Livestock Research for Rural Development 21 (8) 2009 | Guide for preparation of papers | LRRD News | Citation of this paper |
An experiment was conducted at the University of Dschang poultry research farm to evaluate the effect of ginger and garlic essential oils on some blood parameters, growth performance and gut microbial population of broiler chickens. Forty two male and female day old chicks of Arbor acres line were arranged in a fractional factorial experiment of an unbalanced completely randomised design and allotted to three treatments given by stomach tube except for the control in three doses 0 (Control),10mg/kg/day, 20mg/kg/day,and 40mg/kg/day. All diets were iso-nitrogenous, containing 22% and 19% crude protein in the starter and the finisher periods, respectively. The trial lasted for seven weeks and there were no differences in feed intake, body weight gain and the feed conversion ratio among the birds.
All organ weights and carcass
characteristics were not affected by the treatments, except for a decrease (P<
0.05) in relative liver weight of birds on garlic oil treatment compared with
those given ginger oil and control. Similarly, a lower (P< 0.001) proportion of
the head weight of birds given essential oils was observed compared to the
control. Dosages effects showed a decrease in relative weight of organs only for
the head (P<0.001) and the gizzard
(P<0.05) compared to the control. Male broilers
deposited less (P<0.001) than the females.
There were no significant differences observed in the activities of the serum
transaminases (AST & ALT) and blood creatinine level, indicating that none of
the three dosages of essential oils given to birds was toxic. However,
Escherichia coli, and other Enterobacteria counts in the ileo-cæcal digesta
numerically decreased (P<0.05) compared to the control as the doses of essential
oils given increased. The same observation was made for the Salmonella
and Shigella species (P< 0.001).The colony forming units (CFU) of
Staphylococci spp were statistically similar between the two oil-treated
groups, but were significantly (P< 0.01) reduced compared with the control
group. Yeast and mold fungi were found in the ileo-cæcal digesta of all the
groups.
Key words: broiler chickens, essential oils, growth performance, microbial population
Un essai a été réalisé à la Ferme d’Application et de Recherche de l’Université de Dschang pour déterminer l’influence des huiles essentielles du gingembre et d’ail sur quelques parametres sanguins, performances de croissance et la flore intestinale des poulets de chair. Quarante deux poussins d’un jour de deux sexes de la souche Arbor acres étaient arrangés dans un schéma factoriel fractionnel du dispositif expérimental complètement aléatoire. Ils étaient soumis à trois traitements administrés chacun par gavage à l’exception du témoin en trois doses, (0) témoin ,10mg/kg/jour, 20mg/kg/jour et 40mg/ kg/jour. Tous les aliments distribués aux poulets étaient iso protéiniques avec 22 % et 19 % au démarrage et à la finition respectivement. L’essai a duré sept semaines.
L’analyse des resultats obtenus indique qu’il n’y a pas eu de différence significative pour l’ingéré alimentaire, le gain de poids corporel,et l’indice de consommation entre les différents groupes de poulets. A l’exception d’une baisse (P<0.05) de poids relatif du foie au poids vif des poulets soumis à l’huile essentielle d’ail par rapport à ceux sous traitement d’huile de gingembre et control, puis d’une faible (P<0.001) proportion de la tête de poulets sous traitement aux huiles essentielles par rapport au témoin,tous les organes et les caractéristiques de la carcasse n’étaient pas affectés par les traitements. Les doses d’huiles essentielles administrées ont réduit seulement la proportion de la tête (P<0.001) et du gésier (P<0.05) des poulets comparativement au lot témoin. Les poulets mâles ont déposé moins (P<0.05) de graisse que les femelles. Il n’y a pas eu de différence significative entre les traitements pour l’activité des transaminases sériques (AST & ALT) ainsi que pour la teneur en créatinine sanguine indiquant qu’aucune des trois doses d’huile administrées aux poulets était toxique. Toutefois, le nombre d’Escherichia coli, et d’autres entérobactéries dans le digesta iléo-cæcal diminuaient (P< 0.05) par rapport au control au fur et à mesure que les doses d’huiles essentielles administrées aux poulets augmentaient. La même observation était faite pour Salmonella et Shigella spp (P<0.001). Le nombre d’unités formant une colonie de Staphylococci spp était statistiquement semblable pour les deux groupes de poulets soumis aux huiles essentielles mais décroissait (P<0.01) comparativement au témoin. Les levures et moisissures étaient également présents dans le digesta iléo-cæcal de tous les groupes.
