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Abstract: This research investigates the possibility to use highly absorbing materials to dampen indoor RH% variations. The practical MBV of sodium polyacrylate, cellulose-based material, perlite and gypsum is evaluated for a daily cyclic exposure that alternates high (75%) and low (33%) RH% levels for 8h and 16h, respectively. The adjustment velocity to RH% variations and the presence of hysteretic phenomena are also presented. The cellulose-based material proves to be the most suitable for moisture buffering applications. Starting from this material’s properties, the effect of thickness, vapour resistance factor (μ) and mass surface exchange coefficient (Z v) on sorption capacity is evaluated by the use of a numerical model. [Copyright &y& Elsevier]

Abstract: The aim of the present experiment was to study the effect of fish oil and Vitamin E rich diets on semen production, sperm functions and composition in broiler breeders. The following parameters were measured: semen volume and concentration, sperm motility and viability, sperm susceptibility to induced peroxidation, sperm lipid and α-tocopherol contents. Dietary n −3 PUFA were successfully transferred into spermatozoan phospholipid by fish oil feeding according to the following main features: (a) the C22:6n −3 and C22:5n −3 contents were increased, but C22:4n −6 remained the peculiar and major polyunsaturate; (b) the content and proportion of total PUFA did not change; (c) the proportional increase of n −3 PUFA was compensated by the decrease of n −6 PUFA, an increase in the proportion of n −9 fatty acids was also found. The sperm content of α-tocopherol was doubled increasing the dietary availability of the vitamin to 300mg/kg of feed. The specific n −3 PUFA and Vitamin E enrichment of chicken sperm affected cell functions. Significant interactions between the two treatments were also found for some parameters. The best sperm quality condition in control sperm (rich mainly in n −6 PUFA) was found supplying 200mg Vitamin E/kg of feed to the male breeders, and in contrast in n −3 rich sperm supplying 300mg Vitamin E/kg. [Copyright &y& Elsevier]

Abstract: Semen cryopreservation is fundamental both for the practice of artificial insemination, and for the conservation of genetic resources in cryobanks; nevertheless, there is still not an efficient standard freezing procedure assuring a steady and suitable level of fertility in fowl, and consequently there is no systematic use of frozen semen in the poultry industry. This study examined changes in motility (CASA), cell membrane integrity (Ethidium Bromide (EtBr) exclusion procedure and stress test) and DNA fragmentation (neutral comet assay) in fowl spermatozoa before, during and after cryopreservation and storage at −196 °C. An optimized comet assay for chicken semen was studied and applied to the analyses. Semen collected from 18 Mericanel della Brianza (local Italian breed) male chicken breeders was frozen in pellets and thawed in a water bath at 60 °C. Measurements were performed on fresh semen soon after dilution, after equilibration with 6% dimethylacetamide at 4 °C (processed semen) and after thawing. Sperm DNA damage occurred during cryopreservation of chicken semen and the proportion of spermatozoa with damaged DNA significantly increased from 6.2% in fresh and 6.4% in processed semen to 19.8% in frozen-thawed semen. The proportion of DNA in the comet tail of damaged spermatozoa was also significantly affected by cryopreservation, with an increase found from fresh (26.3%) to frozen-thawed (30.9%) sperm, whereas processed semen (30.1%) didn''t show significant differences. The proportion of total membrane damaged spermatozoa (EtBr exclusion procedure) did not increase by 4 °C equilibration time, and greatly and significantly increased by cryopreservation; the values recorded in fresh, processed and frozen semen were 2.9, 5.6, and 66.7% respectively. As regards the proportion of damaged cells in the stress test, all values differed significantly (7.1% fresh semen, 11.7% processed semen, 63.7% frozen semen). Total motility was not affected by equilibration (52.1% fresh semen, 51.9% processed semen), whereas it decreased significantly after cryopreservation (19.8%). These results suggest a low sensitivity of frozen-thawed chicken spermatozoa to DNA fragmentation, therefore it should not be considered as a major cause of sperm injuries during cryopreservation. [Copyright &y& Elsevier]

