Influence of starch intake on growth and skeletal development of weanling horses.

This research examines the impact of starch intake on the growth and skeletal development of young horses. The results suggest that a high-starch diet leads to greater weight and body length gains, but doesn’t necessarily influence bone development, or cause bone conditions.

Overview of the Experiments

• The study involved two experiments featuring 44 weanling horses, or youthful horses recently separated from their mothers.
• The horses were segregated into groups based on the diet they were fed.
• In the first experiment, one group was fed a high-starch, grain-based concentrate and another a low-starch, by-product-based concentrate, both of which were supplemented with hay.
• In the second experiment, the horses were divided to consume either a high-starch or a medium-starch concentrate, along with hay.
• The ratios of concentrates to hay and the overall intake were kept the same for both diets.
• Corn oil was used to equalise the energy content of the diets in both experiments.

Key Findings

• Findings suggested a significant difference in growth metrics, with horses on a high-starch diet experiencing greater body weight and total body length gains.
• However, the diet did not influence other body measurements and bone mineral deposition, showing the starch content may not affect skeletal development.
• Postprandial blood glucose concentrations revealed that horses on the low-starch diet were less efficient in metabolising blood glucose.
• In the second experiment, there was no significant difference in rate of gain, body measurements, or bone mineral deposition between horses on the high-starch diet and those on the medium-starch diet.
• Horses on the medium-starch diet exhibited blood glucose concentrations that peaked earlier and were subsequently lower than those on the high-starch diet.
• The occurrence of osteochondrotic lesions – a form of bone and cartilage disease – was found to be unrelated to diet, and their prevalence decreased irrespective of the diet.

Implications of the Study

• The study provides insights into horse nutrition and growth, indicating that a high-starch diet can promote greater growth in juvenile horses, without negatively impacting bone health.
• However, caution must be exercised in interpreting these findings given the restricted sample size used in this study.
• While the high-starch diet showed more significant weight and length gains, it did not significantly impact other growth metrics and bone health, underscoring the need for a balanced and nutrient-rich diet for overall healthy development.