C. Dalvit

Effect of Holstein Friesian and Brown Swiss Breeds on Quality of Milk and Cheese

In Italy, more than 75% of milk is used for cheese making. For this reason, milk composition and coagulation traits and cheese quality represent the most important tools for the economic development of the dairy sector. In particular, cheese quality varies in relation to cheese-making technology and breed of cow. The aim of this study was to investigate the effect of 3 types of milk, originating from Holstein-Friesian (HF), Brown Swiss (BS), and mixed of both breeds, on vat milk characteristics, cheese yield, and quality in 3 different typical Italian cheese-making conditions (Casolet, Vezzena, and Grana Trentino). One hundred forty-four cows (66 HF and 78 BS) were involved, and a total of 24 vats of milk were evaluated. At maturity, 30, 21, and 16 wheels of Casolet, Vezzena, and Grana Trentino cheese were analyzed. Brown Swiss cows yielded 9% less milk per day than HF cows, but milk showed greater contents of protein, casein, titratable acidity, and better rennet coagulation time and curd firmness than HF milk. The chemical composition and cholesterol content of the 3 types of cheese were similar between breeds, whereas the cheese made with BS milk showed greater contents of monounsaturated and polyunsaturated fatty acids. Cheese made with BS milk had greater b* (yellow component) than HF. Cheese yield, recorded at different ripening times, demonstrated that BS milk yielded more cheese than HF. Mixed milk showed values, on average, intermediate to HF and BS milk characteristics, and this trend was confirmed in cheese yield at different ripening times.

Genetic variation and population structure of Italian native sheep breeds undergoing in situ conservation

The genetic variability and presence of population substructures in 4 native Northern Italian sheep breeds, Alpagota, Brogna, Foza, and Lamon, undergoing in situ conservation, and 1 widespread Italian breed, Bergamasca, were studied by investigating 19 microsatellite markers. The breeds showed considerable genetic variability in terms of number of alleles and heterozygosity, with the exception of Alpagota, which was the least variable (0.607). Nevertheless, a significant deficit of heterozygotes was observed in each breed due to rather increased levels of inbreeding or to the presence of population substructures, probably caused by increased genetic variation in the founder populations. The analyses evidenced clear genetic differentiation (F(ST) = 0.085), reduced levels of admixture, and presence of private alleles among the breeds, confirming their genetic uniqueness. In particular, according to Reynolds genetic distances, Alpagota was the most differentiated, perhaps because it had been bred mostly in a rather isolated area. Loss of any of the investigated breeds would result in a loss of genetic diversity ranging from 0.5 to 1.6% of the total observed gene diversity. Results supported the decision to safeguard these breeds as important reservoirs of genetic diversity and suggested breeding and mating practices to maintain variability and to overcome within-breed substructures.

Carcase characteristics and qualitative meat traits of three Italian local chicken breeds

1. An experiment involving 60 male chickens reared in an organic production system was carried out in order to investigate carcase characteristics and qualitative meat traits of three slow-growing Italian local breeds of chicken (Ermellinata, Padovana and Pépoi). 2. Chicks were randomly selected at hatch, raised together under the same conditions, slaughtered at 190 d of age, dissected for carcase traits, and meat (breast and thigh) stored for subsequent analysis of quality parameters. 3. Ermellinata (EA) chickens were significantly different from Padovana (PA) and Pépoi (PI) chickens for live, carcase and thigh weights. Breeds were also different for breast muscle protein content (EA > PI and PA), shear force (PA < EA and PI) and cooking loss (PI > PA and EA) values. 4. The CIE system values of lightness (L*), redness (a*), and yellowness (b*) evidenced a distinctive darker meat and lighter skin colour of PA breast meat. 5. Polyunsaturated fatty acids composition of breast meat was similar among the analysed breeds. EA had significantly higher saturated but significantly lower monounsaturated fatty acid contents than the other two breeds.

Finding 16S rRNA gene-based SNPs for the genetic traceability of commercial species belonging to Gadiformes

Abstract A SNPs (Single Nucleotide Polymorphism) based analysis was developed to differentiate four economically important species belonging to the Gadiformes order: Pacific cod Gadus macrocephalus, Atlantic cod Gadus morhua, Haddock Melanogrammus aeglefinus and Ling Molva molva. A 430bp fragment of the 16s rRNA gene was amplified using interspecific conserved primer and sequenced. The sequences were aligned and analyzed for the presence of SNPs; three SNPs (MerSNP1, MerSNP7 and MerSNP9) were identified and selected to allow discrimination between the four species. Aplotypes were TCC, CCC, CAT and CAC for Pacific cod, Atlantic cod, Haddock and Ling respectively. Confirmation of results was achieved by sequencing 16s rRNA gene fragments of 16 G. morhua, 7 G. macrocephalus, 15 M. aeglefinus and 5 M. molva samples collected at different fish catching campaign. Nucleotide sequence of 16s rRNA mitochondial gene has been shown to be a useful tool to allow rapid reliable and fully automatable for discrimination of 4 economically important species in fisheries industry.

Comparing profitability of Burlina and Holstein Friesian cattle breeds

Abstract Aim of this study was to compare profitability of Burlina and Holstein Friesian cows in northern Italy. Cow’s profitability was calculated for each breed, with consideration of economic incentive programs and alternative milk pricing scenarios. The difference in annual profitability between Burlina and Holstein Friesian ranged from −€719 to −€274 per cow per year. In a low-input management level with a cow’s incentive payment and a specific cheese market strategy the low milk yield of Burlina can be compensate respect to Holstein Friesian.

