Effect of a Carotenoid Extract from Citrus reticulata By-Products on the Immune-Oxidative Status of Broilers

Although carotenoids generally possess antimicrobial and antioxidant properties, the in vivo synergistic action of carotenoid blends derived from plant-based by-products has not been thoroughly studied. Therefore, the carotenoid characterization and antimicrobial potential of Citrus reticulata extract as well as the impact of this carotenoid-rich extract (CCE) dietary supplementation on the performance, meat quality, and immune-oxidative status of broiler chickens were determined. One hundred and twenty one-day-old hatched chicks (Ross 308) were allocated to two dietary groups, with four replicate pens of 15 birds each. Birds were fed either a basal diet (CON) or the basal diet supplemented with 0.1% CCE (25 mg carotenoid extract included in 1 g of soluble starch) for 42 d. β-Cryptoxanthin, β-Carotene, Zeaxanthin, and Lutein were the prevailing carotenoid compounds in the Citrus reticulata extract. The CCE feed additive exerted inhibitory properties against both Gram-positive (Staphylococcus aureus) and negative (Klebsiella oxytoca, Escherichia coli, and Salmonella typhimurium) bacteria. Both the broiler performance and meat quality did not substantially differ, while the breast muscle malondialdehyde (MDA) concentration tended to decrease (p = 0.070) in the CCE-fed broilers. The inclusion of CCE decreased the alanine aminotransferase and MDA concentration, and the activity of glutathione peroxidase, while the activity of superoxide dismutase was increased in the blood. Catalase and NADPH oxidase 2 relative transcript levels were significantly downregulated in the livers of the CCE-fed broilers. Additionally, Interleukin 1β and tumor necrosis factor (TNF) relative transcript levels were downregulated in the livers of the CCE- fed broilers, while TNF and interferon γ (IFNG) tended to decrease in the spleens and bursa of Fabricius, respectively. The present study provided new insights regarding the beneficial properties of carotenoids contained in Citrus reticulata in broilers’ immune-oxidative status. These promising outcomes could be the basis for further research under field conditions.

Immune-Related Gene Expression Profiling of Broiler Chickens Fed Diets Supplemented with Vinification Byproducts: A Valorization Approach II

Simple Summary

The valorization of grape byproducts appears to be a sustainable bioeconomic strategy that could promote the substitution of synthetic with natural antioxidant compounds in the food and feed industry. The nutritional physiology of broiler chickens requires special attention to the interactions between nutrients and antioxidant mechanisms since the stressor signals of factory farming could impair the immune status, resulting in detrimental effects on broilers’ performance. The objective of this study was to assess the inclusion of grape byproducts (grape pomace, wine lees, and stem extract) on the transcriptional profiling of genes regulating the immune system in the liver, bursa of Fabricius, and spleen. The dietary supplementation of grape byproducts rich in polyphenolic compounds decreased the mRNA levels of the predominant pro-inflammatory receptor in the liver, while in the spleen, the stem extract diet upregulated the aforementioned receptor. Upregulation of interleukin 8 was observed in the bursa of Fabricius and spleen of the stems extract-fed broilers. Although grape byproducts depicting a sustainable source of bioactive compounds with vast antioxidant potential, there were unveiled preliminary insights for immune stimulation at the transcriptional level.

Abstract

The valorization of vinification byproducts portrays a promising bioprocess for the enrichment of animals’ diet with bioactive compounds, such as polyphenols, which could regulate the immune response. Therefore, the impact of dietary grounded grape pomace (GGP), wine lees extract (WYC), and grape stem extract (PE) on the relative transcript level of immune related genes of broiler chickens were examined. Two hundred forty, one-day-old as hatched (male/female) chicks (Ross 308) were allocated to four dietary groups, with four replicate pens each with 15 birds. Birds were fed either a basal diet (CON) or the basal diet supplemented with 2.5% GGP, or 0.2% WYC, or 0.1% PE for 42 d. The relative expression of immune-related genes was investigated using a real-time PCR platform. The mRNA levels of Toll-like Receptor 4 (TLR4) were downregulated (p = 0.039) in the liver of broilers fed the GGP-containing diet compared to the CON, while in the spleen of PE-fed broilers, TLR4 was significantly upregulated (p = 0.043). The mRNA levels of interleukin 8 (IL8) tended to upregulate (p = 0.099) in the bursa of Fabricius and were significantly increased (p = 0.036) in the spleen of broilers fed the PE diet. Vinification byproducts depict a promising sustainable source of polyphenols for the poultry feed industry, but more research is needed under field conditions.