Mots clés: flore intestinale, huiles essentielles, performances de croissance, poulets de chair
The fast growing nature of broilers and their short generation interval has been associated over the years with the use of antibiotic growth promoters used at sub-therapeutic doses in animal feeds in order to improve the quality of the product, with a lower percentage of fat containing a relatively high concentration of polyunsaturated fatty acids and a higher protein content of the meat ( Kinsella et al 1990; Nettleton 1991). Other benefits of these compounds include control of zoonotic pathogens such as Salmonella,Campylobacter, Escherichia coli and Enterococci species in the gut (NOAH 2001).Although birds raised with these feed additives achieved good performance, their potential side effects became a real public health problem worldwide (Bager 1998; Donoghue 2003) and led to the ban of these products by the European Union in January 2006. This decision has therefore stimulated a search for alternatives. Essential oils have been proven to control pathogens due to their antimicrobial activity (Dorman and Deans 2000), to have antioxidative potential (Hui 1996) by delaying lipid oxidation in broiler meat, and to enhance digestion (Brugalli 2003) by stimulating the endogenous enzymes. It is in this respect that essential oils from garlic (Allium sativum) and ginger (Zingiber officinale) supplements were evaluated as natural alternatives to feed antibiotics in broiler diets. Thus, the objective of this study was to investigate the effects of different dosages of essential oils extracted from these two plants on some blood parameters, intestinal microflora population and growth performance of broiler chickens.
Forty two day old Arbor Acres chicks, with equal numbers of males and females were kept in a brooding house for 21 days under a decreasing room temperature regime, that was reduced from 32°C during the first week of life to 26°C at three weeks. The chicks were given an anti-stress agent from the first to the third day of age and before, during and after the vaccinations. In order to boost their immunity they were vaccinated against Newcastle disease and infectious bronchitis on the seventh and 25th days of age, while Gumboro vaccine was administered on the tenth day of the experiment. Birds received feed and water ad libitum every day. The experiment lasted for seven weeks during which feed intake, weekly weight gain and feed conversion ratio were monitored.
The entire flock was affected by coccidiosis from the fourth week of the experiment and was therefore subject to four (04) days of cure with Amprolium coupled with anti-stress administration from the 29th day.
The ingredient and calculated chemical composition of the basal diets are shown in Table1 for the starter and finisher growth periods respectively. The diets were formulated to meet the nutrient requirements of growing broilers.
Table 1. Ingredient and chemical composition of diets |
||
Ingredients |
Starter |
Finisher |
Local maize (7.6% CP) |
51.25 |
55.25 |
Wheat offal (14.12% CP) |
10.00 |
------ |
Wheat bran (11% CP) |
------ |
14.00 |
Soybean meal (48% CP) |
25.00 |
20.00 |
Fish meal (49% CP) |
3.00 |
------ |
Bone meal |
0.50 |
0.50 |
Prot/Vit/Min concentrtratek (10%) |
10.00 |
10.00 |
Sodium chloride (NaCl) |
0.25 |
0.25 |
Totals, kg |
100.00 |
100.00 |
Calculated nutrients content of diets |
||
Metabolizable Energy, Kcal/kg |
2861 |
2932 |
Crude protein, % |
22.8 |
19.3 |
Crude fibre, % |
3.10 |
3.77 |
Calcium, % |
1.17 |
0.97 |
Available Phosphorus, % |
0.46 |
0.42 |
Lysine, % |
1.32 |
1.05 |
Methionine, % |
0.46 |
0.39 |
ksupplied per kg diet concentrate (10%) content: Vit. A 3,000,000 IU; Vit. D3 600,000 IU; Vit.E 4,000 mg;Vit.K3 500 mg ;Vit.B1 200mg; Vit B2 1,000mg ;Vit.B3 2,400mg; Vit B6 400 mg;Vit B12 04 mg; Nicotinic acid 7,000mg; Folic acid 200 mg; Biotin 10 mg; Choline chloride 100,000 mg; Antioxidant 25,000 mg; Iron 8000mg;Copper 2,000mg; Manganese 14,000mg ; Cobalt 200 mg ; Zinc10,000 mg; Iodine 200 mg ; Selenium 20 mg ; Methionine 1.7% ; L-Lysine3%; Calcium 7 %; Available Phosphorus 1.8 %; Crude Protein 40% ; Metabolizable Energy 2100 kcal / kg. |
Ginger roots were harvested from the agricultural zone of Santchou in the Menoua division, in the West Province of Cameroon, while the garlic used came from the northern part of the country. The plant materials were ground in a mortar and pestle in order to liberate the tissues. The plant tissues were mixed with water and were then packed into the cooking unit of a Clevenger-type hydrodistillator. The essential oils collected were then dehydrated using sodium sulphate anhydride before storage at 4°C. Unlike ginger oil, the steam extraction (Oetting 2005) of garlic oil produces two fractions: a hydro-soluble whitish fraction and a hydrophobic yellowish fraction. Essential oils in the hydro-soluble fraction was partitioned with hexane using a separating funnel. The upper hexanic phase was then evaporated to dryness at 40°C under reduced pressure using a rotary evaporator. The dried hydro-soluble garlic oil obtained was mixed with its corresponding hydrophobic fraction and stored at +4°C until use. One kg of garlic yielded 1.9ml of oil weighing 2.0g (0.2%), while 1kg of ginger produced 2.0ml of essential oil weighing 1.7g (0.17%) after 6 hours of distillation.
