Nutrient and fatty acid deposition in broilers fed different dietary fatty acid profiles

Guava leaf extract as a catalyst for enhanced rabbit health and performance in sub-tropical regions: an updated review

For sustainable intensification of rabbit industry, it is imperative to explore the potential of non-conventional feed resources. The researchers were driven to discover solutions for the shortage of feed in livestock production because of the ongoing rise in costs associated with conventional feed resources. Their efforts were directed at enhancing conventional sources and investigating alternative feed sources, including agricultural and agro-based industrial by-products. Therefore, the review examines the possible advantages of using guava leaf extract (Psidium guajava) as an example of non-conventional feed additive to improve the growth performance and overall health of commercially raised rabbits. Guava leaf extract contains a high concentration of bioactive substances, such as antioxidants, vitamins, and vital minerals. These substances have demonstrated advantageous effects on the feed efficiency, growth rate, and overall health of rabbits. This review article provides a thorough analysis of the current understanding and updates the knowledge about the physiological effects of adding guava leaf extract to rabbit diets, with a specific emphasis on its economic benefits. The findings demonstrated notable enhancements in feed conversion efficiency, growth rate, and immune system functionality, coupled with reductions in the total lipids levels and pathogenic microorganisms. Potential avenues for future investigation encompass the refinement of dosage, examination of synergistic impacts with other dietary constituents, and implementation of extended studies to validate the enduring advantages.

Effect of dietary modulation of fiber and fat level on liver and kidney functions, lipid profile, antioxidant and immune parameters in growing Egyptian geese

Determining the optimal requirements from dietary fiber and fat for Egyptian geese is a matter of great concern regarding health, production and growth. Therefore, the current study estimated the effects of different dietary fiber and fat levels on functions of liver and kidney, lipid profile, immunity and antioxidant measurements of the growing Egyptian geese. 150 Egyptian goslings (4 weeks old), with almost the same body weights were randomly allocated into 6 groups (25 goslings/group). All groups were subdivided into five replicates, each replicate contains five geese. Liver and kidney functions, immunity and antioxidant parameters were not significantly affected the different studied levels of fiber and fat or by their interaction. Various levels of fiber significantly affected total cholesterol, triglycerides, LDL-cholesterol and VLDL-cholesterol in a concentration-dependent manner and the lowest the lipid profile values were obtained at 12%. In conclusion, the present findings show that use of dietary fiber up to 12% and 5% dietary fat showed no detrimental effects on the immune status and general health of geese and resulted in the preferable lipid profile. This experiment provides a base for further study about the optimal requirements from dietary fiber and fat for the growing Egyptian geese.

Nutritional significance and health benefits of omega-3, -6 and -9 fatty acids in animals

The balance between omega-3 (ω-3), omega-6 (ω-6) and omega-9 (ω-9) fatty acids (FAs) is very important because these types of oils constitute essential components for the formation of the cell membrane, also they are precursors for a large number of substances in the body. One of the most important strategies for improving the increment of polyunsaturated FAs in poultry and animal meat is the dietary administration of these FAs. Additionally, the different sources of ω-3 or 6 in the diet improve the performance, public health and physiological aspects including anti-oxidative properties and immunity. ω-3 FAs have anti-inflammatory characteristics due to their ability to reduce cytokines liberation. High-level of ω-6 FAs is always associated with an increased incidence of dangerous disorders like depression and heart disease. These FAs showed a tremendous series of beneficial impacts like improved cholesterol levels and a decreased occurrence of coronary heart diseases. This article includes some information on the use of ω-3, ω-6 and ω-9 FAs in animal and human diets. These oils are vital for the physiological and health aspects, and the information mentioned here will improve our understanding of the functions and roles of these FAs in the body.

Whole transcriptome RNA Sequencing Reveals the Global Molecular Responses and circRNA/lncRNA-miRNA-mRNA ceRNA Regulatory Network in Chicken Fat Deposition

