Effect on growth, feed intake and weight gain in broilers

AL-Kassie et al. (Reference AL-KASSIE, MOHSEEN and ABD-AL-JALEEL2011) reported that the inclusion of Turmeric mixture at levels of 0.75% and 1% in the diets improved body weight gain, feed intake and feed conversion ratio (FCR). However, Gowda et al. (Reference GOWDA, DAVID LEDOUX, GOERGE, BERMUDEZ and CHEN2009) found that feeding Turmeric (444 ppm) in the basal diet significantly decreased feed intake in broiler chicks. AL-Sultan (Reference AL-SULTAN2003) fed Turmeric to broiler chicks at the rate of 0.5 and 1.0% and observed that its addition increased body weight and feed conversion ratio (FCR). Durrani et al. (Reference DURRANI, ISMAIL, SULTAN, SUHAIL, CHAND and DURRANI2006) found that broilers fed Turmeric at the level of 0.5% exhibited significantly improved weight gain and FCR, while feed intake decreased significantly in this group compared to control. Similarly dressing percentage, breast weight and thigh weight increased in the group fed 0.5% Turmeric powder. Ahmadi (Reference Ahmadi2010) reported that FCR of broiler chickens was better when feed was supplemented with 0.9% Turmeric powder. Gowda et al. (Reference GOWDA, DAVID LEDOUX, GOERGE, BERMUDEZ and CHEN2009) found that feeding Turmeric (444 ppm) in the basal diet significantly improved weight gain in broiler chicks. Gowda et al. (Reference GOWDA, LEDOUX, ROTTINGHAUS, BERMUDEZ and CHEN2008) concluded that addition of Turmeric at the rate of 0.5% in the feed significantly improved weight gain of aflatoxin affected chicks. Yarru et al. (Reference YARRU, SETTIVARI, GOWDA, ANTONIOU, LEDOUX and ROTTINGHAUS2009) observed that weight gain in aflatoxin-exposed chicks was improved when chicks were treated with 0.5% Turmeric in the diet. Lee et al. (Reference LEE, LILLEHOJ, JANG, KIM, IONESCU and BRAVO2010) reported that broilers diet supplemented with C. longa improved weight gain, which was depressed by infection with E. acervulina when compared to a standard diet. Kumari et al. (Reference KUMARI, GUPTA, RANJAN, SINGH and YADAVA2001) observed that addition of C. longa as feed additive resulted in better growth, feed consumption and FCR in broilers. Allen et al. (Reference ALLEN, DANFORTH and AUGUSTINE1998) reported that weight gain of broilers improved in response to the addition of 1% dietary Turmeric during Emeria maxima infection. Curcumin in the diet increased the activities of pancreatic lipase, amylase, trypsin and chymotrypsin. Dietary feeding of essential oils extracted from herbs can improve the secretion of digestive enzymes and so improve the digestibility of the feeds and enhance the performance of broilers (Al-Kassie et al., Reference AL-KASSIE, MOHSEEN and ABD-AL-JALEEL2011). According to Radwan et al. (Reference RADWAN, HASSAN, QOTA and FAYEK2008) this improvement could be attributed to its contents of essential oils that have active components which possess antimicrobial, antifungal and antioxidant activities; and accordingly may improve the bird utilisation of dietary nutrients. Some other researchers have attributed the higher weight gain to the antioxidant effect of this plant (Osawa et al., Reference OSAWA, SUGIYAMA, INAYOSHI and KAWAKISI1995; AL-Sultan, Reference AL-SULTAN2003).

On the other hand, some authors have not found any beneficial effects of adding Turmeric to the feed of poultry birds. For example, El-hakim et al. (Reference EL-HAKIM, CHERIAN and ALI2009) found no effect of supplementation of 0.2% Turmeric in the feed on feed intake, weight gain or FCR. Emadi and Kermanshahi (Reference EMADI and KERMANSHAHI2007) reported that supplementation of Turmeric has no significant effect on feed intake, weight gain and feed conversion ratio of broiler chicks. This may be a dose-dependent issue.

