The idea is to acidify the blood and get buffering via calcium mobilization. In order to acidify the blood the cations (including potassium) must be minimized in the diet. The explanation in the arcticle above is very thin. In effect, a diet is fed with a mineral balance that results in calcium mobilization. As a result, the cow has elevated blood calcium and therefore reduced risk for milk fever.
Post by organizinlady on Aug 13, 2010 10:25:16 GMT -5
(1) Prevention of Milk Fever
Jeffrey Bewley and Donna M. Amaral-Phillips University of Kentucky Milk fever is a common metabolic disorder in dairy cattle that generally affects older, high producing cows. It may also be referred to as parturient paresis or hypocalcemia. The majority of milk fever cases occur within 48 to 72 hours of calving although some may occur in late lactation. It is estimated that 3 to 8% of cows are affected by this disease with some herds having a prevalence as high as 25 to 30%. Symptoms appear when blood calcium levels are low, hence the name hypo (low) calcemia (calcium). At first, cows experience muscle tremors, lack of appetite, and unsteadiness. Eventually, cows will be unable to rise, body temperature will be low, and constipation may occur. Death can occur if the cow is not treated promptly. In order to understand how to prevent this condition, one must understand why it becomes a problem. The onset of milk production drains on the animal’s blood calcium levels and she is unable to replace this calcium. The body loses its ability to mobilize reserves of calcium in bone and absorb calcium from the gastrointestinal tract. As a result, hypocalcemia affects the cow’s muscle contractions and rumen motility. The key to prevention of milk fever is management of a close-up dry cow group. Alfalfa, a feed high in calcium and potassium, should not be a major ingredient in close-up dry cows diets. In the past, programs have been aimed at reducing calcium levels in feed. Recent research indicates that the key is potassium not calcium. The first step in keeping potassium levels down is to change fertilization practices to prevent high levels in forage (grasses and legumes) intended for use in the close-up dry cow program. About two weeks before calving, a transition diet should be used paying close attention to the amount of sodium, potassium, and chloride in the diet. Adding anionic salts into the diets of transition or close-up dry cows is another control method. They should be added into a grain mix or TMR mixture due to low palatability. Furthermore, they should not be fed throughout the whole dry period. To determine when anionic salts are effective, testing of the urine can be used. Urine should be targeted at a pH of 6.5 to 5.5. Anionic salts work by increasing the cow’s ability to release calcium. Like any other feed additive, determining proper levels of anionic salts needed requires a forage analysis for sodium, potassium, chloride, sulfur, calcium, and phosphorus and the pH of the urine needs to be monitored. To a limited extent, administering a calcium gel immediately after calving also is used as a preventative measure in high-risk cows. A calcium chloride gel can lead to rapid, effective increases in blood calcium levels. This method can be rather expensive but is effective. Care must be taken to ensure that the cow does not aspirate the gel. Nevertheless, the best measure of preventing milk fever remains regulating calcium and potassium levels in the close-up dry cow diet. Prevention of milk fever is economically important to the dairy farmer because of reduced production loss, death loss, and veterinary costs associated with clinical cases of milk fever. FIRST LINK:
When farmers think of milk fever, they generally think of the symptoms mentioned earlier. Many cases, however, do not show the clinical signs of milk fever. This condition is referred to as subclinical hypocalcemia. Because of calcium’s effect on smooth muscle function, rumen function and uterine motility are affected by subclinical hypocalcemia. Thus, milk fever can also lead to a multitude of digestive disorders and reduced reproductive performance. Milk fever has been linked to calving problems, retained placentas, uterine prolapse, metritis, mastitis, poor appetite, displaced abomasums, ketosis, and delayed return to estrus.
Last Edit: Aug 16, 2010 10:10:02 GMT -5 by organizinlady
Post by organizinlady on Aug 13, 2010 10:25:52 GMT -5
(2) Anionic Salts and DCAD-An option for high potassium and calcium forages in transition dairy cow rations
Jonathan Townsend, DVM Purdue University Animal Sciences Department (765) 494-4865 Email: email@example.com Parturient paresis, more commonly known as “milk fever” is a common metabolic disease of dairy cattle that has been estimated by Chuck Guard, DVM at Cornell, to cost dairy producers $334 per clinical case. It is caused by low blood calcium (hypocalcemia) and is most commonly seen in dairy cows that have recently calved. Due to the rapid increase in milk production of the dairy cow after calving serum calcium may be acutely depleted. Calcium is required by muscle tissue for proper activity, therefore low levels of blood calcium (<7.5 mg/dl) will lead to loss of muscle function and the clinical signs of milk fever which include recumbency, bloat increased heart rate, and potentially death. More importantly to the dairy industry is the effect of subclinical hypocalcemia on cow performance. Subclinical hypocalcemia, while not resulting in recumbency or death, can be a major factor in the development of other diseases in dairy cows such as retained placenta, metritis, and displaced abomasum which can lead to suboptimal production and a higher risk of being culled from the herd. The condition of milk fever or hypocalcemia may be easily treated through the use of a variety of calcium preparations that may be administered intravenously, subcutaneously, or orally. While treatment is usually successful and fairly simple, producers and veterinarians would prefer to try to prevent the occurrence of the condition rather than treat affected cows. Prevention of hypocalcemia is somewhat more complicated than treatment but can be successfully achieved. The approaches to prevention rely on nutritional intervention and the attempted manipulation of calcium metabolism in dairy cows. To understand the thought behind these nutritional interventions one must first have a basic concept of calcium metabolism in dairy cows. If a dry dairy cow is fed a diet high in calcium (>100g Ca/day) she can meet her daily calcium requirement through passive absorption of calcium from her gastrointestinal tract. Active transport of calcium from her intestines through the action of a form of vitamin D known as 1,25-dihydroxycholcalciferol (1,25-[OH]2D) or resorption of calcium from her bones due to the action of parathyroid hormone