The objective of this study was to investigate the effects of dietary supplementation of Allium mongolicum Regel or its extracts on the flavor and odor fatty acid deposition and shelf life of lamb Longissimus dorsi muscle in order to provide useful information to reduce lamb odor, extend the shelf life of refrigerated lamb meat, and delay oxidation in lamb meat

Sixty three-month-old male small-tailed Han sheep were selected and randomly allocatedinto four groups of five animals each in triplicate in a randomized block design: 1) a basal diet served as control; 2) the basal diet supplemented with 10 g/d Allium mongolicum Regel powder as AMR; 3) the basal diet supplemented with 3.4 g/d of a water extract of Allicum mongolicum Regel as AWE; and 4) the basal diet supplemented with 2.8 g/d of an ethanol extract of Allicum mongolicum Regel as AFE. The experiment lasted for 75 days, including a 15-day adaptive period and a 60-day experimental feeding period. At the end of the experiment, two lambs from each replicate of each group were randomly selected and slaughtered, and Longissimus dorsi muscle was excised to detect odor fatty acids. Moreover, the degree of lipid and protein oxidation, antioxidant capacity, pH, color, juice loss and microbial load of Longissimus dorsi muscle packaged in air-permeable polystyrene bags were measured during nine days of storage at (4.0 ± 0.5) ℃

1) The deposition of three odor fatty acids was significantly inhibited by dietary supplementation of AMR, AFE or AWE compared with the control group (P < 0.001). 2) Dietary supplementation with Allium mongolicum Regel or its extracts decreased the acid value (AV), peroxide value (POV) and total volatile base nitrogen (TVB-N) content of Longissimus dorsi muscle (P < 0.001). 3) Dietary supplementation with Allium mongolicum Regel or its extracts increased the total antioxidant activity (T-AOC)(P < 0.001), total superoxide dismutase (T-SOD) activity (P < 0.001), and glutathione peroxidase (GSH-Px) activity (P < 0.05), and lowered the thiobarbituric acid reactive substances (TBARS) value. 4) Dietary supplementation with Allium mongolicum Regel or its extracts lowered hue angle (P < 0.01). Besides, the water extract significantly decreased the color parameter b* (yellowness/blueness) and juice loss percentage, whereas AMR powder significantly decreased only the juice loss percentage (P < 0.05). The pH, color and juice loss percentage varied in different manner depending on storage time. 5) Dietary supplementation with Allium mongolicum Regel or its extracts decreased the total bacterial count (P < 0.01).

Overall, dietary supplementation with Allium mongolicum Regel or its extracts can contribute to improve the characteristic flavor and odor of lamb by decreasing odor fatty acid deposition, delaying fat and protein oxidation, improving the antioxidant capacity, maintaining the pH and color, reducing the juice loss percentage, and inhibiting the growth of bacteria.

The aim of this experiment was to investigate the effects of Allium mongolicum Regel and its extracts on the production performance, carcass characteristics, meat quality and serum biochemical indexes of Small Tailed-Han Sheep, and to provide an experimental basis for the development of feed additives for captive sheep.

Sixty 3-month-old, male, Small-Tailed Han sheep were selected and allocated into four groups in a randomized block design. There were four treatments with 3 replications each: 1) a basal diet as the control group; 2) the basal diet supplemented with 10 g·lamb^-1·d^-1Allium mongolicum Regel powder as the AMR group; 3) the basal diet supplemented with 3.4 g·lamb^-1·d^-1Allium mongolicum Regel water extract as the AWE group; and 4) the basal diet supplemented with 2.8 g·lamb^-1·d^-1Allium mongolicum Regel ethanol extract as the AFE group. The experiment lasted for 75 days, including a 15-day preliminary feeding period for adaptation and a 60-day experimental feeding period. The production performance of small-tailed Han sheep was measured during experimental feeding period, and the serum biochemical indexes were measured by fasting jugular blood collection at the end of experimental feeding period, followed by slaughter of 2 sheep randomly selected in each replication and carcass characteristics (Hot carcass weight, Carcass yield, perirenal adipose tissue weight, dorsal subcutaneous adipose tissue thickness and firmness) were measured immediately, meat quality was determined by taking Longissimus Dorsi muscle on the left side of the carcass, and fat color was determined by taking perirenal adipose tissue, tail adipose tissue, dorsal subcutaneous adipose tissue, omental adipose tissue.

The results showed that: compared to the control group, ① the mean daily feed intake was significantly lower (P=0.001), feed conversion ratio was significantly higher (P=0.039) and mean daily weight gain did not differ (P>0.05) for AFE group; ② the addition of Allium mongolicum Regel powder and water extracts was able to significantly reduce the shear force of lamb compared to the control group (P=0.029); ③ there was no significant difference (P>0.050) in the b^* values of perirenal adipose tissue in other groups, while the b^* values of perirenal adipose tissue (P=0.096) and omental adipose tissue (P=0.087) in the alcohol extract group tended to be higher compared with Allicum mongolicum Regel powder group, while the a^* (P=0.044) and C^* (P=0.021) values were significantly higher than those of Allicum mongolicum Regel powder group; ④ the addition of Allium mongolicum Regel and its extract significantly increased the serum total protein (P=0.006), Allium mongolicum Regel and its alcoholic extract significantly increased the serum albumin (P=0.006), and Allium mongolicum Regel alcoholic extract significantly decreased the serum urea nitrogen (P=0.024).

In conclusion, Allium mongolicum Regel and its extracts had no significant effect on carcass characteristics and fat color of captive Small Tailed-Han Sheep. The addition of Allium mongolicum Regel and its alcoholic extract to the diet significantly improved the feed conversion rate of Small-Tailed Han sheep, and Allium mongolicum Regel powder and water extract significantly reduced the shear force of meat. Meanwhile, Allium mongolicum Regel and its alcoholic extract can significantly increase the content of total protein and albumin in serum and promote the absorption of protein of meat sheep.