Effect of dietary supplementation with olive pomaces on the performance and meat quality of growing rabbits

Effects of Rosa roxburghii Tratt seed on the growth performance, meat quality, and sensory evaluation characteristics in growing rabbits

The objective of this study was to observe the effects of Rosa roxburghii Tratt seed (RRTS) on growth performance, meat quality, and sensory characteristic parameters in rabbits. Ninety-six New Zealand White rabbits were allotted to four dietary treatments containing 0 (CON), 120 (LR), 240 (MR), and 360 mg/kg (HR) RRTS. The experimental period lasted for 11 weeks. Thirty-two fattened rabbits were slaughtered, and the Longissimus thoracis et lumborum (LTL) muscle was used for analyses. The feeding of RRTS was significantly (P < 0.05) decreased the feed conversion ratio (FCR). pH45min, pH24h, lightness, redness, drip loss, and percentage of water loss were unaffected (P > 0.05) by dietary treatments, whereas MR and HR treatments resulted in lower (P < 0.05) levels of yellowness and higher (P < 0.05) levels of shear force. LR showed significantly higher (P < 0.05) meat polyphenol compounds and vitamin E relative to the CON. Moreover, compared to the CON, HR treatment showed significantly higher (P < 0.05) vitamin C and glutathione peroxidase, and LR and MR displayed lower (P < 0.05) superoxide anion radicals, and all treatments had higher levels catalase (CAT). C18:2n-6 t, C20:2, C20:3n-6, C20:4n-6, C20:5n-3, C22:5n-3, and C22:6n-3 in LTL meat were higher (P < 0.05) in MR than CON rabbits. Moreover, the LTL muscle sensory evaluation parameters of appearance and fibrousness were improved (P < 0.05). Overall, dietary supplementation with RRTS is a valid strategy for decreasing FCR, and improving meat CAT concentration, C20:5n-3 and C22:5n-3 profiles, and sensory characteristics parameters of rabbits.

Dietary supplementation with olive oil co-products rich in polyphenols: a novel nutraceutical approach in monogastric animal nutrition

In recent years, the increased demand for agri-food products to feed livestock species has stimulated research to identify novel solutions for the valorization of natural waste, according to the modern concept of a circular economy. Numerous studies have shown the use of plant-derived and agro-industrial co-products that are sources of bioactive molecules for preparing animal feeds. Supplementation with co-products derived from the extraction of olive oil (i.e., olive pomace, olive mill wastewater, olive cake and olive leaf) in diet has been widely considered in recent decades, because these wastes are produced in high quantity and their re-use represents an innovative economic and environmental strategy. Olive oil co-products are characterized by various bioactive molecules such as polyphenols, carbohydrates, proteins, and lipids. Among them, polyphenols are the nutraceuticals most studied, showing to promote health effects in both humans and animals. Olive oil co-products and their phenolic extracts have shown many beneficial and promising effects when added to the diets of monogastric animals, by improving performance parameters and maintaining the oxidative status of meat and derived products. This review provides an update on the use of olive co-products in monogastric animal (swine, poultry and rabbit) diets and their effects on the productive performance, meat quality characteristics and gut health status.

Effect of Dietary Ensiled Olive Cake Supplementation on Performance and Meat Quality of Apulo-Calabrese Pigs

The aim of this study was to evaluate the inclusion of different amounts of ensiled olive cake, a major pollutant from olive oil production, in the fattening diets of 30 Apulo-Calabrese pigs as a strategy to partially substitute the traditional cereal-based diet and improve animal performance and meat fatty acid composition. The animals, during a fattening period of 120 days, were fed with three dietary treatments containing increasing levels of ensiled olive cake: 0% (C), 20% (OC20) and 40% (OC40) on dry matter. No effect of the dietary treatment was found on the animal performance and proximate meat analysis results. The inclusion of ensiled olive cake in the diet led to differences in the fatty acid (FA) profile of intramuscular fat, with a higher proportion of monounsaturated fatty acid (MUFA; p < 0.001) and oleic acid (C8:1n-9, p < 0.001) and a lower concentration of polyunsaturated (PUFA, p < 0.001) and linoleic acid (C18:2n-6, p < 0.001). In conclusion, the supplementation of ensiled olive cake at up to 40% in the diets of fattening pigs could represent a useful strategy in Mediterranean areas to naturally improve the nutritional value of meat and valorise a by-product of the olive industry, reducing its environmental impact and promoting the exploitation of this local feed resource according to the principles of the circular economy.

On-Farm and Processing Factors Affecting Rabbit Carcass and Meat Quality Attributes

Rabbit meat has high nutritional and dietetic characteristics, but its consumption rate is comparatively lower than other meat types. The nutritional profile of rabbit meat, by comparison with beef, pork, and poultry, is attributed to relatively higher proportions of n-3 fatty acids and low amounts of intramuscular fat, cholesterol, and sodium, indicating its consumption may provide health benefits to consumers. But, the quality attributes of rabbit meat can be originated from different factors such as genetics, environment, diet, rearing system, pre-, peri-, and post-slaughter conditions, and others. Different rabbit breeds and the anatomical location of muscles may also affect the nutritional profile and physicochemical properties of rabbit meat. However, adequate information about the effect of those two factors on rabbit meat is limited. Therefore, cumulative information on nutritional composition and carcass and meat quality attributes of rabbit meat in terms of different breeds and muscle types and associated factors is more important for the production and processing of rabbits. Moreover, some studies reported that rabbit meat proteins exhibited angiotensin-converting enzyme inhibitory characteristics and antioxidant properties. The aim of this review is to elucidate the determinants of rabbit meat quality of different breeds and its influencing factors. In addition, the proven biological activities of rabbit meat are introduced to ensure consumer satisfaction.