The essential oils of Zingiber officinale and Allium sativum were subjected to gas chromatography–mass spectra (GC/MS) analysis on an argilent apparatus consisting of a model 6890N Network GC system/ 5975 InertXL mass selective detector at 70 eV and 20°C. The capillary column was a CP-Sil 8 CB LB with a 30 m long fused silica, an interior diameter of 0.25mm and a film thickness of 0.25 µm. The carrier gas was helium at a flow rate of 1.2ml/min.The oven temperature was programmed from 50 to 300°C with an initial increase of 10°C/ 1mn .One microlitre of each essential oil sample prepared in acetone (1% concentration) was injected into the apparatus. Identification of oil components was based on their retention indices, which were determined with references to a series of normal alkanes, and by comparison of their mass spectral fragmentation pattern with Nist 89 database and Wiley237 Library (Adams 2001).
Fecal samples collected from the ileo-cecum of the forty eviscerated birds on the farm were put into sterilised vials and conveyed immediately to the laboratory. Then 1g of digesta taken from each sample was added to 9 ml cooked meat broth and mixed for 1minute. A tenfold serial dilution was made by transferring 1ml from each mixture to the same broth volumes. Finally 1ml was pipetted from the 1/1000 dilution test tube of each sample and inoculated on the solid culture medium prepared in Petri dishes the previous day. Dispersion was done using a sterile spreader sterilised after each step over a bunsen flame.
Yeast and mold fungi were cultured on Sabouraud agar medium mixed with 250mg chloramphenicol in order to inhibit any bacterial growth and were incubated at room temperature up to two weeks for identification. Bacterial counts were performed using Salmonella/Shigella agar medium for Salmonella and Shigella species, MacConkey agar for Escherichia coli and other enterobacters, then Chapman Stone medium for Staphylococci spp respectively after aerobic incubation for 24 hours at room temperature.
Blood samples were collected from the jugular vein of birds stunned before slaughter using non-heparinized tubes and immediately subjected to centrifugation at 2000 revolutions per minute for 15 minutes to obtain blood serum. Alanine amino transferase and Aspartate amino transferase activities and creatinine level in samples of blood serum obtained were determined using commercial kits ( Biosystem Reagents and Instruments).
The gavages of essential oil to birds started from the fourth day right to the end of the experiment. The forty two chicks were given three treatments (control, ginger and garlic) having three dosages each (10ppm, 20ppm, 40ppm) except for the control and consisting of six ,eighteen and eighteen birds respectively. They were arranged in a fractional factorial experiment of an unbalanced completely randomised design. Each dosage consisted of three replicates with a male and a female chick per replicate in deep litter pens for the starter period and in battery cages during the finisher period. The daily dosages of essential oil given to birds by oral intubation in proportion to their mean weight gain are shown in Table 2.
Table 2. Daily dosages of essential oils (mg) given to birds orally in proportion to their mean weight gain on a weekly basis |
|||
Period |
Treatment |
Mean weight, g |
Dosage of EO given to birds orally, mg |
Week 1 |
Control |
65.0 |
Water |
T1D1 |
65.8 |
4.67 |
|
T1D2 |
64.2 |
9.10 |
|
T1D3 |
64.2 |
18.2 |
|
T2D1 |
64.2 |
1.30 |
|
T2D2 |
64.2 |
2.60 |
|
T2D3 |
65.8 |
5.30 |
|
Week 2 |
Control |
175 |
Water |
T1D1 |
167 |
11.8 |
|
T1D2 |
161 |
22.8 |
|
T1D3 |
178 |
50.4 |
|
T2D1 |
161 |
3.22 |
|
T2D2 |
167 |
6.71 |
|
T2D3 |
175 |
14.1 |
|
Week 3 |
Control |
487 |
Water |
T1D1 |
461 |
32.7 |
|
T1D2 |
450 |
63.9 |
|
T1D3 |
452 |
128 |
|
T2D1 |
425 |
8.56 |
|
T2D2 |
469 |
18.9 |
|
T2D3 |
483 |
38.9 |
|
Week 4 |
Control |
809 |
Water |
T1D1 |
743 |
52.8 |
|
T1D2 |
758 |
108 |
|
T1D3 |
772 |
219 |
|
T2D1 |
745 |
15.0 |
|
T2D2 |
783 |
31.6 |
|
T2D3 |
716 |
57.7 |
|
Week 5 |
Control |
1159 |
Water |
T1D1 |
1043 |
74.0 |
|
T1D2 |
1078 |
153 |
|
T1D3 |
956 |
271 |
|
T2D1 |
1068 |
21.5 |
|
T2D2 |
1032 |
41.6 |
|
T2D3 |
1142 |
92.0 |
|
Week 6 |
Control |
1727 |
Water |
T1D1 |
1563 |
111 |
|
T1D2 |
1561 |
222 |
|
T1D3 |
1539 |
437 |
|
T2D1 |
1578 |
31.8 |
|
T2D2 |
1462 |
58.9 |
|
T2D3 |
1650 |
133 |
|
Week 7 |
Control |
1921 |
Water |
T1D1 |
1764 |
125 |
|
T1D2 |
1848 |
262 |
|
T1D3 |
1815 |
515 |
|
T2D1 |
1830 |
36.8 |
|
T2D2 |
1896 |
76.4 |
|
T2D3 |
1852 |
149 |
|
T1: ginger essential oil treatment,, T2: garlic essential oil treatment D1: 10 ppm dosage of administration, D2 20 ppm dosage of administration D3: 40 ppm dosage of administration, g : gramme mg : milligramme, EO : essential oil |
The quantity of oil administered was calculated taking into account the proportion of the major oil components and the chicken live weights.
