Francesco Panella

Quantitative and compositional variations of massese sheep milk by parity and stage of lactation

Abstract Effects of parity and length of lactation on physico-chemical characteristics of sheep milk were evaluated on milk samples from the first to the sixth lactation of 100 Massese sheep in Italy. Milk samples were collected twice a month and the following items were studied: quantity of milk, length of lactation, physico-chemical characteristics, amino acids, fatty acids and mineral content of the milk. Milk production showed a decreasing curvilinear trend with days of lactation, according to the formula y=2.1409−0.012x+0.00002x2. Parity had a significant effect on total milk yield (P⩽0.006), and on physico-chemical milk characteristics (P⩽0.001), but had no effect on amino acid, fatty acid and mineral contents. Stage of lactation caused high variability in almost all analytical parameters expressed by linear or quadratic regression, with the exception of several amino acids which were independent of this factor.

The measurement of chest girth as an alternative to weight determination in the performance recording of meat sheep

Abstract The aim of this study was to assess, for two Italian meat sheep breeds (Appenninica and Merinizzata italiana), the relationship between an easily recorded measurement (girth of chest) and the character used for selection purposes (weight), and to define the most appropriate mathematical methods to infer the second from the first. For the Appenninica 1392 lambs were measured, for the Merinizzata italiana 1559 lambs were measured. The possibility of estimating weight through chest girth (CG) measurement was evaluated, separately for each breed, by taking the most suitable model between those including different kinds of regression effect. The model was chosen in relation to the value of the determination coefficient and the sum of square residuals. The prediction accuracy of the model was assessed by comparing the expected values with the observed ones through a number of statistical tests. A further prediction analysis was carried out using the mean values of the observed weights that fell in each 1 cm class of girth, in order to reduce the error derived by the varying numbers of observations per unit of chest girth. The model including the square regression nested within the sex effect and the flock random effect nested within the sex effect was observed to be the most suitable one to predict the weight from the chest girth; the determination coefficients ranged between 0.944 (Appenninica) and 0.955 (Merinizzata). The prediction parameters were: -10.458+ 0.241 (CG) + 0.004 (CG2) for the Appenninica males; -6.121 + 0.093 (CG) + 0.005 (CG2) for the Appenninica females; -6.325 + 0.189 (CG) + 0.004 (CG2) for the Merinizzata males; -4.676 + 0.078 (CG) + 0.005 (CG2) for the Merinizzata females. The correlation between the observed and expected values was always higher than 0.97. The equations estimated using the mean weights for each girth showed extremely high determination coefficients (≅ 0.99) due to the reduction of variability implied by this method. Choosing between the equations calculated on the entire data set or on the mean weights will only be possible after a period of field tests.

A microsatellites-based survey on the genetic structure of two Italian local chicken breeds

The biodiversity safeguard is an important goal of poultry production in every developed country. Nowadays, the high chicken meat demand from the world market has been leading to a large spread of strongly producing commercial chicken lines. The creation of these standard types is causing a progressive loss of genetic variability. Ancona and Livorno are two Italian autochthonous chicken breeds which represent a great resource in terms of specific genetic richness. Aim of this study is to investigate the genetic diversity of these breeds as potential valuable genetic variability source. In fact, in spite of their endangered status, these chicken breeds are very appreciated for their ability to adapt themselves to extensive organic rearing systems. Blood samples from 131 individuals were collected and genotyped through a thirty microsatellitesbased analysis. All the observed descriptive statistical indexes suggested a heterozygosity deficiency and an inbreeding level (mean observed heterozygosity = 0.46, mean expected heterozygosity = 0.53, Fis in Ancona and Livorno = 0.251 and 0.086). The tree from inter-individual DAS distance using Neighbour-Joining algorithm and the FCA analysis showed a higher internal variability in Livorno than in Ancona. STRUCTURE analysis showed the genetic uniqueness of the breeds and the presence of sub-groups in Ancona originating from a possible genetic isolation. This research could be a suitable starting point to set up improved selection schemes and a potential preliminary genotypic test for all the cocks to be used in the selection.