Effect of Farming System (Organic vs. Conventional) and Season on Composition and Fatty Acid Profile of Bovine, Caprine and Ovine Milk and Retail Halloumi Cheese Produced in Cyprus

The present work aimed to evaluate the effect of farming practices and season on the fat and protein content and fatty acid (FA) profile of milk and Halloumi cheese produced in Cyprus. Over a year, raw bulk-tank milk samples from cow, goat, and sheep farms were collected seasonally from all organic (11) and representative conventional (44) dairy farms, whereas Fresh Halloumi cheese samples were collected monthly from retail outlets (48 organic and 48 conventional samples in total). The different farming practices did not affect the milk fat content of ruminants, while protein levels were decreased in organic bovine and caprine milk. Under organic farming practices, milk and cheese contained increased values of total mono-unsaturated FA (MUFA) and poly-unsaturated FA (PUFA), and specific FA, such as oleic, conjugated linoleic, linoleic, and α-linolenic acids. Total saturated FA (SFA) levels were particularly decreased in organic samples and, consequently, the atherogenic indices of milk and cheese were decreased. Season influenced milk and Halloumi cheese FA profile; spring samples had lower SFA and higher PUFA and MUFA concentrations. Overall, the organic farm practices improved the lipid profile of milk and Halloumi cheese, which is more likely attributed to the different feeding strategies applied in organic dairy farms.

Application of Olive By-Products in Livestock with Emphasis on Small Ruminants: Implications on Rumen Function, Growth Performance, Milk and Meat Quality

The olive oil industry has a leading position in the Mediterranean countries, resulting in the production of considerable quantities of the respective by-products (OB) that constitute an important environmental issue. OB contain valuable nutrients and bioactive components that can be re-used under the bioeconomy strategy, and several chemical, physical, and biological processes have been evaluated with the intention to improve their nutritional value. One feasible application of OB is their incorporation in the diets of livestock and especially ruminants due to their high fiber content. As indicated by numerous studies, OB dietary supplementation increases the levels of monounsaturated fatty acids (MUFAs) and decreases that of saturated fatty acids (SFAs) in the milk and meat of ruminants with beneficial effects for consumers' health. At the same time, environmental impact and feeding costs are reduced without detrimental effects on ruminal fermentation, nutrients utilization, growth performance, carcass traits, milk yield and composition.

Impact of Mycotoxins on Animals' Oxidative Status

Mycotoxins appear to be the "Achilles' heel" of the agriculture sector inducing enormous economic losses and representing a severe risk to the health of humans and animals. Although novel determination protocols have been developed and legislation has been implemented within Europe, the side effects of mycotoxins on the homeostatic mechanisms of the animals have not been extensively considered. Feed mycotoxin contamination and the effects on the antioxidant status of livestock (poultry, swine, and ruminants) are presented. The findings support the idea that the antioxidant systems in both monogastrics and ruminants are challenged under the detrimental effect of mycotoxins by increasing the toxic lipid peroxidation by-product malondialdehyde (MDA) and inhibiting the activity of antioxidant defense mechanisms. The degree of oxidative stress is related to the duration of contamination, co-contamination, the synergetic effects, toxin levels, animal age, species, and productive stage. Since the damaging effects of MDA and other by-products derived by lipid peroxidation as well as reactive oxygen species have been extensively studied on human health, a more integrated monitoring mechanism (which will take into account the oxidative stability) is urgently required to be implemented in animal products.