Significance of treatment effects and the interactions were assessed by the
General Linear Model (GLM) and Compare Means options
of Statistical Package for Social Sciences software (version 11.0) as described
by Steel and Torrie (1980) and differences in treatments means were
compared as per the standard method of Duncan (1955).
The results of gas chromatography coupled with mass spectrometry (GM/MS) analyses of the oils are summarised in Table 3 and 4.
Table 3. Chemical composition (%) of the essential oil of Allium sativum |
||
Retention Index |
Library/ ID |
Percent in oil |
888 |
1-propene |
0.7 |
888 |
1-propene, 3,3’-thiobis-sulfide |
1.4 |
919 |
methyl-trans-propenyl-disulfide |
1.1 |
1090 |
disulfide, di-2-propenyl |
37.2 |
1146 |
trisulfide, methyl 2-propenyl |
5.6 |
1243 |
2-vinyl-4h-1,3-dithiin |
0.9 |
1335 |
trisulfide, di-2-propenyl |
49.6 |
1780 |
diallyl tetrasulphide |
1.8 |
Table 4. Chemical composition (%) of the essential oil of Zingiber officinale |
||
Retention Index |
Library/ ID |
Percent in oil |
936 |
α-pinene |
4.1 |
954 |
camphene |
11.9 |
980 |
2-β-pinene |
0.3 |
984 |
6-methyl-5-hepten-2-one |
1.1 |
989 |
Β-myrcene |
1.7 |
1009 |
1-phellandrene |
0.6 |
1037 |
sabinene |
12.0 |
1038 |
1,8-cineole |
5.3 |
1091 |
α-terpinolene |
0.4 |
1095 |
2-nonanone |
0.6 |
1105 |
α-terpinolene |
1.7 |
1155 |
citronellal |
0.4 |
1178 |
endo-borneol |
1.9 |
1198 |
β-fenchyl alcohol |
0.8 |
1251 |
6-octen-1-ol, 3,7-dimethyl |
0.9 |
1277 |
z-citral |
8.2 |
1294 |
Geraniol |
2.6 |
1296 |
geranial |
10.0 |
1316 |
2-undecanone |
0.8 |
1370 |
citronellyl acetate |
0.3 |
1494 |
ar-curcumene |
2.5 |
1497 |
germacrene |
0.8 |
1509 |
zingiberene |
14.0 |
1515 |
farnesene |
4.4 |
1520 |
β-bisabolene |
2.6 |
536 |
β-sesquiphellandrene |
4.8 |
The main constituents identified in Allium sativum essential oil were trisulfide-di-2-propenyl, disulfide, di-2-propenyl and trisulfide-methyl-2-propenyl. In the ginger oil, 26 constituents were identified, with zingiberene, sabinene, camphene, geranial, z-citral and 1,8-cineole as major components.
These results agree with the findings of Suad Khamis et al (2004) in terms of the major constituents in garlic and ginger essential oils but are respectively higher and lower with regards to the highest percentage content of major components.
The overall growth performance of broilers during the experiment is shown in Table 5.
