RNAseq reveals modulation of genes involved in fatty acid biosynthesis in chicken liver according to genetic background, sex, and diet.

Increases in chicken production are mainly due to specialised breeds. However, local breeds are of increasing importance, known for ability to adapt to the environment and unique products. Conventional poultry products contain lower levels of n-3 fatty acids (FAs) compared to those obtained from local breeds, therefore the aim of this study was to evaluate the modulation of expression of genes involved in long-chain polyunsaturated FA (PUFA) biosynthesis pathways according to genetic background, diet conditions, and sex. Animals from two local breeds and a commercial line were fed different diets: control and experimental diet (10% linseed supplementation). For each breed and diet group, both sexes were reared. The RNA was extracted from 36 liver samples and sequenced by RNAseq method. Bioinformatic analysis was carried out to find differentially expressed genes from comparisons between experimental groups. Results showed low impact of diet on differentially expressed genes related to FA biosynthesis, but linseed diet increased percentage of n-3 FAs of liver. Sex and genetic background determined the differential expression of genes related to long-chain PUFA biosynthesis. Specifically, females of local breeds shared 23 up-regulated genes when compared to their respective commercial line groups. Some of the shared genes had a role in de novo triglyceride biosynthesis (MTTPL and GPAM), and in de novo FA biosynthesis (ACACA and SCD) was detected. In conclusion, local breeds are able to better adapt to a diet rich in PUFA, by triggering certain transcriptomic shifts in the liver that allow birds to process the high PUFA content provided by diet.

Can Dietary n-3 Polyunsaturated Fatty Acids Affect Apelin and Resolvin in Testis and Sperm of Male Rabbits?

Apelin and other novel adipokines have been associated with normal and pathological reproductive conditions in humans and animals. In this paper, we used a rabbit model to investigate if apelin and resolvin (RvD1) in testis and sperm are associated with the oxidative status of semen and serum testosterone of rabbits fed different diets enriched with flaxseed (alpha-linolenic acid, ALA) or with fish oil (eicosapentaenoic acid, EPA, docosapentaenoic acid, DPAn-3, and docosahexaenoic acid, DHA). Apelin and RvD1 were detected by ELISA and apelin and the apelin receptor by immunofluorescence. Increased levels of apelin in testes from both enriched diets were shown, particularly in the interstitial tissue of the FLAX group. The FLAX diet enhanced serum testosterone, and both enriched diets showed higher levels of malondialdehyde and RvD1 in the testis. In ejaculated sperm, apelin and its receptor were localized in the entire tail of the control and both treated groups. The ryanodine receptor was investigated in rabbit testis; the fluorescent signal was increased in mature elongated spermatids of the FLAX group. In conclusion, this data seems to indicate that FLAX increases the amount of apelin in testis, suggesting an involvement of this adipokine in male reproduction and probably a role in the resolution of the inflammatory status.

In vitro effect of nerve growth factor on the main traits of rabbit sperm.

BACKGROUND: The nerve growth factor (NGF), a member of the neurotrophins family, plays an important role not only in the nervous but also in other non-nervous systems such as the reproductive system. The aim of the paper is to study the in vitro effect of NGF on rabbit sperm functions. METHODS: Ten adult rabbit bucks were collected five times, and pooled semen samples have been analysed. NGF was quantified in seminal plasma, and the distribution of NGF receptors (TrKA and p75NTR) in sperm was established. Moreover, the dose-effect of NGF on motility rate and track speed was evaluated. Successively, the effect of the neutralisation of NGF receptors was assessed to verify the specific role of each receptor. Untreated sperm were used as control. RESULTS: Our study identified several interesting results: i) We detected NGF in seminal plasma and TrKA and p75NTR in sperm surface. In particular, TrKA is localised in the head and p75NTR in the midpiece and tail of rabbit sperm. ii) Once the optimal dose of NGF (100 ng/mL) was established, its addition affected both kinetics and other physiological traits (capacitation, apoptosis and necrosis) of rabbit sperm. (iii) The neutralisation of TrKA and p75NTR receptors affected sperm traits differently. In particular, sperm speed, apoptosis and capacitation seemed mainly modulated via p75NTR receptor, whereas motile, live cells, necrosis and acrosome reaction were modulated via TrKA. CONCLUSION: For the first time, we showed the presence of p75NTR in rabbit sperm. NGF affects kinetic and other physiological traits of rabbit sperm. Most of these changes are modulated by the receptors involved (TrKA or p75NTR). Considering that some seminal disorders in human have been correlated with a lower NGF concentration and no studies have been done on the possible involvement of NGF receptors, these findings also provide new insights on human fertility.