Suitability of dried olive pulp in slow-growing broilers: performance, meat quality, oxidation products, and intestinal mucosa features

To assess the effect of dietary dried olive pulp (DOP) on growth performance, meat traits and oxidation, and intestinal mucosa features, a total of 180 male slow-growing broiler chickens (Hubbard) were divided into 3 groups and fed 3 isonitrogenous and isoenergetic diets from 14 d of age until slaughter (49 d). The treatments varied according to 3 DOP levels: a control diet without DOP (DOP0, 0%) and 2 test diets containing 5 and 10% of DOP (DOP5 and DOP10, respectively). Duodenal morphometric indices were measured at the end of the feeding period and included: villus height, crypt depth, villus-to-crypt ratio, and villus surface area. Dietary DOP had no adverse effect on growth performance, dressing percentage, or breast yield of broilers. The breast muscle pH at 24 h was significantly higher in birds fed DOP10 diet compared to those on DOP0 and DOP5 diets. Meat color was also affected by dietary treatments. Feeding DOP did not influence breast meat fatty acid composition, whereas meat from DOP-fed broilers resulted less susceptible to lipid and protein oxidation compared to control diet. Including DOP up to 10% in diet resulted in higher duodenal villus height, crypt depth, and villus height to crypt depth ratio as well as villus surface area. Based on our findings, dietary DOP supported productive traits of slow-growing broilers preserving meat from oxidation and improving intestinal morphometric features. As a result, the current study assessed that olive by-product can be used in broiler ration, resulting in a valuable ingredient as replacement for conventional feeds, which could reduce feeding costs due to the low cost of the olive by-product. Thus, using olive by-products as poultry feed may become economically feasible for producers where the olive oil industries play an important economic role.

Can the Introduction of Different Olive Cakes Affect the Carcass, Meat and Fat Quality of Bísaro Pork?

The present study aimed to evaluate the effect of the inclusion of different olive cakes in the diet of Bísaro pigs on the carcass, meat and fat. The carcasses of 40 animals fed a diet with five treatments (T1—Basic diet and commercial feed; T2—Basic diet + 10% crude olive cake; T3—Basic diet + 10% olive cake, two phases; T4—Basic diet + 10% exhausted olive cake; T5—Basic diet + 10% exhausted olive cake + 1% olive oil) were used to study the effect on carcass traits, physicochemical meat quality and lipid composition of meat and backfat. There were no significant differences between treatments for the conformation measurements performed, except for the length at the seventh and last rib (p < 0.05). The percentage of prime cuts of the carcass in Bísaro pig is within the values indicated by the Portuguese Standard 2931. No significant differences between treatments for body weight, pH and carcass weight were found. The values of ultimate pH (5.7), L* (51−52), b* (11−12) and SF (3.4−4.2) observed confirm a non-exudative and firm meat without quality deviations, such as DFD or PSE. Thus, as a general conclusion, the inclusion of different olive cakes in the diet of Bísaro pigs did not cause any negative consequences on the carcass characteristics and conformation as well as in the meat and lipidic quality. In addition, the inclusion of this olive industry by-product in the animal diet would be an important contribution to solving the problem of the great environmental impact from olive-mill wastewaters from the extractive industries.

Production Performance, Egg Quality Characteristics, Fatty Acid Profile and Health Lipid Indices of Produced Eggs, Blood Biochemical Parameters and Welfare Indicators of Laying Hens Fed Dried Olive Pulp

This study aimed to evaluate the long-term dietary effects of dried olive pulp (OP) on production performance, fatty acid profile and health lipid indices and quality characteristics of produced eggs, health and welfare indicators of laying hens. It was carried out in a commercial poultry farm using 300 Isa Brown layers at 23 weeks of age. The hens were randomly and equally divided in six dietary groups CON, OP2, OP3, OP4, OP5 and OP6, according to the inclusion rate of OP in the ration (0%, 2%, 3%, 4%, 5% and 6%, respectively). OP feeding increased the percentage of polyunsaturated fatty acids (PUFA) in eggs, decreased that of saturated fatty acids (SFA) and improved the PUFA to SFA ratio and health lipid indices, as indicated by the decrease of AI and TI and the increase in the h/H ratio of produced eggs, in a dose-dependent way. OP-fed layers presented a lower percentage of broken eggshells compared to controls. No adverse effects on birds’ performance, egg quality traits, health and welfare parameters were observed but a positive impact on Keel Bone Damage (KBD) incidence and belly plumage damage was recorded. OP feeding at the rates of 5% and 6% seems to be beneficial in improving egg nutrition quality.