Elemental Metabolomics: Modulation of Egg Metallome with Flavonoids, an Exploratory Study

The basic principles of elemental metabolomics were applied to investigate whether alteration of egg metallome could be achieved after two flavonoids addition, namely hesperidin and naringin in diets of laying hens. A total of 72 hens were divided into six groups: Control (C) (basal diet), E1 (750 mg hesperidin/kg diet), E2 (1500 mg hesperidin/kg diet), N1 (750 mg naringin/kg diet), N2 (1500 mg naringin/kg diet), and VE (200 mg vitamin E/kg diet). The same diet was provided to birds of all treatments, with the exception of added supplements. The diets had the same vitamin and mineral premix; thus, all birds received the same number of elements because no differences on feed intake existed. The egg elemental profile consisted of As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, V, Zn, and was determined using ICP-MS. Flavonoid supplementation altered the elemental profile. Most notably, in both albumen and yolk, hesperidin increased Ni, Pb, and Sr concentration while it decreased that of Co and Sb. Naringin increased Cd, Cr, Cu, Ni, and V and lowered the concentration of Co and Sb in both yolk and albumen. Vitamin E supplementation, in comparison to the control, decreased Co in both albumen and yolk and also raised Sb in albumen. Flavonoid presence led to the differences in deposition of certain trace minerals in egg compared to that of hens fed a basal diet or a diet with vitamin E supplementation.

Antioxidant status, meat oxidative stability and quality characteristics of lambs fed with hesperidin, naringin or α-tocopheryl acetate supplemented diets

BACKGROUND

Dietary supplementation of sheep with bioactive compounds such as citrus flavonoids appears as a great alternative for improving meat antioxidant capacity and could also have beneficial effects on growth performance, carcass traits and meat quality characteristics. An experiment was therefore conducted to examine the effects of hesperidin or naringin dietary supplementation on lambs' growth performance, antioxidant status and meat quality characteristics. Forty-four male 3-month-old Chios lambs were randomly assigned to four groups: C, fed with a basal diet, or H or N or VE offered the same diet further supplemented with hesperidin at 2500 mg or naringin at 2500 mg or α-tocopheryl acetate (vitamin E) at 200 mg kg^-1 feed respectively. At the end of the experiment (day 35), samples of longissimus thoracis muscle were collected for meat quality evaluation.

RESULTS

Both flavonoids and vitamin E dietary supplementation reduced plasma malondialdehyde (MDA) levels on day 35 (P < 0.05). No significant differences were observed in performance traits and meat quality characteristics among the experimental groups (P > 0.05). Hesperidin and naringin also reduced MDA levels in meat stored at 4 °C for up to 8 days (P < 0.05), although to a lesser extent than α-tocopheryl acetate.

CONCLUSION

Incorporation of flavonoids in sheep diets resulted in an improvement of plasma and meat antioxidant capacity. © 2018 Society of Chemical Industry.

Enrichment of Animal Diets with Essential Oils-A Great Perspective on Improving Animal Performance and Quality Characteristics of the Derived Products

Food industry operates in a competitive market and is continually facing challenges to retain or even increase its market share. Consistent high-quality animal products are required to maintain consumer confidence and consumption. Enrichment of foods with bioactive compounds such as the essential oils appears to improve quality characteristics of the derived products and protects consumers against oxidation and bacterial spoilage effects. Synthetic additives are nowadays questioned due to their suspected carcinogenic potential, and therefore extensive research has been undertaken to identify safe and efficient alternatives. Aromatic plants and their respective essential oils belong to natural products and are generally used in pig, poultry, rabbit and ruminant nutrition. The inclusion of essential oils in livestock diets is nowadays becoming a common practice, since dietary supplementation has been proven a simple and convenient strategy to effectively inhibit the oxidative reactions or microbial spoilage at their localized sites. A wide range of essential oils contain bioactive compounds that have the potential to act as multifunctional feed supplements for animals including effects on growth performance, digestive system, pathogenic bacterial growth and lipid oxidation. However, further studies are needed to clarify their exact action and establish their regular use in animal production.

Effects of dietary hesperidin supplementation on lamb performance and meat characteristics

An experiment was conducted to examine the effects of supplementing feed with hesperidin or α-tocopheryl acetate on lambs' growth performance, carcass and meat characteristics. Sixteen male lambs were randomly assigned to four groups. One of the groups served as control and was given a basal diet, whereas the other three groups were given the same diet further supplemented with hesperidin at 1500 mg/kg, or hesperidin at 3000 mg/kg, or α-tocopheryl acetate at 200 mg/kg. At the end of the experiment, lambs were fasted, weighed and slaughtered. After overnight chilling, samples of Longissimus thoracis muscle were taken and were used for meat quality evaluation. No significant differences were observed in final body weight, body weight gain and organ weights among the four groups. pH, color, water-holding capacity, shear force values and intramuscular fat concentration of Longissimus thoracis muscle were also not significantly influenced by the dietary treatments. Measurement of lipid oxidation values showed that hesperidin supplementation positively influenced meat antioxidant properties during refrigerated storage.