Laying hen egg production and quality

Riasi et al. (Reference RIASI, KERMANSHAHI and FATHI2008) reported that the use of Turmeric in the diet of layers up to 2 g/kg had no adverse effect on egg quality. Radwan et al. (Reference RADWAN, HASSAN, QOTA and FAYEK2008) reported that egg production, weight and mass increased significantly in laying hens fed Turmeric at the level of 0.5% in the basal diet, while yolk weight and yolk index were significantly higher in the group fed with 1.0% Turmeric in the feed. Sawale et al. (Reference SAWALE, GOSH, RAVIKANTH, MAINI and REKHE2009) recorded increased egg production in laying hens treated with a herb-derived mineral toxin binder production containing Curcuma longa. Radwan et al. (Reference RADWAN, HASSAN, QOTA and FAYEK2008) suggested that Curcuma longa may improve the environment in the uterus (specifically the site of calcium deposition) and consequently increase shell weight and thickness. Moorthy et al. (Reference MOORTHY, SARAVAN, MEHALA, RAVIKUMAR and EDWIN2009) found no significant effect of feeding 0.1% Curcuma longa on hen house egg production and percent hen day egg production of Single Comb White Leghorn layers. Riasi et al. (Reference RIASI, KERMANSHAHI and FATHI2008) reported that feeding different levels (0.0, 0.5, 1.0, 1.5 and 2.0 g/kg of feed) of Turmeric to the laying hens had no significant effect on specific gravity, egg shell thickness, egg shell weight and eggs shell weight to egg weight ratio.

Turmeric and hepatotoxicity

Primary hepatic detoxification processes include xenobiotic biotransformation (phase I metabolism) and the subsequent conjugation of the resulting metabolites (phase II metabolism), making them more water-soluble and available for excretion from the body. The microsomal cytochrome P450 (CYP)-dependent mono-oxygenase system in the liver plays an essential role in phase I metabolism (Akahori et al., Reference AKAHORI, TAKATORI, KAWAMURA, ITAGAKI and YOSHIKAWA2005). The CYP enzymes are associated with several biological interactions involving hydroxylation, epoxidation, oxygenation, dehydrogenation, nitrogen dealkylation, and oxidative deamination (Hari Kumar and Kuttan, Reference HARI KUMAR and KUTTAN2006). Yarru et al. (Reference YARRU, SETTIVARI, GOWDA, ANTONIOU, LEDOUX and ROTTINGHAUS2009) reported that Turmeric (0.5%) in the basal diet reduced the expression of hepatic genes CYP1A1 and CYP2H1 in broilers.

Soni et al. (Reference SONI, LAHIRI, CHACKRADEO, BHIDE and KUTTAN1997) reported the protective effect of Curcuma longa in aflatoxin-induced mutagenicity and hepatocarcinogenicity. Emadi and Kermanshahi (Reference EMADI and KERMANSHAHI2007) reported that concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP), the higher level of which is related to liver toxicity, decreased significantly when broilers diet was supplemented with Turmeric ranging from 0.25-0.75%. Essential oils present in Turmeric are known to increase bile flow and bile secretion which may have beneficial effect on liver health (Emadi and Kermanshahi, Reference EMADI and KERMANSHAHI2007; Ahmadi, Reference Ahmadi2010). Ahmadi (Reference Ahmadi2010) stated that curcumin, the major pigment in Turmeric, is known to protect the liver from damage. The carbonyl functional group of curcuminoids from Turmeric was shown to be responsible for its antimutagenic and anticarcinogenic action (Chun et al., Reference CHUN, SOHN and KIM1999). Gowda et al. (Reference GOWDA, DAVID LEDOUX, GOERGE, BERMUDEZ and CHEN2009) found that feeding Turmeric (444 ppm) in the basal diet significantly decreased AST in broiler chicks. Gowda et al. (Reference GOWDA, LEDOUX, ROTTINGHAUS, BERMUDEZ and CHEN2008) reported that addition of Turmeric in the broilers diet deceased necropsy lesion caused by aflatoxicosis. The basis of hepatoprotective action was suggested to be the antioxidant action of curcumin (Ali et al., Reference ALI, MARRIF, NOURELDAYEM, BAKHEIT and BLUNDEN2006).

Antioxidant effects

Free radicals induce oxidative damage to macromolecules, cells and tissues that consequently leads to increased morbidity and mortality rates, with substantial economical losses (St-Pierre et al., Reference ST-PIERRE, COBANOV and SCHNITKEY2003). Earlier reports suggested that Turmeric neutralises superoxide radicals (Iqbal et al., Reference IQBAL, SHARMA, OKAZAKI, FUJISAWA and OKADA2003). Ahmadi (Reference Ahmadi2010) reported that catalase (CAT) and superoxide dismutase (SOD) concentration increased significantly when basal feed of broilers chicks was supplemented with 0.3 and 0.6 g/kg Turmeric powder. In the same experiment, the concentration of melanodealdehyde (MDA), an indicator of oxidative stress, decreased significantly when Turmeric was added into the feed at the rate of 0.3 g/kg. Gowda et al. (Reference GOWDA, LEDOUX, ROTTINGHAUS, BERMUDEZ and CHEN2008) reported that total antioxidant activity and SOD concentrations improved by addition of 0.5% Turmeric. In another experiment, Gowda et al. (Reference GOWDA, DAVID LEDOUX, GOERGE, BERMUDEZ and CHEN2009) found that feeding Turmeric (444 ppm) in the basal diet significantly improved total antioxidant status and CAT concentration in broiler chicks.

