Oral lactose tolerance test in foals: technique and normal values.

The research paper discusses a study assessing oral lactose tolerance in young horses of different ages. The study found that, on average, plasma glucose concentrations significantly increased following oral lactose consumption, though the rise was more pronounced in older foals.

Research Methodology

• The research team conducted oral lactose tolerance tests on 25 healthy foals divided into four groups, based on their ages: approximately 1 week, 4 weeks, 8 weeks, and 12 weeks old.
• Each foal was given lactose monohydrate corresponding to 1 g/kg of their body weight, in a 20% water solution via a nasogastric tube. This was done after a fasting period of 4 hours.
• A control group was also included, made up of 6 foals that were given the same volume of water as the lactose monohydrate given to the principal groups.
• Researchers monitored plasma glucose concentrations before the initial dosing, and then continuously for a further 300 minutes.

Findings

• The study found that following oral lactose intake, mean plasma glucose concentrations of all principal foals increased from 99.76 mg/dl at the start to 176.80 mg/dl by 90 minutes.
• The peak increase in plasma glucose concentrations was noted at various times for different foals – 30 minutes for 8% of foals, 60 minutes for 76%, and at 90 minutes for 16% of the foals.
• There was no notable difference in fasting plasma glucose concentrations among the four age groups of foals or between the principal and control groups.
• However, a significant difference was observed in peak glucose concentrations between the youngest (1 week) and oldest (12 weeks) foals, with the older foals showing higher concentrations.
• The control group of foals that were given only water saw their plasma glucose levels decrease from an average of 79.67 mg/dl to 55.17 mg/dl within 180 minutes.

Significance of the Study

• The study provides valuable insights into the lactose tolerance of foals at different developmental stages.
• The data generated can aid in the understanding of digestive capabilities and the processing of lactose in foals which could inform dietary planning and health management for these young horses.