Few mitochondrial DNA sequences are inserted into the turkey (Meleagris gallopavo) nuclear genome: evolutionary analyses and informativity in the domestic lineage.

Mitochondrial DNA (mtDNA) insertions have been detected in the nuclear genome of many eukaryotes. These sequences are pseudogenes originated by horizontal transfer of mtDNA fragments into the nuclear genome, producing nuclear DNA sequences of mitochondrial origin (numt). In this study we determined the frequency and distribution of mtDNA-originated pseudogenes in the turkey (Meleagris gallopavo) nuclear genome. The turkey reference genome (Turkey_2.01) was aligned with the reference linearized mtDNA sequence using last. A total of 32 numt sequences (corresponding to 18 numt regions derived by unique insertional events) were identified in the turkey nuclear genome (size ranging from 66 to 1415 bp; identity against the modern turkey mtDNA corresponding region ranging from 62% to 100%). Numts were distributed in nine chromosomes and in one scaffold. They derived from parts of 10 mtDNA protein-coding genes, ribosomal genes, the control region and 10 tRNA genes. Seven numt regions reported in the turkey genome were identified in orthologues positions in the Gallus gallus genome and therefore were present in the ancestral genome that in the Cretaceous originated the lineages of the modern crown Galliformes. Five recently integrated turkey numts were validated by PCR in 168 turkeys of six different domestic populations. None of the analysed numts were polymorphic (i.e. absence of the inserted sequence, as reported in numts of recent integration in other species), suggesting that the reticulate speciation model is not useful for explaining the origin of the domesticated turkey lineage.

Genomic variability in Mexican chicken population using copy number variants.

BACKGROUND: Copy number variations are genome polymorphism that influence phenotypic variation and are an important source of genetic variation in populations. The aim of this study was to investigate genetic variability in the Mexican Creole chicken population using CNVs. RESULTS: The Hidden Markov Model of the PennCNV software detected a total of 1924 CNVs in the genome of the 256 samples processed with Axiom® Genome-Wide Chicken Genotyping Array (Affymetrix). The mapped CNVs comprised 1538 gains and 386 losses, resulting at population level in 1216 CNV regions (CNVRs), of which 959 gains, 226 losses and 31 complex (i.e. containing both losses and gains). The CNVRs covered a total of 47 Mb of the whole genome sequence length, corresponding to 5.12% of the chicken galGal4 autosome assembly. CONCLUSIONS: This study allowed a deep insight into the structural variation in the genome of unselected Mexican chicken population, which up to now has not been genetically characterized. The genomic study disclosed that the population, even if presenting extreme morphological variation, cannot be organized in differentiated genetic subpopulations. Finally this study provides a chicken CNV map based on the 600 K SNP chip array jointly with a genome-wide gene copy number estimates in a native unselected for more than 500 years chicken population.

Spermatozoa DNA and plasma membrane integrity after pellet optimized processing for cryopreservation in meat type chicken breeders.

1. Aim of this study was the development of an optimised cryopreservation pellet procedure for chicken semen and the assessment of DNA and membrane integrity in frozen/thawed spermatozoa in a Hubbard F15 meat type selected strain. 2. The following semen processing conditions were studied: spermatozoa working concentration (SWC), 1.5 vs 2 × 109 cells/ml in pre-freezing extender; equilibration of diluted semen at 5°C, 20 vs 40 min; dimethylacetamide concentration, 6% vs 9%; dimethylacetamide equilibration time at 5°C, 1 vs 30 min; thawing at 60°C for 10 vs 50°C for 30 sec. Spermatozoa viability (EtBr exclusion procedure - stress test), mobility (Accudenz® swim-down test) and subjective motility were assessed in fresh and frozen-thawed semen. 3. The lower SWC (1.5 × 109 cells/ml) and the higher dimethylacetamide concentration (9%) had positive significant effects on the recovery rate of motile (22% vs 16%) and viable spermatozoa (39 vs 34%), respectively. 4.Membrane (SYBR14-PI staining) and DNA integrity (comet assay) were assessed before and after freezing/thawing according to the optimised protocol. 5. Recovery rates of spermatozoa with undamaged plasma membrane and DNA were 41% and 76%, respectively. The distribution of spermatozoa in classes of DNA damage was also analysed and discussed. 6. It was concluded that pellet cryopreservation was a damaging process mainly for plasma membrane rather than nuclear DNA in chicken spermatozoa.