Olive Pomace and Pâté Olive Cake as Suitable Ingredients for Food and Feed

Olive oil extraction generates several by-products that represent an environmental issue, mainly for Mediterranean countries where olive oil is mostly produced. These by-products represent an ecological issue for their phenolic components, such as oleuropein, hydroxytyrosol, and tyrosol. However, olive oil by-products can be treated and properly exploited in different fields for their health-promoting properties, and they represent great potential for the food and beverage, cosmetic, and pharmaceutical industries. Furthermore, recovery and treatment processes can contribute to efficient waste management, which can enhance the sustainability of the olive oil industry, and in turn, lead to relevant economic benefits. The solid waste, i.e., olive pomace, could be considered to be a suitable matrix or primary resource of molecules with high added value due to their high phenolic content. Olive pomace, at different moisture contents, is the main by-product obtained from two- or three-phase extraction systems. A commonly used centrifugal extraction system, i.e., a multiphase decanter (DMF), does not require the addition of water and can generate a new by-product called pâté or olive pomace cake, consisting of moist pulp that is rich in phenols, in particular, secoiridoids, without any trace of kernel. Although several reviews have been published on olive wastes, only a few reviews have specifically focused on the solid by-products. Therefore, the aim of the present review is to provide a comprehensive overview on the current valorization of the main solid olive oil by-products, in particular, olive pomace or pâté olive cake, highlighting their use in different fields, including human nutrition.

Health benefits of first and second extraction drum-dried pitted olive pomace

Olive pomace (OP) is the main by-product of olive oil extraction. After pit and skin removal, OP pulp has high concentrations of dietary fiber and phenolics with high antioxidant capacity. This study evaluated mice health benefits of drum-dried pitted OP pulp obtained after first and second oil extraction. Fresh OP was steam blanched, then pits and skins separated in a pulper/finisher, and pulp drum-dried and milled. OP was characterized by proximate analysis, total soluble phenolics (TSP), individual phenolics, and dietary fiber. Drum-dried pitted OP from first and second extraction was formulated at 10% and 20% in a high fat mice diet. Low fat (5%) and high fat (18%) control diets were also used for comparison. First extraction OP had higher TSP than OP from second extraction. Hydroxytyrosol was the main phenolic in OP. Mice weight gain was lower for the four OP diets compared to high and low-fat control diets. Fecal protein was high for all OP diets, indicating poor protein retention in mice, possibly by phenolics binding of protein and enzymes. Liver weight and adipose tissue were lower in mice consuming the four high fat OP diets compared to high fat control diet. Also, there was no effect on blood glucose by OP in diets. Mice gut microbiota analysis indicated that Actinobacteria decreased in the OP diets compared to the two control diets while Bacteroidetes increased, indicating a positive correlation with reduced body fat and weight. Drum-dried pitted OP is a novel agricultural by-product with its bioactive compounds having the potential to be incorporated in feeds and foods providing health benefits. PRACTICAL APPLICATION: Drum-dried pitted olive pomace can be produced from first or second olive oil extraction byproducts to be used as a shelf-stable healthy food or feed supplement.

Dried Destoned Virgin Olive Pomace: A Promising New By-Product from Pomace Extraction Process

At present the olive oil industry produces large amounts of secondary products once considered waste or by-products. In this paper, we present, for the first time, a new interesting olive by-product named “dried destoned virgin olive pomace” (DDVOP), produced by the pomace oil industry. The production of DDVOP is possible thanks to the use of a new system that differs from the traditional ones by having the dryer set at a lower temperature value, 350 °C instead of 550 °C, and by avoiding the solvent extraction phase. In order to evaluate if DDVOP may be suitable as a new innovative feeding integrator for animal feed, its chemical characteristics were investigated. Results demonstrated that DDVOP is a good source of raw protein and precious fiber; that it is consistent in total phenols (6156 mg/kg); rich in oleic (72.29%), linoleic (8.37%) acids and tocopherols (8.80 mg/kg). A feeding trial was, therefore, carried out on sheep with the scope of investigating the influence of the diet on the quality of milk obtained from sheep fed with DDVOP-enriched feed. The resulting milk was enriched in polyunsaturated (0.21%) and unsaturated (2.42%) fatty acids; and had increased levels of phenols (10.35 mg/kg) and tocopherols (1.03 mg/kg).

Impact of Fermented or Enzymatically Fermented Dried Olive Pomace on Growth, Expression of Digestive Enzyme and Glucose Transporter Genes, Oxidative Stability of Frozen Meat, and Economic Efficiency of Broiler Chickens

The use of dried olive pomace as complementary energy sources in poultry feed is still limited due to its low protein and high fiber contents. Bioconversion of olive pomace through solid-state fermentation with or without exogenous enzymes is considered as a trial for improving its nutritional value. This study aimed to evaluate the effects of fermented olive pomace with or without enzymatic treatment on the growth, modulations of genes encoding digestive enzymes and glucose transporters, meat oxidative stability, and economic efficiency of broiler chickens. A total of 1400 day-old broiler chicks (Ross 308) were randomly allocated to seven dietary treatments with 10 replicates of 20 birds/replicate. Treatments included control (basal corn-soybean diet) and other six treatments in which basal diet was replaced by three levels (7.5, 15, and 30%) of fermented olive pomace (FOPI) or enzymatically fermented olive pomace (FOPII) for 42 days. The highest body weight gain was observed in groups fed 7.5 and 15% FOPII (increased by 6.6 and 12.5%, respectively, when compared with the control group). Also, feeding on 7.5 and 15% FOPII yielded a better feed conversion ratio and improved the digestibility of crude protein, fat, and crude fiber. The expression of the SGLT-1 gene was upregulated in groups fed FOPI and FOPII when compared with the control group. Moreover, the expression of the GLUT2 gene was elevated in groups fed 7.5 and 15% FOPII. By increasing the levels of FOPI and FOPII in diets, the expression of genes encoding pancreatic AMY2A, PNLIP, and CCK was upregulated (p < 0.05) when compared with the control. Fat percentage and cholesterol content in breast meat were significantly reduced (p < 0.05) by nearly 13.7 and 16.7% in groups fed FOPI and FOPII at the levels of 15 and 30%. Total phenolic and flavonoid contents in breast meat were significantly increased in groups fed 15 and 30% FOPI and FOPII when compared with the control group and even after a long period of frozen storage. After 180 days of frozen storage, the inclusion of high levels of FOP significantly increased (p < 0.05) the levels of glutathione peroxide and total superoxide dismutase and meat ability to scavenge free radical 1,1-diphenyl-2-picrylhydrazyl. Furthermore, the highest net profit and profitability ratio and the lowest cost feed/kg body gain were achieved in groups fed 7.5 and 15% of FOPII, respectively. The results of this study indicated that dietary inclusion of 15% FOPII could enhance the growth performance and economic efficiency of broiler chickens. Moreover, a higher inclusion level of FOPI or FOPII could enhance the quality and increase the oxidative stability of frozen meat and extend the storage time.

