Research Article

 

Effects of different dietary oil sources and levels on growth performance and serum metabolites in broiler chickens

 

Amr Abd El-Wahab1*, Abeer Aziza1

1Department of Nutrition and Nutritional Deficiency Diseases, Faculty of Veterinary Medicine, Mansoura

University, 35516 Mansoura, Egypt.

 

Editor | Kuldeep Dhama, Indian Veterinary Research Institute, Uttar Pradesh, India.

Received | January 15, 2017; Accepted | March 09, 2017; Published | March 18, 2017

*Correspondence | Amr Abd El-Wahab, Department of Nutrition and Nutritional Deficiency Diseases, Faculty of Veterinary Medicine, Mansoura University, 35516 Mansoura, Egypt; Email: [email protected]

Citation | Abd El-Wahab A, Aziza A (2017). Effects of different dietary oil sources and levels on growth performance and serum metabolites in broiler chickens. Adv. Anim. Vet. Sci. 5(3): 127-132.

DOI | http://dx.doi.org/10.14737/journal.aavs/2017/5.3.127.132

ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331

Copyright © 2017 Abd El-Wahab and Aziza. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

INTRODUCTION

 

Supplementation of dietary fat improves broilers performance regarding feed intake and weight gain (López-Ferrer et al., 2001; Rodríguez et al., 2005). The addition of oil to diet is necessary due to broilers have a high growth rate and a high energy demand (Furlan and Macari, 2002). Moreover, supplementation of dietary fat to poultry diets increases the absorption of fat-soluble vitamins as well as the palatability of the rations (Jeffre et al., 2010). It is well known that polyunsaturated fatty acids (PUFA) in oils are absorbed more easily than those containing saturated fatty acids, and thus PUFA have higher energy content resulted in improve broiler performance (Dvorin et al., 1998; Junqueira et al., 2005). Fatty acids (FA) are necessary components of energy metabolism, cell membrane formation, and signaling processes (Jump et al., 2008). Moreover, the FA that could not be synthesized by the animals and are added to the diets are called essential FA. Evidence shows that feeding very low levels of essential FA in the diet of poultry results in poor reproduction, lowers immunity, rough dry skin and slows growth (Deborah, 1997).

 

The n-3 FA are a group of PUFA that include α-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). It has been stated that n-3 FA reduce risks and prevalence of some chronic diseases such as diabetes, cardiovascular disease, arthritis and cancer (Delgado-Lista et al., 2012). Marine oil is considered the major source of n-3 long chain PUFA in comparison to other types of oil (Hargis and Van Elswyk, 1993). Furthermore, omega-3 FA have anti-inflammatory or less inflammatory properties by decreasing the release of pro-inflammatory eicosanoids and cytokines (Stulnig, 2003). It is well known that omega-3 FA improve immunity, performance, blood lipid profile besides increasing in market weight (Jameel and Sahib, 2014). Furthermore, vegetable sources, such as flax oil and rapeseed oil, may increase linolenic acid the precursor of the whole n-3 family. Therefore, it is important to determine whether performance and dressing percentage would be affected in broilers with using different different oil sources and levels. Against this background, this study evaluated the influences of the inclusion of different oil sources and levels in isocaloric isonitrogenous diets on the growth performance, carcass traits and serum metabolites in broilers.

 

MATERIALS AND METHODS

 

A total of 210 one-day old Cobb chickens were reared and randomly divided into 7 groups till day 38. Each treatment consisted of six replicates with 5 birds per pen. The experiment groups included: Control group (C) with 3% mixed oil (sunflower and soybean oil), and other diets were supplemented with 2% and 4% of linseed oil (LO), fish oil (FO), or soybean oil (SO). Three dietary phases were prepared: Starter diet (day 1-14), grower diet (day 15-28) and finisher diet (day 29-38). All diets were mashed without using any antibiotics growth promoters. Water and feed were provided ad libitum during the whole experiment. The birds were reared under constant lighting and at a starting temperature 32-35 ºC. Temperature was gradually decreased between 25 and 28 ºC over the following 2 weeks. The chicks were vaccinated via drinking water at the 7th day with Hitchner B1 against Newcastle disease. Individual body weight (BW), body weight gain (BWG) and feed conversion ratio (FCR) of broiler chickens were recorded at days 21 and 38 of life.