Effect of heat- and freeze-drying treatments on phytochemical content and fatty acid profile of alfalfa and flax sprouts.

BACKGROUND: Fresh sprouts are healthy foods, low in fats and high in phytochemicals, but have a short shelf-life, hence the need for processing methods that preserve their nutritional value. This work was aimed at evaluating the effect of heat-drying (HD) and freeze-drying (FD) on the phytochemical and fatty acid profiles of alfalfa and flax sprouts, as compared to fresh material. RESULTS: Both FD and HD reduced the phytochemical contents compared to fresh sprouts. FD better preserved phytoestrogens, phytosterols and total tocols compared to HD. However, phytoestrogen and tocol content remained quite high also in HD. The fatty acid profile was affected only by sprouts species, with higher amounts of α-linolenic acid in flax and linoleic acid in alfalfa sprouts. CONCLUSIONS: This work demonstrates that drying does not severely compromise the nutritional value of sprouts and provides a valid support for the choice of the drying method depending on the compound to be preserved, and taking into consideration the different cost of the methods. In addition, sprout powder is easy to handle and, due to its low volume, does not imply a decrease of feed consumption and energy intake, which is relevant in its use as a supplement in human and animal feeding. © 2019 Society of Chemical Industry.

The effects of husbandry system on the grass intake and egg nutritive characteristics of laying hens.

BACKGROUND: The aim of this study was to determine the effect of husbandry system and season on the grass intake and egg quality in laying hens considering that characteristics of organic eggs obtained in a system with no grass in the external area are similar conventional ones. RESULTS: Three hundred and sixty Ancona hens were randomly assigned to three groups: a control group (C), with the hens kept in cages under standard housing conditions; the organic group (O), with the hens kept under an organic production system (4 m² per hen) and the organic-plus group (OP), with the hens maintained under organic conditions but with a larger grass paddock availability (10 m² per hen). The estimated intake of forage, carotenoids and flavonoids of the OP hens was very high as the amounts deposited in eggs, mainly in the spring season. The fatty acid composition of the yolk was significantly affected by pasture. The OP eggs showed lower concentrations of polyunsaturated fatty acids (PUFA) n-6 and a higher percentage of PUFA n-3. CONCLUSIONS: The results showed that the grass intake was largely affected by the husbandry system and highlighted the seasonal effect of grass availability on the nutritional quality of eggs produced in organic systems.

The Healthy Fatty Index Allows for Deeper Insights into the Lipid Composition of Foods of Animal Origin When Compared with the Atherogenic and Thrombogenicity Indexes.

The aim of this research was to validate the effectiveness of the Healthy Fatty Index (HFI) regarding some foods of animal origin (meat, processed, fish, milk products, and eggs) typical of the Western diet and to compare these results with two consolidated indices (atherogenic-AI, and thrombogenic-TI) in the characterization of the nutritional features of their lipids. The fatty acids profile (% of total fatty acids and mg/100 g) of 60 foods, grouped in six subclasses, was used. The AI, TI, and HFI indexes were calculated, and the intraclass correlation coefficients and the degree of agreement were evaluated using different statistical approaches. The results demonstrated that HFI, with respect to AI and TI, seems better able to consider the complexity of the fatty acid profile and the different fat contents. HFI and AI are the two most diverse indices, and they can provide different food classifications. AI and IT exhibit only a fair agreement in regards to food classification, confirming that such indexes are always to be considered indissolubly and never separately, in contrast to the HFI, which can stand alone.

Pro-Atherogenic and Pro-Oxidant Diets Influence Semen and Blood Traits of Rabbit Bucks.