Table 5. Effect of ginger and garlic essential oils and dosage on the overall growth performance of broiler chickens |
||||||||
Parameters |
Mean values for treatment and dosage* |
Level of significance |
||||||
Control |
T1D1 |
T1D2 |
1D3 |
T2D1 |
T2D2 |
T2D3 |
||
Daily feed intake, g/bird |
105 |
104 |
102 |
103 |
102 |
104 |
104 |
ns |
Daily weight gain, g / bird |
42.9 |
38.7 |
41.3 |
40.9 |
40.5 |
40.5 |
41.3 |
ns |
Feed conversion ratio |
2.44 |
2.67 |
2.47 |
2.52 |
2.53 |
2.57 |
2.52 |
ns |
Mortality |
0.00 |
0.00 |
1.00 |
1.00 |
0.00 |
0.00 |
0.00 |
ns |
* Mean values in the same row without superscripts are not significantly different (ns). T1D1 = Ginger essential oil at 10ppm dosage; T1D2 = Ginger essential oil at 20ppm dosage T1D3 = Ginger essential oil at 40ppm dosage; T2D1 = Garlic essential oil at 10ppm dosage T2D2 = Garlic essential oil at 20ppm dosage; T2D3 = Garlic essential oil at 40ppm dosage |
There were no significant differences among treatments for daily feed intake (DFI), daily weight gain (DWG) and feed conversion ratio (FCR), or in the interaction between treatments and dosages, indicating that the two factors acted independently on the growth performance. Similarly, all offals and organs expressed as a proportion of body weight and the carcass characteristics of birds were not affected by treatment and dosage (Table 6).
Table 6: Mean values for effect of ginger and garlic essential oils and dosage on carcass characteristics, offals and organs expressed in % body weight |
|||||||||
Control |
T1D1 |
T1D2 |
T1D3 |
T2D1 |
T2D2 |
T2D3 |
SEM |
P |
|
Live weight |
1994 |
1808 |
1922 |
1906 |
1885 |
1886 |
1925 |
35.71 |
0.535 |
Plucked weight |
1780 |
1615 |
1740 |
1704 |
1708 |
1693 |
1722 |
32.16 |
0.736 |
Eviscerated weight |
1561 |
1385 |
1538 |
1481 |
1506 |
1484 |
1503 |
30.02 |
0.715 |
Carcass weight |
1413 |
1264 |
1392 |
1357 |
1381 |
1360 |
1374 |
27.18 |
0.489 |
Dressing % |
70.6 |
69.8 |
72.6 |
71.1 |
73.29 |
72.23 |
71.2 |
0.392 |
0.492 |
Heart weight |
0.46 |
0.45 |
0.5 |
0.47 |
0.43 |
0.39 |
0.4 |
0.012 |
0.517 |
Liver weight |
1.78 b |
1.56 a |
1.97 a |
1.87 a |
1.62 a |
1.55 a |
1.61 a |
0.061 |
0.039 |
Abdominal fat |
0.31 b |
0.31 a |
0.50 a |
0.47 a |
0.28 a |
0.18 a |
0.19 a |
0.063 |
0.01 |
Pancreas weight |
0.21 |
0.24 |
0.23 |
0.25 |
0.21 |
0.24 |
0.22 |
0.006 |
0.265 |
Gizzard weight |
1.71 |
1.67 |
1.78 |
1.75 |
1.64 |
1.74 |
1.81 |
0.035 |
0.439 |
Leg weight |
4.62 |
3.96 |
4.66 |
3.95 |
4.17 |
4.4 |
4.76 |
0.14 |
0.786 |
Head weight |
3.31 |
2.62 |
2.97 |
2.2 |
2.16 |
2.58 |
2.66 |
0.094 |
0.699 |
a-b Mean values within rows without superscripts are statistically similar |
These results agree with the findings of Jayalakshmi et al (2006), who studied the influence of sunflower acid oil usage on production performance, carcass traits and economics of broilers, and reported no significant differences in body weight gain, cumulative feed consumption, cumulative feed conversion ratio and liveability between treatment groups from the first week till the end of experiment. Similarly, Botsoglou et al (2002 ) observed that supplementation of broiler feed with oregano essential oil for thirty eight days had no growth-promoting effects. Treatments effects of essential oils were only significant for the relative heart and head weights of broilers (Table 7).
