Net Absorption and Metabolism of β-Hydroxy- β-Methyl Butyrate during Late Gestation in a Pig Model

Abstract

The leucine metabolite, β-hydroxy-β-methyl butyrate (HMB), is widely used in human nutrition and animal production as a nutritional supplement. Although the HMB usage during late gestation has been demonstrated to have a positive effect on fetal development, knowledge on net absorption and metabolism of HMB and impact of HMB on branched chain amino acids (BCAAs) metabolism is lacking. To address this, we conducted a study using pigs during the perinatal period as a model organism. Eight-second parity sows were fitted with indwelling catheters in the femoral artery and in the portal, hepatic, femoral, and mesenteric veins. Eight hourly sets of blood samples were taken starting 30 min before the morning meal on day –10 and day –3 relative to parturition. Four control (CON) sows were fed a standard lactation diet from day –15 and throughout the experiment, and 4 HMB sows were fed the control diet supplemented with 15 mg Ca(HMB)2/kg body weight mixed in one third of the morning meal from day –10 until parturition. Blood gases, plasma metabolites, milk compositions, and apparent total tract digestibility of nutrients were measured. Arterial plasma concentrations of HMB (p < 0.001), Cys (p < 0.001), and Lys (p < 0.10) were increased in HMB supplemented sows, while arterial plasma triglycerides concentration was decreased (p < 0.05). The net portal recovery of Ala and Asp were increased in HMB sows (p < 0.05). Sows fed HMB had increased hepatic vein flow and net hepatic fluxes of Met, Asn, and Gln (p < 0.05). In contrast, the femoral extraction rates of Ala and Ser were decreased by dietary HMB supplementation (p < 0.05). Dietary HMB treatment and sampling time relative to feeding had an interaction on arterial concentrations, net portal fluxes, and femoral extraction rates of BCAAs. The net portal recovery of HMB was 88%, while 14% of supplemented HMB was excreted through urine and 4% through feces. Moreover, the gastrointestinal tract metabolized 8% while the liver metabolized 12%. Finally, 26% of the daily intake of HMB was secreted via colostrum at the day of farrowing. This study demonstrated that dietary HMB supplementation increased net uptake of amino acids and increased fatty acid oxidation through improving blood flow and insulin sensitivity during the late gestation. Most importantly, oral HMB administration could maintain a stable postprandial absorption and altered metabolism in BCAAs. Net portal flux of HMB at 5.5 to 6.5 h after feeding approached zero, indicating that HMB ideally should be administrated two or three times, daily.

β-Hydroxy-β-Methylbutyrate (HMB) Supplementation Prevents Bone Loss during Pregnancy—Novel Evidence from a Spiny Mouse (Acomys cahirinus) Model

“…In the present study, no statistically significant differences in body weight were found between groups of females supplemented with HMB and those not receiving HMB supplementation, as reported previously [ 41 ], which is also in agreement with some other studies conducted on pigs [ 42 , 43 , 44 ]. Our data also showed that pregnancy did not affect the body weight of the mice immediately after delivery as compared with non-breeding females.…”

Supplementing sows with the leucine metabolite beta-hydroxy-beta-methylbutyrate and vitamin D3 improves piglet birth weights that may lead to increased weaning weights

“…This may mean that if piglets are to receive optimal benefit either late gestation or during lactation that the dose needs to be fed at least twice daily, which if mixed in the complete feed would be compatible with most commercial practices. In the study by Nissen et al, milk HMB levels were increased on day 10 of lactation and, in more recent studies, HMB in colostrum and milk has been shown to increase similarly to the study presented here (Wan et al, 2017;Hu et al, 2020). Additionally, Hu et al (2020) found that 26% of the HMB dosage ended up in the colostrum.…”

“…In the study by Nissen et al, milk HMB levels were increased on day 10 of lactation and, in more recent studies, HMB in colostrum and milk has been shown to increase similarly to the study presented here (Wan et al, 2017;Hu et al, 2020). Additionally, Hu et al (2020) found that 26% of the HMB dosage ended up in the colostrum. Wan et al (2017) found that this lactational intake of HMB by the piglets resulted in improved growth characteristics that were carried through to slaughter, weight at 180 days, average daily gain, and a trend for improved feed efficiency.…”

“…Nissen et al (1994a) failed to show an increase in birth weight when HMB was only fed for approximately 2 days pre-farrowing, and this study as well as others would indicate that HMB needs to be fed for at least 10 days pre-farrowing to observe an effect on early piglet weight (Tatara et al, 2007;Tatara et al, 2012;Wan et al, 2016b;Davis et al, 2021). Hu et al (2020) showed that 4-6 h after feeding HMB, net portal flux had returned to near baseline. This may mean that if piglets are to receive optimal benefit either late gestation or during lactation that the dose needs to be fed at least twice daily, which if mixed in the complete feed would be compatible with most commercial practices.…”

Evaluation of Feeding Beta-Hydroxy-Beta-Methylbutyrate (HMB) to Mouse Dams during Gestation on Birth Weight and Growth Variation of Offspring

“…The daily pattern of HMB intake may influence its effect on the birth weight of progeny. Hu et al [33] studied the absorption and metabolism of HMB fed to pregnant sows once daily. They reported that the net portal flux of HMB peaked at 30 min after a meal and approached zero at about 6 h post prandial.…”