The ethidium bromide (EtBr) exclusion procedure, a fluorometric method for measuring sperm cell viability, was studied to optimize the use of this technique on boar, rabbit and rooster semen. Diluted semen was used for boars and roosters. Diluted rabbit semen did not allow for reliable fluorescence readings; the interference of granules characteristic of rabbit seminal plasma was suggested as its cause. Therefore, rabbit semen was washed on several Percoll® and Optiprep™ density gradients, with the aim of removing the granules from the sperm suspension. The complete absence of granules was not obtained, however, the best result was provided by the 35/70% Percoll® density gradient. Most spermatozoa formed a loose pellet with low contamination. Although the washing procedure resulted in a selective action, Percoll® washed semen was used to assess the EtBr procedure. The fluorescence intensities of stained fresh and stained digitonin-permeabilized samples were corrected, respectively, for the nonspecific fluorescence measures of fresh and digitonin-permeabilized samples both unstained. The contribution of the dye was subtracted from the corrected values, then the ratio between the corrected values of fresh and permeabilized cells provided the proportion of damaged cells in the sample. The working cell concentration range giving a constant proportion of damaged cells was set using diluted semen for boars and roosters (8–32×106 cell/ml) and Percoll® washed semen for rabbits (4–16×106 cell/ml). The reliability of the fluorometric method was compared with the traditional nigrosin–eosin (NE) staining technique. The intactness of sperm samples containing known proportions of fresh and killed cells was measured in defined working cell ranges. For boars and roosters the values determined by fluorometry agreed closely with those determined using the NE method. [Copyright &y& Elsevier]

The study aimed to characterize meat quality traits of Milanino chickens reared according to a specific free-range farming program. A total of 120 birds was reared straight-run in outdoor pens (8 m²/bird) from 35 d of life and fed ad libitum a low (16%) protein diet. At 180 d of age, 20 birds (10 birds/sex) were slaughtered, and carcass weight data were recorded. After processing, carcasses were refrigerated at 4°C for 24 hours. Then, the right breast and thigh with skin were collected and color parameters, pH, water-holding capacity (WHC), and chemical composition were determined. The left breast and thigh were stored at -20°C until cooking loss and tenderness evaluation. Milanino was confirmed to be a heavy breed with a sexual dimorphism in relation to adult body weight. A high general carcass yield was recorded. Milanino meat was characterized by high protein and low fat contents compared with the standard broiler meat. Differences in meat composition were recorded according to the sex: females presented higher values of dry matter (breast and thigh), protein (breast), and fat (breast and thigh) contents. The meat with skin presented an intense luminosity, and this trait was higher in the females. The muscle color was characterized by high redness and yellowness indices with differences according to the sex: Higher yellowness index was observed in female carcasses, while higher redness index was detected in male breast samples. The pH muscle values were similar to those reported in other autochthonous breeds. WHC values did not show variation between sexes. In contrast, cooking loss values recorded in thigh samples were lower in males compared to females. The degree of tenderness of Milanino meat was not affected by the sex. However, the potential loss of water and the toughness in Milanino meat were low compared to other local chicken breed meat. The present results support the breeding of Milanino chickens for meat production according to its specific straight-run free-range system. [ABSTRACT FROM AUTHOR]

Genetic variation enables both adaptive evolutionary changes and artificial selection. Genetic makeup of populations is the result of a longterm process of selection and adaptation to specific environments and ecosystems. The aim of this study was to characterize the genetic variability of México's chicken population to reveal any underlying population structure. A total of 213 chickens were sampled in different rural production units located in 25 states of México. Genotypes were obtained using the Affymetrix Axiom R® 600 K Chicken Genotyping Array. The Identity by Descent (IBD) and the principal components analysis (PCA) were performed by SVS software on pruned single nucleotide polymorphisms (SNPs). ADMIXTURE analyses identified 3 ancestors and the proportion of the genetic contribution of each of them has been determined in each individual. The results of the Neighbor-Joining (NJ) analysis resulted consistent with those obtained by the PCA. All methods utilized in this study did not allow a classification of Mexican chicken in distinct clusters or groups. A total of 3,059 run of homozygosity (ROH) were identified and, being mainly short in length (<4 Mb), these regions are indicative of a low inbreeding level in the population. Finally, findings from the ROH analysis indicated the presence of natural selective pressure in the population of Mexican chicken. The study indicates that the Mexican chicken clearly appear to be a unique creole chicken population that was not subjected to a specific artificial selection. Results provide a genetic knowledge that can be used as a basis for the genetic management of a unique and very large creole population, especially in the view of using it in production of hybrids to increase the productivity and economic revenue of family farming agriculture, which is widely present in México. [ABSTRACT FROM AUTHOR]

