Manage dry period for healthy, productive female ruminants
By Guy Jodarski, DVM
With dairy cows, goats and ewes the goals are healthy, productive mothers that deliver vigorous offspring, milk well, do not lose too much condition and breed back on time. These goals can be achieved by properly managing the dry period and transition to lactation. This article will use the dairy cow as a model for organic ruminants, but the principles outlined for dairy cattle also apply to small ruminants like sheep and goats.
The rest or “dry” period between the cessation of milk flow and birthing (start of lactation) is hugely important. Organic livestock farmers must take an active role managing this time. Proper nutrition and management during the dry period will prevent many disease problems and result in increased milk production.
It’s tempting to simply dry cows off and not actively manage them until they calve and return to milking. The “hands off” approach sometimes works in pasture-based systems. However, many times it will result in health problems and poor production of milk. Effort expended on managing the dry period and transition back to production will be well rewarded for the investment.
There are two major challenges for ruminants returning to milk production after being dry and pregnant. The first is the transition from relatively low to high metabolic demand. The second is immune-suppression that occurs following the birth of offspring. Common fresh cow diseases like milk fever, ketosis and displaced abomasum (DA or “twisted stomach”) are typically the result of cows being unable to adjust to the high metabolic demand and associated feed changes of early lactation.
Retained placenta (RP), mastitis and other infections like pneumonia are often consequences of poor immune function in fresh cows. There is a large surge of the stress hormone cortisol at the time of birth, which weakens the immune response and makes the fresh cow more likely to have problems with infections.
Demand for increased energy, protein and other nutrients starts during the late stages of pregnancy. The fetus grows most in the last few weeks of gestation, which requires more energy intake for the mother as she nears the time of giving birth. This is especially important for sheep and goats that are either carrying multiple offspring or are lambing or kidding for the first time. Increase the energy content of the diet for small ruminants in late pregnancy to avoid pregnancy toxemia or small, weak lambs and kids.
After delivering, the mother’s nutritional needs escalate rapidly as she starts producing milk. It’s important to adjust the diet throughout these times —either by directly changing the ration over time or, alternatively, by providing pregnant ruminant mothers with opportunities to select different feeds and supplements. Ideally, we should follow a balanced approach by changing feeding practices at different stages of lactation while also providing a selection of feed and supplements for the animal to choose from.
Manage dry period in stages
Dry-period management should be divided into stages to make sure the cows’ needs are properly met. It’s important to assess body condition sometime around mid-lactation—thin animals need to be fed more energy so they gain weight during the last third of lactation and reach ideal condition before dry-off. For dairy cows, this is a body condition score (BCS) of 3.5 to 4.0 on a 5-point scale.
I like to see cows checked for somatic cell count (SCC) at least 30 days prior to dry-off. If a cow has a high SCC at this time, you can work on treating her with organic remedies before she goes dry. If you’re not on a regular testing program for individual cow SCC (like monthly DHI), then you should use a California mastitis test (CMT) paddle to check the milk.
Stop milking all at once
At the time of dry-off, my preference is to stop milking the cow all at once rather than skipping milkings. Cows need a full udder for 3 or 4 days in order to get the signal to stop milking. If production is too high before dry-off (which would make it difficult to go dry), change the diet to make it less nutrient-dense (energy and protein) or limit water intake to lessen the flow of milk and make dry-off easier.
During the early dry period (sometimes called “far-off”), cows need much less energy and protein than when milking. Adjust feeding for these cows to maintain condition but not to gain or lose weight. Most dry cows will not require grain unless forage quality is very poor. Do not feed forages or graze pastures that are high in potassium as this will promote milk fever. Pasture quality does not have to be excellent for dry cows; graze more mature pastures or use dry cows and heifers to follow milk cows when they are moved to the next paddock during the grazing season.
Offer dry cow minerals either free choice or mixed with feed. Dry cow minerals are higher in phosphorus than milk cow minerals. Typical milk cow mineral contains calcium and phosphorus in a 2:1 or 3:1 Ca:P ratio. Dry cow mineral should have a 1:1 or 1:2 Ca:P ratio. If you don’t separate dry cows from the milking herd, you should offer high phosphorus mineral free choice so the dry cows can consume enough phosphorus. Be sure to supplement trace minerals like copper, zinc, manganese, and, especially, selenium.