 

On the final day of the experimental period (day 38), all birds were slaughtered. Thereafter, all entrails in the carcass were removed and the empty carcass, liver, spleen and bursa of Fabricius were separately weighed (each of them was proportioned to the live pre-slaughter weight).

 

At the same time of slaughtering the blood samples were taken and immediately centrifuged for separating serum. The samples were frozen at -20 ºC until analysis for determination of total protein (Cannon et al., 1974) and albumin (Young, 2000).

 

The fatty acids analyses were done according to (Cherian and Sim, 1992). Briefly, the oil samples of 250 µl were resolubilized into 2 ml of boron trifluoride-methanol-hexane solution (35% boron trifluoride, 45% methanol, 20% hexane). The tubes containing the resolubilized oil samples were heated in a water bath (90-100 °C) for 60 min. After cooling, 2 ml of hexane and 2 ml distilled water were added. Then the samples were mixed and allowed to separate. The hexane (upper) layer was withdrawn then for separation of fatty acids by gas chromatography (Thermo-nicolet, USA) about 2 µl of hexane layer was taken.

 

All analyses were done using the software SPSS 20 (SPSS Inc, Chicago, Illinois) to evaluate the influence of different dietary levels and sources of oil on growth performance and carcass traits. One-way ANOVA and Duncan’s multiple comparisons of the means to compare data obtained. Data were expressed as means standard errors. Differences between treatments were considered significant when P < 0.05.

 

RESULTS AND DISCUSSION

 

The composition of the experimental diets was formulated to meet the nutrient requirements of broilers as recommended for the Cobb strain (Table 1). No marked differences in the chemical composition were noted between the experimental diets in each dietary phase. The fatty acid profiles of supplemented oils are shown in (Table 2). The linoleic acid (C18:2 n-6) content in SO was comparatively higher than those of LO and FO (56%, 10.9% and 2.2%, respectively). However, the α-linolenic acid (C18:3 n-3) content was higher in LO (64.12%) than in SO (7.50%) and FO (1.33%). The long chin fatty acids (EPA and DHA) were higher in FO (10.65% and 8.64%, respectively) than SO and LO.

 

The impact of different sources of oil in diets of broilers on growth performance is shown in (Table 3). In the period from day 1 to 21 of life, supplementation of the basal diets with 2% and 4% LO significantly improve BW (683 g and 697 g, respectively) and BWG in comparison to those fed control or 2% SO diets. In the group fed diet supplemented with 2% FO from day 1 to 21 of life showed significant increase in BW (668 g) and BWG (632 g) compared to those fed diets supplemented with 2% SO or without supplementation (control). However, no significant differences were noted in BW and BWG between groups fed diets supplemented with SO (2% or 4%) or with 4% FO and the control group.

 

Regarding BW in the period from day 22 to 38 of life, the group fed diet with addition of 4% LO had significant increase in BW (1743 g) compared to other experimental groups (except for group fed 2% LO). Moreover, no significant differences in BW (day 22-38) were found between all experimental groups except for group fed 4% LO (Table 3). The groups fed 2% or 4% LO had the most favourable FCR (1.88 and 1.83, respectively) compared to other expe-

 

Table 1: Ingredients (g/kg) and chemical composition of experimental diet

 

