Adipose tissue growth and cellularity: changes in bovine adipocyte size and number.

Forty crossbred steers of similar birth date and fed the same growing-finishing diet were used to study adipocyte changes in six fat depots during growth from 11 to 19 mo of age. Steers were slaughtered at 2-mo intervals. Adipose tissue samples were obtained from kidney, mesenteric and brisket fat and subcutaneous, intermuscular and intramuscular fat from the 10th to 12th rib section.

Examination of a lognormal distribution equation for describing distributions of diameters of bovine adipocytes.

Samples of subcutaneous, intermuscular and mesenteric adipose tissues from beef steers were fixed with osmium tetroxide, and freed adipocytes were counted with an automatic particle counter to determine whether a lognormal distribution function would describe adipocyte size distributions more accurately than a normal distribution function. Modes and medians of size distributions generally were larger than means for adipocyte size distributions modeled with a lognormal distribution function. Normalized third and fourth moments of predicted lognormal distributions often were close to 0 and 3, respectively, which are expected values for a normally distributed population.

Fatty acid synthesis from lactate in growing cattle.

Rates of fatty acid synthesis from lactate and acetate and activities of selected lipogenic and NADPH-generating enzymes were determined in subcutaneous, intermuscular and intramuscular adipose tissues of cattle that were 11-19 months of age. Fatty acid synthesis from lactate and acetate increased from 11 to 13 months of age in subcutaneous and intermuscular adipose tissues; synthesis from lactate increased until 17 months of age. In intramuscular adipose tissue, synthesis from lactate also increased until 17 months of age while that from acetate continually increased.