Essential fatty acid status and characteristics associated with colostrum-deprived gnotobiotic and conventional lambs. Growth, organ development, cell membrane integrity and factors associated with lower bowel function.

A factorial experiment involving gnotobiotic (GN) and conventional (CV) colostrum-deprived lambs and diets formulated to be adequate or deficient in linoleic acid was conducted to determine the effect(s) of the intestinal microflora on the essential fatty acid (EFA) status of the host and subsequent physiological consequences, i.e., growth, organ development, cell membrane integrity and lower bowel function. Lambs were obtained by sterile surgical procedures and housed in sterile isolators or in conventional metabolism stalls for 60 d. Skimmed cow's milk with 6% hydrogenated coconut oil and vitamins A, D and E added with and without .32% of the total calories as linoleic acid was homogenized, bottled and autoclaved, then fed to appetite three to four times daily. The GN lambs supplemented with linoleic acid gained significantly faster between 13 and 41 d of age and more efficiently between 27 and 41 d than the other treatment groups. The absence of dietary linoleic acid decreased liver and spleen weights and, in general, suppressed development of organs except the brain. Red blood cell hemolysis was not affected by treatment. Although showing signs of chronic mild diarrhea, the GN neonatal ruminant differed in Cl- concentration and dry matter percentage of its lower bowel contents from the "classic rodent model." The results indicate that neonatal colostrum-deprived lambs have an EFA requirement, as evidenced by decreased growth and performance characteristics in the GN linoleic deficient vs GN supplemented group, and suggests that the required level is in excess of .32% of the total caloric intake as linoleic acid.(ABSTRACT TRUNCATED AT 250 WORDS)