Farm animal are often fed with food that includes aromatic herbs in order to make their meat smell good.
A characteristic example is feeding pigs with aromatic herbs which has resulted in better quality of their meat. Moreover, in this recent year, the consumers’ pressure to reduce the composition and the quantity of fat in meat products has led in attempting to modify meat by changing diet strategies. This in combination with the ban of antibiotics as feed additives in animal nutrition have made it of significant importance to explore new ways to improve and protect the health status of farm animals, to guarantee better animal performance and to increase the nutrient availability of the meat products. Therefore, the feed industry is highly interested in alternatives, such as herbs, spices, botanicals, their extracts that can have a wide range of activities. This article is based on literature related to the use of herbs in farm animals.

They are various effects of botanicals and herbs intake by farm animals. Specifically, beneficial effects that may arise from the activation of feed intake are secretion of digestive secretions, immune stimulation, anti-bacterial, anti-viral or anti-inflammatory activity and antioxidant properties (Wenl, 2003).
Several studies have demonstrated the possibility of change the quality of meat and meat products thanks to the modification of animal diet, addition of vegetables, herbs, fibres, spices etc, elimination of fats and reduction of saturated fatty acid, additives and other ingredients (Nieto and Ros, 2017).

Specifically, a study was conducted to evaluate the effects of an herbal extract mixture on pigs’ performance and meat quality. For the experiment, 60 pigs were used in total that had similar mass. The pigs were divided in three groups, one group of pigs was fed with standard feed, the second was fed with the same feed with 150mg BHT (butylated hydroxytoluene) per 1kg of feed, and, lastly, the third group received the same feed with 500mg of an herbal extract mixture per 1kg of feed. The herbal extract mixture was consisted of sage, nettle, lemon balm and cornflower. Even though the use of herbal extracts had no effect on the performance of the
pigs, it improved meat oxidative stability, lowered cholesterol and the TI (thrombogenicity index) and increased the PUFA (polyunsaturated fatty acids) index in meat. Therefore, improvements in indices that show the fat and lipid quality were observed and it was concluded that herbs have a beneficial effect on pork-health promoting properties (Hanczakowska et al. 2015).

Another study conducted in 2005 by Cullen et al investigated the effect of including garlic and rosemary in the pig diet on nutrient digestibility, pig performance, carcass characteristics and on sensory characteristic of pork meat. The results they got from their experiments on 70 pigs of similar weight, showed that addition of garlic reduced feed intake and improved FCR (food conversion ratio) while the addition of rosemary showed no beneficial effects on growth performance or carcass characteristics (Cullem et al, 2005).
Moreover, the ban on the non-therapeutic use of antibiotic growth promoters and limitation on the use of other drugs in Europe has resulted in the increase of digestive disorders and mortality in rabbits. This in combination with the increasing demand for natural products have led in looking for plant-based alternatives. Therefore, plants and their extracts are being used in animal nutrition as appetizers, digestive and physiological stimulants, colorants, and antioxidants and for the prevention and treatment of certain pathological conditions.
Furthermore, several seeds and plants, such as thyme leaves, a mixture of the three plants Lupinus albus L., Trigonella foenum-graecum L., Cassie senna L, and black cumin seeds, oregano, green tea, rosemary and many more have shown several beneficial effects on the health of the rabbits. The effects among many other include anti-inflammatory, anti-bacterial, immunomodulatory and antioxidant results (Dalle Zotte et al, 2016).

Including herb distillates into livestock diets can have positive effects. The inclusion of herb distillates (distilled rosemary leaves) in the diet of pregnant ewes increased carbonic acid, carnosol and rosmarinic acid in the lab meat. And fresh lamb meat from distilled rosemary diet showed lower DPPH values and higher total ferric reducing antioxidant power, indicating that rosemary reduced lipid oxidation (Nieto and Ros, 2017).
Moreover, the effect of including oregano essential oil supplements in the feed on the lamb’s meat was examined. In total, 16 lambs were divided into two groups for comparison purposes.
The first group received standard feed, whereas the second consumed the same feed with the difference that it was uniformly sprayed with oregano essential oil (1ml/kg). As regards the final body weight, body weight gain and carcass yield, no differences were observed. However, pH and colour parameters showed an increase and results showed that incorporation of oregano essential oil had a strong antioxidant effect (Simitzis et al, 2008). Additionally, in another research, the effect of adding rosemary and lemongrass herbs to the daily feed of Damascus goats, showed an increase in the nutrient digestibility, better results in milk yield and positive effect on ruminal fermentation, the process of feed conversion into energy sources (Kholif et al, 2017).
Herbs and botanicals develop their first activity in the feed of farm animals as flavour and can, therefore, have a big influence on the eating pattern, the secretion of digestive fluids and the total feed intake. Herbs and/or phytochemicals can influence selectively the microorganisms by an anti-microbial activity or by a favourable stimulation of the eubiosis of the microflora.

