Animal & In Vitro Studies

HMB improved measures of immune function and decreased mortality in young rainbow trout.

HMB increased immnoglubulins in spw colostrum (IgG) which resulted in better immunity in the piglets.

HMB increased the number of antibody secreting cells (ASC) after vaccination utilizing both in vitro and in vivo vaccination techniques.

HMB was an immunomodulator of fish lymphocytes. HMB increased induced lymphocyte proliferation as well as the respiratory burst and potential killing activities of the lymphocytes.

HMB decreased muscle proteolysis in isolated rat and chicken muscle in vitro which confirms earlier observations of decreased protein degradation in humans undergoing strenuous exercise.

HMB decreased the activities of proteolytic enzymes activated by dexamethasone.

HMB increased in vitro immune function in chicken macrophages.

HMB enhances cellular and humoral immunity in young broilers.

HMB fed in the drinking water was just as effective as HMB fed in feed for improving immune function and reducing mortality of broilers.

HMB decreased horse muscle damage and increased aerobic metabolism and performance during actual racing conditions.

HMB improved in vitro and in vivo immune function in rainbow trout and carp which resulted in better growth and reduced mortality

Siwicki, A.K., P. Ostaszewski, J.C. Fuller, Jr., S. Nissen, and M. Studnicka, 1998 In vitro effects of ß-hydroxy-ß-methylbutyrate (HMB) on measures of immune function and immunocompetence in fish, J. Anim. Sci. 76:(Suppl. 1):136
HMB improved in vitro and in vivo immune function in rainbow trout and carp which resulted in better growth and reduced mortality

Abstract not available.

HMB supplement showed no difference in muscle glycogen concentrations in intensively training horses.

HMB improved indicators of immune function in growing pigs by increasing respiratory burst activity, potential killing activity of phagocytes, lymphocyte proliferation, plasma lysozyme activity, and IgG level.

HMB can increase oxidative capacity and stabilize muscle cell membranes.

HMB reduced body fat and cholesterol in the blood and intestinal tissue of rabbits.

HMB was shown to have no effect on glutathione levels following dexamethasone treatment in young rats.

HMB increased blood glucose and decreased blood triglycerides in response to conditioning.

HMB supplementation to training horses increased endurance and aerobic metabolism as indicated by hematocrit and hemoglobin levels.

HMB increased fat oxidation in muscle cells.

Calcium HMB is as efficient as calcium acetate in binding phosphate in vitro which may predict its effective role in vivo. HMB may be effective in lowering phosphate in uremia.

HMB did not significantly increase immune function in baby pigs; however, a trend toward improved growth was observed in weanling pigs.

HMB decreased mortality by up to 72 percent and showed small increases in muscle growth in broiler chickens (summary of five studies conducted at three sites).

HMB decreased subcutaneous fat depots in cattle but increased intramuscular fat in the longissimus muscle.

Three studies are summarized and show that feeding HMB increased milk fat percentage, baby pig growth and tended to increase survivability of baby pigs.

HMB improved growth in lambs that had previously limited feed intakes and slower growth rates.

HMB decreased nonspecific mortality during conditions of environmental extremes in male broilers.

HMB improved growth, immune function, and decreased the severity and incidence of a natural pox virus infection in sheep.

HMB is found in most foods in low levels but is four to ten times higher in alfalfa, poultry byproducts, and certain vegetables.

HMB fed to calves injected with ACTH partially prevented the resulting cortisol-induced decrease in immune function.

Feeding leucine and KIC increased plasma HMB levels to that seen when HMB is fed. Feeding IVA also increased HMB suggesting nonoxygenase conversion to HMB.

HMB increased milk fat percentage in lactating goats.

HMB is produced across the hind legs of pigs when high levels of leucine are fed.

HMB decreased morbidity by 40 percent and mortality by 50 percent in young stressed calves (four studies).

HMB is produced in the body from leucine and KIC in sheep and pigs.

In vitro leucine was shown to suppress lymphocyte function while HMB tended to increase function. HMB did not substitute for leucine in the media for growth of cells.