Several studies have shown that curcumin has a strong capability for scavenging superoxide radicals, hydrogen peroxide and nitric oxide (NO) from activated macrophages, reducing iron complex and inhibiting lipid peroxidation (Ali et al., Reference ALI, MARRIF, NOURELDAYEM, BAKHEIT and BLUNDEN2006; Gowda et al., Reference GOWDA, DAVID LEDOUX, GOERGE, BERMUDEZ and CHEN2009; Yarru et al., Reference YARRU, SETTIVARI, GOWDA, ANTONIOU, LEDOUX and ROTTINGHAUS2009). Curcumin is known to augment antioxidant status especially through SOD which could be due to the increased expression of SOD gene in the chickens fed Turmeric (Cheng et al., Reference CHENG, LIU and AI2005). Antioxidant enzymes, such as CAT within the peroxisomes and cytosolic GPx, are involved in the conversion of hydrogen peroxide, a powerful and potentially harmful oxidizing agent, into water and molecular oxygen (Liska, Reference LISKA1998). Yarru et al. (Reference YARRU, SETTIVARI, GOWDA, ANTONIOU, LEDOUX and ROTTINGHAUS2009) observed that Turmeric in the diet increased the expression of hepatic SOD and glutathione peroxidase (GPx). Curcumin has a unique conjugated structure including two methoxylated phenols and an enol form of ß-diketone and the structure shows a typical radical trapping activity as a chain-breaking antioxidant. Masuda et al. (Reference MASUDA, MAEKAWA, HIDAKA, BANDO, TAKEDA and YAMAGUCHI2001) proposed that antioxidant effect of curcumin is associated with its polyunsaturated lipids, which consisted of an oxidative coupling reaction at the 3-position of the curcumin with the lipid and a subsequent intra-molecular Diels-Alder reaction. Reddy and Lokesh (Reference REDDY and LOKESH1994) suggested that dietary Turmeric lowers lipid peroxidation by enhancing the activities of antioxidant enzymes (SOD, CAT, and GPx). Miquel et al. (Reference MIQUEL, RAMIREZ-BOSCA, RAMIREZ-BOSCA and ALPERI2006) reported that curcuma longa may help to prevent antioxidant deficiency with resulting protection of mitochondria against premature oxidative damage with loss of ATP synthesis and specialized cellular functions. The other beneficial components of Turmeric are tetrahydro curcumin, niacin, curlone and cinamic acid, but are in low concentration and contribute very little to the overall antioxidant activity (Ahmadi, Reference Ahmadi2010).

Anti-coccidial effects

Avian coccidiosis is an intestinal disease caused by several species of Eimeria protozoa and represents an economically important parasitic infection for the poultry industry worldwide (Lee et al., Reference LEE, LILLEHOJ, JANG, KIM, IONESCU and BRAVO2010). Coccidiosis is one of the most detrimental and lethal management diseases of poultry. It causes high mortality in affected flocks. Abbas et al. (Reference ABBAS, IQBAL, KHAN, ZAFAR and ZIA2010) found maximum coccidiostatic effect with Turmeric added at 3% levels in the diet as compared to other infected groups receiving Turmeric containing rations, which were comparable with using a standard coccidiostat i.e., salinomycin sodium. In the same study, the peak excretion of oocysts was delayed about 1 or 2 days relative to the control infected group. Lee et al. (Reference LEE, LILLEHOJ, JANG, KIM, IONESCU and BRAVO2010) reported that faecal oocyst shedding from birds experimentally infected with E. acervulina was significantly decreased when broiler chickens were fed with a diet containing C. longa. Khalafalla et al. (Reference KHALAFALLA, MÜLLER, SHAHIDUZZAMAN, DYACHENKO, DESOUKY, ALBER and DAUGSCHIES2011) reported that curcumin at concentrations of 25, 50, 100, 200 and 400 μM showed considerable effects on Emeria tenella sporozoite morphology and viability in a dose-dependent manner after incubation over 3, 6, 18 and 24 hours. In the same experiment, in comparison to the untreated control, sporozoite infectivity was reduced at curcumin concentrations of 100 and 200 μM by 41.6% and 72.8%, respectively. Allen et al. (Reference ALLEN, DANFORTH and AUGUSTINE1998) reported that mid-small intestinal lesion scores induced by Emeria maxima were reduced in broilers fed with 1% dietary Turmeric during infection. Khalafalla et al. (Reference KHALAFALLA, MÜLLER, SHAHIDUZZAMAN, DYACHENKO, DESOUKY, ALBER and DAUGSCHIES2011) suggested that the ability of curcumin (diferuloylmethane) to kill extra cellular stages of E. tenella could be due to its cytotoxic damage affecting parasite viability, morphology and hence activity. Allen et al. (Reference ALLEN, DANFORTH and AUGUSTINE1998) proposed the anticoccidial activity of Turmeric is due to its antioxidant properties.

