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Thesis (M.S.)—University of Nebraska—Lincoln, 1968. Department of Animal Science.


Copyright 1968, the author. Used by permission.


Two experiments were conducted with a total of 110 Yorkshire x Hampshire crossbred pigs to determine the effect of dietary levels and ratios of calcium and phosphorus on gain, feed intake, feed conversion, bone breaking strength (BKS), bone weight, percent bone ash and incidence of atrophic rhinitis (AR) in growing-finishing swine.

In the first experiment, 50 pigs averaging 27.4 kg of body weight were fed diets varying in calcium levels from 0.35% to 0.65% and in phosphorus from 0.65% to 1.40% of the diet.Sixty crossbred pigs were used in a second experiment to study performance of pigs fed diets varying in levels of phosphorus and amounts of inorganic phosphorus.Calcium was held constant at 0.35% in all diets. Phosphorus levels were increased in equal increments (0.10%) with inorganic phosphorus.

The results of these experiments show that calcium and phosphorus levels and ratios can vary considerably without significantly affecting daily gain and feed conversion of pigs.Levels and ratios of the two elements do affect bone formation as shown by BKS and bone weight data.In these experiments bone weight seemed to be nearly as good a measurement of bone formation as BKS strength.

Increasing inorganic phosphorus levels in low calcium diets had a favorable effect on daily gain, feed intake, BKS and bone weight.

Within the levels and ratios of calcium and phosphorus studied, there was no relationship between dietary calcium and phosphorus and atrophic rhinitis in growing-finishing swine.

Advisor: E. R. Peo, Jr.