Influence of level of feeding and nutrient content of the concentrate on growth and development of yearling horses.

The research observed the influence of different feeding levels and nutrient contents on the growth and development of yearling horses, showing that those given the ad libitum concentrate intake showed better weight and girth gains.

Research Methodology

• Three experiments were conducted involving 63 Thoroughbred and Quarter Horse yearlings.
• The aim was to evaluate the effect of different feeding levels, protein, and calculated energy content of pelleted concentrates on the horses’ growth and bone development.
• The horses were housed in drylot paddocks and were individually fed concentrates twice a day. Hay was fed to all of them as a group.

Experiment Observations

• Yearlings offered a corn-based concentrate (with 3.56 Mcal of digestible energy per kg) consumed similar levels of dry matter as those fed with a mixed-grain concentrate (with 3.32 Mcal of digestible energy per kg), but consumed slightly more digestible energy.
• There were no noticeable differences in the growth or bone development between the groups.
• Yearlings that were fed restricted levels of concentrate, which provided roughly the amount of protein and digestible energy recommended by the National Research Council (NRC), had lesser weight and girth gains compared to those given ad libitum concentrate intake during two 1.5-hour feeding times each day.

Additional Observations

• Limiting concentrate intake had no significant effect on skeletal growth, but resulted in numerically lower values for bone radiographic density.
• Adding protein to a diet that was already restricted to approximate NRC energy intake recommendations did not affect weight gain, body measurements or bone mineral deposition. However, growth and development was found to be less than that resulting from higher intakes of a lower protein concentrate.

Conclusion

• The study suggests that yearling horses that are provided with ad libitum concentrate intake during two 1.5-hour feeding times each day have better weight and girth gains compared to those given a restricted diet.
• Moreover, even though restricting concentrate intake doesn’t have a significant effect on skeletal growth, it can result in lower values for bone radiographic density.