The aim of the present trial was to study the effect of different freezing rates on the survival of cryopreserved rooster semen packaged in straws. Slow and fast freezing rates were obtained keeping straws at different distances in the vapor above the surface of the nitrogen during freezing. Adult Lohmann roosters ( n = 27) were used. Two experiments were conducted. In Experiment 1, semen was packaged in straws and frozen comparing the distances of 1, 3 and 5 cm in nitrogen vapor above the surface of the liquid nitrogen. In Experiment 2, the distances of 3, 7 and 10 cm above the surfaces of the liquid nitrogen were compared. Sperm viability, motility and progressive motility and the kinetic variables were assessed in fresh and cryopreserved semen samples. The recovery rates after freezing/thawing were also calculated. In Experiment 1, there were no significant differences among treatments for all semen quality variables. In Experiment 2, the percentage of viable (46%) and motile (22%) sperm in cryopreserved semen was greater when semen was placed 3 cm compared with 7 and 10 cm in the vapor above the surface of the liquid nitrogen. The recovery rate of progressive motile sperm after thawing was also greater when semen was stored 3 cm in the vapor above the surface of the liquid nitrogen. More rapid freezing rates are required to improve the survival of rooster sperm after cryopreservation and a range of distances from 1 to 5 cm in nitrogen vapor above the surface of the liquid nitrogen is recommended for optimal sperm viability. [ABSTRACT FROM AUTHOR]

The Milanino is an Italian chicken breed included in a conservation project run by the University of Milan. It is characterized by good fertility, heavy body weights, high adaptation ability to adverse climate conditions, and disease resistance. Because of these characteristics, the Milanino could represent an important genetic resource for alternative production systems. This research was aimed at studying the effect of bird density on growth and slaughter performance, as well as stress response in Milanino chickens kept in outdoor pens. One hundred and sixty Milanino chickens were randomly assigned to 2 experimental groups kept at different densities (2 m²/bird and 8 m²/bird) and were slaughtered at 185 days of age. Growth and slaughter performance and stress condition were recorded. The interaction bird density * sex * age significantly affected body weight and an opposite trend was found between females and males: heavier females were found in the high-density group, while heavier males were found in the low-density group. Bird density did not affect carcass weight data. The stress marker (H/L ratio) was significantly higher in birds kept at the higher density (2 m²/bird). In conclusion, the Milanino provided satisfactory growth performance with different rearing density but the lower density, 8 m²/bird, should be preferred to minimize welfare problems for male birds. [ABSTRACT FROM AUTHOR]

The effects of post-thaw Helium–Neon (He–Ne) laser irradiation on mobility and functional integrity of frozen/thawed chicken, pheasant and turkey spermatozoa were investigated. Cytochrome C oxidase (COX) activity was also determined as a measure of the effect of irradiation on mitochondrial bioenergetics. Semen samples from each species were collected, processed and frozen according to the pellet procedure. After thawing, each semen sample was divided into two subsamples: the first one was the control; the second one was irradiated with a single mode continuous He–Ne laser wave (wavelength 632.8nm; 6mW; 3.96J/cm2). Then the samples were assessed for sperm mobility (Accudenz® swim-down test), viability (SYBR-14/PI staining), osmotic-resistance (HOS test) and COX activity. The irradiation was effective P <0.05 increasing sperm motility in the turkey semen (0.228±0.01 compared with 0.294±0.02). The irradiation also caused an increase (P <0.05) of the COX activity in pheasant (+135±4%) and turkey (+116±4%) sperm, without affecting viability and osmotic-resistance. The COX was positively correlated (P <0.05) with the viability of chicken sperm, however no significant interactions were found between mobility and COX activity in the three avian species. Due to the difference in energetic metabolism among avian species used in this study, the He–Ne laser irradiation has a differential action on bio-stimulation of turkey, chicken and pheasant spermatozoa. The present results are the first to elucidate the possibility for restoration of motility of cryopreserved avian spermatozoa by bio-stimulation provided via He–Ne laser irradiation. [ABSTRACT FROM AUTHOR]