Immunomodulatory effect

Al-Sultan (Reference AL-SULTAN2003) reported that the higher levels of Turmeric inclusion (0.5 and 1.0%) increased both erythrocytic and total leukocytic count in broilers, which may be due to curcumin, an active compound in Curcuma longa (Antony et al., Reference ANTONY, KUTTAN and KUTTAN1999). Kumari et al. (Reference KUMARI, GUPTA, RANJAN, SINGH and YADAVA2001) recorded significant high antibody titres in broiler chicks fed with C. longa at the level of 1g/kg. Kurkure et al. (Reference KURKURE, PASWAR, KONGOLE, GANORKAR, BHANDARKAR and KALOREY2001) reported that Turmeric restored the reduced humoral response caused by aflatoxin induced immuno-suppression, suggesting humoral immune-stimulatory potential. Sawale et al. (Reference SAWALE, GOSH, RAVIKANTH, MAINI and REKHE2009) recorded increased haemagglutination titre in laying hens treated with herbomineral toxin binder containing C. longa. Serum antibody titre was significantly higher in Turmeric fed broilers challenged with EtMIC2, an apical complex protein which plays an important role in host cell invasion of Eimeria parasites (Lee et al., Reference LEE, LILLEHOJ, JANG, KIM, IONESCU and BRAVO2010). Interleukins are a group of cytokines that are important components of the immune system. They play a physiological role in inflammation and a pathological role in systemic inflammatory states and are now well recognized (Tayal and Kalra, Reference TAYAL and KALRA2007). Yarru et al. (Reference YARRU, SETTIVARI, GOWDA, ANTONIOU, LEDOUX and ROTTINGHAUS2009) reported that Turmeric (0.5%) resulted in increased expression of IL-2 and IL-6 expression. Lee et al. (Reference LEE, LILLEHOJ, JANG, KIM, IONESCU and BRAVO2010) reported that the level of transcripts encoding the pro-inflammatory cytokine IL-1β in the intestinal duodenum was significantly increased in uninfected chickens fed with Turmeric at day post-hatch compared with the control group. In the same study, the level of transcript encoding IL-6, IL-15 and IFN-γ were also increased.

It has been shown that curcumin can modulate the immune system. Mucosal CD4 (+) T and B cells increases in animals treated with curcumin, suggesting that it modulates lymphocyte-mediated immune functions (Churchill et al., Reference CHURCHILL, CHADBURN, BILINSKI and BERTAGONLLI2000).

Toxicological effects

Turmeric is considered to have low toxicity as revealed in human and animals trials (Ali et al., Reference ALI, MARRIF, NOURELDAYEM, BAKHEIT and BLUNDEN2006). There are no reports of adverse effects of either Turmeric or its analogue, except in rare cases. It is estimated that adults in India ingest 80-200 mg of cucumin daily. Administration of high doses of Turmeric for variable periods has been found to induce hepatotoxic effects in mice and rats (Deshpande et al., Reference DESHPANDE, LALITHA, INGLE, RASTE, GARDE and MARU1998; Kandarkar et al., Reference KANDARKAR, SHARDA, INGLE, DESHPANDE and MARU1998). In broiler chicks, Al-Sultan and Gameel (Reference AL-SULTAN and GAMEEL2004) reported that the use of Turmeric (2.5, 5.0 and 10.0%) caused parenchymal and portal infiltration of mononuclear cells and hyperaemia of portal vessels. No other studies on toxicological effects in birds can be found in the current literature.