Antioxidant Capacity, Inflammatory Response, Carcass Characteristics and Meat Quality of Hu Sheep in Response to Dietary Soluble Protein Levels with Decreased Crude Protein Content

Abstract

Manipulating dietary nutrients, especially protein fractions, holds significance in enhancing the antioxidant capacity and immunity function of ruminants. This study investigated the impact of dietary adjustments in soluble protein (SP) levels, in conjunction with a reduction in crude protein (CP) content, on the antioxidant capacity, inflammatory response, carcass characteristics, and meat quality of sheep. This study had four dietary treatments, including a control diet (CON) adhering to NRC standards with a CP content of 16.7% on a dry matter basis and three diets with an approximately 10% reduction in CP content compared to CON with SP levels (% of CP) of 21.2 (SPA), 25.9 (SPB) and 29.4% (SPC), respectively. Thirty-two healthy male Hu sheep, with an initial live weight of 40.37 ± 1.18 kg and age of 6 months, were randomly divided into four groups to receive these respective diets. Our data revealed no significant differences in slaughter performance among treatments (p > 0.05), although low-protein treatments decreased the stomachus compositus index (p p p p p p p p longissimus lumborum muscle. In summary, reducing CP by 10% with an SP proportion of ~25–30% improved meat quality without compromising antioxidant capacity and immunity function, while lower SP levels had adverse effects.

Keywords

• soluble protein
• low-protein diets
• antioxidant capacity
• inflammatory response
• carcass characteristics
• meat quality