Dietary treatments1
	Starter						Grower			Finisher
Ingredients	C 2% 4%						C 2% 4%			C 2% 4%
Corn grain (8%)	568.5		590.8			544.4	626.4	648.8	603.7	667.4	687.3	645.0
SBM (44%)	322.3		287.0			357.4	265.6	230.4	300.8	205.6	178.7	264.5
Corn gluten (60%)	42.3		64.6			22.6	42.9	64.4	21.4	64.3	80.4	20.0
Oil	30.0		20.0			40.0	30.0	20.0	40.0	30.0	20.0	40.0
DiCaP	17.5		17.6			17.4	16.2	16.3	16.1	14.3	14.4	14.1
Limestone	10.7		11.0			10.4	10.3	10.6	10.1	9.8	10.0	9.4
Vit&Min premix2	2.5		2.5			2.5	2.5	2.5	2.5	2.5	2.5	2.5
Common salt	3.4		3.4			3.4	3.4	3.4	3.4	3.2	3. 2	3.2
DL-Methionine	0.8		0.6			0.9	0.7	0.6	0.9	0.4	0.3	0.7
DL-Lysine	2.0		2.5			1.0	2.0	3.0	1.1	2.5	3.2	0.6
Chemical analyses, g/kg DM
DM		876		881	871		875	882	872	873	878	872
Crude ash		59.8		59.5	59.6		74.7	74.5	73.8	64.3	64.4	64.8
Crude protein		215		216	213		194	193	196	183	181	185
Crude fibre		30.2		30.5	30.8		26.2	26.7	26.9	26.1	26.5	26.4
Crude fat		95.3		87.4	103.2		95.7	88.1	104.5	96.1	87.8	105.2
Calcium		13.3		13.0	12.9		12.6	12.4	12.8	10.6	10.3	11.0
Phosphorus		7.62		7.23	7.43		7.11	7.18	7.65	6.77	6.54	6.44
Sodium		1.32		1.24	1.28		1.41	1.33	1.24	1.21	1.54	1.37
Potassium		11.1		10.8	11.4		10.8	10.5	10.4	10.1	10.5	10.8
Lysine		14.7		14.3	14.9		15.7	15.2	15.8	13.8	13.6	13.2
Methionine		6.51		6.22	6.71		7.20	7.55	7.34	5.82	5.78	5.33
ME3(MJ/kg)		13.0		13.1	13.2		13.3	13.2	13.6	13.2	13.4	13.5

 

1Control (C) 3% mixed oil (soybean oil and sunflower), 2% and 4% for other experimental oils 2Vitamins and minerals premix per each kilogram diet: retinol, 2.48 mg; cholecalciferol, 25 µg; DL-ɑ-tocopherol, 60 mg; menadione sodium bisulphite, 2 mg; thiamine, 2 mg; riboflavin, 5 mg; pyridoxine, 3 mg; cyanocobalamin, 0.01 mg; niacin, 27 mg; folic acid, 1 mg; biotin, 0.05 mg; pantothenic acid, 10 mg; Mn, 60 mg; Zn, 50 mg; Cu, 10 mg; I, 0.1 mg; Se, 0.1 mg; Co, 0.1 mg; Fe, 50 mg 3ME (MJ/kg) = 0.01551 crude protein + 0.03431 crude fat + 0.01669 starch + 0.01301 sugar (nutrients in g/kg diet; FMVO, 2007)

 

perimental groups. These results are consistent with the findings of (López-Ferrer et al., 2001) who found a higher weight gain in chickens fed diets high in LO levels. Also, according to Aziza et al. (2016) who found that the chickens infected with E.Tenella and fed diet supplemented with 3% and 5% LO had a significant increase in BW development and BWG compared with chickens fed FO and corn oil. Moreover, Stanaćev et al. (2013) observed that there was significant increase in BW of broilers fed diet supplemented with 4% flax oil compared with those fed diet supplemented with 4% SO. On the other hand, Almeida et al. (2009). did not observe any significant influence on feed intake, BWG or FCR when they replaced SO by LO in the diet of broilers. A negative effect of addition of 6% LO to the broiler diet mixture was noted (Bartos et al., 2004).

 

Farhoomand and Checaniazer, (2009). found that broiler chickens fed diet supplemented with 2% FO showed higher BW and BWG and the best FCR than those fed diet supplemented with poultry fat. However, previous studies concluded that the inclusion of FO in the diets cause significant reduction in terms of performance (final BW or FCR), in comparison to using vegetable oils (Huang et al., 1990; Nash et al., 1995). Also, according to Navidshad (2009) who found that final BW and daily BWG of broilers decreased significantly by FO inclusion in diets (2% or 4%). However some researchers stated that broiler diets containing different energy sources; sunflower oil, linseed oil, and soybean oil did not affect growth performance of broilers significantly (Fébel et al., 2008).