Genomic DNA fingerprinting of indigenous chicken breeds with molecular markers designed on interspersed repeats.

In Italy more than fifty different local breeds of chicken (Gallus gallus L.) are known to have been present in the past. The overall situation is now critical since most of these breeds are becoming extinct or threatened and only a few are subject of conservation plans. The use of molecular markers for the analysis of chicken populations could help in characterizing their genetic variation and preserving them from genetic erosion. valuable and irreplaceable sources of chicken germplasm from indigenous populations of the veneto region were analyzed by means of DNA fingerprinting with molecular markers designed on interspersed mini- and microsatellite repeats. The identification of either among-breed discriminant or breed-specific markers was based on the S-SAP and M-AFLP systems derived from the AFLP technology. Genomic DNA fingerprints were generated in 84 individuals belonging to six local breeds (Ermellinata, Padovana, Pépoi, Polverara, Robusta Lionata and Robusta Maculata) and one commercial line used as reference standard. A number of variation statistics were computed to assess the genetic variability within and relatedness among breeds: the effective number of alleles per locus (n(e)= 1.570), total and single-breed genetic diversity (H(T)= 0.366 and H(S)= 0.209, respectively) and the fixation index (G(ST)= 0.429). The mean genetic similarity coefficients within and between local breeds were 0.769 and 0.628, respectively. Markers useful for the genetic traceability of breeds revealed significant sequence similarities with either genic or intergenic regions of known chromosome position. Sequence tagged site primers were designed for the most discriminant markers in order to develop multiplex non-radioactive genomic PCR assays. Analysis of the population structure along with individual assignment tests successfully identified all breed clusters and subclusters. The vast majority of animals were correctly allocated to their breed of origin, demonstrating the suitability and reliability of the chosen AFLP-derived marker systems for detecting population structure and tracing individual breeds. The local breeds have been preliminarily identified according to sequence-specific SNPs and haplotypes and the polymorphism information content of genomic AFLP-derived markers is reported and critically discussed.

Estimation of genetic diversity over time in an in-situ marker assisted conservation scheme of local chicken breeds.

Abstract The aim of this research was to study the genetic variability of two local chicken breeds (Ermellinata di Rovigo and Robusta Maculata) involved in a conservation programme, over a period of three years. Samples were collected in 2002 and in 2005 and analysed using 15 microsatellite markers. Obtained results evidenced that Robusta Maculata was genetically less variable than Ermellinata di Rovigo even after three years of conservation activities. During the studied period the observed heterozigosity was maintained and the excess of homozygous animals found in both breeds in 2002 was strongly reduced in 2005. These findings suggested that the conservation activities helped to overcome the probable presence of population substructures and to limit inbreeding. Moreover, this study evidenced the usefulness of microsatellite markers to monitor genetic diversity in conservation programmes for animal breeds.

Genetic diversity in some local chicken breeds using microsatellite markers

Abstract Genetic relationships among Veneto native breeds of chickens were studied on the basis of microsatellites polymorphisms. A total of 100 DNA samples from 2 local chicken breeds (45 Robusta Lionata and 43 Robusta Maculata) and a commercial broiler line (12 Golden Comet) were analyzed using 19 microsatellite markers. The average number of alleles per locus was 4.05 and the expected heterozigosity resulted lower for the local breeds than the broiler line. The Robusta Lionata breed and the broiler line showed a significant deficit and excess of heterozygotes, respectively, deviating from Hardy-Weinberg equilibrium. Nei’s standard genetic distances corrected for bias due to sampling of individuals (Da), based on allele frequencies, were calculated among breeds. The local breeds resulted very similar confirming the same genetic origin. The results suggested that microsatellite markers are a useful tool for studying the genetic diversity among local chicken breeds.

A proteomic approach to study local chicken breeds characterization

Abstract Aim of this study is to apply a proteomic approach for characterization of local chicken breeds. The experiment involved a total of 29 males of Pépoi, Padovana, and Ermellinata local chicken breeds. Sarcoplasmic protein fractions of breast muscle were analysed by bidimensional electrophoresis. Image analysis followed by statistical analysis enabled to differentiate groups of individuals on the similarities of protein expression. Individuals were distinguished into clusters and groups, corresponding to the breed of origin. Results evidenced a possible utilisation of proteomic approach in the field of breed characterization studies as an alternative to genomic analyses performed using molecular markers, both for breed and product traceability purposes.

Assessing genetic variability in two ancient chicken breeds of Padova area

Abstract Genetic diversity in two ancient indigenous chicken breeds of the Veneto region was assessed using Amplified Fragment Length Polymorphism (AFLP) markers. A total of 63 individuals were analysed using three selected AFLP primer combinations that produced 66 clear polymorphisms. The breeds analyzed were the Padovana and the Polverara (two ancient breeds) and a reference broiler line. The expected heterozygosity (Het) did not differ significantly among breeds. The variability at AFLP loci was largely maintained across breeds, as indicated by the coefficient of genetic differentiation (Gst) value. The lowest genetic distance is found between the Padovana and Polverara breeds suggesting that they could be genetically close.