Cryopreserving turkey semen in straws and nitrogen vapour using DMSO or DMA: effects of cryoprotectant concentration, freezing rate and thawing rate on post-thaw semen quality.

1. This study was designed to identify a suitable protocol for freezing turkey semen in straws exposed to nitrogen vapour by examining the effects of dimethylacetamide (DMA) or dimethylsulfoxide (DMSO) as cryoprotectant (CPA), CPA concentration, freezing rate and thawing rate on in vitro post-thaw semen quality. 2. Pooled semen samples were diluted 1:1 (v:v) with a freezing extender composed of Tselutin diluent containing DMA or DMSO to give final concentrations of 8% or 18% DMA and 4% or 10% DMSO. The semen was packaged in 0.25 ml plastic straws and frozen at different heights above the liquid nitrogen (LN2) surface (1, 5 and 10 cm) for 10 min. Semen samples were thawed at 4°C for 5 min or at 50°C for 10 s. After thawing, sperm motility, viability and osmotic tolerance were determined. 3. Cryosurvival of turkey sperm was affected by DMSO concentration. Freezing rate affected the motility of sperm cryopreserved using both CPAs, while thawing rates showed an effect on the motility of sperm cryopreserved using DMA and on the viability of sperm cryopreserved using DMSO. Significant interactions between freezing rate × thawing rate on sperm viability in the DMA protocol were found. 4. The most effective freezing protocol was the use of 18% DMA or 10% DMSO with freezing 10 cm above the LN2 surface and a thawing temperature of 50°C. An efficient protocol for turkey semen would improve prospects for sperm cryobanks and the commercial use of frozen turkey semen.

Growth performance, carcass characteristics and meat composition of Milanino chickens fed on diets with different protein concentrations.

Milanino is a heavy Italian chicken breed included in a conservation project of the University of Milan and is an important genetic resource for alternative production systems. This research was aimed to study the effect of the dietary protein concentration on growth, slaughter performance and meat composition in free-range reared Milanino chickens. A total of 120 Milanino chickens were fed on different protein concentrations (HP = 20% CP and LP = 16% CP), reared according to a free-range system and slaughtered at 150 and 180 d of age. Growth, slaughter performance and meat (breast and thigh) composition were recorded. The protein concentration of the diet did not affect the overall Milanino mean body weight recorded in the straight-run group in the whole rearing period. However, the growth rate within sex was significantly different between the dietary treatments: heavier females were found in the HP group from 125 d onwards, while no differences were recorded in male body weights. The protein concentration of the diet did not affect carcass weight data or meat composition. The present results suggest the use of a low-protein diet for rearing straight-run Milanino chickens for long rearing periods. However, in females, a high-protein diet is recommended from 125 d of age onwards.

Quality and lipid composition of spermatozoa in rabbits fed DHA and vitamin E rich diets.

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. alpha- and delta-tocopherol, present in rabbit sperm in similar amount, were not affected by dietary treatment. delta-tocopherol content had a significant linear negative regression with age and showed a significant negative correlation with the susceptibility to peroxidation values.

Slaughter performance and meat quality of Milanino chickens reared according to a specific free-range program.

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.

Looking at genetic structure and selection signatures of the Mexican chicken population using single nucleotide polymorphism markers.

Genetic variation enables both adaptive evolutionary changes and artificial selection. Genetic makeup of populations is the result of a long-term 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® 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.

Genomic and genetic variability of six chicken populations using single nucleotide polymorphism and copy number variants as markers.

Genomic and genetic variation among six Italian chicken native breeds (Livornese, Mericanel della Brianza, Milanino, Bionda Piemontese, Bianca di Saluzzo and Siciliana) were studied using single nucleotide polymorphism (SNP) and copy number variants (CNV) as markers. A total of 94 DNA samples genotyped with Axiom® Genome-Wide Chicken Genotyping Array (Affymetrix) were used in the analyses. The results showed the genetic and genomic variability occurring among the six Italian chicken breeds. The genetic relationship among animals was established with a principal component analysis. The genetic diversity within breeds was calculated using heterozygosity values (expected and observed) and with Wright's F-statistics. The individual-based CNV calling, based on log R ratio and B-allele frequency values, was done by the Hidden-Markov Model (HMM) of PennCNV software on autosomes. A hierarchical agglomerative clustering was applied in each population according to the absence or presence of definite CNV regions (CNV were grouped by overlapping of at least 1 bp). The CNV map was built on a total of 1003 CNV found in individual samples, after grouping by overlaps, resulting in 564 unique CNV regions (344 gains, 213 losses and 7 complex), for a total of 9.43 Mb of sequence and 1.03% of the chicken assembly autosome. All the approaches using SNP data showed that the Siciliana breed clearly differentiate from other populations, the Livornese breed separates into two distinct groups according to the feather colour (i.e. white and black) and the Bionda Piemontese and Bianca di Saluzzo breeds are closely related. The genetic variability found using SNP is comparable with that found by other authors in the same breeds using microsatellite markers. The CNV markers analysis clearly confirmed the SNP results.