 

Table (4) shows that feeding 4% LO resulted in significantly higher dressing percent (71.55%) in comparison to those fed FO 4% or control diets. Similarly, El-Yamany et al. (2008) observed a significant improvement in quails dressing percent with addition of flax oil to the diet. Rega-

 

Table 2: Fatty acid composition (%) of the experimental oils used in broiler diets

 

Fatty acids	LO	FO	SO
Myristic(14:0)	0.23	4.06	0.25
Palmitic (16:0)	8.09	10.88	12.73
Palmitoleic (16:1)	ND	5.85	0.03
Stearic (18:0)	5.66	3.79	4.59
Oleic (18:1)	11	43.61	18.89
Linoleic (18:2 n-6)	10.90	2.2	56.00
α-Linolenic (18:3 n-3)	64.12	1.33	7.50
Eicosonoic acid (20:1)	ND	5.45	ND
Archidonic acid (20:4 n-6 )	ND	1.05	ND
Eicosapentaenoic acid (EPA, 20:n3)	ND	10.65	ND
Docosahexanoic (DHA, 22:n3)	ND	8.64	ND
Σ SFA1	13.9	18.7	17.5
ΣMUFA2	11.0	54.9	18.9
Σ Omega 6	10.9	3.3	56.0
Σ Omega 3	64.1	20.6	7.50

 

ND=not detected, LO=Linseed oil, FO=Fish oil, SO=Soybean oil,

1SFA: saturated fatty acids, 2MUFA:Monounsaturated fatty acids

 

rding the weight of lymphoid organs in this study, therewere no significant differences between control and treatment groups. There was slight numerically reduction of the relative spleen weight (0.27%) in group supplemented with 4% FO and slight increase of liver percentage (3.22%) in group supplemented with 4% LO (Table 4). Stanaćev et al. (2013) found no significant differences in carcass weight and most of relative organs weight (liver, gizzard, heart, wings) among broilers chickens fed different sources of oil (soybean oil, rapseed oil, and flax oil) and levels (4% and 8%). It has been stated that the injected antigens in the thymus, spleen, and bursa of Fabricius (major lymphoid organs) in poultry interact with mature lymphocytes and other immune cells during the immune challenge (Grasman, 2002). Seidavi et al. (2014) found a slight reduction of relative spleen weight in groups supplemented with FO and he attributed this to the anti-inflammatory properties of FO supplementation, which could reduce the proliferation of the mature lymphocytes. Wang et al. (2000) observed that using surplus levels of n-3 PUFA in diets of laying chickens led to promote growth of the major lymphoid organs (thymus, spleen and bursa of Fabricius) up to 4 week of age. Nevertheless, at the age of 4 week onward, the weight of immune tissue began to decline. This could be the possible explanation for not finding any significant differences because all lymphoid organs were measured at the end of experiment (day 38). Crespo and Esteve-Garcia (2002) reported that there was a numerical increase in liver weight of broiler chickens (day 53) fed LO compared with chickens fed soybean or tallow oils.

 

Table (5) summarizes the effect of different dietary sources and levels of oil on serum total protein and albumin at the end of the experimental period. A significant increase in serum total protein (5.92 g/dl) and globulin (2.49 g/dl) in group supplemented with 2% FO was noted.

 

Table 3: Growth performance in broilers fed diets supplemented with different sources and levels of oil (Means ± SE

 

Parameters	Dietary treatments1   LO FO SO Control 2% 4% 2% 4% 2% 4%
1-21 d
BW (g)	605b±6.61	683a±19.80	697a±16.94	668a±18.01	626ab±18.22		612b±10.37	639ab±13.49
BW G (g)	569b±6.61	648a±22.8	664a±16.44	632a±19.8	591ab±18.22		577b±10.65	606ab±13.49
FCR	1.45±0.04	1.40±0.06	1.40±0.04	1.43±0.1	1.43±0.07		1.45±0.02	1.43±0.05
22-38 d
BW (g)	1530b±36.83	1654ab±44.45	1743a±47.43	1512b±62.34		1506b±34.05	1538b±43.19		1638b±71.20
BWG (g)	925b±59.81	971b±44.28	1046ab±30.99	844c±19.9		880b±22.90	926b±24.25		999ab±40.26
FCR	1.92ab±0.06	1.88b±0.13	1.83b±0.09	1.95a±0.057		1.94a±0.05	1.90ab±0.1		1.89b±0.07

