**6. Effect of PE on the immune status of birds**

results show an improvement in feed efficiency in association with improved NE but not with ME. The beneficial effects of supplementary PE to poultry diets may therefore be mediated via a decrease in the energy required for maintenance, thereby providing more energy for growth. The improvement in feed efficiency is likely explained by increases in dietary NE, suggesting that PE may be improving the metabolic efficiency of the conversion of energy into tissue. Usually NE is described as the ME of the diet corrected for the energy losses that result from the heat released during absorption of the dietary nutrients and accretion of body mass [35]. Changes in maintenance energy are more likely to be detected by determination of NE but not ME. Thus confirming that dietary ME may not be the most sensitive method to

**Table 2.** The effect of supplemental plant extracts in wheat and maize based diets on broilers daily feed intake (FI), daily weight gain (WG), gain to feed (G:F) ratio, dietary apparent metaboilisable energy (ME), dietary net energy (NE),

**Items treatment factor FI1**

Cereals

PE

Cereals & PE

Probabilities of statistical differences

Source: adapted from [47–51].

concentration of hepatic vitamin E and coenzyme Q10.

1

2

**(g DM/b/d)**

112 Phytochemicals - Source of Antioxidants and Role in Disease Prevention

**WG1 (g/b/d)** **G:F1 (g/g)**

W 42.1 31.7 0.753 14.05 10.00 82.4 91.4 M 43.6 32.6 0.747 14.23 9.47 86.7 79.4

no 42.1 31.1 0.739 14.08 9.56 72.5 74.7 yes 43.6 33.2 0.762 14.05 9.90 96.7 96.1 SEM 0.496 0.460 0.0064 0.061 0.092 7.03 9.80

W + 0 42.0 31.4 0.746 13.93 9.76 63.7 77.1 W + PE 42.2 32.0 0.760 14.16 10.23 101.2 105.8 M + 0 42.3 30.8 0.732 14.22 9.37 81.3 72.3 M + PE 45.0 34.4 0.763 14.24 9.57 92.2 86.4 SEM 0.702 0.651 0.0091 0.087 0.127 9.95 13.85

Cereals 0.030 0.166 0.499 0.037 <0.001 0.542 0.221 PE 0.037 0.002 0.015 0.159 0.008 <0.001 0.032 Cereals x PE 0.074 0.030 0.347 0.211 0.309 0.062 0.458

W, wheat-based diet; M, maize-based diet; PE, supplemental plant extracts (100 g PE/t).

There were 38 observations per treatment (three experiments involving male Ross 308 broilers).

There were 24 observations per treatment (two experiments involving male Ross 308 broilers).

**ME1 (MJ/kg DM)**

**NE1 (MJ/kg DM)**

**Vit E2 (μg/g)** **CoQ10 2 (μg/g)**

> As shown in **Figure 2** the expression of CD 40 LG, IFN-G, and IL-6 was reduced (P < 0.001 and P < 0.05, respectively) in birds fed PE compared to the control fed chickens in accordance with other reports [18, 19]. There was a cereal X PE interaction for IL12B, showing that dietary PE reduced IL-12B expression in a wheat but not in a maize based diet (P < 0.05). Both, IL-6 and IFN-G, are major pro-inflammatory cytokines, so if the levels of these cytokines are decreased this would indicate that there are lower levels of inflammation than in the other groups, presumably due to plant extracts. Birds fed with diets supplemented with the same PE mixture also reduced the expression of CD40LG and IL-12B genes. The IFN-G cytokine belongs to the T helper (Th) type 1 response and is driven by IL-12 production. Th1 type response drives the cell mediated inflammatory responses largely to intracellular pathogens [54] but chronically

high levels of these cytokines in the intestine may have a damaging effect on the gut integrity, compromising nutrient absorption and overall gut health. The results of this study suggest that feeding PE may dampen chronic gut inflammation that may be partially attributed to the improved feed efficiency and dietary net energy.

**References**

DOI: 10.2527/jas.2007-0459

PNS2005449

03.007

10.3382/japr.2010-00168

2015;**2**:21. DOI: 10.3389/fvets.2015.00021

461-487. DOI: 10.1080/00071668.2010.506908

2011;**20**:115-120. DOI: 10.3382/japr.2010-00163

Experimental Biology. 1999;**37**:238-242

361-379. DOI: 10.1039/B005311M

[1] Windisch W, Schedle K, Plitzner C, Kroismayr A. Use of phytogenic products as feed additives for swine and poultry. Journal of Animal Science. 2008;**86**(14\_suppl):E140-E148.

Plant Extracts, Energy, and Immune Modulation in Broilers

http://dx.doi.org/10.5772/intechopen.77220

115

[2] Murugesan GR, Syed B, Haldar S, Pender C. Phytogenic feed additives as an alternative to antibiotic growth promoters in broiler chickens. Frontiers in Veterinary Science.

[3] Acamovic T, Brooker JD. Biochemistry of plant secondary metabolites and their effects in animals. Proceedings of the Nutrition Society. 2005;**64**(3):403-412. DOI: 10.1079/

[4] Dibner JJ, Richards JD. Antibiotic growth promoters in agriculture: History and mode of

[5] Applegate TJ, Klose V, Steiner T, Ganner A, Schatzmayr G. Probiotics and phytogenics for poultry: Myth or reality? Journal of Applied Poultry Research. 2010;**19**:194-210. DOI:

[6] Wallace RJ, Oleszek W, Franz C, Hahn I, Baser KHC, Mathe A, Teichmann K. Dietary plant bioactives for poultry health and productivity. British Poultry Science. 2010;**51**:

[7] Harborne JB. Twenty-five years of chemical ecology. Natural Product Reports. 2001;**18**:

[8] Mountzouris KC, Paraskevas V, Tsirtsikos P, Palamidi I, Steiner T, Schatzmayr G, Fegeros K. Assessment of phytogenic feed additive effect on broiler growth performance, nutrient digestibility and caecal microflora composition. Animal Feed Science

[9] Bravo D, Utterback P, Parsons CM. Evaluation of a mixture of carvacrol, cinnamaldehyde, and capsicum oleoresin for improving growth performance and metabolizable energy in broiler chicks fed corn and soybean meal. Journal of Applied Poultry Research.

[10] Juin H, Elgaard T, Chicoteau P.Effect of a citrus extract (NOR-SPICE AB) on broiler performances. British Poultry Science. 2003;**44**:810-811. DOI: 10.1080/00071668.2003.10871381 [11] Cross DE, McDevitt RM, Hillman K, Acamovic T. The effect of herbs and their associated essential oils on performance, dietary digestibility and gut microflora in chickens from 7 to 28 days of age. British Poultry Science. 2007;**48**:496-506. DOI: 10.1080/00071660701463221

[12] Brenes A, Roura E. Essential oils in poultry nutrition: Main effects and modes of action. Animal Feed Science and Technology. 2010;**158**(1-2):1-14. DOI: 10.1016/j.anifeedsci.2010.

[13] Dhuley JN. Anti-oxidant effects of cinnamon (Cinnamomum verum) bark and greater cardamom (Amomum subulatum) seeds in rats fed high fat diet. Indian Journal of

and Technology. 2010;**168**:223-231. DOI: 10.1016/j.anifeedsci.2011.03.020

action. Poultry Science. 2005;**84**:634-643. DOI: 10.1093/ps/84.4.634
