammation and infection of the lining of the uterus. Most of the same conditions that predispose cattle to retained placenta are also factors that lead to metritis. There are many nutritional practices that dairymen may implement that will help prevent these two conditions. Following are a few suggestions:
   1. Properly balance the transition dry-cow ration to prevent hypocalcemia and other metabolic diseases.
   2. Provide supplemental vitamin E/selenium in the diet or by injection prior to calving.
   3. When assisting delivery, practice good hygiene and gentle assistance to prevent excessive trauma and secondary uterine infections.
   4. Provide assistance in delivery only when in the correct stage of labor and when signs of proper presentation are apparent.
   5. Administer oxytocin immediately after calving.
   6. Administer an oral calcium supplement in the form of a drench or calcium gel tube.
   7. Administer vaccinations appropriately to prevent reproductive diseases.
   8. Maintain cow comfort and a low stress environment in the dry period.
   9. Provide cows with twins extra time in the dry period (an extra 2 weeks).
      
      
4. Displaced Abomasum: Displaced abomasum is generally a condition of early post-partum cows where the fourth compartment of the cow’s stomach displaces under the large first compartment of the stomach and becomes trapped on the left side. The clinical signs of a displaced abomasum include a sudden drop in milk production, a loss of appetite, a lack of stomach fill, mild dehydration, sunken eyes, and a loss of body condition. The displacement must be corrected surgically at some expense, and the loss of milk production is significant over the cow’s lactation. Although the causes of abomasal displacement are not completely understood, there are many theories and predisposing factors that are known to lead to this condition. Hypocalcemia (low blood calcium) is thought to lead to decreased tone and movement of the abomasum and thus lead it to be loose and mobile. Poor appetite or intake after calving is a tendency believed to lead to abomasal displacement. The large space left by the evacuated uterus and then the lack of appetite leaves a large space and opportunity for the abomasum to displace. Inadequate fiber in the diet has been shown to lead to an increase in the incidence of displaced abomasum. Acidosis, lack of cud chewing, and decreased appetite associated with these is thought to be the reason a lack of fiber is linked to the condition.
   
   Abomasal displacement is commonly associated with other physical and metabolic diseases. Conditions such as retained placenta, uterine infection, mastitis, milk fever, lameness and any other condition that can decrease dry matter intake would predispose cattle to develop a DA (displaced abomasum). A few suggestions that may aid in the prevention of displaced abomasums include the following:
   1. Feed balanced transition dry-cow rations to prevent hypocalcemia.
   2. Feed high-quality, palatable feeds and practice good feed bunk management to encourage good dry matter intake.
   3. Using a high volume (5-10 gallons) drench at calving has been shown to increase appetite after calving and fill the void left by the newborn calf.
   4. Balance transition dry-cow and fresh cow rations to minimize acidosis, encourage maximal dry matter intake, and help the cow adapt gradually to new feed.
   5. Use best management practices to prevent conditions that may lead to a drop in dry matter intake. Prevention of mastitis, retained placenta, uterine infections, milk fever, and lameness will all help in reducing the incidence of displaced abomasum.
   6. Carefully monitor and ensure that adequate fiber levels and particle size are maintained in rations to promote cud-chewing and stomach health.
   7. Feed and push up feed regularly and never feed to an empty bunk.
   8. Avoid conditions that may lead to slug feeding and overcrowding. Group heifers and cows separately to minimize competition.
      
       

      This shows a person “pinging” a cow to identify a DA. To do this procedure, the left flank area is thumped while listening with a stethoscope. If the abomasum is displaced and distended with air, a hollow sounding “ping” can often be heard. The “pinging” sound is sometimes compared to the sound of a basketball hitting the cement.

       

      If the video does not play, you must install an MPEG video player on your computer (e.g. Windows Media Player). Click here to download Windows Media Player. Or Install Internet Explorer from our CD Manual.