Effect of docosahexaenoic acid and alpha-tocopherol enrichment in chicken sperm on semen quality, sperm lipid composition and susceptibility to peroxidation.

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 alpha-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 alpha-tocopherol was doubled increasing the dietary availability of the vitamin to 300 mg/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 300 mg Vitamin E/kg.

Effect of cooling rate on the survival of cryopreserved rooster sperm: Comparison of different distances in the vapor above the surface of the liquid nitrogen.

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 5cm in nitrogen vapor above the surface of the liquid nitrogen. In Experiment 2, the distances of 3, 7 and 10cm 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 3cm compared with 7 and 10cm 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 3cm 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 5cm in nitrogen vapor above the surface of the liquid nitrogen is recommended for optimal sperm viability.

The preferential mobilisation of C20 and C22 polyunsaturated fatty acids from the adipose tissue of the chick embryo: potential implications regarding the provision of essential fatty acids for neural development.

The aim of this study was to determine the relative mobilisation of the different fatty acyl components of the triacylglycerol (TAG) of the chick embryo's adipose tissue in the light of the specific requirements of the developing neural tissues of the embryo for C20-22 polyunsaturated fatty acids. Pieces of adipose tissue, obtained from embryos at various developmental stages, were incubated in vitro in Dulbecco's Medium containing serum albumen. The fatty acid compositions of the initial tissue TAG and of the free fatty acid (FFA) mobilised from the tissue during 1 h of incubation were determined and compared. The composition of the FFA released into the medium under conditions of basal (i.e., unstimulated) lipolysis was markedly different in several respects from that of the TAG from which it originated. The polyunsaturated fatty acids, 20:4n-6, 20:5n-3, 22:5n-3 and 22:6n-3, were consistently found to be preferentially released into the medium, whereas the major fatty acyl constituents of the tissue, 16:0 and 18:1n-9, were selectively retained in the TAG. For example, at day 18 of development, the proportions (% w/w of fatty acids) of 20:5n-3 and 22:6n-3 released into the incubation medium were respectively 6.5 and 7.5 times higher than in the original tissue TAG. Glucagon stimulated the overall rate of mobilisation by approx. 2-fold and also partially suppressed the preferential mobilisation of C20-22 polyunsaturates. These results may be relevant to the elucidation of the means by which essential polyunsaturates are delivered from the yolk to the neural tissues of the embryo, with the implication of a mediatory role for the embryonic adipose tissue in this transfer.

Changes in sperm quality and lipid composition during cryopreservation of boar semen.

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.

The effects of dietary supplementation with docosahexaenoic acid on the phospholipid fatty acid composition of avian spermatozoa.

This study represents an attempt at the dietary manipulation of the fatty acid composition of chicken spermatozoa in order to enhance the levels of n-3 polyunsaturates at the expense of the n-6 fatty acids, which normally predominate in the lipids of avian semen. Male chickens were provided with either a control diet supplemented with maize oil or the test diet supplemented with fish oil (Tuna Orbital Oil) from 10 weeks of age. Semen samples were collected from the birds after 30 and 48 weeks of supplementation. The fish oil diet induced a significant but limited increase in the proportion of 22:6n-3 in the spermatozoan phospholipid in parallel with an equivalent decrease in the proportions of 20:4n-6 and 22:4n-6. However, since the maximal level of 22:6n-3 in the phospholipid that was achieved by fish oil feeding was less than 10% (wt/wt of fatty acids), these changes fell far short of representing a switch from the typical avian pattern to that more characteristic of the n-3 enriched mammalian semen. Analysis of the fatty acid compositions of the constituent classes of phospholipid in the spermatozoa indicated that, in both dietary states, the phosphatidylethanolamine fraction contained much greater proportions of n-6 and n-3 C20-22 polyunsaturates than the phosphatidylcholine fraction. The results indicate that the typical fatty acid profile of the spermatozoa of domesticated poultry, characterised by the predominance of C20-22 n-6 polyunsaturates, displays a considerable degree of resistance to manipulation by dietary means and does not adopt the "mammalian" type of profile following supplementation with n-3 fatty acids.