Many dietary factors can affect sperm traits. We compared the effect of diets rich in pro-oxidant (flaxseed oil) and pro-atherogenic (coconut oil) substances without added antioxidants on semen traits, using the rabbit as an animal model. Thirty rabbit bucks (8 months old) were fed three diets for 150 days: CNT (control) a standard diet; HA (high-atherogenic) standard diet + 3% coconut oil, and HO (high-oxidizing) standard diet + 3% flaxseed oil. Semen samples were collected weekly for the evaluation of qualitative traits (kinetics, viability) and the oxidative damage (MDA and cytokines). Blood was collected at the start (T0) and end (T8) of the experimental period for the assessment of the oxidative damage (MDA and isoprostanoids), lipid profile, and testosterone. A worsening of sperm kinetics and viability was recorded in the HA group. Lipid oxidation in seminal plasma, as well as isoprostanoids in blood (F3-IsoPs and F4-NeuroPs), increased in both the HO and HA groups. A high level of TNF-α, a marker of inflammatory status, was recorded in the seminal plasma of the HA group. The resulting outcomes were mainly attributable to the different fatty acid profiles (SFA vs. PUFA) of the diets, which modulated an inflammatory/oxidative response.

Impact of chronic heat stress on behavior, oxidative status and meat quality traits of fast-growing broiler chickens.

This research aimed to investigate, through a multifactorial approach, the relationship among some in-vivo parameters (i.e., behavior and blood traits) in broilers exposed to chronic HS, and their implications on proximate composition, technological properties, and oxidative stability of breast meat. A total of 300 Ross 308 male chickens were exposed, from 35 to 41 days of age, to either thermoneutral conditions (TNT group: 20°C; six replicates of 25 birds/each) or elevated ambient temperature (HS group: 24 h/d at 30°C; six replicates of 25 birds/each). In order to deal with thermal stress, HS chickens firstly varied the frequency of some behaviors that are normally expressed also in physiological conditions (i.e., increasing "drinking" and decreasing "feeding") and then exhibited a behavioral pattern finalized at dissipating heat, primarily represented by "roosting," "panting" and "elevating wings." Such modifications become evident when the temperature reached 25°C, while the behavioral frequencies tended to stabilize at 27°C with no further substantial changes over the 6 days of thermal challenge. The multifactorial approach highlighted that these behavioral changes were associated with oxidative and inflammatory status as indicated by lower blood γ-tocopherol and higher carbonyls level (0.38 vs. 0.18 nmol/mL, and 2.39 vs. 7.19 nmol/mg proteins, respectively for TNT and HS; p < 0.001). HS affected breast meat quality by reducing the moisture:protein ratio (3.17 vs. 3.01, respectively for TNT and HS; p < 0.05) as well as the muscular acidification (ultimate pH = 5.81 vs. 6.00, respectively; p < 0.01), resulting in meat with higher holding capacity and tenderness. HS conditions reduced thiobarbituric acid reactive substances (TBARS) concentration in the breast meat while increased protein oxidation. Overall results evidenced a dynamic response of broiler chickens to HS exposure that induced behavioral and physiological modifications strictly linked to alterations of blood parameters and meat quality characteristics.

Shape and fractures of carina sterni in chicken genotypes with different egg deposition rates reared indoor or free-range.

Commercial laying hens have high frequency of damage to the keel bone (KB), which causes negative effects on health and welfare. KB damage may consist in fractures (KBF) and deviations (KBD). The aim of the present study was to compare the KB shape, by means of Geometric Morphometric, and the occurrence of fractures in different chicken genotypes reared either free-range (FR) or in enriched cages. Moreover, the relationship between KB shape, genotype and rearing system was analysed. Sixty birds/genotype (2 Italian local breeds, Bionda Piemontese and Robusta Maculata, their crossbreeds with Sasso and Lohmann Brown) were used. All the hens fed the same commercial feed throughout the trial. Body weight, egg production, feed intake and mortality were recorded from 25 to 66 weeks of age. Ca intake (IN) and output (OUT) were estimated and Ca OUT/IN was calculated. FR affected the occurrence of KB deviations but not the shape, whereas the fractures were mainly affected by genotype. Local breeds had a lower prevalence of KBF with similar level of KBD but with different shapes. Crossbreeds seemed to be a suitable compromise between egg deposition rate and occurrence of KB damages.