Fat deposition is a vital factor affecting the economics of poultry production. Numerous studies on fat deposition have been done. However, the molecular regulatory mechanism is still unclear. In the present study, the whole-transcriptome RNA sequencing in abdominal fat, back skin, and liver both high- and low-abdominal fat groups was used to uncover the competitive endogenous RNA (ceRNA) regulation network related to chicken fat deposition. The results showed that differentially expressed (DE) genes in abdominal fat, back skin, liver were 1207(784 mRNAs, 330 lncRNAs, 41 circRNAs, 52 miRNAs), 860 (607 mRNAs, 166 lncRNAs, 26 circRNAs, 61 miRNAs), and 923 (501 mRNAs, 262 lncRNAs, 15 circRNAs, 145 miRNAs), respectively. The ceRNA regulatory network analysis indicated that the fatty acid metabolic process, monocarboxylic acid metabolic process, carboxylic acid metabolic process, glycerolipid metabolism, fatty acid metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathway took part in chicken fat deposition. Meanwhile, we scan the important genes, FADS2, HSD17B12, ELOVL5, AKR1E2, DGKQ, GPAM, PLIN2, which were regulated by gga-miR-460b-5p, gga-miR-199-5p, gga-miR-7470-3p, gga-miR-6595-5p, gga-miR-101-2-5p. While these miRNAs were competitive combined by lncRNAs including MSTRG.18043, MSTRG.7738, MSTRG.21310, MSTRG.19577, and circRNAs including novel_circ_PTPN2, novel_circ_CTNNA1, novel_circ_PTPRD. This finding provides new insights into the regulatory mechanism of mRNA, miRNA, lncRNA, and circRNA in chicken fat deposition.

Olive pomace oil and acid oil as alternative fat sources in growing-finishing broiler chicken diets

The aim of the present study was to investigate the effect of dietary supplementation of olive pomace oil and olive pomace acid oil, which are rich in monounsaturated fatty acids (FA) but differ in free FA content, on growth performance, digestibility and FA profile of abdominal fat and breast meat. A total of 3,048 one-day-old mixed-sex broiler chickens (Ross 308) were randomly distributed into 24 pens and 3 dietary treatments (8 replicates per treatment). Experimental diets were administered for growing (from 22 to 29 d) and finishing (from 30 to 39 d) periods, consisting of a basal diet supplemented with 6% (as-fed basis) palm oil (PO), olive pomace oil (O), or olive pomace acid oil (OA). Animals fed O achieved the lowest feed conversion ratio (P < 0.01), together with the highest AME value (P = 0.003), but no differences were observed between OA and PO. Regarding FA digestibility, O and OA showed higher values than PO for all FA in both apparent ileal digestibility (AID) and apparent total tract digestibility. Comparing the AID between O and OA, no differences were observed for total FA, monounsaturated FA, or polyunsaturated FA, but animals fed OA showed lower AID values for saturated FA than those fed O (P < 0.001). The FA profile of abdominal fat and breast meat reflected that of the diet, with higher monounsaturated FA and lower saturated FA in animals fed O and OA compared to those fed PO. In sum, the inclusion of both olive pomace oil and acid oil in growing-finishing broiler chicken diets led to great performance parameters and high FA digestibility values, together with an enrichment with monounsaturated FA in abdominal fat and breast meat compared to the use of palm oil. However, a better AID of saturated FA and feed conversion ratio is achieved with O compared to OA.

A comparative evaluation on the energetic values and digestibility of fatty acids in rice bran oil and palm oil for broilers

The objective of this study was to compare the digestibility of energy and fatty acids (FA) in rice bran oil (RBO) and palm oil (PO) fed to growing Arbor Acre (AA) broilers. A corn-soybean meal basal diet and the basal diet supplemented with 8% RBO or PO were evaluated. A total of 72 AA male broilers (initial BW = 1,173 ± 6 g; age = 22 d) were randomly divided to 3 dietary treatments with 6 replicates of 4 broilers in each. The growth performance and the ME and FA digestibility in oils were compared with a balance experiment of broilers from d 22 to 28. The ME of the RBO diet was greater (P < 0.05) than PO diet and basal diet, and the ME of the PO diet was greater (P < 0.05) than basal diet. However, no statistical difference was observed in the ME intake of broilers fed basal, RBO, and PO diets. To maintain daily ME intake, broilers ingested more basal diet relative to other diets, resulting in increased CP intake (P < 0.01) and retention (P < 0.01) than broilers fed diets supplemented with RBO and PO. This finding resulted in greater (P < 0.01) BWG and ADG from d 22 to 28 for broilers fed the basal diet relative to other diets, but there was no difference for BWG and ADG across oil sources. However, broilers fed RBO had numerically greater BWD and ADG than those fed PO, likely because the RBO provided greater AME, AMEn, AME/GE, AMEn/GE (P < 0.01) as well as ether extract (EE) digestibility (P = 0.0536) relative to PO. The digestibility of palmitic (C16:0), stearic (C18:0), oleic (C18:1), and linoleic (C18:2) were greater (P < 0.01) in RBO than PO, which positively influenced the energy values for RBO. These results indicate RBO has greater ME and digestibility of EE and FA, which positively influenced the growth performance of AA broilers. Therefore, RBO can be used to replace PO in broiler diets.