Whole Blood Transcriptome Profiling Reveals Positive Effects of Olive Leaves-Supplemented Diet on Cholesterol in Goats

Simple Summary

The aim of this study was to analyze the whole blood transcriptome of lactating goats fed a dietary supplementation with 10% olive leaves, one of the main by-products deriving from the olive oil chain supply. This evaluation was effective in identifying the differential regulation of the gene coding for apolipoprotein B mRNA editing enzyme catalytic subunit 2 (APOBEC2), which showed downregulated in goats that received the dietary supplementation. Taking into account the strong association between plasma apoB and low-density lipoprotein, an evaluation was performed of both blood and milk cholesterol. The obtained data demonstrated a significant lower concentration of circulating cholesterol and cholesterol released into the milk through the mammary gland, demonstrating positive effects of olive leaves feeding on animal welfare and potential health benefits for consumers.

Abstract

Agro-industrial by-products represent an important source of compounds credited with high biotechnological potential. In the last decade, considerable interest has developed toward the use of these matrices as dietary supplements in the zootechnical field, paying particular attention to the qualitative aspects associated with animal products. However, less is known about the effect of these matrices on gene expression and thus on animal metabolism. Therefore, the aim of this study was to analyze the whole blood transcriptome of lactating goats fed a dietary supplementation with 10% olive leaves (OL), one of the main by-products deriving from the olive oil chain supply. By applying a false discovery rate (FDR) < 0.05 and a Log2 Fold change (Log2Fc) lower than −0.5 or higher than +0.5, it was possible to identify the differential regulation of gene coding for the apolipoprotein B (apoB) mRNA editing enzyme catalytic subunit 2 (APOBEC2), which showed downregulation in goats that received the dietary supplementation. An evaluation of both blood and milk cholesterol was performed, taking into account the strong association between plasma apoB and low-density lipoprotein (LDL). Results showed significantly lower concentrations of circulating cholesterol and cholesterol released into the milk through the mammary gland, demonstrating positive effects of OL feeding on animal welfare and potential health benefits for consumers.

Dietary Polyphenol Supplementation in Food Producing Animals: Effects on the Quality of Derived Products

Simple Summary

Polyphenols are secondary plant metabolites mainly known for their antioxidant properties. Their use as feed additives in the nutrition of farm animals is becoming increasingly popular as they are particularly exposed to oxidative stress which is reflected in a lipoperoxidation of the final product. For this reason, it is essential to preserve the quality and the safety of meat and milk products by attenuating oxidative deterioration. Moreover, polyphenols present the advantage of being more acceptable to the consumers than synthetic counterparts, as they are considered to be “non-toxic”. The present review presents an overview of several studies focused on the dietary supplementation of polyphenols to monogastric and ruminants, as well as their direct addition to meat and dairy products, with particular emphasis on their antioxidant effects on the final product.

Abstract

The growing interest in producing healthier animal products with a higher ratio of polyunsaturated to saturated fatty acids, is associated with an increase in lipoperoxidation. For this reason, it is essential to attenuate oxidative deterioration in the derived products. Natural antioxidants such as polyphenols represent a good candidate in this respect. The first part of the review highlights the occurrence, bioavailability, and the role of polyphenols in food-producing animals that, especially in intensive systems, are exposed to stressful situations in which oxidation plays a crucial role. The second part offers an overview of the effects of polyphenols either supplemented to the diet of monogastric and ruminants or added directly to meat and dairy products on the physicochemical and sensorial properties of the product. From this review emerges that polyphenols play an important, though not always clear, role in the quality of meat and meat products, milk and dairy products. It cannot be ruled out that different compounds or amounts of polyphenols may lead to different results. However, the inclusion of agro-industrial by-products rich in polyphenols, in animal feed, represents an innovative and alternative source of antioxidants as well as being useful in reducing environmental and economic impact.

Functional compounds from olive pomace to obtain high-added value foods - a review

Olive pomace, the solid by-product from virgin olive oil extraction, constitutes a remarkable source of functional compounds and has been exploited by several authors to formulate high value-added foods and, consequently, to foster the sustainability of the olive-oil chain. In this framework, the aim of the present review was to summarize the results on the application of functional compounds from olive pomace in food products. Phenolic-rich extracts from olive pomace were added to vegetable oils, fish burgers, fermented milk, and in the edible coating of fruit, to take advantage of their antioxidant and antimicrobial effects. Olive pomace was also used directly in the formulation of pasta and baked goods, by exploiting polyunsaturated fatty acids, phenolic compounds, and dietary fiber to obtain high value-added healthy foods and / or to extend their shelf-life. With the same scope, olive pomace was also added to animal feeds, providing healthy, improved animal products. Different authors used olive pomace to produce biodegradable materials and / or active packaging able to increase the content of bioactive compounds and the oxidative stability of foods. Overall, the results highlighted, in most cases, the effectiveness of the addition of olive pomace-derived functional compounds in improving nutritional value, quality, and / or the shelf-life of foods. However, the direct addition of olive pomace was found to be more challenging, especially due to alterations in the sensory and textural features of food. © 2020 Society of Chemical Industry.

