Soybean Oil, Linoleic Acid Source, in Lamb Diets: Intake, Digestibility, Performance, Ingestive Behaviour, and Blood...

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Ruminant Physiology

Background:

• Dietary fat supplementation, particularly soybean oil (SO), is explored to enhance energy density in feedlot lamb diets.
• Understanding the impact of increasing SO levels on nutrient utilization and metabolic responses is crucial for optimizing lamb growth.

Purpose of the Study:

• To evaluate the effects of varying soybean oil inclusion levels on the feeding behavior, nutrient digestibility, performance, and blood metabolites of feedlot lambs.
• To determine the optimal level of soybean oil inclusion for fattening lambs based on productive parameters.

Main Methods:

• Forty Santa Inês lambs were fed diets with 0, 30, 60, 90, or 120 g/kg dry matter (DM) of soybean oil for 40 days.
• Measurements included dry matter intake, nutrient digestibility, average daily gain, feeding behavior, and blood N-ureic concentration.

Main Results:

• Soybean oil inclusion linearly reduced DM intake, crude protein, non-fibrous carbohydrates, and total digestible nutrients.
• Apparent digestibility of crude protein, ether extract, and NDFom increased with SO, while NFC digestibility decreased.
• Average daily gain declined with SO inclusion, though feeding time increased and rumination efficiency decreased. Blood N-ureic concentration was reduced.

Conclusions:

• Soybean oil can be included in feedlot lamb diets, with an optimal level of up to 41 g/kg DM recommended.
• Dietary adaptation strategies mitigated negative lipid effects, but high energy density constrained performance.
• Further research into energy metabolism and rumen function with high-fat diets is warranted.