Partial substitution of alfalfa hay by Berberis vulgaris leaf modulated the growth performance, meat quality and antioxidant status of fattening lambs.

BACKGROUND

Undoubtedly, global warming has caused a decrease in the production of agricultural commodities. This problem has increased the price of animal feed due to competition with human consumption. Meanwhile, the physiology of ruminants gives them the ability to use by-products and agricultural waste and supply their requirements for growth, maintenance and even production. Berberis vulgaris is a plant native to Iran, and after separating the fruit, its waste (mainly leaf) is unused and causes environmental pollution. The leaves of this plant contain significant amounts of phenolic compounds, alkaloids and anthocyanins that have antioxidant properties.

OBJECTIVES

This experiment was conducted with the aim of determining the chemical properties of barberry leaves, such as crude protein, phenolic compounds, tannins and alkaloids. The effects of substituting of B. vulgaris leaf (BVL) in the diet on performance characteristics of fattening Baluchi lambs were evaluated. The quality and antioxidant status of meat and blood parameters such as glucose, cholesterol, blood urea nitrogen and liver enzymes were investigated.

MATERIAL AND METHODS

A total of 21 male of 5-6 months old lambs with a mean body weight of 30.60 ± 1.28 kg were randomly assigned to one of three dietary treatments with different levels of BVL: 1-diet without BVL (control), 2-diet containing 7.5% BVL (BVL7.5), and 3-diet containing 15% BVL (BVL15; dry matter [DM] basis). Blood samples were harvested after overnight fasting from the jugular vein at 0, 28, 56 and 84 days. The lambs were slaughtered after 84 days of feeding trial and longissimus dorsi (LD) muscle was dissected. Meat quality and antioxidant stability status were measured.

RESULTS

15% substitution of alfalfa hay by BVL (BVL15) increased DM intake) and decreased average daily gain (p ≤ 0.05). The LD muscle (p ≤ 0.05), liver (p ≤ 0.01) and plasma (p ≤ 0.05) samples of lambs fed either BVL7.5 or BVL15 displayed a greater total antioxidant capacity than that of lambs fed the control diet. Also, malondialdehyde concentration was decreased in plasma (p ≤ 0.01) and LD muscle of lambs (p ≤ 0.05) fed both BVL7.5 and BVL15. In addition, higher a* and C* values (p ≤ 0.05) were observed in the meat of lambs fed BVL15 than those fed with the control, while the lightness (L*) in BVL15 was lower, compared to other experimental diets CONCLUSIONS: Overall, our results indicated that 7.5% substitution of alfalfa hay by BVL may positively modulate the antioxidant status of fattening lambs and improve the colour stability of meat without negative effects on performance characteristics.