Dietary Supplementation with Olive Mill Wastewater in Dairy Sheep: Evaluation of Cheese Characteristics and Presence of Bioactive Molecules

Simple Summary

Using polyphenols from olive oil waste as feed supplements in animal diets can be a strategy to reduce adverse environmental effects of this by-product and to enhance the quality of products of animal origin. The aim of the study was to assess the effects of adding a polyphenolic concentrate from olive oil wastewater to a typical sheep diet on the nutraceutical and quality characteristics of cheese. The experiment was carried out on thirty-six Sarda ewes, divided into two homogenous groups fed a standard diet composed of hay and concentrate. In one of the two diets, the concentrate was supplemented (25 g/kg) with polyphenols obtained from olive mill wastewater using a special filtration system. Data showed that the polyphenol supplementation in the ewe’s diet resulted in the presence of tyrosol and hydroxytyrosol sulphate metabolites in milk and cheese. Furthermore, these compounds were able to provide a direct antioxidant effect on cheese with no modification in its chemical composition.

Abstract

The aim of the study was to define the chemical characteristics, antioxidant capacity, oxidative status, sensory properties, and the presence of polyphenols in ovine cheese obtained after dietary administration of spray-dried olive mill wastewater (SDP). SDP is a waste from olive oil production rich in bioactive molecules obtained by further processing the olive mill wastewater through a spray-drying system. Thirty-six sheep were randomly assigned to two experimental groups that received a standard diet based on hay and concentrate. The concentrate fed to the SDP group was supplemented with SDP at a rate 25 g/kg (as fed). The trial lasted 9 weeks. Milk from the two treatment groups was separately collected and used for manufacturing cheese. Cheese quality parameters and proximate composition were not affected by the dietary treatment, whereas the antioxidant status and oxidative stability of cheese were positively affected. Polyphenol analyses in cheese were performed through liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The concentration of hydroxytyrosol and tyrosol, and their sulphate metabolites, were higher in cheese from supplemented sheep. These findings suggest that polyphenol metabolites can play a major role in the beneficial effects observed in food produced from sheep fed SDP.

Olive Cake Meal and Bacillus licheniformis Impacted the Growth Performance, Muscle Fatty Acid Content, and Health Status of Broiler Chickens

Olive cake meal (OCM) is characterized by its high nutritional value and is used as an alternative source of protein and fats in poultry diets. However, due to the high percentage of fiber in OCM, beneficial bacteria cells are used to improve the digestion rates. Therefore, the influence of OCM and Bacillus licheniformis (BL) on the growth, nutrient utilization, blood chemistry, and muscle fatty acid profile of broilers was exclusively examined in this study. Three hundred and sixty birds were randomly divided into six experimental groups (6 replicates/10 birds each): Control, OCM (2%), OCM (4%), BL, OCM (2%)/BL, and OCM (4%)/BL groups. Although feed intake was not meaningfully influenced by dietary treatments, weight gain was enhanced and feed conversion ratio was reduced (p < 0.05). The abdominal fat was lowered in broilers fed OCM (2%), OCM (4%), OCM (2%)/BL, and OCM (4%)/BL diets without a difference to those fed BL only (p < 0.05). Interestingly, blood total protein, albumin, Newcastle disease (ND) titer, and high-density lipoprotein (HDL) cholesterol were significantly increased, while total cholesterol was decreased by the mixture of OCM and BL (p < 0.05). Muscle oleic and linoleic acids, as well as vitamin E, increased significantly in broilers fed both OCM (4%) and BL, while linolenic acid increased in all groups except those fed BL and control diets (p < 0.05). Liver malondialdehyde (MDA) was decreased by feeding BL or both OCM at 2% or 4% and BL (p < 0.05). In conclusion, the inclusion of BL to OCM diets resulted in improved fat utilization and, accordingly, enhanced growth, nutrient utilization, and antioxidative response in broilers. Based on the obtained results, it is recommended to use BL to improve the nutritional value of OCM and to increase the feed utilization of OCM by broilers.

Effects of Dried Olive Pulp Dietary Supplementation on Quality Characteristics and Antioxidant Capacity of Pig Meat

Olive pulp belongs to agro-industrial by-products, and its addition into livestock diets generally result in neutral or positive effects on performance. However, the data concerning the effects of olive by-products on pork meat characteristics are scarce. The aim of this preliminary study was therefore to examine the effects of dried olive pulp (DOP) dietary supplementation on quality parameters and oxidative stability of pig meat. Twenty finishing pigs were allocated to two groups: C that was provided with a control diet, and DOP that was fed with an isonitrogenous and isoenergetic diet supplemented with dried olive pulp at the level of 50 g/kg or 5%. As indicated, cold carcass weight, pH, lightness, redness, cooking loss, and tenderness were not influenced by DOP inclusion. Only meat yellowness (a*) was significantly decreased in DOP meat samples. Moreover, meat oxidation values tended to decrease in the DOP group after one day, but no further differences were observed after four, six, and eight days of refrigerated storage. It can be concluded that DOP dietary supplementation could be recommended as a feasible approach, especially in the Mediterranean region to reduce diet formulation costs, while no significant side effects on pork meat quality are observed.