Enrichment of Broiler Chickens' Meat with Dietary Linseed Oil and Lysine Mixtures: Influence on Nutritional Value, Carcass Characteristics and Oxidative Stress Biomarkers

This study aimed to evaluate the effect of four combinations of dietary linseed oil and lysine mixtures on performance, fatty and amino acid profiles, oxidative stress biomarkers, cell energy and meat quality parameters of broiler chickens. One hundred and sixty broiler chicks were allocated into four groups. Birds of groups 1–4 were fed diets containing optimum lysine and 2% of linseed oil, optimum lysine and 4% of linseed oil, high lysine and 2% of linseed oil, and high lysine and 4% of linseed oil, respectively, for a period of 35 days. High linseed oil or lysine levels did not affect the performance of the tested birds, but the high level of dietary linseed oil decreased the concentrations of muscles’ saturated fatty acids (SFA). The highest values of ω-3 polyunsaturated fatty (ω-3 PUFA) and arachidonic acids with lowest levels of monounsaturated fatty (MUFA) were detected in the muscles of birds fed diets containing high linseed oils and/or lysine levels. High linseed oil or lysine levels provided the best essential amino acid profile and improved antioxidant components as well as cell energy, and tenderness and redness of the meat. Conclusively, high dietary lysine and linseed oil combinations improved the nutritional value, antioxidant status and cell energy of broiler chickens’ meat.

Meat Quality of Commercial Chickens Reared in Different Production Systems: Industrial, Range and Organic

Meat is an important part of the human diet since it provides several nutrients. However, the amount of these nutrients can differ according to several factors. With this in mind, the present research was designed with the main objective of evaluating the effect of production system of broiler chickens (industrial, range and organic) on meat quality. The physicochemical, chemical and nutritional characteristics were determined in breast and drumstick meat. The organic chickens presented the lowest amounts of fat and cholesterol and the highest amounts of protein. The colour was also influenced by the production system, where organic and range chickens had the highest values of redness in both cuts (breast and drumstick). In addition, the content of essential fatty acids (C18:2n-6 and C18:3n-3) and other fatty acids with high biological importance, such as eicosapentanoic acid (EPA; C20:5n-3), docosapentanoic acid (DPA; C22:5n-3) and docosahexanoic acid (DHA; C22:6n-3) were higher in organic samples compared to industrial or range chickens. The amino acids content did not vary with the production system. With regard to mineral contents, organic chickens had the highest values of iron in drumstick and significantly lower values of magnesium in both cuts than industrial chickens. On the whole, the meat of the organic chickens showed better nutritional characteristics than those produced in range or industrial conditions.

Effect of dietary fat level and source on performance and immune system response of turkeys

An experiment was conducted to determine effects of different levels and sources of fats in diets on growth performance, carcass characteristics and immune response of turkeys during four periods (0-21, 22 to 42, 43 to 63 and 64 to 70 days of age). A completely randomized design with five treatments, six replicates and eight B.U.T.6 turkey chickens per replicate was used. Treatments included: Control diet, diet containing 2.5% of soybean oil, diet containing 2.5% fat supplement, diet containing 5% soybean oil, diet containing 5% fat supplement. The results showed that using 5% of soybean oil increased average daily gain of turkeys (89.04 g) throughout the experimental period (0-70 days) compared with the control group (81.11 g; p < 0.05). Treatments containing 2.5 and 5% soybean oil improved feed conversion ratio compared to control group (p < 0.05). Soybean oil at the levels of 2.5 and 5% was led to higher spleen and bursa percentages compared to other treatments, respectively (p < 0.05). The level and source of dietary fat had not significant effect on antibody titer against Newcastle virus vaccine on 42 and 70 days of age (p > 0.05). It can be concluded that supplementing diet with 5% soybean oil improved the performance of turkeys.

Effect of dietary fat type on intestinal digestibility of fatty acids, fatty acid profiles of breast meat and abdominal fat, and mRNA expression of lipid-related genes in broiler chickens