The long-term solution to providing good mineral nutrition for your animals is to work with a soils and agronomy advisor to increase mineral content of homegrown feeds by balancing soil minerals and promoting good soil biology. Test harvested forages and pasture clippings periodically to track progress in this area. Injectable trace mineral supplements (like MuSe or Multi-min) can be used to help with deficiencies in the short term, but ultimately, you should not have to rely on these measures. Check with your certifier to make sure the injectable supplement you want to use is allowed.
One trace mineral supplement that most livestock farmers should be using is selenium. Most areas of North America are selenium-deficient (except some areas of the Western U.S.). Supplement dry cows to the maximum FDA-allowed level of selenium, and make sure that most (more than 50%) of that is provided in the form of chelated selenium (selenomethionine or yeast selenium) rather than the salt form (sodium selenite).
Make sure animals that are dry get plenty of exercise. Making cows walk a reasonable distance between feed and water is one strategy to increase exercise.
Manage ‘close-up’ cows
Later in the dry period (the last three weeks of gestation or so), it’s important to start changing the diet to allow the rumen microflora to adjust to feeds the cow will be eating after she freshens. Managing “close-up” cows for the transition to lactation is important. Some larger dairy farms have a special group for these cows. It’s important to start increasing energy and protein in the diet gradually before calving to meet the increased needs of the cow in late gestation.
Be careful not to move cows to new groups during the last week to 10 days before calving. Cows will be stressed by moves to new groups, and may not eat well if there is limited feeding space or they are timid.
Cows normally eat less a day or two before calving, but if they decrease dry matter intake during the last two weeks of gestation the results are often fresh cow problems like ketosis and RP. Feeding free choice kelp throughout the dry period is strongly recommended. Kelp provides a wide variety of trace minerals and iodine in readily absorbable form. Feed between 2 and 4 ounces per cow daily if you can’t feed kelp free choice.
Keep dry cows comfortable
Make sure dry cows are clean and comfortable at all times. Dry cows are susceptible to new mastitis infections shortly after dry-off and again when they are close to calving. If a farm experiences mastitis or high SCC problems in fresh cows, it often traces back to a sanitation problem during the dry period. Provide plenty of clean, dry bedding during the non-grazing season.
Dry cows must be provided with some kind of cooling during hot weather. Shade, wetting cows, fans or a combination of these should be used to maintain cow comfort during times of heat stress. Cows can lose a pregnancy if heat stress is too severe.
Pay attention to water quality and intake throughout the dry period—remember, water is the number-one nutrient for keeping animals healthy.
Also, watch out for possible stress from electromagnetic fields (EMF), which is commonly called “stray voltage”), especially when animals are confined during the non-grazing season. Keep “hot” wires away from buildings, feeding areas and waterers. Turn off electric fences and cow trainers as much as possible.
After dry-off it’s very important to check udders around a week after going dry. Look for swelling or uneven quarters. Palpate (feel) any quarter that appears swollen or different than the others. If a quarter feels firm or warm, open the teat and strip out the milk. If there’s mastitis or abnormal milk, treat the cow like an organic milking cow with mastitis: strip at least daily (more often is better) and use the mastitis treatments you would use to treat milking cows. Do not leave an infected quarter unmilked or untreated. Some farmers like to milk out the residual milk from all cows one week after dry-off, others let the milk reabsorb on its own. Use the method that works for you, but always check the udders about one week after the cows go dry.
In summary, take good care of your livestock during late pregnancy and dry periods. Carefully monitor feeding and nutrition during this time. Make sure pregnant animals get plenty of exercise. Keep expectant ruminant mothers clean, dry and comfortable. Your efforts will be rewarded with healthy, productive animals and offspring.
Guy Jodarski, DVM, has a 26-year-old livestock practice in Neillsville, Wis., with an emphasis on organic and sustainable dairy cattle herd health. He is a staff veterinarian for Organic Valley CROPP Cooperative. He focuses on ways to keep food animals healthy without the use of antibiotics, synthetic hormones and chemicals.
January | February 2014