are not required and are therefore these pathways shut down. However when the cow calves and starts producing large volumes of milk her calcium requirements also increase dramatically and more calcium must be absorbed from the diet and resorbed from bone. Unfortunately, if these pathways have been shut down there will be a delay until they can start providing calcium to meet the cow’s requirements. This delay causes excessive calcium to be removed from the bloodstream and the development of milk fever. One nutritional intervention that may be used to prevent the shut down of active transport of calcium from the intestine or resorption of calcium from bone is feeding a low calcium diet to close-up dairy cows and then switching them to a high calcium diet post-calving. The recommended levels of calcium in the diet of the pre-fresh cows in this system is <20 g Ca/day. This low level of dietary calcium is very difficult to achieve. Fortunately, the incidence of milk fever has been demonstrated to also be decreased if dietary calcium is kept below 60g/day which is somewhat more achievable. In addition to calcium restriction, it has also been noted that phosphorus levels greater that 80g/day also increase the incidence rate of milk fever through inhibition of 1, 25-(OH)2D. Therefore, for proper cow health it is essential that dietary calcium and phosphorus levels be closely monitored. More recently, another nutritional approach has been attempted for the prevention of hypocalcemia. This approach is known as the dietary cation-anion difference (DCAD) and involves the inclusion of anionic salts in the rations of close-up dairy cows. The theory behind the use of anionic salts is that the feeding of negatively charged anions such as chloride and sulfate will make the blood of the cow slightly acidic. The response of the cow will be to mobilize and absorb more calcium in attempt to buffer the acid in her bloodstream and therefore all of the mechanisms required for maximal calcium supply will be active at the time of calving. To achieve an effect nutritionists will attempt to increase the number of anions and decrease the number of positively charged cations (such as potassium, sodium, and calcium) to produce a diet that is higher in anions than cations. Although many slightly different formulas exist one common one used for the calculation of the DCAD is: (Na + K) – (Cl + S) From this equation it becomes obvious that forages high in potassium (such as alfalfa) need to be avoided as much as possible. However, the use of anionic salts makes the use of some higher potassium (and calcium) forages in close-up dairy cow diets possible. To monitor whether anionic salts are performing as hoped the urine pH of cows on anionic salts needs to be checked. The level of anionic salts in the diet should be adjusted until urine pH’s are in the range of 5.5 to 6.5 (Jerseys should be at the lower level of this range while Holsteins can be in the upper portion of the range). As most things in life there are problems in using anionic salts. The major problem encountered by producers and nutritionists is a lack of palatability. This is the last thing we want to have happen in close-up dry cows that may already be experiencing a decrease in dry matter intake. Fortunately, some of the newer proprietary anionic salt products are much more palatable than the original salts that were used in diets. In conclusion, milk fever or hypocalcemia is large problem in the dairy industry. Dietary levels of potassium and calcium in the rations of close-up dairy cows play a major role in causing the occurrence of this medical condition. The use of anionic salts provides an option to producers with limited access to forage with low potassium or calcium levels.
Last Edit: Aug 16, 2010 10:14:55 GMT -5 by organizinlady
AZAmy: Wish I could help you with pics. I'm sure someone will chime in soon.
Jan 23, 2018 11:49:44 GMT -5
breezyridge: Same here. I'm looking for photos of homemade hay feeders suitable for 1-2 cows. The photos posted in old emails are not displayed-very sad
Feb 24, 2018 13:35:09 GMT -5
musicalmilking: Anyone want to make an offer on my two Dutch Belted cows? They are in the auction barn. I must sell them in March.
Feb 26, 2018 10:19:12 GMT -5
countrykrista: If i separate the 2 cows do you think they will calm down and not charge me once they get to know me?
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claytonpaul: A bull was put on her herd Late Last May so she was expected to be due between May1 and August. They quoted me August so I wouldn't be disappointing by a late arrival.
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Trim: I'm baaaaacccckkkk!
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alpacalexi: My mini jersey cow is pregnant, however the last couple days her udder has deflated. My vet saw her on the 23 and said delivery in a couple weeks Is there a reason for her deflating?
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Trim: She probably aborted a while back. That happened to one of my animals. She was bagging up but within a short while of her "due date" she began to deflate. I had no idea what had happened. I was seriously bummed out.
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mamacherri10: good afternoon! I have not been on the website in a long time. Have a new jersey milk cow and am looking to see how long she needs to be dried up prior to calving? She is due the third week of May.
Mar 10, 2020 14:33:11 GMT -5
steven888: Dry her up now, she needs 6 wks of rest.
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highlandteen: five to six weeks is generally suggested
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biubiu: I think that CBD oil will be more popular. Because in is nice product for medicine and for simple guys.
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guernseygirl: Can someone let me know if my pictures are showing up in the Auction Barn post? There should be 5 photos
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wyatt: I treat cow s like people when doctoring.
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ashlyn911: This is Fern! She’s an almost two year old heifer (Jersey/Brown Swiss). Her due date is Sunday.
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hjp: Any tips on how to add a photo to a post?
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correll17: We just purchased a dexter cox that is bred, due in April. We brought her home and was walking the fence, head butting the fence, so we got another dexter, now she is constantly headbutting her. Any ideas?
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gentlepaw: At Gentle Paw, we want to not only create pet products but also create a safe and happy environment for all of our furry friends.
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