A group of 240-day-old Ross cockerels were used in a 4-week experiment to assess the effect of the fat type on the intestinal digestibility of fatty acids (FAs), the FA profiles of breast meat and abdominal fat, and the mRNA expression of six hepatic lipid-related genes. Experimental diets were supplemented with rapeseed oil, pork lard or palm oil at 60 g/kg. In the control diet, wheat starch was substituted for the fat source. The highest ileal digestibility of the fat and all FAs (except stearic acid) was observed in chickens fed lard. The content of fat in the breast meat of chickens was not significantly influenced by the fat supplements. The FA profiles of breast meat and abdominal fat reflected the FA composition of the diet. In the meat of chickens fed rapeseed oil, oleic acid was the predominant FA. Palmitic acid was the most abundant FA in the meat of chickens fed lard or palm oil. Oleic acid was the most abundant FA in the abdominal fat of all chickens. The highest mRNA expression of desaturases (Δ5-, Δ6- and Δ9-) was observed in chickens fed palm oil. The mRNA expression of hepatic FA synthase was higher in chickens fed palm oil or lard than in chickens fed rapeseed oil. The expression of HMG-CoA reductase was higher in chickens fed palm oil than in those fed rapeseed oil or lard. It can be concluded that rapeseed oil and lard are better sources of lipids than palm oil. These former two sources contain more digestible fatty acids and provide a lower concentration of SFAs in the meat and fat of chickens.

Effects of Olive Leaf and Marigold Extracts on the Utilization of Nutrients and on Bone Mineralization using Two Different Oil Sources in Broilers

The aim of this study was to investigate the effects of olive leaf and marigold extracts on the apparent total tract digestibility (ATTD) of the principal nutrients and energy, as well as on mineral utilization (Ca, P, Mg, Mn, Fe, Cu and Zn) in relation to bone characteristics in broilers fed walnut- or linseed oil-supplemented diets. Thirty-six 12-day-old commercial broilers Ross 308 were reared in metabolic cages, assigned to one of the six dietary treatments (3 × 2 factorial design): three supplements (not supplemented, olive leaf extract, or marigold extract), and two oils (walnut or linseed oil). The results showed that the marigold extract reduced Zn and P balances and tended to lower the balance of ash and Mg, and the ATTD of Zn and Mg. Diets with linseed oil increased the ATTD of acid detergent fiber and reduced the ATTD of the organic residue and Cu. No differences in the bone characteristics of tibia were observed between treatments. These results indicated that the inclusion of marigold extract had a negative effect on the Zn and P balance, and that neither extract had any major effect on the digestion and utilization of energy and other investigated nutrients, or on bone mineralization, irrespective of the oil source included in the diet.

Deposition of Dietary Bioactive Fatty Acids in Tissues of Broiler Chickens

This study examined the deposition of dietary bioactive fatty acids (FAs), including medium-chain and essential FAs, in tissues of broiler chickens. Six hundred newly hatched chicks were allotted to 4 treatments, 6 replicates of 25 chicks per treatment. The chicks were fed diets containing 0%, 1.6%, 4.0%, or 6.4% medium-chain triglycerides (MCTs) for 36 d. The abdominal fat deposition, fat content, and FA composition of breast meat, thigh meat, and abdominal fat were measured. The accumulation rate (AR) of bioactive FAs in the tissues was estimated as the slope of the linear regression between the FA composition of tissues and diets. Results showed that a diet containing 6.4% MCTs reduced the abdominal fat deposition and fat content of thigh meat (P<0.05). Essential FAs had higher AR than did medium-chain FAs. The AR of C10:0 was higher than that of C8:0. Moreover, C6:0 could not be detected in the tissues of broiler chickens. In conclusion, essential, but not medium-chain, FAs could efficiently deposit in tissues of broiler chickens.

Effect of a dietary probiotic, Lactobacillus johnsonii BS15, on growth performance, quality traits, antioxidant ability, and nutritional and flavour substances of chicken meat

To determine whether Lactobacillus johnsonii BS15 supplementation improves the growth performance and meat quality of broilers, 450 1-day-old male chicks (Cobb 500) were randomly divided into three groups: control group (basal corn-soybean diet), L-BS15 group (basal diet + 1 × 105 colony-forming unit BS15/g as feed), and H-BS15 group (basal diet + 1 × 106 colony-forming unit BS15/g as feed). These diets were fed for 42 days. Abdominal fat decreased (P < 0.05) as the concentration of BS15 increased. BS15 supplementation significantly increased the pH at 24 h after sacrifice and decreased drip loss and shearing force (P < 0.05), although meat colour and pH at 40 min after sacrifice remained unchanged. Antioxidant capacity and total protein and intramuscular fat levels were unchanged by the treatments, but BS15 supplementation significantly increased inosine monophosphate level and decreased total cholesterol and triglyceride levels (P < 0.05). The levels of proline, total amino acids, and flavour-related amino acids were increased (P < 0.05) by BS15 supplementation, but the levels of other amino acids did not change significantly. BS15 supplementation significantly decreased (P < 0.05) C16:0, C22:4n-6, and n-6 :  n-3 ratio and increased (P < 0.05) C18:3n-3, C20:5n-3,C22:6n-3, total polyunsaturated fatty acid (PUFA), n-3 PUFA and PUFA : saturated fatty acid ratio. These findings suggest that L. johnsonii BS15 supplementation improves the meat quality of broilers by increasing the shelf life and flavour and nutritional substances. In addition, BS15 supplementation can induce changes in fat deposits and fatty acid composition.