Immuno-physiological and antioxidant responses of Siberian sturgeon (Acipenser baerii) fed with different levels of olive pomace

Nowadays, use of the natural plant derivatives as an immunostimulant in aquaculture is becoming more useful than antibiotics which are destructive to target animals, consumers, and the environment. The present study aimed to evaluate the efficacy of dietary substitution of wheat flour at 2, 5, 7.5, and 10% of olive pomace (OP₂, OP₅, OP_7.5, and OP₁₀) in some immune-physiological and antioxidant variables of yearling Siberian sturgeon (Acipenser baerii) weighing 165 ± 6.8 g at 19.1 ± 1.52 °C for 56 days. Fifteen fish per tank were randomly accommodated in triplicates per treatment and the control group was also included. No significant difference was seen in hematological indices including red blood cells (RBS) and immunocompetent cell population sizes among the treated groups (P > 0.05). Also, malondialdehyde (MDA) activity and superoxide dismutase (SOD) in serum remained unaffected in different treatments (P > 0.05). Total protein (TP), high-density lipoprotein (HDL), catalase (CT), and lysozyme were affected by dietary OP levels (P < 0.05), and the highest value was observed at the OP₅ diet, but no influence was seen in serum IgM by OP. These data show that application of olive pomace as a partial substitute of wheat flour in the diet of Siberian sturgeon is feasible with stimulatory and antioxidant functions.

Thyme oil inclusion levels in a rabbit ration: Evaluation of productive performance, carcass criteria and meat quality under hot environmental conditions

The aim of this study was to determine the impact of thyme essential oil supplementation in rabbit rations on performance, carcass criteria, and meat quality under hot environmental conditions. A total of 75, 4-week-old Californian male rabbits were assigned to 5 dietary treatments until 12 weeks of age. The rabbits were reared in an open house system (38 °C average ambient temperature and 26% to 35% relative humidity). Treatments were as follows: unsupplemented standard ration, negative control (CON); standard ration supplemented with 1.50 g/kg olive oil as carrier, positive control (POS); POS + 50 mg/kg thyme oil (TO1); POS + 100 mg/kg thyme oil (TO2); and POS + 150 mg/kg thyme oil (TO3). Dietary thyme oil up to 150 mg/kg improved (P < 0.001) feed intake and growth performance in comparison to CON. The highest average daily gain and most efficient feed conversion ratio (linear, P < 0.001 and quadratic, P < 0.001) were found for TO1 followed by TO2, TO3 and POS, respectively. The incorporation of thyme oil improved (P < 0.001) carcass criteria and decreased (P < 0.001) perirenal and scapular fat without any side effects on internal organs. Notably, the water holding capacity of rabbit meat was greater (P < 0.001), and the lipid oxidation was lower (P < 0.01) in rabbits fed treated rations compared with CON. Differences were also recorded in oxymyoglobin and metmyoglobin contents in rabbit meat among treatments. In conclusion, thyme oil of a specified composition and to be added to a rabbit ration up to 100 mg/kg using 1.50 g/kg olive oil as a carrier can be used as an efficient feed additive for improving productive performance of rabbits under hot environmental conditions.

Effect of a cauliflower (Brassica oleraceae var. Botrytis) leaf powder-enriched diet on performance, carcass and meat characteristics of growing rabbit

The aim of this study was to investigate the effect of a cauliflower leaf powder (CLP)-enriched diet on the performance, quality and antioxidative potential of rabbit meat. No significant differences were found for live performance parameters between rabbits fed with standard (SD) and CLP diet. Dietary supplementation influenced the meat traits of rabbits: CLP meat showed significantly lower drip loss after 48 h, cooking loss, and a significantly higher lightness (L*) and redness (a*) values, vitamin A and vitamin E content, and oxidative stability, compared to SD meat. Moreover, the CLP supplementation caused a significant decrease in SFA and increase in PUFA percentage of rabbit intramuscular fat. The statistical analysis also showed a significant effect of dietary fortification on phenolic content and antioxidant activity of rabbit meat which resulted higher in meat of CLP group. This study highlighted that dietary fortification with CLP is a valid strategy to produce rabbit meat with better technological and functional quality.

Effect of substituting guinea grass with sunflower hulls on production performance and digestion traits in fattening rabbits