Wool quality in Gentile di Puglia sheep breed as measure of genetic integrity

Abstract The Gentile di Puglia is a breed created in the 15th century by crossing Merino Spanish rams and “gentile” ewes reared in some areas of Southern Italy, mainly Apulia and Basilicata. The crisis of the wool industry, the poor quantity of milk, the inadequacy of Gentile di Puglia to be milked by machine and the passage from transhumant to permanent rearing caused a dramatic reduction of this population, which was largely crossed with other breeds and declined from about one million heads in the sixties to 5,000 at the present time. In order to save the ancient typical Gentile di Puglia breed, the aim of this work was to estimate the “genetic integrity” of the remaining Gentile di Puglia population by means of an analysis of wool quality measured through the diameter of the fibre and the homogeneity of the fleece. Our hypothesis was that the animals originated from outcrosses to other Merino derived breeds specialised for meat would show larger diameters of the fibres and a reduced homogeneity of the fleece. The research was carried out using Herd Book registered animals from 9 farms: 1 from Isernia, 2 from Campobasso and 6 from Foggia province. The statistical analysis on the diameter of the fibre was carried out on a dataset of 38,200 observations (200 records x 191 animals) divided in four classes (ultrafine, fine, croisè, ordinary). The high frequencies of ultrafine and fine fibre classes show that the quality of the wool is still good in the population. This consideration can be extended to all the farms involved in the study that could therefore be suitable in the conservation programs for this breed. The homogeneity of the fleece was also good in providing further evidence of the genetic integrity of the population. Other analysis carried out on the quality of the wool in relation to the body size confirmed that the observed Gentile di Puglia is well representative of the ancient breed.

The role of mitochondrial DNA to determine the origin of domestic chicken

Mitochondrial DNA (mtDNA) is has recently lost relevance especially when utilised to study species that are characterised with a history of several migrations. Nonetheless, mtDNA can still represents a useful additional tool in the study of molecular genetic diversity. The reason for the adoption of mtDNA is that it is easy to amplify because it appears in multiple copies in the cells and the mitochondrial gene content is strongly conserved across generations. Thousands of published studies have reached conclusions about population history, patterns of gene flow, genetic structure, and species limits, on the basis of mtDNA sequence variation. MtDNA has been used to study phylo-geographic structure of avian species, and to identify the number of maternal lineages and their geographic origins. Most studies of chicken mtDNA rely on sequences of partial control region but recent researches used the complete mtDNA genome to reconstruct the history of animal domestication. The first genetic study on mtDNA suggests that the Indochinese Red Junglefowl subspecies Gallus gallus gallus is the primary ancestor of the domestic chicken (Gallus gallus domesticus). Other studies showed that at least three subspecies of Gallus gallus were enrolled in the origin of domestic chicken breeds, and that there may be at least two domestication centres: one in Southeast Asia and one in the Indian subcontinent. The authors suggested nine highly divergent clades (named clade A-I) related to geographical distribution in a wide range of domestic chickens and Red Junglefowls across Eurasian regions. Understanding when chickens were transported out of domestication centres and the directions in which they were moved provides information about prehistoric human migration, trade routes and cultural diffusion. MtDNA has been used to infer regions of domestication and to identify the number of maternal lineages and their geographic origins in macroevolution studies.

Suitability of linear scoring in meat sheep: the practical case of Merinizzata Italiana breed

Linear scoring is widely applied in domestic animal species, mainly in cattle and horses. There are only few cases of linear scoring in sheep, probably because the small body size and the narrow range of the classes make difficult to correctly evaluate the measures. In this paper the results of a linear scoring test carried out on Merinizzata Italiana sheep breed in order to verify the feasibility of this method in sheep, are reported. Twenty untrained people, with three different levels of scoring experience in meat sheep morphology, evaluated 52 pluriparous ewes for body length, chest circumference, chest width, rump height, rump width, and withers height; to check for misclassification, their scores were compared with a reference score, previously obtained measuring the same animals by the suitable tools (measuring tape and a Lydtin stick). The percentage of correct scoring ranged from 44.4% for body length to 61.8% for withers height, and was not affected by the experience of the judge. In all characters, the distance of the class from the trait mean had a significant effect in increasing the intensity of misclassifications; the judge’s experience showed a positive effect in reducing the intensity of the misclassification for body length, that was the hardest trait to score. These results encourage to further verifying in practice the linear scoring in the Merinizzata Italiana sheep and in other meat breeds.

Social network analysis in encouraging role-players in the beef market to take breeding decisions: a methodological study

The aim of the research is to apply the social network analysis (SNA) to the Italian Romagnola beef meat market in order to better understand the interrelationships of the supply chain. Knowledge of the market exchange system is very important in order to be able to choose the most suitable breeding approach. The analysis was carried out using data concerning the heifers exchanged during the year 2008 within the framework of the activities of the Italian consortium of white bullock producers of the central Apennine region of Italy (Vitellone Bianco dell’Appennino Centrale). The social network analysis shows that very few of the possible links between the agents are used and that this leads to a lack of competitiveness. At the same time, the agents have shown to be able to place themselves at the most important points along the supply chain. Furthermore, the results of the analysis show the need for a stronger farming phase with a greater emphasis on the farmers, given that, from an economic point of view, they are the most important role-players.