Original Research: Effect of various dietary fats on fatty acid profile in duck liver: Efficient conversion of short-chain to long-chain omega-3 fatty acids

Omega-3 fatty acids, especially long-chain omega-3 fatty acids, have been associated with potential health benefits for chronic disease prevention. Our previous studies found that dietary omega-3 fatty acids could accumulate in the meat and eggs in a duck model. This study was to reveal the effects of various dietary fats on fatty acid profile and conversion of omega-3 fatty acids in duck liver. Female Shan Partridge Ducks were randomly assigned to five dietary treatments, each consisting of 6 replicates of 30 birds. The experimental diets substituted the basal diet by 2% of flaxseed oil, rapeseed oil, beef tallow, or fish oil, respectively. In addition, a dose response study was further conducted for flaxseed and fish oil diets at 0.5%, 1%, and 2%, respectively. At the end of the five-week treatment, fatty acids were extracted from the liver samples and analyzed by GC-FID. As expected, the total omega-3 fatty acids and the ratio of total omega-3/omega-6 significantly increased in both flaxseed and fish oil groups when compared with the control diet. No significant change of total saturated fatty acids or omega-3 fatty acids was found in both rapeseed and beef tallow groups. The dose response study further indicated that 59-81% of the short-chain omega-3 ALA in flaxseed oil-fed group was efficiently converted to long-chain DHA in the duck liver, whereas 1% of dietary flaxseed oil could produce an equivalent level of DHA as 0.5% of dietary fish oil. The more omega-3 fatty acids, the less omega-6 fatty acids in the duck liver. Taken together, this study showed the fatty acid profiling in the duck liver after various dietary fat consumption, provided insight into a dose response change of omega-3 fatty acids, indicated an efficient conversion of short- to long-chain omega-3 fatty acid, and suggested alternative long-chain omega-3 fatty acid-enriched duck products for human health benefits.

Camelina sativa cake for broilers: Effects of increasing dietary inclusion from 0 to 24% on tissue fatty acid proportions at 14, 28, and 42 d of age

The benefits to human from the consumption of omega-3 polyunsaturated fatty acids (N-3 PUFAS) have been recognized. Camelina sativa is an oilseed crop grown for biofuel production. Feeding its cake with 10 to 20% remaining oil (28 to 30% α-linolenic acid [ALA]) has the potential to enrich poultry products with n-3 PUFA. An experiment was conducted to assess lipid deposition in brain, liver, breast, and thigh tissue by increasing inclusions of camelina cake (CC) fed to broiler chickens. Male chicks (744, Ross 308) housed in 24 cages were fed 0, 8, 16, or 24% CC for 42 d, 6 replicates per CC level. At the end of the starter (14 d), grower (28 d), and finisher (42 d) phase, brain, liver, breast, and thigh samples were collected from 3 birds/cage and diets were analyzed for fatty acid content. Feeding increasing CC inclusions from 0 to 8, 16, and 24% increased dietary ALA (5.3, 11.1, 15.2, 17.8, respectively) as a proportion of the total fatty acid content. All diets provided a similar level of long-chain n-3 PUFA (about 0.9%). Irrespective of growth phase, increases in dietary CC inclusion led to a linear increase (P<0.001) in the proportion of ALA in breast, thigh, and liver (76, 128, 288%, respectively), but not in brain tissue. An increase in dietary CC inclusion led to a linear increase (P<0.001) in the proportion of long-chain n-3 PUFAs, including docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) in liver (109 and 80%, respectively) and brain (24 and 6%, respectively) tissue. However, in breast and thigh tissue, increases in dietary CC inclusion led to an increase in only (P<0.005) DPA (24 and 27%, respectively). The predominant n-3 PUFA in liver and brain tissue feeding 24% CC was DHA (48% and 88%, respectively), unlike in breast and thigh meat, where ALA increased (65 and 86%, respectively). The labeling claim requirement for n-3 PUFA enrichment (300 mg/100 g meat) was exceeded in breast and thigh by feeding a 24% CC diet for 28 d or 16% CC diet for 42 d, respectively.

