It’s important to understand that a dairy cow’s nutritional requirements during the “close-up” period – those last 3 to 4 weeks prior to calving – are significantly higher than when she’s initially dried off after completing a lactation. The single largest challenge in getting fresh cows to peak with high milk production and minimal metabolic issues at the start of a new lactation is maintaining her energy status.
The energy status in a fresh cow is often deficient because cows always eat less prior to calving. Hormonal changes that occur in the days immediately preceding calving reduce feed intakes 20 pounds or less just before calving. To further complicate the matter, many dry cow diets are low in caloric density because grain has been removed from the diet for most of the dry period.
How to transition through close-up time
The most important aspect of getting a cow to transition through the close-up period successfully is to make sure the diet gets the rumen bacteria up to speed to digest the copious amounts of feedstuffs the cow needs to consume after freshening. In other words we need to do everything we can to get her to eat as much as possible. This generally means that the close-up diet must contain at least a percentage of the same ingredients that will be fed in the milking cow diet after freshening.
The less prepared the rumen is for the increase of additional starchy feedstuffs at the time of freshening, the less ability the cow will have to be able to maximize feed intake and be able to meet her nutritional needs for maintenance and milk production. During the close-up period she should have a smooth transition to a higher concentrate diet that will enable her to produce a lot of milk while still avoiding those nasty metabolic disorders. A diminished feed intake can cause a cow to go into negative energy balance, which forces her to mobilize body fat for energy.
Cows have difficulty converting body fat to energy because the liver can’t process fat rapidly enough. This sets the stage for the development of ketosis. By maintaining high dietary energy levels, excessive mobilization of body fat can be reduced. Diets balanced with proper protein and digestible fiber during the weeks prior to calving will also help prevent a vast majority of post-calving problems that so many dairies experience. Negative energy status is even more pronounced in the colder months and ketosis can be very common in fresh cows that have spent their entire dry period in the cold of winter.
Be aware of cow comfort levels
Cow comfort becomes an important factor in managing the close-up cow. Keeping feed bunks and maternity areas clean and uncrowded allows the cow to maximize her feed intake and will reduce the stress of calving. Having pens and alleyways in close proximity to the maternity area in the event that difficult calvings need to be assisted will also reduce the stress factor. Maternity areas that are crowded, muddy and poorly designed don’t make for an acceptable environment for a cow to have access to feed bunks and giving birth.
The dietary cation-anion difference (DCAD) also plays a role in reducing the tendency toward developing milk fever which, in turn, plays a role in the onset of ketosis and twisted stomachs. The purpose of monitoring the DCAD balance is to be sure that there’s enough acidification in the blood stream to adequately mobilize calcium to all the organs. We know that potassium and sodium contribute to alkalosis of the blood and therefore we try to limit these two elements in the close-up diet. (Note: Don’t confuse this acidification of the blood with acidosis of the rumen.)
Picking appropriate forages
Whenever possible choose forages for your close-up cows that are low in potassium. Some crop ground can have a higher chloride level which, when taken up by the forage, will help counteract the potassium found in the forage. This, in turn, allows for the inclusion of higher calcium levels in the diet. For many years it was believed that too much calcium in a close-up diet contributed to milk fever. Keeping the DCAD balance slightly acidotic with low potassium/high chloride forages actually allows us to feed higher levels of calcium, which is exactly what our fresh cow needs to keep her entire musculature system working and also produce 15 or more gallons of milk in the first weeks postpartum.
Testing urine pH on a regular basis is probably the most effective way in determining if your close-up ration is having the desired results. A pH over 8 indicates that there is little or no anionic action occurring in the cow’s system. A pH in the range of 6 to 6.5 indicates that the cow’s system is slightly anionic. It’s recommended that Jersey cows have a pH closer to 6.
A properly balanced close-up diet requires additional protein, energy, vitamins and minerals fed at higher levels than the far-off dry cow diet. A simple ration consisting only of corn silage and grassy hay will often provide less than 10 percent total crude protein. A protein level of at least 12 percent is recommended for far-off dry cows and around 15-16 percent for close-up cows. Unless there is high protein hay in the diet, these protein levels usually cannot be met without the inclusion of a protein meal such as soybean or canola.
A close-up/transition cow program can result in an additional 1,000 to 2,000 pounds of milk during the lactation that follows. Yet, a common argument I hear is “I don’t have a good place to keep a few close-ups and feed them separately” or “It’s going to cost too much to feed a special ration to the close-up cows.” A properly formulated close-up diet may very well cost an additional 50 cents to dollar per head per day for the three- to four-week close-up period compared to a diet that does not meet her needs. A close-up diet will reduce the chances of retained placentas, milk fever, mastitis, ketosis, twisted stomachs and ovarian cysts and the vet bills that go along with those metabolic issues. And an additional 2,000 pounds of milk during the course of the following lactation will return many more times the cost of the investment.
Cover Photo by skhoward/istock