جستجوی مقالات مرتبط با کلیدواژه "روغن هسته انار" در نشریات گروه "علوم دام"

Improvement of the quality of animal products by new scientific and practical methods is one of the important goals of animal nutritionists. Rearing systems based on low access to pasture decrease the useful fatty acids in animal products. Several studies have been shown that feeding strategies are known as the most effective factor on alteration of fatty acid composition of muscle and fatty tissues in ruminants. Therefore, this study aimed to assess the influence of Pomegranate seed oil (PSO) with higher ratio of unsaturated fatty acids, steroidal and polyphenolic compounds on blood metabolites and fatty acid profiles in bicepsfemoris muscles in the fattening lambs.

Twenty one male Sanjabi lambs (BW=27.5±2.6 kg, 3-4 months old) were used to evaluate the effects of PSO supplementation on blood parameters and fatty acid pattern of bicepsfemoris muscle. Lambs were randomly distributed between three treatments (control, and diets containing 2 and 4% of PSO) and were fed adlibitum for 90 days. The experimental diets were formulated (DM basis) to be isonitrogenous (CP=14.7%) and isocaloric (ME=2.6 Mcal/kgDM) and to meet NRC (2001) .Blood samples were taken from each lamb (10 ml) at the end of first, second, and third months and metabolite parameters concentration in blood were measured. Samples of Bicepsfemoris muscle were dissected and homogenized for determination of fatty acid composition to the procedure described by Folch et al. (1957). Fatty acid derivatives were prepared by methylation of the fatty acids (Metcalfe and Schmitz, 1961). The pattern of Fatty acids were determined by using gas chromatography apparatus (17, 37). This study was based on completely randomized design. Data were analyzed statistically by general linear model (GLM) procedure and means comparing were done by Duncan's multi-domain test with SAS (2004) software version 9.1 (51).

Results show that concentration of AST, ALT and ALP, insulin, uric acid and creatinine, were not affected by different levels of PSO in diet. No significant difference was observed in the amount of palmitic, stearic, myristic, linoleic acid (C18: 2) and linolenic acid (C18: 3) in bicepsfemoris muscle. Addition of PSO at level of 4% decreased (P <0.05) the MUFA level compared to control (47.69 vs. 39.08). Mean PUFA and PUFA to SFA ratio in bicepsfemoris muscle of lambs received PSO were higher than those in the control group (2.3 and 2.2 times, respectively). However, these differences were not significantly different. Total amount of omega-3 fatty acids (PUFA n-3) significantly increased due to feeding PSO.

Due to positive trend observed in MUFA, n-3 fatty acids and PUFA: SFA ratio, with increasing the levels of PSO, addition 4% of this oil in the diet of fattening lambs is recommended.