Effect of Different Dietary n-6 to n-3 Fatty Acid Ratios on the Performance and Fatty Acid Composition in Muscles of Broiler Chickens

The objective of this study was to investigate the different dietary ratios of n-6 to n-3 (n-6/n-3) fatty acid (FA) on performance and n-6/n-3 FA in muscles of broiler chickens. A total of 300 one-day-old Cobb chicks were randomly assigned to 3 treatments of 10 replicates in each (10 birds/replicate). Birds were fed on a corn-soybean meal-based diet containing 1% oil during starter (day 1 to 21) and 2% oil during finisher (day 22 to 39) phases, respectively. Treatments of high, medium and low dietary n-6/n-3 FA were formulated by replacing rice bran oil with linseed oil to achieve n-6/n-3 FA close to >20:1, 10:1 and 5:1, respectively. Average daily gain, average daily feed intake, and feed conversion ratio were similar (p>0.05) among the treatments. Serum glucose, cholesterol and triglycerides concentrations were not affected (p>0.05) by dietary treatments. In breast, concentration of C18:3n-3 was significantly greater (p = 0.001) for medium and low vs high n-6/n-3 FA, while concentrations of C20:5n-3, C22:6n-3, total n-3 FA, and n-6/n-3 FA were significantly higher for low vs medium, and medium vs high dietary n-6/n-3 FA. In contrast, concentrations of C18:2 and mono-unsaturated FA (MUFA) were lower for low vs high dietary n-6/n-3 FA. In thigh muscles, concentrations of C20:5n-3 were higher (p<0.05) for medium and low vs high dietary n-6/n-3 FA, and concentrations of C18:3n-3, C22:6, and n-3 FA were greater (p<0.05) for medium vs high, low vs medium dietary n-6/n-3 FA. However, concentrations of C18:1, MUFA, n-6/n-3 were lower (p<0.05) for low and medium vs high dietary n-6/n-3 FA. In conclusion, lowering the dietary n-6/n-3 FA did not affect the performance of chickens, but enhanced beneficial long-chain n-3 FA and decreased n-6/n-3 FA in chicken breast and thigh, which could be advantageous for obtaining healthy chicken products.

Effects of dietary olive oil on growth performance, carcass parameters, serum characteristics, and Fatty Acid composition of breast and drumstick meat in broilers

This experiment was conducted to evaluate the effects of dietary olive oil on growth performance, carcass parameters, serum characteristics, and fatty acid composition of breast and drumstick meat in broiler chickens. A total of 480 broilers were randomly allotted into three dietary treatments, including T (basal diet, 5% tallow), O1 (2% olive oil+3% tallow), and O2 (5% olive oil). During d 0 to 21, broilers fed the diet supplemented with 5% olive oil showed lower (p<0.05) body weight gain (BWG) and feed intake (FI) compared with those fed the T diet. Serum triglyceride concentration was reduced (p<0.05), while high density lipoprotein (HDL)-cholesterol concentration was increased (p<0.05) in the O2 treatment group compared with the T and O1 treatment groups. The addition of olive oil to the diets induced a reduction (p<0.05) in the total saturated fatty acid (SFA) contents in breast and drumstick meat, and increased (p<0.05) the total unsaturated fatty acid (USFA) contents and USFA/SFA ratios. In conclusion, a diet with 5% olive oil could decrease BWG and FI of broilers during the starter period (wk 0 to 3), and cause an increase in the serum HDL-cholesterol level, while decreasing the serum triglyceride concentration. Furthermore, USFA level and USFA/SFA ratios in breast and drumstick meat were increased by dietary supplementation of 2 or 5% olive oil.

Influence of dietary fat source on growth performance responses and carcass traits of broiler chicks

This study was conducted to determine the effects of three different fat sources and their combination on growth performance, carcass traits and intestinal measurements of broiler chickens reared to 42 d of age. Two hundred day-old male broiler chicks (Ross 308) were randomly assigned to one of five treatments with four replicates of 10 chicks based on a completely randomized design. The dietary treatments consisted of 4% added fat from three different sources and their combination as follows: T, diet containing 4% tallow; CO, diet containing 4% canola oil; SFO, diet containing 4% sunflower oil; TCO, diet containing 2% tallow+2% canola oil; TSFO, diet containing 2% tallow+2% sunflower oil. Dietary fat type affected significantly BW and gain as well as feed efficiency in birds fed the TCO diets compared with those fed the other diets. Dietary fat type also modified meat yield, resulting in a higher breast and drumstick yields in the birds fed TCO and TSFO diets, respectively. Most of internal organ relative weights and small intestine measurements were not influenced by dietary treatments, except for the abdominal fat pad weight that was lower in birds fed SFO and for small intestinal length that was influenced by fat source. Results from the current study suggested that the supplementation with a combination of vegetable and animal fat sources in broiler diet supported positively growth performance and carcass parameters.