A Possible Role for Nerve Growth Factor and Its Receptors in Human Sperm Pathology.

Nerve growth factor (NGF) signalling affects spermatogenesis and mature sperm traits. In this paper, we aimed to evaluate the distribution and the role of NGF and its receptors (p75NTR and TrKA) on the reproductive apparatus (testis and epididymis) and sperm of fertile men (F) and men with different pathologies, namely varicocele (V) and urogenital infections (UGIs). We collected semen samples from 21 individuals (31-40 years old) subdivided as follows: V (n = 7), UGIs (n = 7), and F (n = 7). We submitted the semen samples to bacteriological analysis, leucocyte identification, and analysis of sperm parameters (concentration, motility, morphology, and viability). We determined the seminal plasma levels of NGF, interleukin 1ß (IL-1ß), and F2-isoprostanes (F2-IsoPs), and the gene and protein expression of NGF receptors on sperm. We also used immunofluorescence to examine NGF receptors on ejaculated sperm, testis, and epididymis. As expected, fertile men showed better sperm parameters as well as lower levels of NGF, F2-IsoPs, and IL-1ß compared with men with infertility. Notably, in normal sperm, p75NTR and TrKA were localised throughout the entire tail. TrKA was also found in the post-acrosomal sheath. This localisation appeared different in patients with infertility: in particular, there was a strong p75NTR signal in the midpiece and the cytoplasmic residue or coiled tails of altered ejaculated sperm. In line with these findings, NGF receptors were intensely expressed in the epididymis and interstitial tissue of the testis. These data suggest the distinctive involvement of NGF and its receptors in the physiology of sperm from fertile men and men with infertility, indicating a possible role for new targeted treatment strategies.

Lipid metabolism analysis in liver of different chicken genotypes and impact on nutritionally relevant polyunsaturated fatty acids of meat.

Humans and mammalian species are unable to synthesize significant amounts of polyunsaturated fatty acids (PUFA), which therefore must be introduced with the diet. In birds, lipogenesis takes place primarily in the liver, whereas adipose tissue serves as the storage site for triacylglycerols (TG, composed by 80-85% esterified fatty acids). However, both the nature (unsaturation level, n-3, or n-6 series) and the allocation (such as constituents of complexed lipids) of PUFA are very important to evaluate their function in lipid metabolism. The objective of the present investigation was to study the liver lipid metabolism, with particular attention to non-esterified fatty acids (NEFA), TG, phospholipids (PL), FADS2 gene expression, and Δ6-desaturase activity of three chicken genotypes, Leghorn (Leg), Ross 308 (Ross), and their crossbreed (LxR), by LC/MS analysis. The concentration of single fatty acids in muscle was quantified by GC-FID. The results showed that the Ross has a lipid metabolism related mainly to storage and structural roles, exhibiting higher levels of TG, phosphatidylethanolamine (PE) and phosphatidylcholine (PC) that are largely unsaturated. Meanwhile Leg showed a relevant amount of n-3 NEFA characterized by a higher phosphatidylserine (PS) unsaturation level, FADS2 gene expression and enzyme activity. The LxR seem to have a moderate trend: n-6 and n-3 NEFA showed intermediate values compared with that of the Ross and Leg and the TG trend was similar to that of the Ross, while PE and PC were largely unsaturated (mainly 6 and 7 UNS most of the metabolic energy for storage fatty acids in their tissues (TG) whereas, the Leg birds were characterized by different lipid metabolism showing in their liver a higher content of n-3 NEFA and higher unsaturation level in PS. Furthers details are needed to better attribute the lipid energy to the different metabolic portion.

Indexing of Fatty Acids in Poultry Meat for Its Characterization in Healthy Human Nutrition: A Comprehensive Application of the Scientific Literature and New Proposals.

