Abstract: The aim of this research was to evaluate the effect of Canola Oil (CO) on the carcass selected tissues of male broiler chickens. A total of 90 Ross 308 strains were randomly divided into 3 experimental treatments with 3 replicates were arranged in a completely randomized design. The experimental period lasted 6 weeks. Experimental diets include basal diet with 0% CO; basal diet with 2% CO and basal diet with 3% CO. Meat fatty acids profiles with Gas Chromatography technique were determined. According to results the MUFAs content for breast meat in T₂ and T₃ treatment were significantly (p<0.05) decreased compared to control group but in thigh meat MUFAs contents compared to control group significantly (p<0.05) increased. For PUFAs a similar response was observed in breast and thigh meat and was achieved significant changes in PUFAs contents compared with control group but for breast meat more incorporation of PUFAs than thigh. For increase of nutritional value of broiler meat, 3% of canola oil suitable for enrichment.

INTRODUCTION

It is well known that the diet plays an important role in altering meat fatty acid composition (Yaquoob, 2003, 2004; Stulnig, 2003; Salamatdoustnobar et al., 2007, 2008). Recently supplementation of diets with lipids from oilseeds for intensive poultry production has been observed. These contain predominantly n-6 Poly- unsaturated Fatty Acids (PUFAs) and consequently, poultry lipids have comprised higher levels of n-6 fatty acids and lower levels of n-3 PUFAs.

Canola oil are one of the few lipid stheces rich in n-3 and their inclusion in poultry diets could contribute to increased the concentrations of PUFAs in poultry lipids (Salamatdoustnobar et al., 2007; Lopez-Ferrer et al., 1999). Fat inclusion in broiler diets affects carcass fat quality because dietary fatty acids are incorporated with little change into the bird body fats (Salamatdoustnobar et al., 2008). The purpose of this experiment was to determine of canola oil effects on the meat fatty acids and compared MUFAs and PUFAs contents in broiler chick’s meat.

MATERIALS AND METHODS

A total of 90 male one day old age (ROSS 308) broiler chicks in three treatment and replication for 6 weeks were used as experimental animals. Diets were is caloric and is nitrogenous with the following characteristics:

The diets ingredients' are shown in Table 1-3, respectively. In the end of breeding period (42 days), two chicks were randomly taken from each replicate for meat sampling. The meat samples of breast and thigh carefully minced and its oil extract with chloroform. Crude lipids were analyzed by Gas Chromatography (GC). Data's were statistically analyzed using one-way ANOVA and means were compared by Duncan multiple range test.

Statistical analyses: Data were analyzed in a complete randomized design using the GLM procedure of SAS version 8.2 (SAS Inst. Inc., Cary, NC).

Where:

Table 1:	Percentage composition of experimental diet in starter period
1Vitamin content of diets provided per kilogram of diet: vitamin A, D, E and K. 2Composition of mineral premix provided as follows per kilogram of premix: Mn, 120,000 mg; Zn, 80,000 mg; Fe, 90,000 mg; Cu, 15,000 mg; 1,600 mg; Se, 500 mg; Co, 600 mg

Table 2:	Percentage composition of experimental diets in growth period

Table 3:	Percentage composition of experimental diets in finisher period

RESULTS AND DISCUSSION

Results show that CO in this experimental could affect fatty acids profiles in whole carcass. The MUFAs found in breast and thigh meat were Myristoleic acid, Palmitoleic acid, Oleic acid, Vaccenic acid and Gondoic acid (Table 4 and 5). The Myristoleic acid (C14:1n5) content for breast meat were significant difference (p<0.0.5) between T₃ and T₁ and for thigh meat Myristoleic acid content in T₂ and T₃ treatments was significant compared with control group (p<0.05). Results for Palmitoleic acid (C16:1n7) for both breast and thigh meat show that T₂ treatment were higher and in the thigh meat was significant (p<0.05).

The incorporation of canola oil in diets was smallest effect on oleic acid (C18:1n9) and that were not significant. Vaccenic acid (C18:1n7) only were significantly affected in breast meat in T₂ but in thigh meat was not significant. Mean while Gondoic acid (C20:1n9) content in breast meat and thigh meat were significant difference and affected T₂ and T₃ treatment. A number of studies have examined the effects of dietary PUFAs sthece such as vegetable oil, on the fatty acids composition of the broiler carcass.

Table 4:	Least square means for fatty acid profiles in broilers breast meat fed canola oil

Table 5:	Least square means for fatty acid profiles in broilers thigh meat fed canola oil

Many of studies were conducted enhance human dietary intake of long chain n-3, have beneficial effects to human health (Miller and Robisch, 1969; Hulan et al., 1988; Phetteplace and Watkins, 1990; Nash et al., 1995). The Polyunsaturated fatty acids for T₂ and T₃ breast and thigh meat include Linoleic acid, α-Linolenic acid, Eicosapentaennoic acid and Docosahexaenoic acid were significant difference compared to control group (p<0.05). The content of Linoleic acid (c18:2n6cis) in breast meat for T₃ treatment was 15.35 and compared with T₁ with 12.33 g kg^-1, respectively was significant (p<0.05) and for thigh meat T₂ and T₃ were significant compared to control group and from 10.2 g kg^-1 reached to 11.53 and 12.00 g kg^-1 for T₂ and T₃, respectively. Similar results have previously been reported by other researchers, who found a higher deposition of long-chain PUFAs in breast muscle compared with thigh (Hulan et al., 1988; Lopez-Ferrer et al., 1999; Gonzalez-Esquerra and Leeson, 2000; Crespo and Esteve-Carcua, 2001; Salamatdoustnobar et al., 2007). Results show that α-Linolenic acid (C18:3n3) content in breast and thigh meat samples for T₃ treatment with 0.87 and 0.74 g kg^-1 could significantly increased (p<0.05). The fatty acid composition of the broiler carcass lipids is generally a reflection of the fatty acid profile of the diet fed. This is consistent with the results of a number of earlier studies (Hulan et al., 1988; Yau et al., 1991; Zollistsch et al., 1997). According to results Eicosapentaennoic acid (C20:5n3) in breast and thigh meat for T₂ and T₃ in compared to other levels were significant (p<0.05). Docosahexaenoic acid (C22:6n3) content for breast meat only in T₃ was significant and for thigh meat both T₂ and T₃ could significantly increased this fatty acid (p<0.05).

These data are consistent with those obtained on other studies (Herod and Kinsella, 1986; Phetteplace and Watkins, 1989; Olomu and Baracos, 1991). Since the fatty acid, composition of broiler chicken carcass may be influence considerably by that of the diet (Miller and Robisch, 1969; Hargis and Elswyk, 1993).

It's expected that diets containing oils and fats will influence carcass fatty acid composition affecting their predominant fatty acids. With regards to results total of MUFAs for breast meat, CO could significantly decreased their content, but for thigh meat results show that only 2% of CO compared to control group was higher (p<0.05). PUFAs content of breast meat like of thigh meat usage CO in T₂ and T₃ could significantly increase compared to control group and from 14.03 with ascending rate reached to 16.08 and 19 g kg^-1, respectively and for thigh meat usage CO in T₂ and T₃ treatment with 14.12 and 15.57 g kg^-1 significantly increased to control group (p<0.05). A similar response was observed in breast and thigh meat and produced significant changes in PUFAs contents but more incorporation of PUFAs than thigh.

ACKNOWLEDGEMENT

Financial support for this study (Islamic Azad University, Shabestar Branch) was provided.