Table 7. Treatments effects of essential oils on the gut microbial population, on the activities of serum alanine amino transferase (ALT), serum aspartate amino transferase (AST), blood creatinine level, and on offals and organs expressed in % of body weight |
||||
Parameter |
Mean values of treatments ± Standard Error |
Levels of significance |
||
Control |
Ginziber officinale |
Allium sativum |
||
Staphylococci spp Salmonella and Shigella species E.coli and other enterobacters Serum creatinine level, mg/dl Serum ALT activity, U/L Serum AST activity, U/L Heart weight, g Head weight, g |
4.747 x10-3b ± 0.00 3.917 x10-3a ± 0.00 1.000 x10-2a ± 0.00 0.437a ± 0.11 9.87a ± 4.46 23.13a ± 13.12 0.458b ± 0.03 3.31b ± 0.23 |
2.611 x10-3a ± 0.00 6.597 x10-4b ± 0.00 8.902 x10-3a ± 0.00 0.334a± 0.07 12.70a ± 2.74 21.06a ± 8.07 0.473b ± 0.01 2.59a ± 0.14 |
2.426 x10-3a± 0.00 2.478 x10-4bc± 0.00 2.172 x10-3b ± 0.00 0.411a ± 0.06 9.72a ± 2.57 11.20a ± 7.57 0.413a ± 0.01 2.47a ± 0.13 |
p< 0.001 p< 0.05 p< 0.001 ns ns ns p< 0.05 p< 0.001 |
a-c Mean values in the same row with different superscripts are significantly different |
The results indicate a lower (P<0.05) relative heart weight of broiler chickens on the garlic essential oil treatments compared with those in the ginger oil treatment and control. Similarly, a decrease (P<0.001) in the proportion of the head was observed in birds given in the essential oils treatments compared with the control.
These findings agree with the reports of Tubtim and Wasiksiri (2007), who subjected male and female Sprague-Dawley rats to a 28-day repeated dose oral toxicity study with Litsea cubeba essential oil and obtained changes in relative liver and kidney weights in certain treated groups compared with the control.
Dosage effects also exclusively affected the head weights (Table 8).
Table 8. Dosages effects of essential oils on the microflora enumeration,on the activities of serum alanine amino transferase (ALT), serum aspartate amino transferase (AST),blood creatinine level, on offals expressed as % of body weight |
|||||
Parameters |
Mean values of dosages ± Standard Error |
Level of significance |
|||
Control |
10ppm |
20ppm |
40ppm |
||
Staphylococci spp Salmonella and Shigella species E.coli and other enterobacters Serum creatinine level, mg/dl Serum ALT activity, U/ L Serum AST activity, U/ L Head weight, g |
4.75 x10-3d ± 0.00 3.92 x10-3b ± 0.00 1.00 x10-2 b±0.00 0.44a ± 0.11 9.87a ± 4.32 23.1a ± 13.04 3.31b ± 0.23 |
3.62 x10-3c± 0.00 6.17 x10-4a± 0.00 5.24 x10-a±0.001 0.28a ± 0.08 12.23a ±3.05 23.1a ± 13.04 2.39a ± 0.16 |
2.58 x10-3b± 0.00 4.18 x10-4a± 0.00 5.49 x10-3a±0.00 0.53a ± 0.08 8.73a ± 3.24 24.6a ± 9.78 2.77a ± 0.17 |
1.254 x10-3a ± 0.00 2.933 x10-4a ± 0.00 5.640 x10-3a ± 0.00 0.31a ± 0.08 12.08a ± 3.24
11.31a ± 9.7 |
p< 0.001 p< 0.001 p< 0.001 ns ns ns p< 0.001 |
a-d Mean values within a row with no common superscripts differ significantly |
The relative head weights of birds given different dosages of essential oils were statistically similar but significantly (P<0.001) lower compared to the controls. These results are consistent with those observed by Barreto et al (2008), who assessed the efficacy of different plant extracts as alternatives to antimicrobial growth promoters in broiler diets and reported no effects of experimental treatments on organs morphometrics, except for a lower liver relative weight (P<0.05) of birds fed the diet containing red pepper extract, which showed the lowest change in relative liver weight compared to those on the control diet.
The sex effects of essential oils on the parameters studied are shown in Table 9.