Dietary antioxidant supplementation enhances lipid and protein oxidative stability of chicken broiler meat through promotion of antioxidant enzyme activity

Recent nutrigenomic studies have shown that animal nutrition can have a major influence on tissue gene expression. Dietary antioxidant supplements can enhance the quality of meat through modification of tissue metabolic processes. This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler breast meat stored in an oxygen-enriched package (HiOx: 80% O₂/20% CO₂) in comparison with air-permeable polyvinylchloride (PVC) or skin packaging systems during retail display at 2 to 4°C for up to 21 d. Broilers were fed either a diet with a low-oxidized (peroxide value 23 mEq of O₂/kg) or high-oxidized (peroxide value 121 mEq of O₂/kg) oil, supplemented with or without an algae-based Se yeast and organic mineral antioxidant pack for 42 d. Lipid and protein oxidation and tissue enzymatic activity were analyzed. In all packaging systems, lipid oxidation (TBA reactive substances) was inhibited by up to 32.5% (P < 0.05) with an antioxidant-supplemented diet when compared with diets without antioxidants, particularly in the HiOx and PVC systems. Protein sulfhydryls were significantly protected by antioxidant diets (e.g., by 14.6 and 17.8% for low-and high-oxidized dietary groups, respectively, in PVC d 7 samples). Glutathione peroxidase, catalase, and superoxide dismutase activities were significantly higher (P < 0.05) in antioxidant-supplemented diets compared with the basal diet, regardless of oil quality. Also, serum carbonyls were lower in broilers fed a low-oxidized antioxidant-supplemented treatment. The results demonstrate that dietary antioxidants can minimize the oxidative instability of proteins and lipids, and the protection may be linked to improved cellular antioxidant enzymatic activity.

Performance and Fatty Acid Composition of Adipose Tissue, Breast and Thigh in Broilers Fed Flaxseed: A Review

Interest on the enrichment of poultry meat with n-3 fatty acids has increased given its important role in human health. Flaxseed is the main sources of n-3 fatty acids, and contains between 45 to 71% of total fatty acids of the oil as α-linolenic acid. This paper reviews the plausibility of n-3 enrichment. Its focus is on the processing of flaxseed and begins by summarizing the benefits of supplementation on broiler performance. The literature on altering the FA deposition in different tissues is then reviewed, and the factors that affect the incorporation of n-3 PUFA into edible tissues of poultry are investigated. Flaxseed supplementation caused a reduction in the abdominal fat pad, and the main fatty acid deposited in the tissue is LNA. The use of fold-change analysis allowed interpreting and determining the variation of results within experiments that do not report data in similar units of measure. The fold change analysis identified three categories of desaturation response to feeding flaxseed to broilers, resulting in different values for EPA and DHA in both breast and thigh tissues: high, medium and low fold-changes. The use of flaxseed oil, whole or ground flaxseed 14 to 21 day before slaughter is recommended to poultry producers as feeding strategies to optimize n-3 enrichment, without compromising animal performance. Enriched DHA deposition could be accomplished feeding whole flaxseed.

Effect of dietary supplementation of the combination of gallic and linoleic Acid in thigh meat of broilers

This study was performed to investigate the combined effect of dietary supplementation of gallic and linoleic acid (GL) on the antioxidative effect and quality of thigh meat from broilers. Broilers received 3 dietary treatments: i) commercial finisher diet (control), ii) 0.5% GL (gallic:linoleic acid = 1 M:1 M), and iii) 1.0% GL during the 22 to 36 d. The pH value of broiler thigh meat was increased by GL supplementation. Water holding capacity of the thigh meat was enhanced by the 1.0% dietary GL supplementation. Antioxidative effect (total phenolic content, DPPH radical scavenging activity, ABTS(+) reducing activity, reducing power, and TBARS value) in the thigh from the broilers improved significantly with 1.0% GL. Linoleic acid and docosahexaenoic acids were higher in the broilers fed both levels of dietary GL. However, volatile basic nitrogen content and microbiological quality was not shown to be different between control and treated group. Results indicate that 1.0% dietary supplementation of GL can improve the antioxidant activity of broiler thigh meat and may enhance the meat quality.