Chicken meat is becoming the most consumed in the world for both economic and nutritional reasons; regarding the latter, the lipid profile may play positive or negative roles in the prevention and treatment of diseases. In this study, we define the state of the art of lipid-based nutritional indexes and used the lipid content and fatty acid profile (both qualitative and quantitative) of breast meat of two poultry genotypes with different growth rates and meat traits. Further, we summarize and review the definitions, implications, and applications of nutritional indexes used in recent years and others of our own design to provide a useful tool to researchers working in the field of meat quality (not only in poultry) to select the most appropriate index for their own scientific purposes. All indexes show advantages and disadvantages; hence, a rational choice should be applied to consider the nutritional effect of meat on human health and for a possible assessment of the most suitable rearing systems (genotype, feeding, farming system or postmortem handling).

Validation of a behavior observation form for geese reared in agroforestry systems.

Agroforestry systems, which are based on the integration of trees and animals, represent a useful practice for implementing the "One Welfare" concept. Geese could adapt well to these systems due to their kinetic and grazing abilities. However, the lack of specific ethograms and animal-based measures have not yet allowed a deep assessment of their welfare and behavior. The aim of this study was to develop and validate a protocol to evaluate the behavior of geese reared in two agroforestry systems (i.e., apple orchard and vineyard). Thus, a behavior observation form (BOF) including a specific ethogram was proposed, and its interobserver reliability, content, criterion and construct validity were determined. Moreover, the influence of the time of day and type of agroforestry system on geese's behavior was also investigated. Agreement and principal component analyses, as well as the comparison between data collected through direct observation by the BOF and indirect observation by a computerized system, supported the reliability and validity of the proposed protocol. While the BOF also highlighted differences in the behavior expressed by the geese according to the time of day and the environmental context, both the vineyard and apple orchard systems seem to meet their biological and behavioral needs.

Dietary Isoflavone Aglycons from Soy Germ Pasta Improves Reproductive Performance of Aging Hens and Lowers Cholesterol Levels of Egg Yolk.

This study compared dietary isoflavone aglycones with the glycoside conjugates in a novel model of postmenopausal status, the aging domestic hen (Gallus gallus domesticus), to determine the effects on reproductive performance, cholesterol levels, and nutritional quality of eggs laid. Hens, 18 mo old, were randomized into four groups (n = 10/group) and fed for 28 d a conventional poultry corn/soymeal diet (Control), or diets supplemented with isoflavone glycosides from soy germ (diet A), isoflavone aglycons from a soy germ pasta (diet B), or conventional pasta lacking isoflavones (diet C). The egg-laying rate was recorded daily, plasma isoflavones and cholesterol were measured, and the nutritional composition of the eggs was determined. Egg-laying declined over a 4-week period in hens in the Control group and those fed isoflavone glycosides (diets A and C), whereas hens fed isoflavone aglycons (diet B) significantly increased their egg-laying efficiency. The total egg count and egg yield were significantly higher in hens fed isoflavone aglycons, and their plasma cholesterol concentrations were lower and the eggs laid had a 30% lower yolk cholesterol content. None of these effects were observed with diets containing similar levels of isoflavone glycosides. These studies recapitulate the clinical effects of soy germ pasta enriched with isoflavone aglycons and lend support to the greater efficacy of a diet rich in isoflavone aglycons.

Poultry Meat and Eggs as an Alternative Source of n-3 Long-Chain Polyunsaturated Fatty Acids for Human Nutrition.

The beneficial effects of n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) on human health are widely known. Humans are rather inefficient in synthesizing n-3 LC-PUFA; thus, these compounds should be supplemented in the diet. However, most Western human diets have unbalanced n-6/n-3 ratios resulting from eating habits and the fact that fish sources (rich in n-3 LC-PUFA) are not sufficient (worldwide deficit ~347,956 t/y) to meet the world requirements. In this context, it is necessary to find new and sustainable sources of n-3 LC-PUFA. Poultry products can provide humans n-3 LC-PUFA due to physiological characteristics and the wide consumption of meat and eggs. The present work aims to provide a general overview of the main strategies that should be adopted during rearing and postproduction to enrich and preserve n-3 LC-PUFA in poultry products. The strategies include dietary supplementation of α-Linolenic acid (ALA) or n-3 LC-PUFA, or enhancing n-3 LC-PUFA by improving the LA (Linoleic acid)/ALA ratio and antioxidant concentrations. Moreover, factors such as genotype, rearing system, transport, and cooking processes can impact the n-3 LC-PUFA in poultry products. The use of a multifactorial view in the entire production chain allows the relevant enrichment and preservation of n-3 LC-PUFA in poultry products.

