Two experiments were conducted to determine the stability of microencapsulated and non-microencapsulated forms of vitamins in diets during extrusion and pelleting. We investigated the recovery of vitamins in swine diets after extrusion at 100 °C, 140 °C, or 180 °C. Next, two diets were conditioned at 65 °C (low temperature; LT) or 85 °C (high temperature; HT), and pellets were formed using a 2.5 × 15.0 mm (low length-to-diameter ratio; LR) or 2.5 × 20.0 mm (high length-to-diameter ratio; HR) die. The extrusion temperature had a significant effect on the recovery of vitamins E, B₁, B₂, B₃, and B₅ in the diets. The diet extruded at 100 °C had higher B₁, B₂, B₃, and B₅ vitamin recoveries than diets extruded at 140 °C and 180 °C. Microencapsulated vitamins A and K₃ had greater stability than non-microencapsulated vitamins A and K₃ at 100 °C and 140 °C extrusion. In the diet extruded at 180 °C, microencapsulated vitamins A, D₃, and K₃ had higher recoveries than non-microencapsulated vitamins A, D₃, and K₃. The recovery of vitamin K₃ in diets after LTLR (low temperature + low length-to-diameter ratio) or HTLR (high temperature + low length-to-diameter ratio) pelleting was greater (p < 0.05) than after LTHR (low temperature + high length-to-diameter ratio) and HTHR (high temperature + high length-to-diameter ratio) pelleting. Our results clearly show that low extrusion temperature and low pellet temperature, and a low length-to-diameter ratio (L:D ratio) for pellet mill die are recommended for pig feed. Moreover, microencapsulated vitamins had greater stability compared to non-microencapsulated vitamins.

Epidemiologic studies showed that higher vitamin K (VK) consumption correlates with a reduced risk of osteoporosis, yet the dispute remains about whether VK is effective in improving bone mineral density (BMD). We sought to discover the anti-osteoporotic effect of menaquinone-4 (MK-4) and evaluate the expression of critical genes related to bone formation and bone resorption pathways in the body. Fifty female C57BL/6 mice (aged 13 weeks) were randomly arranged to a sham-operated group (SHAM, treated with corn oil) and four ovariectomized groups that were administered corn oil (OVX group), estradiol valerate (EV, 2 mg/kg body weight as the positive control), low or high doses of VK (LVK and HVK; 20 and 40 mg MK-4/kg body weight, respectively) by gavage every other day for 12 weeks. Body and uterine weight, serum biochemical indicators, bone microarchitecture, hematoxylin-eosin (HE) staining, and the mRNA expression of critical genes related to bone formation and bone resorption pathways were assessed. Either dose of MK-4 supplementation increased the alkaline phosphatase (ALP), decreased the undercarboxylated osteocalcin (ucOC) and tartrate-resistant acid phosphatase (TRACP, p < 0.05) levels, and presented higher BMD, percent bone volume (BV/TV), trabecular thickness (Tb.Th), and lower trabecular separation (Tb.Sp) and structure model index (SMI, p < 0.05) compared with the OVX group. Additionally, both doses of MK4 increased the mRNA expression of Runx2 and Bmp2 (p < 0.05), whereas the doses down-regulated Pu.1 and Nfatc1 (p < 0.05) mRNA expression, the high dose decreased Osx and Tgfb (p < 0.05) mRNA expression, and the low dose decreased Mitd and Akt1 (p < 0.05) mRNA expression. These data show the dual regulatory effects of MK-4 on bone remodeling in ovariectomized mice: the promotion of bone anabolic activity and inhibition of osteoclast differentiation, which provides a novel idea for treating osteoporosis.

Two in vitro experiments were conducted to investigate the effects of choline chloride, copper sulfate (CuSO₄) and zinc oxide (ZnO) on the stability of vitamin A (VA), vitamin D₃ (VD₃), vitamin E (VE), vitamin K₃ (VK₃), vitamin B₁ (VB₁), vitamin B₂ (VB₂), vitamin B₆ (VB₆), niacin, and pantothenic acid in vitamin and vitamin/trace mineral (VTM) premixes for weanling piglets after 0, 1, 2, 3, 6 and 12 months of premix storage. We developed predicted equations to estimate vitamin retention during storage. Two vitamin premixes (with or without choline) were formulated and stored at 25 °C and 60% humidity to establish the storage stability of vitamin premixes. Additionally, four VTM premixes were used to evaluate the effect of choline chloride (0 vs. 40,000 mg/kg) and trace minerals (Low CuSO₄ + ZnO vs. High CuSO₄ + ZnO) on vitamin stability in VTM premixes stored at room temperature (22 °C). In general, as storage time increased, residual vitamin activity decreased (p < 0.05). The results confirmed that VD₃, VE, VB₂, VB₆, niacin and pantothenic acid were highly stable during storage, while the retention of VA, VK₃ and VB₁ was significantly affected by storage time and the presence of choline and high concentrations of Cu and Zn in the premix. After one year of storage, the retention of VE, VB₂, VB₆ niacin, and pantothenic acid was more than 90% in vitamin and VTM premixes. The retention of VD₃ was more than 90% in vitamin premixes and more than 80% in VTM premixes after one year of storage. We conclude that current microencapsulation techniques for vitamin premixes appear to be inadequate to guarantee VA, VK₃, and VB₁ concentrations in VTM premixes.