Use of palm-oil by-products in chicken and rabbit feeds: effect on the fatty acid and tocol composition of meat, liver and plasma

This study was undertaken in the framework of a larger European project dealing with the characterization of fat co- and by-products from the food chain, available for feed uses. In this study, we compare the effects, on the fatty acid (FA) and tocol composition of chicken and rabbit tissues, of the addition to feeds of a palm fatty acid distillate, very low in trans fatty acids (TFA), and two levels of the corresponding hydrogenated by-product, containing intermediate and high levels of TFA. Thus, the experimental design included three treatments, formulated for each species, containing the three levels of TFA defined above. Obviously, due to the use of hydrogenated fats, the levels of saturated fatty acids (SFA) show clear differences between the three dietary treatments. The results show that diets high in TFA (76 g/kg fat) compared with those low in TFA (4.4 g/kg fat) led to a lower content of tocopherols and tocotrienols in tissues, although these differences were not always statistically significant, and show a different pattern for rabbit and chicken. The TFA content in meat, liver and plasma increased from low-to-high TFA feeds in both chicken and rabbit. However, the transfer ratios from feed were not proportional to the TFA levels in feeds, reflecting certain differences according to the animal species. Moreover, feeds containing fats higher in TFA induced significant changes in tissue SFA, monounsaturated fatty acids and polyunsaturated fatty acids composition, but different patterns can be described for chicken and rabbit and for each type of tissue.

Effect of antioxidant inclusion and oil quality on broiler performance, meat quality, and lipid oxidation

The objective of the present study was to evaluate the effect of antioxidant inclusion and oil quality on broiler performance, meat quality, shelf life, and tissue oxidative status. Ross 308 male broilers were allotted to a randomized complete block design in a 2 × 2 factorial arrangement. Factors consisted of antioxidant (ethoxyquin and propyl gallate) inclusion at 2 levels (0 or 135 mg/kg) and oil quality (fresh soybean oil, control diet peroxide value <1 mEq/kg, or oxidized soybean oil, diet peroxide value 7 mEq/kg). Each treatment included 12 pen replicates comprising 24 birds for a total of 1,152 birds on trial allotted to 48 pens. On the final day of the study, 1 bird from each pen was killed by cervical dislocation and used for determination of tissue oxidative status. Another 5 broilers from each pen were processed at a commercial slaughtering facility. Immediately after processing, carcasses were transported to the University of Illinois Meat Science Laboratory (Urbana) for further analysis. With the exception of 2 responses (liver vitamin A and serum vitamin A), no interactions were found between antioxidant inclusion and oil quality. Body weight and weight gain were increased by dietary antioxidant inclusion (P < 0.001) and fresh oil (P < 0.001). Feed intake was increased in broilers fed the antioxidant (P = 0.047) and fresh oil (P = 0.062). Antioxidant inclusion had no effect on G:F (P = 0.18). Antioxidant supplementation had no effect on carcass weight (P = 0.202), dressing percentage (P = 0.906), breast yield (P = 0.708), or breast ultimate pH (P = 0.625) and had minimal effect on breast color. Antioxidant supplementation (P = 0.057) reduced breast thiobarbituric acid reactive substances after 7 d of display. Fresh oil decreased liver thiobarbituric acid reactive substances, whereas antioxidant inclusion increased serum and liver vitamin A and E concentration. The presence of an antioxidant in the feed protects lipids from further oxidizing, therefore increasing broiler performance and improving shelf life when using oxidized oil.

Effect of dietary fat sources on fatty acid deposition and lipid metabolism in broiler chickens

The hypothesis tested was that dietary vegetable fats rich in saturated fatty acids, when compared with a vegetable oil rich in linoleic acid, increase fat deposition in broiler chickens and affect synthesis or oxidation, or both, of individual fatty acids. Diets with native sunflower oil (SO), a 50:50 mix of hydrogenated and native SO, palm oil, and randomized palm oil were fed to broiler chickens. Intake of digestible fat and fatty acids, whole body fatty acid deposition, hepatic fatty acid profile, and hepatic enzyme activities involved in fatty acid oxidation and synthesis were measured. The fat deposition:digestible fat intake ratio was significantly lower for the SO group in comparison with the groups fed the vegetable fats rich in saturated fatty acids. The difference between digestible intake and deposition of C18:2, reflecting its maximum disappearance rate, was highest for the SO group and lowest for the palm oil- and randomized palm oil-fed birds. The calculated minimal rate of de novo synthesis of monounsaturated fatty acids (MUFA), calculated as deposition minus digestible intake, was more than 50% lower for the SO group than for the other 3 dietary groups. Based on the fatty acid profiles in the liver, it would appear that increasing contents of C18:2 decrease the desaturation of saturated fatty acids into MUFA. It is concluded that a diet rich in C18:2 in comparison with different kinds of vegetable saturated fatty acids decreases the deposition of fat, especially of MUFA. It appears to be caused by a higher β-oxidation and a reduced de novo synthesis of MUFA, but this conclusion is not fully supported by the measured activities of enzymes involved in fatty acid synthesis and oxidation.