Fatty acid composition, glutathione peroxidase and superoxide dismutase activity and total antioxidant activity of avian semen.

This work demonstrates that spermatozoa from five avian species (chicken, turkey, guinea fowl, duck and goose) are all characterised by high proportions of polyunsaturated fatty acids, from 46 (turkey) to 55% (duck) of total. For each of the species, the most abundant fatty acids were arachidonic (20:4n-6) and docosatetraenoic (22:4n-6) acids, representing between 22 (turkey) and 40% (chicken) of total. Significant activities of the major isozymes of superoxide dismutase and glutathione peroxidase, which protect against the peroxidation associated with high degree of fatty acid unsaturation, were found in spermatozoa from all species. The seminal plasma also had these activities and showed additional mechanisms for protecting spermatozoa from peroxidation. In general terms, these lipid and enzyme proteins were similar between the five avian species and different from those reported for mammalian sperm.

Viability, susceptibility to peroxidation and fatty acid composition of boar semen during liquid storage.

The changes in viability, susceptibility to peroxidation and fatty acid composition of total phospholipid were studied in boar spermatozoa during 5 day liquid storage in a standard or alpha-tocopherol (alphaT) enriched diluent. The sperm rich fraction of the ejaculates was collected from 6-month old boars. Sperm viability progressively decreased during storage and alphaT inclusion into the diluent significantly inhibited this trend. alphaT inclusion also decreased significantly peroxidation (TBARS production of spermatozoa). Spermatozoa stored in the treatment diluent became rapidly enriched in alphaT with a concomitant decrease of alphaT content in the medium. The proportion of polyunsaturates, mainly 22:6n-3, decreased with a complementary increase in the content of the saturates, mainly 18:0. The inclusion of alphaT into the diluent was effective in totally preventing the significant decrease of 22:6n-3 observed in sperm phospholipid in the control samples during the storage period. It is concluded that the alphaT inclusion in the boar semen diluent increased cell viability through its prevention of an oxidative reduction in the levels of the major polyunsaturated fatty acids, namely 22:6n-3.

Assessment of sperm viability in boar, rabbit and rooster: a modification of the fluorometric ethidium bromide exclusion procedure.

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 x 10(6) cell/ml) and Percoll washed semen for rabbits (4-16 x 10(6) 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.

Heritabilities and genetic correlations of conformation and plumage characteristics in pheasant (Phasianus colchicus).

Data were obtained from 588 pedigreed pheasants of an unselected population. Body weight, shank length (SL), plumage measurements, and plumage score were analyzed to estimate heritabilities and genetic and phenotypic correlations. All measurements were made at 28 and 120 d of age. The h2 estimates (sire component) were the following: .27 and .30 for BW at 28 (BW28) and at 120 d (BW120), respectively; .34 and .79 for SL at 28 (SL28) and at 120 d (SL120), respectively; .30 and .13 for rectrices length (RL) at 28 (RL28) and at 120 d (RL120), respectively; .14 for primary remex at 28 d (PR); .21 for primary remex 1 at 28 d (PR1); .23 for secondary remiges length (SRL); .34 for body weight gain (BWG); .35 for shank length gain (SLG). Negative genetic correlations between BW and SL with plumage traits at 120 d were found. The magnitude of heritability indicates that selection for BW is possible but the negative association with plumage traits must be carefully considered. The improvement of housing conditions could lead to birds with a well-developed plumage, because environment influenced variability of plumage traits.

Egg related parameters affecting fertility and hatchability in the Italian bantam breed Mericanel della Brianza.

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 =< 33 g, EW2 = 33-36 g, EW3 = 36-39 g and EW4 =≥ 39 g. 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.

The post-thaw irradiation of avian spermatozoa with He-Ne laser differently affects chicken, pheasant and turkey sperm quality.

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 632.8 nm; 6 mW; 3.96 J/cm(2)). 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.