Fatty acid synthesis in ruminating and nonruminating goats.

Abstract

Fatty acid synthetic rates were determined in several tis sues of ruminating ( R ) and nonruminating ( NR ) goats. The R goats were fed goat milk for 1 month and then a hay and grain diet for the next 3 months. The NR goats were fed goat milk for 4 months. Rates of fatty acid synthesis from acetate and glucose were determined in perirenal adipose tissue, small intestine, brain, and liver. With either acetate or glucose as a precursor, rates of lipogenesis were greatest in perirenal adipose tissue and least in liver. When acetate was used as a precursor, no dietary effects were noted for any of the four major tissues except liver in which fatty acids were synthesized more readily in R goats than in NR goats. Fatty acid synthesis from glucose occurred more readily in perirenal adipose tissue of NR goats than of R goats, whereas small intestine had a greater synthesis rate in R goats. Synthesis rates in liver and brain were similar in both NR and R goats. When acetate was used as a precursor, 99% of total fatty acid synthesis occurred in adipose tissue from either R or NR goats. When glucose was precursor, 98% of the fatty acid synthesis occurred in adipose tissue of NR goats and 84% in adipose tissue of R goats. The lowest per centage of total fatty acid synthesis was in liver. Glucose stimulated acetate conversion to fatty acids in tissues of both R and NR goats; the stimulation was greatest in adipose tissue. Therefore, adipose tissue is the principal anatomical site of lipogenesis in either R or NR goats, and acetate is used as a precursor at much higher rates than is glucose. J. Nutr. 108: 1733-