The ban of in-feed antibiotics has already been implemented in Europe and producers are faced with a vast number of alternatives which are currently available at the market. Natural Growth Promoters (NGP) have gained considerable significance in many markets all over the world. In addition to acidifiers, probiotics and prebiotics, extensive research has been carried out to identify powerful phytogenic agents as sustainable solutions in antibiotic-free feeding systems. A blend of essential oils and prebiotic carbohydrates (Biomin® P.E.P.) has proven highly efficacious in in vitro as well as in vivo experiments. The success of Biomin® P.E.P. is due to profound laboratory tests, in which antimicrobial activities of a large number of active ingredients originating from different phytogenic materials have been elucidated to identify the most beneficial ingredient composition for our phytogenic formula. However, in vitro tests do not necessarily reflect the situation under practical conditions. Therefore, numerous trials have been conducted with pigs, poultry and calves to determine the in vivo performance of the phytogenic additive. Recently, the efficacy of Biomin® P.E.P. has been evaluated in two field trials on a commercial farm in France. The results of these trials are presented in this article.Introduction
In recent years, the forthcoming ban of Antibiotic Growth Promoters (AGP) in livestock nutrition, which has been implemented in Europe in January 2006, has driven research activities regarding the potential of essential oils as Natural Growth Promoters. Several essential oils have been considered to prevent sows and piglets from intestinal disorders and to improve growth performance. Moreover, many herbs and spices are known for their flavoring properties, thus having the potential to stimulate voluntary feed intake. Finally, dietary supplementation of indigestible carbohydrates such as fructooligosaccharides (FOS) supports the development of a beneficial gut microflora by stimulating growth of Lactobacilli and Bifidobacteria.
At present, there is an increasing number of phytogenic products available at the market. However, due to a large variation in chemical composition, these products vary greatly in their efficacy and a scientific proof regarding their in vivo effects is often missing. A unique phytogenic feed additive (Biomin® P.E.P.) has been developed to optimize digestive processes and to improve growth performance in different categories of livestock. The phytogenic additive is based on a synergistic combination of essential oils originating from oregano, anis and citrus peels in combination with FOS.Evaluation of phytogenics in field trials with sows and piglets
Two field trials were conducted on a commercial farm in north-western France (Brittany) to assess the impact of a specific blend of essential oils and FOS (Biomin® P.E.P. 1000) on reproductive parameters, growth performance and economics in sows and piglets.
In Trial 1, 158 lactating sows were allocated to two dietary treatments with seven replications per treatment: (1) commercial control diet (n = 82), (2) control diet + Biomin® P.E.P. 1000 at 2 kg/t (n = 76). Diets and drinking water were offered ad libitum.
In Trial 2, 1080 piglets, weaned at 21 d of age, were fed a commercial starter feed for 3 d post-weaning. Subsequently, piglets were fed phase 1 feed until 48 d of age and, thereafter, phase 2 feed until the conclusion of the experiment (79 d of age). Phase 1 feed contained flubendazole (15 ppm), colistine (360 million UI) and chlortetracycline (1000 ppm), while phase 2 feed contained a commercial acidifier. Both phase 1 and 2 feed were either supplemented or not supplemented with Biomin® P.E.P. 1000 at 1 kg/t, resulting in two treatments with 540 piglets per treatment. Each treatment included nine replications. Moreover, the piglet feeds were pelleted.Benefits in sows
As shown in Table 1, supplementation of the diets with the phytogenic additive increased litter weight and individual body weight (BW) of piglets at weaning by 6.5 and 0.4 kg, respectively. Moreover, the number of weaned piglets per litter was slightly higher when the phytogenic additive was included in the diets (11.2 vs. 10.9 kg).Table 1.
Effect of a phytogenic additive on reproductive parameters of lactating sows (Trial 1)
Addition of the phytogenic additive to the diets of sows increased feed costs. However, an additional margin resulting from increased performance of piglets produced considerable economic benefits, as indicated by a high return on investment amounting to 11:1.Benefits in piglets
In piglets, addition of the phytogenic blend to the diets improved overall average daily gain (ADG) and feed conversion rate (FCR) by 5 and 6%, respectively (Figures 1 and 2).
The highest reduction (8%) in FCR was obtained during the nursery period, whereas the increment in ADG was highest in magnitude (6%) during the post-weaning period, indicating the beneficial impact of phytogenic supplementation on digestive processes in the early stages of life.Figure 1.
Effect of a phytogenic additive on average daily gain of piglets (Experiment 2)Figure 2.
Effect of a phytogenic additive on feed conversion rate of piglets (Experiment 2)
Addition of Biomin® P.E.P. to the diets increased feed costs by 3 and 4%, respectively, in phase 1 and 2, resulting in an increase in overall feed costs per piglets by 2%. Based on actual market prices for feedstuffs and pigs, the return on investment resulting from the use of Biomin® P.E.P. in piglets amounted to 15:1 under the practical conditions of the present experiment. Mode of action of phytogenics
The use of herbs and spices has a long tradition in the flavoring of human foods. Moreover, due to their antioxidative, antimicrobial, fungicidal and physiological activities, phytogenic compounds have found their application in human medicine and in food preservation since ancient times. In animal nutrition, the use of phytogenics is a relatively new approach to promote overall health and growth performance. In particular, essential oils represent a source of highly concentrated active ingredients.