Table 9. Sex effects of essential oils on gut microbial counts, on the activities of serum alanine amino transferase (ALT), serum aspartate amino transferase (AST), blood creatinine level, and on carcass characteristics, offals and organs expressed in % of body weight |
|||
Parameters |
Male |
Female |
Level of Significance |
Live weight |
2024 ± 48.6 |
1802 ± 43.3 |
p< 0.01 |
Plucked weight |
1816 ± 43.0 |
1616 ± 38.3 |
p < 0.01 |
Eviscerated weight |
1605 ± 38.2 |
1396 ± 34.0 |
p < 0.001 |
Carcass weight |
1451 ± 36.6 |
1284 ± 32.6 |
p < 0.01 |
Dressing percentage |
71.7 ± 0.56 |
71.21 ± 0.50 |
ns |
Heart weight |
0.44 ± 0.17 |
0.44 ± 0.16 |
ns |
Liver weight |
1.68 ± 0.94 |
1.74 ± 0.88 |
ns |
Pancreas |
0.22 ± 0.01 |
0.24 ± .008 |
ns |
Gizzard weight |
1.74 ± 0.52 |
1.72 ± 0.49 |
ns |
Abdominal fat |
9.42 x 10-2 ± 0.08 |
0.54 ± 0.77 |
p < 0.001 |
Head weight |
2.63 ±0.13 |
2.65 ± 0.12 |
ns |
Legs weight |
4.84 ± 0.17 |
3.88 ± 0.16 |
p < 0.001 |
Staphylococci count |
2.44 x 10-3 ± 0.00 |
3.18 x 10-3 ± 0.00 |
p < 0.05 |
Salmonella and Shigella species |
1.01 x 10-3 ± 0.00 |
8.66 x 10-4 ± 0.00 |
p < 0.05 |
Escherichia coli and other Enterobacters |
5.83 x 10-3 ± 0.00 |
6.38 x 10-3 ± 0.00 |
ns |
Blood creatinin level |
0.43 ± 0.06 |
0.33 ± 0.06 |
ns |
AST activity |
11.89 ± 7.67 |
19.75 ± 6.83 |
ns |
ALT activity |
9.00 ± 2.55 |
12.22 ± 2.27 |
ns |
Enzymes activities in the serum, creatinine level in the blood and microflora enumeration
The details of treatments and dosages effects of essential oils on enzymes activities in the serum, creatinine level and on the gut microbial load are shown in Tables 7 and 8. The effect of essential oil treatments on the aspartate amino transferase activitiy, alanine amino transferase activity, and creatinine level in the blood did not differ from the control. Similarly, Tubtim and Wasiksiri (2007) administered different doses of Litsea cubeba essential oil to male and female Sprague-Dawley rats by stomach tube for twenty eight days and obtained no significant difference from the control group for these same blood parameters.
There was a significant decrease (P<0.001) in the number of colony forming units (CFU) of Escherichia coli and other enterobacteria in digesta of ileo-cecum, compared with the control as the dosage of essential oils used increased. The same observation was made for the Salmonella and Shigella species (P<0.05).The counts of Staphylococci spp did not differ between the oil treated groups of birds but were significantly (P<0.001) reduced as compared to the control. These findings agree with the reports of Jang et al (2007), who obtained a significant decrease (P<0.05) in the number of Escherichia coli in ileo-cecal digesta of birds fed diets containing antibiotics when compared to those on a control treatment after feeding ROSS 308 broilers for five weeks with a basal diet and diets supplemented with a blend of commercial essential oils or antibiotics.
Similarly, Hinton and Linton (1988), Izat et al (1990), Oliveira (1996) and Byrd et al (2001) demonstrated that the addition of lactic acid, formic acid and propionic acid to diets and drinking water efficiently controlled Salmonella and Shigella species, Escherichia coli and other Enterobacteria in poultry. Yeast and mold fungi were also found in the ileo-cecal digesta of all the groups.
Female birds put on more (P<0.001) abdominal fat and had more zoonotic pathogens in their gut than the males (Pym and Solvyns 1979; Broadbent et al 1981; Ross Breeders 1996; Rondelli et al 2003). However, the carcasses and the legs of male broilers weighed more than those of females. There were no significant differences in the activities of blood parameters and organs such as the gizzard, pancreas, liver and the heart between male and female birds.
These results agree with the reports of Souza et al (1995), who evaluated the carcass traits of four commercial broiler lines, Arbor Acres, Hubbard, Cobb and Ross, under the same nutritional management and found higher leg and thigh yield in Hubbard males and higher breast yield in the Ross line.
The forty five consecutive days of ginger and garlic oils administration to broilers in this experiment did not exert any growth-promoting effects.
The treatment effects of these essential oils had a positive impact on the gut microflora as they reduced their loads as compared to the control, contributing to some extent to health maintenance.
However, the essential oil-treated groups could not draw much growth benefits from the decrease in counts of zoonotic pathogens present in their intestine, because unlike rabbits and ruminants, they have very little nutritional advantage from this situation.
Adams R P 2001 Identification of essential oil components by Gas Chromatography/Mass Spectrometry. Allured Publishing, Carol Stream, IL.
Bager F 1998 Consumption of antimicrobial agents and occurrence of antimicrobial resistance in bacteria from food animals, food and humans in Denmark, Dansk,Copenhagen, Zoonocenter, Denmark.
Barreto M S R, Menten J F M, Racanicci A M C, Pereira P W Z and Rizzo P V 2008 Plant extracts used as growth promoters in broilers. Revista Brasileira de Ciência Avicola. Volume 10 No.2 Campinas http://www.scielo.br/scielo.php?pid=S1516-635X2008000200006&script=sci_arttext
Botsoglou N A, Florou-Paneri P, Christaki E, Fletouris D J and Spais A B 2002 Effect of dietary oregano essential oil on performance of chickens and on iron-induced lipidoxidation of breast, thigh and abdominal fat tissues. British Poultry Science 43[2]: 223-230
Broadbent L A, Wilson B J and Fischer C 1981 The composition of the broiler chickens at 56days of age: output, components and chemical composition. British Poultry Science 22:385-390.