The objective of this study was to evaluate the use of sunflower hulls (SH) to substitute guinea grass (GG), traditionally used as a fibre source in the diets of fattening rabbits, on production performance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, gastrointestinal tract development and caecal fermentation. A total of 160 mixed sex Hyla commercial meat rabbits were allocated to 4 experimental groups (40 per treatment) differing in the SH level inclusion in the diet offered to rabbits from 40 to 90 d of age: 0, 30, 60 and 90 g/kg on as-fed basis: SH0, SH30, SH60 and SH90 groups, respectively. Growth performance was recorded from 47 to 90 d of age, CTTAD of nutrients from 86 to 90 d of age, and gastrointestinal tract development, caecal fermentation and carcass traits were determined at 90 d of age. Increasing substitutions of SH in the diet indicated effects on growth performance, as higher feed intake and lower feed efficiency were observed in SH90 compared with SH0 (<em>P</em>-linear&lt;0.05). Moreover, the higher SH substitution diet (SH60 and SH90) increased the relative caecum weight (<em>P</em>-linear&lt;0.05). A linear negative effect of SH inclusion was observed for the digestibility of neutral detergent fibre (CTTAD from 0.294 to 0.232) and acid detergent fibre (CTTAD from 0.182 to 0.136; <em>P</em>-linear&lt;0.05). Dietary SH substitution level had a quadratic effect on the villus height of the duodenum, jejunum and ileum obtained (<em>P</em>-quadratic&lt;0.05), and the highest were observed in the SH60 group. There was a quadratic effect on the pH of caecum content (<em>P</em>-quadratic&lt;0.05), and the lowest was 6.08 in SH30 group. The total volatil fatty acids increased linearly with increasing SH in diets (from 71.11 to 76.98 mmol/L; <em>P</em>-linear&lt;0.05), and when dietary SH increased, the proportion of acetate tended to increase (<em>P</em>-linear&lt;0.05), and the proportions of propionic and butyric were decreased (<em>P</em>-linear&lt;0.05, respectively). Substitution of GG with SH had no effect on carcass characteristics and meat quality. The current work shows that SH can replace up to 60 g/kg in diets for fattening rabbits, with no adverse impact on aspects of production performance or digestion traits.

Olive mill wastewater phenolic concentrate as natural antioxidant against lipid-protein oxidative deterioration in chicken meat during storage

Considering that many plant-derived substances show antioxidant and antimicrobial properties, natural antioxidant administered through feed in livestock animals could increase the shelf life of meat and meat products. The aim of this work was to study the effect of olive oil by-products on chicken meat lipid and protein oxidation and oxidative stability during storage. Two hundred and ninety-seven 22-day-old fast growing (Ross 308) female chicks were randomly assigned to three experimental grower-finisher diets: i) a basal control diet (CTR), ii) CTR diet supplemented with a low dosage (4.8%) of olive mill wastewater extract (L-OW) and iii) CTR diet supplemented with a high dosage (9.9%) of olive mill wastewater extract (H-OW). Breast meat of animals belonging to each experimental group was sliced, overwrapped with oxygen-permeable packaging and analysed at three different storage times (zero, three and seven days). At the three sampling times considered, for all samples, colour coordinates (a*), saturation index, Hue angle, peroxide value, thiobarbituric reactive substance, carbonyl assay and the oxygen radical absorbance capacity determinations were performed. No differences in colour were detected among the groups in all the sampling times considered. In conclusion, the supplementation of chicken diet with olive mill wastewater extract (OW) affected oxidation of meat, retarding lipid and protein oxidation and improving antioxidant activity during storage.

White lupin bran and its effects on the growth performance, carcass characteristics and digestibility of nutrients in fattening rabbits

<p>The purpose of the present study was to evaluate the effects of including white lupin bran (WLB) in a fattening rabbit diet on growth, carcass traits and nutrient digestibility. The C diet (control) based on alfalfa meal, whereas the WLB 5 and WLB 15 diets were based on white lupin bran (crude protein 152 g/kg, neutral detergent fibre 524 g/kg as-fed basis). The WLB 5 diet contained 50 g of white lupin bran/kg instead of 50 g of alfalfa meal/kg, whereas the WLB 15 diet contained 150 g of white lupin bran/kg, 5 g of soybean meal/kg and 10 g of sugar beet pulp/kg instead of 165 g of alfalfa meal/kg. The diets had similar digestible protein/digestible energy ratios. A total of 150 Hyplus rabbits between the ages of 30 to 73 d were randomly allocated into one of 3 groups and fed one of the 3 experimental diets. Additionally, another 30 Hyplus rabbits (10 per dietary treatment) at the age of 30 d were selected to determine coefficients of total tract apparent digestibility (CTTAD) of diets between 63 and 67 d of age. The dietary treatments did not affect the final live weight of rabbits (mean=2969 g). There was a higher feed intake (+30 g/d; P&lt;0.001) in both groups of rabbits fed the WLB 5 and WLB 15 diets compared to rabbits fed the C diet, which led to impaired feed conversion ratios (P&lt;0.001). Sanitary risk index was not affected by dietary treatment. The rabbits fed the WLB 15 diet exhibited a higher drip loss percentage (+0.65%; P&lt;0.001) than the rabbits fed the other diets, as well as a lower dressing-out percentage (by 1.6%; P=0.024). The CTTAD of the lignocellulose fraction (acid detergent fibre) was significantly higher in rabbits fed the WLB 5 and WLB 15 diets than in those fed the C diet. White lupin bran may be used as a dietary fibrous by-product without significant impairment of the nutritive value of the diet. This lupin by-product can be included in diets for fattening rabbits up to 15% as a partial replacement of alfalfa meal.</p>

Effects of olive-cake supplementation on fatty acid composition, antioxidant status and lipid and meat-colour stability of Barbarine lambs reared on improved rangeland plus concentrates or indoors with oat hay plus concentrates

