Serum beta-carotene and alpha-tocopherol in horses fed beta-carotene via grass-meal or a synthetic beadlet preparation with and without added dietary fat.

This research study compared the bioavailability of beta-carotene in horses from two different sources – grass meal and a synthetic source. The study found that both sources resulted in similar levels of bioavailability regardless of additional dietary fat content.

Research Design and Methodology

• This study was designed based on a Latin square format where four horses were provided beta-carotene either from grass meal or from a synthetic source named Lucarotin. Both these sources were administered with or without added vegetable fat to observe the impact on beta-carotene’s bioavailability.
• Alongside beta-carotene, a nutritionally complete diet was served to the horses, supplemented with alpha-tocopherol.
• The experiment consisted of distinct treatment and washout periods. Each treatment period lasted for four weeks, after which a washout period of 4 weeks was observed with minimal intake of beta-carotene and alpha-tocopherol.

Results and Observations

• The serum response showed about a 10-fold increase in beta-carotene levels within four weeks of supplementation – from an average initial concentration of 0.05 micromol/l to 0.53 micromol/l.
• The source of beta-carotene and addition of fat did not show any significant impact on the serum response on beta-carotene load.
• No traces of beta-carotene were detected in the urine samples of the participants, while the majority (55 to 81%) was excreted through faeces.
• Similarly, alpha-tocopherol values were significantly higher during supplementation periods as compared to the washout periods. The addition of dietary fat did not affect its serum response, and most of it was also excreted through faeces.
• The added dietary fat did, however, result in a significant decrease in serum cholesterol levels.

Conclusions

• The natural (grass meal) and synthetic (Lucarotin) source of beta-carotene demonstrated the same level of bioavailability and were not affected by additional fat content. The beta-carotene was absorbed and utilized equally from both sources.
• The consumption of additional dietary fat had no influence on the bioavailability of beta-carotene or alpha-tocopherol but somehow contributed to lower serum cholesterol levels.