Abstract: Local chicken breeds are a vital reservoir of gene resources and their conservation has a technical role related to the future development of the productive system, as well as a social-cultural role. The aim of this study was to evaluate the effects of egg weight, egg storage period and egg weight loss on hatchability of fertile eggs in the Italian bantam breed Mericanel della Brianza. Fourteen females and eight males were kept in floor pens and divided in 8 families (1M:1 or 2F) during the reproductive season (March–June). Birds received a photoperiod of 14L:10D and were fed ad libitum. Egg production and egg weight were recorded daily. Eggs were divided in 4 weight groups: EW1=<33g, EW2=33–36g, EW3=36–39g and EW4=≥39g. Eggs were stored at 18°C and classified in 3 egg storage groups: ES1=0–4, ES2=5–9 and ES3=10–15 days. Egg weight loss was recorded and distributed in 5 different classes: EWL1=<10%, EWL2=10–15%, EWL3=16–20%, EWL4=21–25%, EWL5=>25%. Fertility, embryo mortality and hatchability were recorded. The mean values during the reproductive season were 82% fertility and 50% hatchability of fertile eggs. The best combination of fertility and hatchability values were recorded in EW2 and lower fertility was recorded in EW1 (P <0.05). Hatchability decreased under 50% after 10 day storage period before incubation and the best hatchability was recorded in EWL1. The present results contribute to the knowledge on reproductive parameters necessary to improve the reproductive efficiency of this Italian breed within a conservation plan. [Copyright &y& Elsevier]

Abstract: The effects of fish oil (FO) and vitamin E (vE) dietary supplementation on semen quality, sperm susceptibility to lipid peroxidation, tocopherols content and fatty acid profiles were studied in rabbits. Fifty-two rabbit bucks randomly divided in four groups received a control diet and enriched diets containing either FO (1.5%, w/w), vE (200mg/kg) or both. Semen volume, concentration, motility and viability were analysed at various time-points and the lipid composition was assessed on sperm cells. The phospholipid fatty acid profile was determined: n-6 PUFA were the major fatty acids found, with a proportion of 42%, whereas the n-3 PUFA accounted for nearly 1%, mainly represented by C22:6n-3 (docosahexaenoic acid, DHA). FO supplementation produced a seven-fold increase in the content of DHA in sperm phospholipids and a comprehensive rearrangement of the phospholipid fatty acid composition, while an unexpected negative effect of feeding high level of vE on the proportion of total PUFA was found. Despite the remarkable changes observed in sperm lipid composition, semen quality parameters were not affected by the dietary treatments and the interaction between the two dietary supplements had a significant effect only on sperm concentration. An increase in semen production by ageing and a concomitant rise in sperm susceptibility to in vitro peroxidation was found. α- and δ-tocopherol, present in rabbit sperm in similar amount, were not affected by dietary treatment. δ-tocopherol content had a significant linear negative regression with age and showed a significant negative correlation with the susceptibility to peroxidation values. [Copyright &y& Elsevier]

Abstract: Egg yolks are commonly used in diluents in order to improve the freezability of semen. Two aspects of the role of lipids in boar semen freezability are reported in this article. The first one concerns the eventual exchanges of lipid components between the spermatozoa and the yolk-based diluent during cryopreservation. Two types of yolk have been considered as ingredients in diluents for cryopreservation: yolks with a standard fatty acid composition and yolks enriched in docosahexaenoic acid (DHA). The relation between lipid exchanges and the quality of fresh semen is considered. The other aspect concerns the possibility to enhance the freezability of boar spermatozoa by altering the plasma membranes under the influence of dietary fatty acids. Spermatozoa were damaged significantly by the cryopreservation cycle in all experiments. Spermatozoa with the best fresh quality had accumulated the largest quantity of lipids upon thawing. A general decrease in the proportion of polyunsaturated fatty acids was observed after thawing. The yolks enriched in n-3 fatty acids failed to improve the quality of sperm following cryopreservation. The proportion of DHA was significantly higher in spermatozoan phospholipids from thawed cells that had been in contact with n-3 yolks. A significant reduction in cholesterol was observed in spermatozoa after the cryopreservation cycle, which correlated with an increased number of acrosome-reacted cells and changes in the parameters of motility. The addition of 3% fish oil to the daily boar ration significantly increased the content of DHA (from 33 to 45% of the total fatty acids) in the spermatozoa. Ejaculate concentrations were significantly increased in the experimental group. DHA-enriched semen did not show improved freezability, at least not as assessed by in vitro parameters. [Copyright &y& Elsevier]