The Effect of Interaction NGF/p75NTR in Sperm Cells: A Rabbit Model.

BACKGROUND: Nerve Growth Factor (NGF) plays an important role in the reproductive system through its receptor's interaction (p75NTR). This paper aims to analyze the impact of NGF p75NTR in epididymal and ejaculated rabbit semen during in vitro sperm storage. METHODS: Semen samples from 10 adult rabbit bucks were collected four times (n = 40) and analyzed. NGF was quantified in seminal plasma, and the basal expression of p75NTR in sperm was established (time 0). Moreover, we evaluated p75NTR, the apoptotic rates, and the main sperm parameters, at times 2-4 and 6 h with or without the administration of exogenous NGF. RESULTS: Based on the level of p75NTR, we defined the threshold value (25.6%), and sperm were divided into High (H) and Normal (N). During sperm storage, p75NTR of H samples significantly modulated some relevant sperm parameters. Specifically, comparing H samples with N ones, we observed a reduction in motility and non-capacitated cell number, together with an increased percentage of dead and apoptotic cells. Notably, the N group showed a reduction in dead and apoptotic cells after NGF treatment. Conversely, the NGF administration on H sperm did not change either the percentage of dead cells or the apoptotic rate. CONCLUSION: The concentration of p75NTR on ejaculated sperm modulates many semen outcomes (motility, apoptosis, viability) through NGF interaction affecting the senescence of sperm.

Intake of nutrients (polyunsaturated fatty acids, tocols, and carotenes) and storage efficiency in different slow-growing chickens genotypes reared in extensive systems.

An extensive rearing system (ERS) for poultry requires an outdoor run, which enhances the foraging activity of chickens. Slow-growing (SG) strains are more adapted to ERS than fast-growing (FG); and generally, have higher levels of bioactive compounds in their meat. The aim of this paper was to assess the storage efficiency of n-3 and n-6 polyunsaturated fatty acids (PUFA), tocols and carotenes in the meat of seven commercial SG genotypes (SG1-7). One hundred SG chicks/strain of both sexes were included and their walking activity (High- or Low-W) was classified: SG1-4, HW comprised more than 10% of the time budget, and SG5-7, less than 10% (LW). Chickens were reared in pens (4 pens/strain) with indoor (0.10 m2/bird) and outdoor (4 m2/bird) areas, and they were fed the same diet ad libitum (starter feed for 1-21 d, grower feed from 22 d to slaughter at 81 d). The chickens were weighed weekly; feed consumption and grass intake were also estimated. At 81 days of age, 32 chickens/genotype were selected on the basis of the average weight (1:1, M:F) and slaughtered. The breast, thigh and drumstick meat were excised from 30 carcasses/genotype, sampled and stored at -20°C until analysis. Nutrients (e.g., n-3, n-6, carotenes and tocols) of feed, grass and meat were analyzed. The storage efficiency of nutrients was estimated as the ratio between the amount deposited in the body muscles (OUT) and the dietary intake (feed and grass, IN). The genotype affected chickens foraging behavior and the intake of nutrients. For SG1, SG2 and SG3, more than 50% of the intake of n-3 came from grass, whereas in the other genotypes, less than 20%. Accordingly, chickens that foraged more showed better meat nutritional profiles (less fat, more n-3 and antioxidants), which, in ERS, was ascribed to grass ingestion. However, the storage efficiency of nutrients into meat was inversely correlated with the grass intake: strains with higher grass intake (SG1, SG2, and SG3) had lower storage rates. Several hypotheses were proposed to explain these trends.

Dietary Freeze-Dried Flaxseed and Alfalfa Sprouts as Additional Ingredients to Improve the Bioactive Compounds and Reduce the Cholesterol Content of Hen Eggs.