Brugalli I 2003 Alimentação alternativa: a utilização de fitoterápicos ou nutracêuticos como moduladores da imunidade e desempenho animal. Anais do Simposio sobre Manejo e Nutrição de Aves e Suínos; Campinas, São Paulo. Brasil. Campinas: CBNA;pp.167-182.
Byrd J A, Hargis B M, Caldwell D J, Bailey R H, Herron K L, McReynolds J L, Brewer R L, Anderson R C, Bischoff K M, Callaway T R and Kubena L F 2001 Effect of lactic acid administration in the drinking water during preslaughter feed withdrawal on Salmonella and Campylobacter. Poultry Science 80:278-283
Donoghue D J 2003 Antibiotic residues in poultry tissues and eggs: Human health concerns? Poultry Science 82 [4]: 618-621
Dorman H J D and Deans S G 2000 Antimicrobial agents from plants: antibacterial activity of plant volatile oils. Journal of Applied Microbiology 88: 308-316
Duncan D B 1955 Multiple range and F-test. Biometrics 11:1-42
Hinton R H and Linton A H 1988 Control of Salmonella infections in broilers chickens by the acid treatment of their feed. Veterinary Record 123: 416-421
Hui Y H 1996 Oleoresins and essential oils. In: Hui YH, editor. Bailey's industrial oil and fat products. New York: Wiley-Interscience Publication ;cap.6, p.145-153.
Izat A L,Tidwell N M, Thomas R A, Reiber M A, Adams M H, Colberg M and Waldroup P W 1990 Effects of a buffered propionic acid in diets on the performance of broiler chickens and on the microflora of the intestine and carcass. Poultry Science 69: 818-826
Jang I S, Ko Y H, Kang S Y and Lee C Y 2007 Effect of a commercial essential oil on growth performance, digestive enzyme activity and intestinal microflora population in broiler chickens. Animal Feed Science and Technology 134: 304-315
Jayalakshmi N S, Mathivanan R, Amutha R, Edwin S C and Viswanathan K 2006 Production performance and carcass traits of broilers fed with sunflower acid oil. International Journal of Poultry Science 5 [9]: 890-894
Kinsella J E, Lokesh B and Stone R A 1990 Dietary n-3 polyunsaturated fatty acids and amelioration of cardiovascular disease: possible mechanism. American Journal of clinical Nutrition 52:1-28
NOAH (National Office of Animal Health) 2001 Antibiotics for animals. http://www.noah.co.uk/issues/antibiotics.htm Last accessed 28 October 2001.
Nettleton J A 1991 n-3 Fatty acids composition of plant and seafood sources in human nutrition. Journal of American Dietetic Association 91: 331-337
Oetting L L 2005 Extratos vegetais como promotores do crescimento de leitões recém-desmamados [tese]. Piracicaba (SP): Escola Superior de Agricultura "Luiz de Queiroz"
Oliveira E O 1996 Uso de acidos graxos de cadeia no controle de Salmonella emragoes de aves.Piracicaba.USP/ESALQ,p.72 ( Dissertagao-Mestrado)
Pym R A E and Solvyns A J 1979 Selection for food conversion in broilers: body composition of birds selected for increased body-weight gain, food consumption and food conversion ratio. British Poultry Science 20: 87-97
Rondelli S, Martinez O and Garcia P T 2003 Sex effect on productive parameters, carcass and body fat composition of two commercial broilers lines. Revista Brasileira de Ciência Avicola. Volume 5 No.3 Campinas
Ross Breeders (RB) 1996 Producing quality broiler meat. Ross broiler management manual. Ross Breeders Limited , Midlothian, United Kingdom.
Souza P A, Sousa H B A,Campo E F and Brognoni E 1995 Desempeño y características de carcasa de diferentes líneas comerciales de pollos parrilleros. XIV Congreso Latinoamericano de Avicultura. Chile. p.108-118
Steel R G D and Torrie J H 1980 Principles and Procedures of Statistics. A Biometric Approach. Mc Grow Hill book Co.Inc, New York,USA, 2nd edition.
Suad Khamis S Al-Burtamani, Majekodunmi O Fatope, Ruchi G Marwah, Anthony K Onifade and Salim H Al-Saidi 2004 Chemical composition, antimicrobial and antifungal activities of the essential oil of Haplophyllum tuberculatum from Oman. Journal of ethnopharmacology 96: 107-112
Tubtim S and Wasiksiri A 2007 28-day
repeated dose oral toxicity study of Litsea
cubeba essential oil in
Sprague-Dawley rats. Thailand Journal of Pharmacological Science 31:
74-82
Received 15 April 2009; Accepted 5 May 2009; Published 5 August 2009