The effects of dietary oregano oil supplementation on pig meat characteristics

The effects of different concentrations of dietary oregano essential oil supplementation on finishing pig meat characteristics were investigated in the present study. Thirty-two barrows and thirty-two gilts were divided into four equal groups. During the experimental period, which started when the animals were 5 months old and finished after 35 days, the first group was fed the control diet (group C), whereas the other three groups consumed the same diet, with the only difference that the feed was supplemented with oregano essential oil at concentrations of 0.25, 0.5 and 1 ml/kg of fed diet (groups OR1, OR2 and OR3, respectively). At the end of the experiment, pigs were fasted for 12 h, weighed and slaughtered. After overnight chilling, a 50 cm loin section was removed from the half of the carcasses (8 pigs per nutritional treatment; 4 barrows and 4 gilts) and transported to laboratory for further examination. No significant differences were observed after dietary oregano essential oil supplementation in final body weight (kg), body weight gain (g) and dressing out (%). Tenderness of longissimus muscle, expressed as shear force value, pH values at 45 min and 24 h postmortem, colour parameters and sensory attributes of eating quality were not significantly influenced by the dietary treatment. Moreover, the lipid oxidation results suggested a lack of antioxidant effect for the oregano essential oil. In conclusion, carcass and meat quality attributes were unchanged, indicating that the dietary administration of different levels of oregano essential oil did not exert any effect on pig meat parameters in the present experiment.

Effect of dietary oregano oil supplementation on lamb meat characteristics

The effect of dietary oregano essential oil supplementation on lamb meat characteristics was investigated. Eight male and eight female Chios lambs were divided into two equal groups. The first group was fed with the control diet consisting of concentrated feed and alfalfa hay, whereas the second group consumed the same diet, the only difference being that the concentrated feed was uniformly sprayed with oregano essential oil (1ml/kg). Duration of the experimental period was two months. No differences were observed after oregano essential oil supplementation in final body weight (kg), body weight gain (g) and carcass yield (%). Tenderness of longissimus thoracis muscle, expressed as sarcomere length and shear force value, was not influenced by the treatment, whereas pH and colour parameters (yellowness-redness) appeared to increase (P<0.05). Moreover, results showed that dietary incorporation of oregano essential oil exerted strong antioxidant effects retarding lipid oxidation (MDA formation) in meat during refrigerated and long-term frozen storage (P<0.001).

Effect of breed and age on sexual behaviour of rams

The objective of this study was to highlight the problems that arise during the reproduction between thin-tailed rams and fat-tailed ewes. At the same time, particular emphasis laid on the influence of sheep breed, sheep age, time after ram introduction and day of the ewe estrus cycle on ram and ewe sexual behaviour. Rams were subjected to sexual performance tests by being individually exposed to 12 ewes for 3 h daily, 19 consecutive days. The 16 rams of the experiment were separated according to their age (9 and 21 months old) and breed (Chios and Karagouniki), and the 96 ewes of Chios fat-tailed breed, were divided by age (9 and 21 months old). The main characteristics of courtship behaviour, like sniffing, nudging, flehmen response and following were recorded and studied in detail. Mature Chios rams, which were the only one with previous experience of Chios ewes, exhibited higher rates of sexual interest per ewe than the other rams (P < 0.05). On the other hand, rams sniffed and nudged more young than mature ewes (P < 0.05), probably due to the fact that young ewes did not express intense symptoms of estrus. Young rams exhibited substandard sexual interest towards mature ewes, when they first came in contact with them (P < 0.05). In general, Karagouniki thin-tailed rams exhibited reduced rates of mating behaviour when they courted with Chios fat-tailed ewes in comparison with Chios rams (P < 0.05). Moreover, as the time after ram introduction passed, the frequency and duration of sexual behaviour components decreased (P < 0.001). Finally, the effect of the day of the experiment was only significant in the case of sniffing, which increased during the first 2 days and then declined and stabilized (P < 0.01). As it was demonstrated, ram age and ram breed played a fundamental role in the exhibition of sexual interest elements.