Minimizing Broken Cow Risks

By Mike Hutjens, Extension Dairy Specialist, University of Illinois - A new term has appeared at dairy meetings and discussions; broken cows. Broken cows can be defined as fresh cows culled in the first 60 days after calving. Two significant losses can occur.
calendar icon 19 September 2006
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A valuable dairy cow was culled resulting in a loss of $1500 to $2500. The current lactation's milk production was not harvested resulting in a loss of $2000 or more in gross income. Minnesota researchers evaluated five years of DHI data and reported 24 percent of cows left as broken cows. Three metabolic areas can be evaluated to determine if your herd has too many broken cows related to these topics.

Hypocalcemia

 Cows with hypocalcemia have low blood calcium (<8 mg/dl), but not low enough to cause the cow to go down with clinical milk fever (< 5.0 mg /dl). Cows with this disorder have sluggish early lactation milk production, low dry matter intake, and higher incidences of displaced abomasums, retained placenta, ketosis, mastitis, and other fresh cow disorders. In a national US survey conducted in 2002 on over 1400 dairy cows, researchers determined that 25, 42 and 53 percent of 1st, 2nd and 3rd lactation and over cows, respectively, had blood calcium levels of below 8 mg/dl. Four practices used on transition cows to solve hypocalemia are listed below.

Treatment 1. Dairy farmers report drenching or offering free choice five to fifteen gallons of warm water containing calcium propionate, yeast culture, and/or electrolytes immediately after calving results in more cows cleaning, few displaced abomasums, and healthy cows. Table 1 contains an example drench product. Several excellent commercial products are also available.

Treatment 2. Administered a tube or gel product containing 50 to 55 grams of calcium to cows immediately after calving turning "dull-looking or sluggish cows" into healthy cows that were hungry and alert.

Treatment 3. Older cows (cows with three or more calvings or cows that experienced problems at earlier calvings) receive an intravenous infusion of calcium solution to avoid problems.

Treatment 4. Adding anionic products to properly balance dietary cation anion difference (DCAD) can prevent hypocalcemia by causing the cow's blood to become slightly acidic. This slight metabolic acidosis helps parathyroid hormone (PTH), the main hormone that controls the blood level of calcium, to function properly. All four examples share one common factor; adding supplemental calcium or maintaining blood calcium levels at calving can improve health and performance.  

Sub-clinical ketosis

 One week before calving, cows will drop in dry matter intake reducing energy intake, increase NEFA (non- esterfied fatty acids), and increase blood ketones. Washington data indicate blood ketones can increase from 3 to 8 mg per deciliters during the transition period (ketotic cows are over 14 mg/dl). The impact of higher blood ketones is not clearly understood, but may initiate fatty liver development and impair liver metabolism. Feeding low levels of calcium propionate (113 grams) or drenching with 300 to 500 milliliters of propylene glycol has minimized cow health problems. Adding protected choline in transition cow diets has also improved milk yield by five pounds in New York field studies by exporting liver fat reducing fatty liver risks.

Transition SARA

Subacute rumen acidosis (SARA) continues to plague fresh cows as cows are shifted to higher energy rations and changing rumen fermentation patterns and microbe environments. Dairy managers attempt to minimize SARA by using close-up and fresh-cow groups to step up nutrient concentrations and shift feed ingredients, provide more bunk space (three feet per cow) to encourage feed intake, and develop pens for fresh heifers only (reduce competition). Feed additives that minimize SARA include yeast culture (reduced lactic acid levels and maintain dry matter intake), direct-fed microbes (stabilize rumen fermentation), and sodium bicarbonate (buffer rumen pH and stimulate dry matter intake). Signs of SARA include off-feed, changes in fecal consistency, displaced abomasums, ketosis, and lameness.

In Summary

Broken cows are an expensive fact on dairy farms (Table 2). Review your records to see how many broken cows may have left your farm in 2004, look for causes, and evaluate your feeding, housing, and transition cow environment that contributes to this loss.

Table 1. Example drench product
Product Amount
Calcium propionate 1.0 pound
Propylene glycol 300 milliliters
Yeast culture 0.25 pound
Potassium chloride 0.25 pound
Magnesium sulfate 0.25 pound
Salt (sodium chloride) 0.10 pound

Table 2. Relationship of metabolic disorders and economic losses.
Disease Cost ($) Die (%) Culled (%) Lost Milk (lb) Extra Days open
Milk Fever $334 8 12 1100 5
Ketosis $145 1 5 440 --
Retained Placentas $285 1 18 750 19
Displaced abodmasum $340 2 10 840 6

April 2005

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