Effects of feeding different alfalfa hay on carcass characteristics, meat quality, and fatty acid profile of growing lambs fed complete pelleted diets

Herein, 40 growing male lambs of the Al-Naimi breed were randomly divided into 4 groups and fed a single diet with four particle sizes and lengths of alfalfa forage (1, 5, 10, or 15 mm) in a pelleted complete diet (PCD); lambs were housed individually for 14 weeks. Compared with lambs in the control group, lambs fed either SLF10 or SLF15 diets exhibited increased slaughter weight, carcass weights (hot and cold), and the percentage of liver, heart, and trimmings (P < 0.05), whereas they exhibited reduced thickness of back and body wall fats (P < 0.05). Furthermore, the water-holding capacity and springiness of meat were the greatest (P < 0.05) in the control group lambs (SLF1). Additionally, the nutritional indices showed a significant improvement; the thrombogenicity index corresponding to the palmitic acid C16:0 content was higher in the SLF1 group than in other groups (P < 0.01). Therefore, a particle size of alfalfa of 10–15 mm in PCD improved carcass characteristics and meat quality in growing lambs without compromising the FA profile and indicators of healthy nutrition.