Genetic differentiation between Segugio dell'Appennino and Segugio Maremmano dog breeds assessed by microsatellite markers

The domestic dog (Canis Familiaris) was the first species to be tamed and bred to occupy a variety of functions. The Segugio dell’Appennino and Segugio Maremmano are two Italian breeds used extensively as hunting dogs. Microsatellites and other genetic markers are useful tools in evaluating the within and between breed genetic variation. The aim of this study was to investigate genetic differentiation among the two breeds through the analysis of 21 microsatellite markers. The two populations share the same geographical regions but have been over time selected on different parameters to achieve specific functions. All the analysed microsatellite markers were polymorphic and the average number of alleles per locus was 8.19. The mean FIT index (0.051; P<0.05) highlights that at some point in time, the normal gene flow among the animals was disrupted, giving rise to a heterozygote deficiency in both breeds, and this is confirmed by the mean FST fixation index (0.010; P<0.05) clearly indicating an absence of a significant genetic differentiation between the two breeds. The mean FIS value was significantly different from zero (0.042) (P<0.05) reconfirming the presence of a lack of heterozygosity in the studied samples. The values of observed and expected heterozygosity were similar in the two breeds. AMOVA, PCA and STRUCTURE analysis, all emphasise the lack of significant differences among the two breeds in terms of genetic differentiation. The presence of a population substructure is probably due to a genetic introgression from different Segugio breeds, that can be confirmed with further studies.

Genetic parameters for the weights and yields of carcass cuts in Chianina cattle.

Chianina is the tallest and heaviest beef cattle breed in the world and 1 of the most appreciated breeds on the Italian meat market. A selection program focused on improving Chianina carcass quality could provide a further economic advantage to Chianina breeders. However, the current European carcass scoring system [i.e., the SEUROP (S=superior, E=excellent, U= very good, R=good, O=fair, and P=poor) grid] is not suitable for use in selective breeding programs; methods based on carcass cuts would be much more efficient. Here, the genetic parameters of weights and yields (percentage of carcass weight) of the main commercial cuts were estimated on 842 Chianina carcasses (heifers and bullocks) using a mixed model that takes into account the fixed effects of herd, year of slaughter, and sex and the random additive effect of the animal; the carcass weight was also considered in cuts yield. The average carcass weights were 492.6 ± 86.52 kg (males) and 312.1 ± 68.74 kg (females), and the largest cut was the round, with a weight of 58.6 ± 19.35 kg and yield of 24.4 ± 1.28% in males and 40.2 ± 17.59 kg and 25.3 ± 1.41% in females. The variability in cut weight was greater than that in yield percentage. The cut weight heritabilities ranged from 0.74 (chuck) to 0.21 (short plate) whereas the yield heritabilities ranged from 0.88 (loin) to 0.40 (brisket). The genetic correlations were generally high and positive between weights; correlation values with yields were lower and could be positive or negative. These findings suggest that a selection program to improve the carcass quality of Chianina beef using cuts data could potentially achieve good results.

Mitochondrial DNA variants of Podolian cattle breeds testify for a dual maternal origin

Background Over the past 15 years, 300 out of 6000 breeds of all farm animal species identified by the Food and Agriculture Organization of the United Nations (FAO) have gone extinct. Among cattle, many Podolian breeds are seriously endangered in various European areas. Podolian cattle include a group of very ancient European breeds, phenotypically close to the aurochs ancestors (Bos primigenius). The aim of the present study was to assess the genetic diversity of Podolian breeds and to reconstruct their origin. Methodology The mitochondrial DNA (mtDNA) control-regions of 18 Podolian breeds have been phylogenetically assessed. Nine non-Podolian breeds have been also included for comparison. Conclusion The overall analysis clearly highlights some peculiarities in the mtDNA gene pool of some Podolian breeds. In particular, a principal component analysis point to a genetic proximity between five breeds (Chianina, Marchigiana, Maremmana, Podolica Italiana and Romagnola) reared in Central Italy and the Turkish Grey. We here propose the suggestive hypothesis of a dual ancestral contribution to the present gene pool of Podolian breeds, one deriving from Eastern European cattle; the other arising from the arrival of Middle Eastern cattle into Central Italy through a different route, perhaps by sea, ferried by Etruscan boats. The historical migration of Podolian cattle from North Eastern Europe towards Italy has not cancelled the mtDNA footprints of this previous ancient migration.