 

1Control 3% mixed oil (soybean oil and sunflower), 2 and 4% for LO = Linseed oil , FO= Fish oil, SO= Soybean oil

a,bMeans in the same row with different superscripts are significantly different (p < 0.05

 

Table 4: Effect of addition different sources and levels of oil in diets of broilers on carcass trait (Means ± SE)

 

Parameter	Dietary treatments1   LO FO SO Control 2% 4% 2% 4% 2% 4%
Dressing, %	63.20b±1.27	67.59ab±1.41	71.55a±4.30	67.96ab±0.74	63.31b±0.46	68.28ab±1.13	68.28ab±1.17
Liver, %	2.87a±0.060	2.73ab±0.064	3.22a±0.289	2.45ab±0.088	2.56ab±0.113	2.25ab±0.049	2.38ab±0.095
Spleen, %	0.32±0.003	0.32±0.008	0.306±0.04	0.31±0.017	0.270±0.040	0.313±0.038	0.293±0.003
Bursa of Fabricius, %	0.12±0.008	0.14±0.025	0.14±0.010	0.13±0.025	0.14±0.010	0.14±0.010	0.16±0.006

 

1Control 3% mixed oil (soybean oil and sunflower), 2 and 4% for LO = Linseed oil, FO= Fish oil, SO= Soybean oil

a,bMeans in the same row with different superscripts are significantly different (p < 0.05)

 

Table 5: Effect of supplementation different sources and levels of oil in diets of broilers on serum metabolites (Means ± SE)

 

Parameter (g/dl)	Dietary treatments1   LO FO SO Control 2% 4% 2% 4% 2% 4%
Total protein	3.61bc±0.24	3.80b±0.17	4.13b±0.11	5.92a±0.28	4.25b±0.12	4.05b±0.16	4.10b±0.09
Albumin	2.41b±0.10	2.44b±0.005	2.81ab±0.65	3.43ab±0.01	2.62b±0.17	2.54b±0.04	3.13ab±0.18
Globulin	1.2 c±0.046	1.36c±0.042	1.32c±0.050	2.49a± 0.057	1.63b± 0.04	1.51bc±0.050	0.97d±0.02

 

1Control 3% mixed oil (soybean oil and sunflower), 2 and 4% for LO = Linseed oil, FO= Fish oil, SO= Soybean oil

a,bMeans in the same row with different superscripts are significantly different (p < 0.05)

 

A marked increase in serum albumin content (3.43 g/dl) was found in the group fed 2% FO. Moreover, the lowest numerical contents for total protein and albumin were found for group fed control diet (3.61 and 2.41 g/dl, respectively). The group fed 4% SO diet had a significant low serum globulin concentrations (0.97 g/dl) compared to other experimental groups (Table 5). With the same concept, Al-Mayah (2009) showed that 50 g/kg of diet FO increased serum globulins and maintained proper immune function in chickens fed after vaccination against ND. Also, Tobarek et al. (2002) observed that broilers fed FO before or after vaccination with Hitchner B1 at 7th day or with LaSota at 21th day of age resulted in a significant increase of globulins. Moreover, Michel (2002) found that using FO in diet of quail had a significant increase of globulins in comparison to that fed the same amount of SO. In addition, Jameel et al. (2015) stated that supplementation diet with 0.5% LO significantly increased serum total protein concentration in broilers.

 

CONCLUSIONS

 

In conclusion, the FO is not favourable oil as it considered the most expensive in comparison to other oils with a low final BW. Using 4% of LO had significantly higher BW but might be more expensive than SO. However, using 2% LO or 4% of SO have almost the same final BW. Moreover, supplementation with 2% and 4% LO to broiler diets improved growth performance, while addition of FO improved immunity.

 

CONFLICT OF INTEREST

 

The authors declare that they have no conflict of interest.

 

Authors Contribution

 

AA planned the study, carried out the analyses, acquisition of data, wrote the manuscript and critically reviewing the manuscript. AA, carried out the analyses, tracking of data, performed the statistical analyses and wrote the manuscript. All authors read and approved the final manuscript.

 

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