In recent years the fat content and fatty acid composition of foods have been highlighted as consumers have become more aware of the relationships between dietary fat and the incidence of diseases (Corpet, 2011; Daley et al., 2010). Increasing ruminant’s meat content of PUFA and conjugated linoleic acid isomers accepted as targets to improve nutritional quality of ruminant meat (Mapiye et al., 2012). Among all possible factors, feeding strategies, especially dietary supplementation with PUFA rich oils, are known as the most effective factor on alteration of fatty acid composition (Boles et al., 2005). However, conflicting results have been reported on altering fatty acid content of meat by supplementing ruminant diets with lipid sources high in PUFA (Ivan et al., 2001; Radunz et al., 2009).
To study the effects of pomegranate seed oil (PSO) supplementation on non-carcass components weight, carcass characteristics and some meat quality attributes 21 male Sanjabi lambs (BW=27.5±2.6 kg, 3 months old) were used. Lambs were randomly distributed among three treatments (control, control% PSO, and control%PSO) and were fed ad libitum for 90 days before slaughter. Four lambs from each treatment were slaughtered. After slaughter, non-carcass component (head, skin, feet, lungs and trachea, liver, heart, kidneys, spleen, gastro-intestinal tract, testicles, and kidney and abdominal fat depots), were removed and weighed. Following a 24 h chilling period, the carcasses were cut into different anatomical regions (neck, behind of neck, ribs, loin, fore shank, brisket, flank, long leg and fat tail) and the weight of each region was recorded. The carcass fat depth over the midpoint of LD muscle at the 12th rib was measured; fat thickness was assessed at three sites on the location. The LD muscle depth (B), width (A), and area were measured on the cut surface of the LD muscle at the 12th rib. Enough samples of longissimus dorsi (LD) and biceps femoris (BF) muscles were vacuum-packed and frozen at −20°C until subsequent determination of meat quality attributes. Samples of LD and BF muscles, without any subcutaneous fat, were ground to homogeneity and the percentage of moisture, ash, fat, and protein was determined using AOAC (2000) methods. Meat colour was measured on both muscles after ageing for 24 h at 4°C. Meat colour of bloomed (1 h at 21 °C) samples was assessed using the L*, a* and b* system (CIE, 1986) with a Hunter Lab colourimeter (Konica Minolta, Chroma meter model CR-400, Japan). To measure cooking loss (%), samples of LD and BF muscles were weighed, placed in plastic bags, and cooked in a water bath, at 75°C for 60 min as described by Hoffman et al. (2003). After cooking, samples were dried and cooking loss (%) was estimated by means of percentage of weight loss of the cooked sample to initial sample weight. Cooked samples were used to determine shear force value. Three sub-samples (3×1×1 cm3) were taken from each cooked sample. Shear force values of each subsample was determined using a Testometric machine (Model M350-10CT, England) equipped with a Warner Bratzler (WB) shear force apparatus.
Empty total digestive tract and empty reticulum had significantly higher mass in lambs fed 2% PSO supplemented diet (P0.05). In other species, on the other hand, Engle et al. (2000) and Najafi et al. (2012) reported that dietary linoleic acid decreased kidney and pelvic fat percentage in Angus steers and Mahabadi goat kids, respectively. This discrepancy may be attributed to difference in PUFAs content of the diet among different studies (Solomon et al., 1992). The carcass cut weights of lambs were not affected (P>0.05) by the oil supplementation at 2 or 4%. This result agrees with those in which no significant effects on weights or percentage of carcass cuts were observed as a result of supplementing lambs (Boles et al., 2005) or kids (Najafi et al., 2012; Roy et al., 2013) diets with various oils. Similarly, other measured carcass characteristics of the lambs including subcutaneous fat depth, and longissimus depth, width and area were not affected (P>0.05) by oil supplementation. Similar studies in lambs (Radunz et al., 2009; Boles et al., 2005) have reported no effect of oil supplementation on rib eye area of lambs fed high unsaturated oils. In the present study, PSO inclusion in lamb diet did not make any significant change (P>0.05; Table 3) in moisture, protein and ash contents of LD muscle; although feeding this oil in 4% level caused a significant (P0.05). In contrast to the findings of the current study, fish oil (Najafi et al., 2012), soybean oil (Bessa et al., 2005), safflower oil (Boles et al., 2005) and soybean and linseed oils (Francisco et al., 2015) supplementation in lambs diet did not alter meat colour indexes. In the present study, cooking loss and WB shear force in LD and BF muscles were not affected by oil supplementation (P>0.05). Other findings in goat (Najafi et al., 2012) and lambs (Manso et al., 2009; Radunz et al., 2009; Francisco et al., 2015) confirm that oil supplementation is ineffective (P>0.05) on cooking loss percentage and WB shear force.
The results of this study suggest that pomegranate seed oil supplementation in the diet of fattening lambs up to 4% have potential to improve colour indexes of meat without negative impact on carcass characteristics and physical attributes of meat.

This study was conducted to determine the effects of addition of the pomegranate seed oil (PSO) in the diet on growth performance, diet digestibility and rumen fermentation parameters of fattening lambs. Twenty one Sanjabi lambs, with average body weight of 27.5±2.6 kg and 3 months of age, were used in a completely randomized design with 3 treatments and 7 replicates.The experimental treatments included diet free of PSO (control diet), and diets containing 2 and 4% of PSO. Daily feed intake, diet digestibility and rumen fermentation parameters were measured by standard methods. The lambs were weighed at the beginning and the end of the finishing period for estimation of average daily gain (ADG). The DMI in the lambs fed on the diets containing PSO was higher than that of control (P