The effects of feeding system (indoor vs rangeland) and olive-cake (OC) supplementation (control vs supplemented) on fatty acid (FA) composition, lipid oxidation status and meat-colour stability were studied. Lambs were fed indoor with hay (OH) or reared on improved rangeland (RL). All lambs received concentrate at a rate of 400 g/head.day. Twenty-four 6-month-old Barbarine lambs with an average weight of 24.3 ± 1.1 kg were assigned into the following four groups: OH without OC, OH with OC, RL without OC and RL with OC. Supplemented groups received 280 g/day of OC. Lambs were reared for ~3 months and then slaughtered at 33 kg. Feeding lambs on rangeland increased proportions of polyunsaturated fatty acids (PUFA, P < 0.05), n-3 PUFA (P < 0.01) and long-chain n-3 PUFA (P < 0.01) and decreased those of C16:0 and monounsaturated fatty acids (P = 0.052). Higher PUFA : saturated FA (SFA) (P < 0.001) and lower n-6 : n-3 PUFA (P < 0.01) ratios were found for RL lambs. The peroxidisability index was higher (P = 0.024) for RL lambs. Whereas, a lower malondialdehyde concentration (P < 0.001) was found for meat of RL group after 5-day storage, because of a higher vitamin E concentration (P < 0.001) and catalase activity (P = 0.002). Moreover, colour was more stable for meat of RL lamb. OC supplementation reduced only superoxide dismutase activity (P = 0.033) and did not have any effect on lipid peroxidation and colour stability. No interactions were noted between the feeding system and olive-cake supplementation. Meat lambs produced on rangeland had a healthier fatty acid composition. Lipids were more stable to oxidation than was meat produced indoor with hay and concentrate.

Effect of substituting guinea grass with soybean hulls on production performance and digestion traits in fattening rabbits

The objective of this study was to evaluate the use of soybean hulls (SH) to substitute guinea grass (GG), traditionally used as fibre source in the diets of fattening rabbits on performance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, gastrointestinal tract development and caecum fermentation. A total of 160 mixed sex Hyla commercial meat rabbits were allocated to 4 experimental groups (40 per treatment) differing in the SH level inclusion in the diet offered to rabbits from 40 to 90 d of age: 0, 50, 100 and 200 g/kg as-fed basis: SH0, SH50, SH100 and SH200 groups, respectively. Growth performance was recorded from 40 to 90 d of age, CTTAD of nutrients from 86 to 90 d of age, and gastrointestinal tract development, caecum fermentation and carcass traits were determined at 90 d of age. Average daily feed intake and the feed/gain ratio were lower in SH100 and SH200 groups than in SH0 group (P0.05). In conclusion, our results suggest that SH can substitute GG in the diets of fattening rabbits up to 200 g/kg in diet with no adverse effects on the growth performance, feed efficiency, carcass traits and meat quality.

Tribology study of hydroxyapatite (HAp) scaffold blended single based binder via rheology and mechanical properties

Purpose

This paper aims to investigate the vital characteristic of an innovative ceramic injection molding (CIM) process for orthopedic application with controlled porosity and improved tribological and mechanical properties which were affected by complex tribological interactions, whether lubricated like hip implants and other artificial prostheses. The main objective is to maximize the usage of palm stearin as a single based binder as the function of flow properties during injection molding process.

Design/methodology/approach

The binder used in this present study consists of 100 per cent palm stearin manufactured by Kempas Oil Sdn Bhd and supplied by Vistec Technology Sdn Bhd. The feedstock was prepared by using a Z-blade mixer (Thermo Haake Rheomix OS) and Brabender mixer model R2400. The feedstock prepared was injection molded using a manually operated vertical benchtop machine with an average pressure of about 5-7 bars. The firing step included the temporary holds at intermediate temperatures to burn out organic binders. At this stage, the green molded specimen was de-bound using a single-step wick-debinding method.

Findings

The maximum content of ceramic material is applied to investigate the efficiencies of net formulation that can be achieved by ceramic materials. The longer the viscosity will change with shear rate, the higher the value of n obtained instead. From the slope of the curves obtained in Figure 3, the value of n for the feedstock was determined to be less than 1, which indicates a pseudoplastic behavior and suitability for the molding process. Moreover, high shear sensitivity is important in producing complex and intrinsic specimens which are leading products in the CIM industry.

Originality/value

The feedstock containing HAp powder and palm stearin binder was successfully prepared at very low temperature of 70°C, which promoting a required pseudo-plastic behavior during rheological test. The single binder palm stearin should be optimized in other research works carried out, as palm stearin is most preferred compared to other polymeric materials that provided high energy consumption when subjected to the sintering process. Besides the binder is widely available in Malaysia, low cost and harmless effect during debinding process.

Nutritive value of co-products derived from olivecake in rabbit feeding

<p>Olive cake is one of the main agro-industrial co-products in the Mediterranean area of Spain, with high availability almost all year round. In addition, most of the product is dehydrated, which increases its interest in monogastric species such as rabbits. Nineteen samples from various Spanish oil mills using different processing methods were analysed for their chemical composition and in vitro digestibility. The average composition was [in dry matter (DM) basis]: ash (9.64%), neutral detergent fibre (52.0%), acid detergent fibre (36.8%), acid detergent lignin (19.1%), crude protein (CP) (11.3%), insoluble neutral (8.0%) and acid detergent crude protein (5.15%), ether extract (10.9%) and gross energy (21.9 MJ/kg). DM and CP in vitro digestibility were, on av., 53.4 and 41.4% respectively. High variability was observed among the samples for most of the traits studied. Fibrous fractions were highly correlated among them and negatively with ether extract content, whereas CP was little related to other feed components. A stepwise regression analysis allowed us to determine regression equations to predict DM and CP in vitro digestibilities from chemical composition (R2=0.80 and 0.91, respectively). As regards the current results, olive cake has potential use for rabbits as a source of insoluble fibre and lignin. Crude samples (not oil extracted) combined with sieving to retain the smaller particles have an additional interest, because of their higher energy value and significant supply of high quality fat.</p>