Document Type

Dissertation - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)


Animal Science


Two experiments were conducted to determine the interrelationships between various dietary calcium and phosphorus levels and acid-base-forming effects of the diet concerning feedlot performance and ovine phosphatic urolithiasis. Another experiment involved the interrelationships between calcium, phosphorus and potassium. All lambs used in these experiments were Texas feeder lambs of mixed breeding weighing approximately 27-30 kg. In experiment I, the treatment variables incorporated into an all concentrate, corn-soybean meal diet included 0.28 and 0.55% phosphorus, 0.14 and 0.28%-calcium and O and 2% sodium bicarbonate in a factorial design. For Experiment II, a 15% hay diet and an incomplete factorial design were utilized. In this case the treatment variables consisted of O and 2% sodium bicarbonate, 0, 22 and 0.47% phosphorus and 0.31, 0.56 and 1.06% calcium at the 0.56% calcium level, both ground limestone and calcium chloride were used while only ground limestone was utilized at the higher calcium level. Sodium bicarbonate was fed only in the low phosphorus series of treatments. When feeding an all-concentrate or 15% hay diet to lambs, the· addition of 2% sodium bicarbonate had no effect on feed consumption or weight gains. However, this level of sodium bicarbonate increased ovine phosphatic urolithiasis when fed in an all-concentrate diet principally due to an increase in urinary ph. On the other hand sodium bicarbonate increased urine pH but did not promote stone formation in lambs fed a diet with 15% hay. Lower urinary phosphorus concentrations (0. 8-24 mg. /100 ml. with 15% hay diet vs. 19-99 mg. /100 ml. with all-concentrate diet) appeared to be the limiting factor in calculi formation with diets containing hay. (See more in text)

Library of Congress Subject Headings

Sheep -- Diseases
Urinary organs -- Calculi



Number of Pages



South Dakota State University