Long-Term Calcium-Phosphorus Studies in Confined Dairy Cows

Authors

  • George Ward
  • E. P. Call

DOI:

https://doi.org/10.21423/aabppro19787783

Keywords:

calcium-phosphorus studies, calcium balance, phosphorus balance, alfalfa hay, sorghum, chlorine deficiency, salt consumption

Abstract

Calcium balance can be kept near even or positive in early lactation if calcium and phosphorus intakes and vitamin D consumption are adequate. Adequate calcium consumption promotes more rapid uterine involution and earlier ovulation. Phosphorus consumption must be adequate from day to day. There is no phosphorus-sensitive mechanism to elicit phosphorus resorption from bone. That mechanism is only calcium-sensitive. Inadequate phosphorus intake depresses appetite as well as preventing bone accretion. Phosphorus balance, with adequate phosphorus intake, largely depends on calcium adequacy since the calcium-tophosphorus ratio in bone is constant.

Our study comparing monosodium phosphate with calcium phosphate as supplements for an alfalfa hay and sorghum grain ration may have shown a chlorine deficiency. Salt was omitted from the grain but was available ad libitum. Very little salt consumption was the unique characteristic associated with the sodium phosphate treatment. Elevated chine, slab-sidedness, and tucking up in the flank were noted in the cows which ate little salt. Salt appetite appears to be sodium-sensitive.

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Published

1978-12-11

Issue

Section

General Session