       

5. Udder edema: Udder edema is swelling caused by an accumulation of fluid in the subcutaneous tissue in the ventral brisket, abdomen, and udder of fresh, lactating dairy cattle. It is most common in first calf heifers, and many nutritional factors have been implicated in the cause of this condition. It is a potentially harmful and costly condition which can damage the teats and udders of fresh cows and heifers. Severe cases of udder edema will stretch and strain supportive ligaments of the udder, sometimes causing them to rupture and fail. Udder edema during cold weather greatly increases the incidence of frozen teat ends. Minerals, especially the strong cations like potassium and sodium, appear to contribute to udder edema. Very low protein diets and insufficient supplementation with magnesium have also been linked to cases of this condition. Over-conditioned cows and those with extended dry periods also seem to be more predisposed to developing udder edema. Many dairymen have pointed to high levels of grain and concentrate in the transition ration as a cause of udder edema. The following are a few ideas that may help in controlling a problem with udder edema:
   1. Limit sodium and potassium in transition cow rations. Salt feeding should be limited but not totally restricted. Sodium bicarbonate should not be fed to dry cows. Magnesium should be fed at a rate of 0.4% of the ration dry matter. The potassium should not be fed at a ratio greater than a 4:1 with magnesium. Because they greatly aid in controlling excessive potassium levels in the ration, low-potassium feeds should be identified and selected for use in the transition rations.
   2. Care should be taken when mixing transition rations that no leftover feed from the lactating ration is left in the mixing wagon. The buffers and salt content of the mineral supplement in the leftover lactating feed will greatly disturb the balance of minerals in the close-up dry cow ration.
   3. Anionic salts and negative DCAD (dietary cation: anion difference) rations have been shown to control or minimize the incidence of udder edema.
   4. Balance transition rations to carefully and gradually increase the energy, protein, and other nutrients to be a step between the far-off dry cow ration and the milking ration.
   5. Be aggressive in breeding programs to prevent over-conditioned cows and early dry-offs.
       
6. Rumen acidosis and Laminitis (see also page F285): Rumen acidosis is a condition where an excess of starch and other carbohydrates are fermented in the rumen to volatile fatty acids. If the intake of carbohydrates is excessive, the animal takes in a large meal, or is able to sort the feed to selectively feed on grain, the pH in the rumen may drop below 6.0. This level of acid has the potential to injure, damage or irritate the lining of the stomach. It can then lead to loss of appetite, indigestion, loss of body condition, decreased milk production, liver abscess, laminitis, and displaced abomasum. Laminitis is a condition affecting the sensitive layer of hoof where it connects with the bone. There is a very delicate and sensitive circulatory system in this area that is easily affected by toxins, infection, changes in circulatory flow, and excessive stress or strain. Rumen acidosis is very commonly followed by laminitis as toxins or bacteria are released from the damaged wall of the stomach. Mastitis, retained placentas, and uterine infections can also lead to cases of laminitis. Cows may also experience laminitis if they are injured, are made to stand on concrete too long, or stand on one leg because of pain in the opposite leg. There are several things that dairymen can do to help prevent the incidence of acidosis and laminitis. Following are a few suggestions:
   1. Maintain enough fiber levels and particle size in the ration to stimulate good cud-chewing. Cud chewing causes the release of lots of saliva which contains sodium bicarbonate. This helps greatly in buffering the acid in the rumen.
   2. Feed some rumen buffering components in the lactating ration. Phosphates and sodium bicarbonate are good buffering agents. Some dairymen even feed sodium bicarbonate free choice in addition to the buffering agents in the ration.
   3. Measure and monitor starch and carbohydrate levels in the ration. Limit NFC (non-fiber carbohydrates) to a maximum of 40% of the ration and limit starch levels to less than 28% of the ration.
   4. Monitor mixing so that rations are not over-mixed or under-mixed. Over-mixing will decrease particle size and leave the ration short on effective fiber. Under-mixing will allow the cows to sort in the feed bunks. Both conditions may lead to rumen acidosis and laminitis.
   5. When harvesting forages, especially ensiled feed, ensure that chop length is at least set at 3/8 to 1/2 inch theoretical cut length. This will ensure adequate particle length in the ration.
   6. Balance transition cow rations to adapt and transition the cow’s stomach to new feeds, new energy, and new carbohydrate levels in a step-wise manner.
   7. Feed and push up feed on a regular basis. Practice good feed bunk management to limit slug feeding.
   8. Separate heifers and cattle to limit competition at the feed bunk.
   9. Practice good management practices that will promote cow comfort, adequate laying time, and limit the amount of time cows spend standing on concrete.