Eggs are a complete food with high-quality proteins; a 2:1 ratio of unsaturated to saturated fatty acid (SFA); and a good amount of minerals, as well as vitamins or antioxidant compounds. Seeds or mature plants were usually added to the feed to improve egg quality. This study aimed to evaluate the effect of alfalfa and flax freeze-dried sprouts supplementation in diets of laying hens on egg oxidative status and key bioactive compounds. Thirty Sassò hens were fed with three different diets: standard, standard + 3% freeze-dried alfalfa sprouts, or flaxseed sprouts. Ten pools of 10 egg yolks per group were collected at 0, 4, and 8 weeks and analyzed. Supplementation with sprouts enriched the phytosterols, phytoestrogens, tocols, carotenes, vitamin D, and n-3 fatty acid contents in the eggs. Cholesterol content was lower in both sprout-supplemented groups, and a decrease in its oxidative products was also observed. It was found that a 3% freeze-dried sprouts supplementation of approximately 56 days improves the egg quality. Further studies are necessary to verify higher supplementing doses and the applicability of this strategy in the commercial egg production chain.

Expression of genes and localization of enzymes involved in polyunsaturated fatty acid synthesis in rabbit testis and epididymis.

The metabolism of polyunsaturated fatty acids (PUFAs) plays an important role in male reproduction. Linoleic and alpha-linolenic acids need to be provided in the diet and they are converted into long chain polyunsaturated fatty acids by steps of elongation and desaturation, exerted by elongases 2 (ELOVL2) and 5 (ELOVL5) and Δ5- (FADS1) and Δ6-desaturase (FADS2). This study aims to assess the gene expression and localization of enzymes involved in the synthesis of n-3 and n-6 long-chain PUFAs in control rabbits and those fed diets containing 10% extruded flaxseed. Enzyme and PUFA localization were assessed in the testes and epididymis by immunofluorescence. Testes showed high gene expression of FADS2, ELOVL2 and ELOVL5 and low expression of FADS1. Intermediate metabolites, enzymes and final products were differently found in Leydig, Sertoli and germinal cells. FADS2 was localized in interstitial cells and elongated spermatids; ELOVL5 in meiotic cells; FADS1 was evident in interstitial tissue, Sertoli cells and elongated spermatids; ELOVL2 in interstitial cells. Epididymal vesicles were positive for FADS1, ELOVL2 and ELOVL5 as well as docosahexaenoic, eicosapentaenoic, and arachidonic acids. This knowledge of fatty acids (FA) metabolism in spermatogenesis and the influence of diet on FA profile could help identify causes of male infertility, suggesting new personalized therapy.

A Dynamic Model for Estimating the Interaction of ROS-PUFA-Antioxidants in Rabbit.

Defining optimal nutrition in animals and humans remains a main scientific challenge. The objective of the work was to develop a dynamic model of reactive oxygen species (ROS)-polyunsaturated fatty acid (PUFA)-antioxidant homeostasis using the rabbit as a model. The problem entity was to evaluate the main metabolites generated from interactions between traits included in the conceptual model and identified by three main sub-models: (i) ROS generation, (ii) PUFA oxidation and (iii) antioxidant defence. A mathematical model (VENSIM software) that consisted of molecular stocks (INPUTs, OUTPUTs), exchange flows (intermediate OUTPUTs) and process rates was developed. The calibration was performed by using standard experimental data (Experiment 1), whereas the validation was carried out in Experiments 2 and 3 by using supra-nutritional dietary inputs (VIT E+ and PUFA+). The accuracy of the models was measured using 95% confidence intervals. Analytical OUTPUTs (ROS, PUFA, Vit E, Ascorbic acid, Iso-/NeuroProstanes, Aldehydes) were well described by the standard model. There was also good accuracy for the VIT E+ scenario, whereas some compensatory rates (Kc1-Kc4) were added to assess body compensation when high levels of dietary PUFA were administered (Experiment 3). In conclusion, the model can be very useful for predicting the effects of dietary treatments on the redox homeostasis of rabbits.