John, I have been taught that water belly is the result of an calcium/phos imbalance. I have a paper on it that I will share here. And I don't mind telling you that some of it is over my head: :shock:
Calculi causes waterbelly. A good mineral program can prevent
waterbelly. In W. Montana a big Hereford ranch (sorry!) there had alot
of waterbelly. They never fed any mineral. Too bad, because it could
have helped them a bunch. But you know, this mineral deal wasn't
talked about 15-20 years ago like it is now. We didn't know what
a difference a good mineral can make. It's all about immune system.
Here is the article and I retyped it here...WHEW!! That was a job!
Urinary Calculi can be a prominent and important cause of death in cattle and sheep; more specifically in the male due to theri smaller and more restrictive urinary systems. Furthermore, male castrates tend to have a higher incidence of urinary calculi than do intact males, and this is attributed to their less developed urinary tract.
Calculi can be defined as an abnormal concretion in the body usually formed of mineral salts and located somewhere in the urinary system.
As these calculi move into a smaller and more restrictive space in the urinary, they form blockages. As urinary pressure builds up, it eventually reptures the urinary bladder or urethra and spills urine into the body cavity and nearby tissues resulting in a condition called "water belly."
This problem is most commonly seen in feedlot and range steers. Feedlot cattle usually encounter on of two types of urinary calculi--that being a phosphatic type calculi--while range cattle experience the other kind of calculi referred to as a siliceious calculi.
Phosphatic Urinary Calculi
Causes:
High urinary phosphorus levels: Usually feedlot cattle are fed grains or oil meals which generally provide more phosphorus than what may be required for ration specs. In addition, these types of feedstuffs increase the amount of mucoproteins in urine which combine with the phosphatic products in the already alkaline urine to form calculi. Conversely, by replacing high calcium leguminous type forages with teh concentrates, we tend to reduce the Ca (Calcuim)

ratio which allows urinary levels to climb.
Urine Alkalinity:When overformulated amounts of alkali-forming elements are fed (sodium, potassium and magnesium) the result in increased urine alkalinity and increased incidence of calculi. This can be compared to feeding acid-forming elements (sulpher, phosphorus and chlorine.)
Low Urine Output:
There is an inverse relationship between urine volume and concentrations of minerals in the urine. Simply put, the more water that is consumed, the more dilute the urine will be of minerals and other excretory products. This is one reason we see increased frequency of this condition in the winter feeding months as water consumption tends to drop. It is prudent to mention that water hardness has been shown to have no correlation to the occurance of urinary calculi and, in fact, calcium and magnesium, which contribute to water hardness, actually act to prevent urinary calculi.
Prevention
Blockage from urinary calculi can occur at any time throughout the feeding period, however, the largest percentage occurs after the first 21 days. A program for preventing or decreasing the occurance of phosphatic urinary calculi needs to have one of the following parts satisfied in order to be effective: 1)lower the urinary phosphorus levels; 2)acidification of the urine 3)increased urine volume.
1. We can lower the urinary phosphorus levels by monitoring and managing phosphorus levels in the ration; and just as importantly, mangaging the Ca

ratio a 1.2-2.1
(There is more, but I want to move on to water belly in grazing animals)--
Siliceous Urinary Calculi
Grazing ruminents are more frequently affected by urinary calculi having silica (SiO2) as the primary element; hence the name siliceous urinary calculi.
CAUSES:
The source of SiO2, seems to be present in range grasses and forages put up for preservation and winter/off season type feeding. Range plants tend to increase in silica content with maturity and leaching soluble components. Research conducted in SD over a 2-year period revealed that native grasses increased in SiO2 content from about 5% on a DM basis in June to 8% in Nov. It is possible to surmise that the increased incidence of SUC in the winter months could come from feeding forages high in silica and the natural decrease in water intake.
PREVENTION:
The most practical means of prevention seem to be those in which we can reduce the slica content of the forages consumed. This would include moving away from oat hay and straw and sticking with alfalfa or other legumes or low fiber grains such as corn and sorghum, as well as using the salt trick to increase water consumption resulting in increased urinary flow. This can be done in range cattle by using a high salt, free choice mineral, such as Vigortone range minerals, placed close to an accessible water source to allow for and encourage increased water consumption. A daily intake of salt comparable to one gram of salt/kg of body weight has been shown to increase water consumption adequately to aid in reducing SUCU.
--Steve Stafford Vigortone Ruminent Specialist
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So Doug, that hi calcium you have been feeding is just what you needed to do.