Effect of dietary inclusion of a herbal extract mixture and different oils on pig performance and meat quality

Highlights

• Effects of herbal extracts and oils on pig performance and meat quality were tested.

• Used plant extracts and oils did not change pig weight gains nor feed utilization.

• Beneficial health aspects of meat from pigs fed with herbal extracts were observed.

• Herbal extracts improved oxidative stability as well as smell and taste of meat.

Abstract

The aim of the study was to evaluate the effect of a herbal extract mixture on pig performance and meat quality. The experiment was performed on 60 fatteners (60 ± 0.5–112 ± 2.0 kg). Group I (control) was fed with standard feed; groups II and III received the same feed supplemented with 150 mg BHT or 500 mg of a herbal extract mixture (sage, nettle, lemon balm and coneflower) per kg of feed, respectively. In each group, half of the animals received 4% rapeseed oil, the other half soybean oil. The herbal extracts had no effect on animal performance but significantly improved meat oxidative stability, lowered cholesterol and TI index and increased PUFA content in meat. Slight differences between animals fed with rapeseed or soybean oils were observed. Gilt meat had significantly better (P ≤ 0.01) AI, TI, and h/H indices than barrow meat. It was concluded that herbal extracts have a beneficial effect on pork health-promoting properties due to changes in lipid fraction.

Introduction

Herbs and their extracts have been used in human and veterinary medicine for a long time (Viegi, Pieroni, Guarrera, & Vangelisti, 2003). Herbs have many positive effects, of which antimicrobial and antioxidant activity is the most important (Windisch, Schedle, Plitzner, & Kroismayr, 2008). According to a European Union directive, antibiotics and chemical growth promoters have been withdrawn from farm animal feeds (Anadón, 2006); recently, herbs or herbal extracts have attracted increasing interest as an alternative feeding strategy to replace them (Hernández, Madrid, Garcia, Orengo, & Megias, 2004). The health-related effect of plants depends on their content of active principles. Sage (Salvia officinalis) contains phenolics, mainly flavonoid glycosides, which exert anti-inflammatory and antioxidative activity (Lu & Foo, 2001). Lipid peroxidation is reduced by nettle (Urtica dioica), which also enhances the antioxidant defense system in rats (Kanter et al., 2003). Another plant with similar properties is lemon balm (Melissa officinalis) whose antimicrobial activity in vitro was found by Mahady et al. (2005). Also, purple coneflower (Echinacea purpurea), used previously in folk medicine, is now the subject of research and its immunologic activity established (Goel et al., 2005).

The quality of fat in animal tissue results not only from genetic background but also from feed components, especially plant-origin oils rich in polyunsaturated fatty acids (PUFA). Data available in the literature indicate that dietary fat affects the fatty acid profile of carcass lipids determining fat and meat quality (Benz et al., 2011b, Xu et al., 2010). From the health point of view, high content of PUFA in pork is desirable; however, their influence on meat oxidative stability, shelf life and processing is undesirable. Moreover, they lead to deterioration of organoleptic quality, since compounds formed during the oxidation process have a negative effect on the meat's taste and flavor (Faustman and Cassenas, 1990, Guo et al., 2006). Fat and meat quality should thus be balanced by feed additives or supplementation.

To our knowledge, there are no reports of the combined impact of herbal extract mixture and oils rich in polyunsaturated fatty acids on growth performance and pork quality. However, these different feeding supplements could have additive or interactive effects. Therefore, a study was conducted to test the hypothesis that dietary supplementation of rapeseed or soybean oils and herbal extract mixture (sage, nettle, lemon balm and coneflower) could improve the performance and meat quality of fattening pigs. In addition, the effect on fatty acid profile, meat oxidative stability and sensory traits induced by herbal extract mixture compared to synthetic antioxidant (BHT, butylated hydroxytoluene) was also investigated.

The aim of the present experiment was to assess the effect of supplementation of feeds containing rapeseed or soybean oils with a mixture of extracts from sage, nettle, lemon balm and coneflower on the performance and meat quality of fattening pigs.