In the field trials reported herein, addition of the phytogenic formula successfully improved performance and economics, both in sows and piglets. As shown in the present study, excellent and highly replicable results have been obtained with BIOMINs phytogenic blend based on a unique combination of essential oils and FOS. The mode of action of phytogenics is usually rather diverse and intensive research has been focused on identification of active ingredients which may have beneficial effects on gut health and performance. In practice, additives with a multifunctional mode of action are favorable since the status of health and performance of the animal is usually affected by a large number of different factors. Feeding the animal always implies feeding and managing its gut microflora. Thus, the key strategy is to support a beneficial gut microflora at the expense of pathogenic bacteria (Figure 3). Figure 3.
Gut microflora management in livestock
On the one hand, due to a pronounced antimicrobial efficacy, the blend of essential oils in Biomin® P.E.P. reduces the total number of microorganisms in the gut. On the other hand, FOS, as a source of indigestible carbohydrates, has a prebiotic effect by selectively supporting the growth of beneficial gut bacteria such as Bifidobacteria or Lactobacilli. A well-balanced gut microflora is essential in critical phases such as lactation or weaning, since it prevents the gut from pathogenic invasion, thus limiting the incidence of diarrhea in weanling pigs or urinary tract infections and mastitis-metritis-agalactia syndromes in lactating sows. Since the piglet feeds were pelleted, our results further confirm that the phytogenic formula investigated in the present study is highly stable and, thus, is not degraded substantially during the pelleting process.
An extensive study, carried out at the University of Natural Resources and Applied Life Sciences, Vienna (Kroismayr et al., 2005), has been directed to evaluate the effects of phytogenics in comparison with an AGP on gastrointestinal parameters in piglets. Supplementation of diets with the phytogenic additive reduced the numbers of gut microorganisms and this decrease was even similar in magnitude as compared with the AGP treatment (Figure 4). Moreover, the reduction in microbial activity in the gut resulted in lower fermentation rates of protein and carbohydrates, as indicated by decreased levels of ammonia, toxic amines and volatile fatty acids as well as reduced activity of immune cells in the gut. A decrease in the total number of microorganisms in the gut means reduced need for immune response as well as less competition for available nutrients along with potentially increased nutrient absorption rates for the host animal.
Phytogenics may also increase the activity of endogenous digestive enzymes. According to Williams and Losa (2001), oral administration of herbs and spices stimulates the secretion of saliva and gastric acid, which is essential for activation of pepsinogen as precondition for optimal protein digestion. Considering the inadequate levels of gastric acid which are naturally present in the stomach of young piglets, phytogenics may assist in improving digestive processes, particularly during the early stages of life, finally resulting in higher performance (Figures 1 and 2).Figure 4.
Effect of a phytogenic additive (Biomin® P.E.P.) on gut microflora of piglets (Kroismayr et al., 2005)
Inclusion of feed additives into diets usually causes higher feed costs for the producer. However, in the present trials, the increase in performance produced additional revenue that exceeded the costs for the additive by far, finally resulting in an exceptionally high return on investment of 11:1 and 15:1 in the sow and piglet trial, respectively. This indicates that a suitable combination of essential oils and FOS is highly competitive, not only in terms of health and performance, but also under economical aspects.Conclusion
In conclusion, phytogenics are a cost-efficient tool to support animal health and growth performance. Since they do not pose any risk regarding antibiotic resistance in pathogenic bacteria or residues in animal products such as meat, eggs or milk, phytogenics are expected to gain high consumer’s acceptance and are generally regarded as safe alternative to AGP. Particular attention, however, has to be paid on the composition of preparations which are available at the market. Only a well-balanced combination of active ingredients with different properties can be expected to function synergistically in order to bring about the desired benefits for the producer.Literature
Kamel, C. (2000): Natural plant extracts: Classical remedies bring modern animal production solutions. 3rd Conference on Sow Feed Manufacturing in the Mediterranean Region. March 22–24, Reus, Spain, pp. 31–38.
Kroismayr, A. et al. (2005) Effect of essential oils or Avilamycin on microbial, histological and molecular – biological parameters of gut health in weaned piglets. Proceedings 4. BOKU-Symposium Tierernährung, Vienna, Austria, pp. 140–146.
Mathe, A. (1996) Essential oils as phytogenic feed additives. In: 27th International Symposium on Essential Oils: Essential Oils Basic and Applied Research. Edited by Franz, Ch., Mathe, A., Buchbauer, G. pp. 315–321. Allured Publishing Corporation, Vienna, Austria.
Williams, P. and Losa, R. (2001) The use of essential oils and their compounds in poultry nutrition. World Poultry 17, 14–15.