Dietary Preference of Newly Weaned Pigs and Nutrient Interactions According to Copper Levels and Sources with Different Solubility Characteristics

摘要

Strategies for promoting early feed acceptance and avoiding pig rejection to new feed are a priority for maximizing their feed intake. Animal preference or aversion for a particular feed or nutrient is a behavioral expression coordinated by a complex biological system. After weaning, Cu blood level decrease, which is probably intensified by a low feed intake. This can lead to suboptimal Cu level for the normal functioning of the body. In the present study two experiments were performed to assess the pig Cu preference. In Exp.1 (dose preference) pigs were given a choice between diets supplemented with Cu at 15 mg/kg or 150 mg/kg. In Exp.2 (source preference) diets supplemented with Cu at 150 mg/kg were offered with either sulfate or hydroxychloride source. An in vitro assay was performed to determine the Cu solubility of each source in similar conditions to those found in the oral cavity and digesta. Our results show that pigs chose diets with higher Cu levels, probably to re-establish homeostasis after weaning. Pigs preferred diets with Cu hydroxychloride compared to Cu sulfate, probably due to their solubility differences. A better understanding of pig feed preferences after weaning and their feeding behavior would improve early feed acceptance.