This results in better nutrient utilisation and absorption and in the stimulation of the immune system. Additionally, intake of herbs can contribute to the nutrient requirements of the animals and stimulate the endocrine system and intermediate nutrient metabolism. However, it should be mentioned that intake of herbs may have conflicting results based on the composition of plant secondary metabolites (Wenk, 2003).
Furthermore, extracts of several herbs and spices have anti-inflammatory effect. Specifically, extracts of black pepper, cinnamon, mint, chamomile, marigold and ginger are just some of the relevant examples. Molecules that have major anti-inflammatory effect action are flavonoids and terpenoids, as they suppress the metabolism of inflammatory prostaglandins. Also, many of the active components of herbs and spices can prevent lipid peroxidation through quenching free radicals or through the activation of enzymes with antioxidant activity (Frankic, 2009).
Generally, the effects of herbs are beneficial for the health and growth of farm animals and their impact on the physiological properties can all result in high productivity, healthy animals and quality animal products, meaning good taste and smell quality.

The effects of herbs and spices have been tested primarily on human and laboratory, however, only few trials have been performed on farm animals. Apart from that, it is a really good change to adapt farm animal diets that are more natural based and include herbs and plants in their feed. Moreover, literature review did not indicate any methods of estimating the value of the use of herbs that did not involve the death of the animal and then, the analysis of their meat.
The only alternatives include evaluating their performance, their body weight, change in the feed intake and any change in the body weight. However, these parameters do not provide any indication about the quality and improvements to their meat, that can only be proved after the analysis of their carcasses. Overall, the perspective of improving the general health and consequently the meat quality of farm animals through natural feeding with the addition of herbs is showing promising results.

 

References

  • Cullen, S.P., Monahan, F.J., Callan, J.J. and O’Doherty, J.V., 2005. The effect of dietary garlic and rosemary on grower-finisher pig performance and sensory characteristics of pork. Irish journal of agricultural and food research, pp.57-67.

  • Dalle Zotte, A., Celia, C. and Szendrő, Z., 2016. Herbs and spices inclusion as feedstuff or additive in growing rabbit diets and as additive in rabbit meat: A review. Livestock Science, 189, pp.82-90.

  • Frankic T, Voljč M, Salobir J, Rezar V. Use of herbs and spices and their extracts in animal nutrition. Acta Agric Slov. 2009;94(2):95-102.

  • Hanczakowska, E., Świątkiewicz, M. and Grela, E.R., 2015. Effect of dietary inclusion of a herbal extract mixture and different oils on pig performance and meat quality. Meat Science, 108, pp.61-66.

  • Kholif, A.E., Matloup, O.H., Morsy, T.A., Abdo, M.M., Elella, A.A., Anele, U.Y. and Swanson, K.C., 2017. Rosemary and lemongrass herbs as phytogenic feed additives to improve efficient feed utilization, manipulate rumen fermentation and elevate milk production of Damascus goats. Livestock Science, 204, pp.39-46.

  • Nieto, G. and Ros, G., 2017. Dietary Administration of Animal Diets with Aromatic and Medicinal Plants: Influence on Meat Quality. Active Ingredients from Aromatic and Medicinal Plants.

  • Simitzis, P.E., Deligeorgis, S.G., Bizelis, J.A., Dardamani, A., Theodosiou, I. and Fegeros, K., 2008. Effect of dietary oregano oil supplementation on lamb meat characteristics. Meat Science, 79(2), pp.217-223.

  • Wenk, C., 2003. Herbs and botanicals as feed additives in monogastric animals. Asian-Australasian Journal of Animal Sciences, 16(2), pp.282-289.