Date of Award

1985

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Abstract

Two consecutive summer and winter trials involving low and high-heat increment diets were fed to growing-finishing swine, and three trials evaluating crystalline lysine utilization were conducted during the starting phase of growth. Dehydrated alfalfa meal and vegetable oil in factorial combination were fed during the winter months. Crystalline lysine and vegetable oil, also in factorial combination, were fed during the summer months. In the lysine utilization trials, crystalline or protein-bound lysine were each fed at three levels. Response criteria evaluated were rats and efficiency of gain, serum T(,3), T(,4) and cholesterol level in the winter and summer trials; and rate and efficiency of gain, liver lysine alpha-ketoglutarate reductase activity and serum lysine concentration in the lysine utilization trails. Dehydrated alfalfa meal decreased rats and efficiency of gain in both winter trails with the largest adverse effect in winter trial 1 when it was included in the diet at 10%. Pigs fed low protein crystalline lysine supplemented diets had lower rates and efficiencies of gain than pigs fed high protein diets. Vegetable oil increased rats and efficiency of gain in both the winter and summer trials with the greatest beneficial effect occurring during the summer months. Dehydrated alfalfa meal had no effect on thyroid hormone levels. Low protein, crystalline lysine supplemented diets had inconsistent effects on thyroid hormone levels. Serum cholesterol was increased by vegetable oil in the diets. Pigs fed crystalline lysine supplemented diets grew as fast and efficiently as pigs fed protein-bound lysine. There was a linear response in gain for incremental lysine addition. Liver lysine alpha-ketoglutarate reductase activity of pigs fed the crystalline lysine supplemented diets was higher than that of pigs fed the protein-bound lysine diets. The enzymatic activity responded quadratically to increased level of lysine in the diet regardless of the source. Serum lysine level of pigs fed the crystalline lysine diets was higher than that of pigs fed the protein-bound lysine diets. The level of lysine in serum increased linearly with increased level of lysine in the diets. Lysine concentration in serum was affected by interval of bleeding.

Pages

117

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