This study was conducted to investigate the stability of five commercial vitamin A products in vitamin premixes and vitamin-trace mineral premixes. The five commercial products used were: Xinhecheng, Zhejiang medicine, Kingdomway, DSM, and BASF. The vitamin A products were stored in three vitamin premixes (for suckling, weanling, and finishing pigs) or in vitamin-trace mineral (VTM) premixes (for suckling, weanling, and finishing pigs). Vitamin premixes were stored in an environmentally controlled chamber set at 25 °C and 60% humidity. The VTM premixes were stored at room temperature (approximately 22 °C). Sampling was performed on d 0, 90, 180, 270, and 360. Stability was reported as the residual vitamin A activity (% of initial) at each sampling point. For the stability of vitamin premixes, all interactive and main effects of storage time and vitamin A product were not significant. For the stability of VTM premixes, there was no significant interaction effects between storage time, vitamin A product and main effect of vitamin A product, but the main effect of storage time was significant (p < 0.01). In conclusion, a longer storage time reduced vitamin A activity in VTM premixes but there was no difference in the stability of commercially available vitamin A.

Two studies were conducted to determine the stability of vitamin K₃ (VK₃) in swine diets during extrusion or pelleting. The two sources were menadione sodium bisulfite (MSB) and menadione nicotinamide bisulfite (MNB), and the three formulations were crystal micro-capsule formulation and micro-sphere formulation. The recovery of six types of VK₃ in swine diets was investigated after extrusion at 100 °C or 135 °C in Experiment 1. The recovery of six types of VK₃ was investigated when the diets were pelleted at 60 °C (low temperature; LT) or 80 °C (high temperature; HT) and the length to diameter ratios were 5.2:1 (low length to diameter ratio; LR) or 7.2:1 (high length to diameter ratio; HR) in Experiment 2. In Experiment 1, MNB recovery (72.74%) was higher than MSB recovery (64.67%) after extrusion, while recovery of VK₃ of crystal (74.16%) was higher than the recovery of micro-capsule (65.25%) and micro-sphere (66.72%). The recovery of VK₃ (70.88%) was higher when extruded at 100 °C than that at 135 °C (66.54%). In Experiment 2, MNB recovery (86.21%) was higher than MSB recovery (75.49%) after pelleting, while the recovery of VK₃ of micro-capsule (85.06%) was higher than the recovery of crystal (81.40%) and micro-sphere (76.09%). The recovery of VK₃ (75.50%) was lower after HTHR pelleting than LTLR (83.62%), LTHR (81.52%) or HTLR (82.76%) treatment. Our results show that MNB has greater stability than MSB. VK₃ of crystal or VK₃ of micro-capsule were recommended for extrusion or pelleting, respectively.

Six types of vitamin K₃ (VK₃); two sources (menadione sodium bisulfite, MSB; menadione nicotinamide bisulfite, MNB), and three different forms (crystal, micro-capsule, and micro-sphere) were used to determine the retention of VK₃ in vitamin premixes (Experiment 1) or vitamin trace mineral (VTM) premixes (Experiment 2) after 1, 2, 3, and 6 months of storage. The retention of VK₃ in vitamin premixes was evaluated at 25 °C/60% relative humidity or 40 °C/75% relative humidity in an incubator in Experiment 1 and in VTM premixes (choline chloride: 0 vs. 16,000 mg/kg) stored at room temperature in Experiment 2. The VK₃ retention in vitamin premix or VTM premix decreased significantly with the extension of storage time (p < 0.05). In Experiment 1, the VK₃ retention was higher in the 25 °C/60% incubator (56%) than in the 40 °C/75% incubator (28%). The MNB retention (52%) was higher than MSB retention (32%). The retention of VK₃ in micro-capsules (43%) or micro-spheres (48%) was higher than the crystal form (35%) after six months of storage. In Experiment 2, there was no difference between the retention of MSB (49%) or MNB (47%). The retention of VK₃ of micro-capsule (51%) or micro-sphere (54%) was higher than that of crystal form (40%). The VK₃ retention was higher in the choline-free group (51%) than in the choline group (47%) after six months of storage. Finally, the predicted equations of VK₃ retention with storage time in vitamin premixes or VTM premixes were established. The R² of the prediction equations was ≥0.9005, indicating that time is an important factor in predicting VK₃ retention. In conclusion, the higher temperature-relative humidity, choline had negative effects on VK₃ retention during premix storage. MNB retention was higher than MSB during storage of vitamin premix. The encapsulated forms of VK₃, micro-capsules and micro-spheres, could improve VK₃ storage stability in vitamin premix and VTM premix.