251 research outputs found
Prediction of dry-cured ham weight loss and prospects of use in a pig breeding program
No full textLarge ham weight losses (WL) in dry-curing are undesired as they lead to a loss of marketable product and penalise the quality of the dry-cured ham. The availability of early predictions of WL may ease the adaptation of the dry-curing process to the characteristics of the thighs and increase the effectiveness of selective breeding in enhancing WL. Aims of this study were (i) to develop Bayesian and Random Forests (RFs) regression models for the prediction of ham WL during dry-curing using on-site infrared spectra of raw ham subcutaneous fat, carcass and raw ham traits as predictors and (ii) to estimate genetic parameters for WL and their predictions (P-WL). Visible-near infrared spectra were collected on the transversal section of the subcutaneous fat of raw hams. Carcass traits were carcass weight, carcass backfat depth, lean meat content and weight of raw hams. Raw ham traits included measures of ham subcutaneous fat depth and linear scores for round shape, subcutaneous fat thickness and marbling of the visible muscles of the thigh. Measures of WL were available for 1672 hams. The best prediction accuracies were those of a Bayesian regression model including the average spectrum, carcass and raw ham traits, with R2 values in validation of 0.46, 0.55 and 0.62, for WL at end of salting (23 days), resting (90 days) and curing (12 months), respectively. When WL at salting was used as an additional predictor of total WL, the R2 in validation was 0.67. Bayesian regressions were more accurate than RFs models in predicting all the investigated traits. Restricted maximum likelihood (REML) estimates of genetic parameters for WL and P-WL at the end of curing were estimated through a bivariate animal model including 1672 measures of WL and 8819 P-WL records. Results evidenced that the traits are heritable (h2 ± SE was 0.27 ± 0.04 for WL and 0.39 ± 0.04 for P-WL), and the additive genetic correlation is positive and high (ra = 0.88 ± 0.03). Prediction accuracy of ham WL is high enough to envisage a future use of prediction models in identifying batches of hams requiring an adaptation of the processing conditions to optimise results of the manufacturing process. The positive and high genetic correlation detected between WL and P-WL at the end of dry-curing, as well as the estimated heritability for P-WL, suggests that P-WL can be successfully used as an indicator trait of the measured WL in pig breeding programs
Genetic analysis of Spondylosis Deformans and effect of inbreeding on the degree of osteophytes development in Italian Boxer dogs
No full textSpondylosis deformans is a degenerative disease of the spine exhibiting the presence of one or more osteophytes, showing different degrees of development at the level of vertebral bodies (Morgan, 1967). A recent study (Carnier et al., 2004), although conducted on a relatively small sample of Italian Boxer dogs, showed that additive genetic variation for the degree of osteophytes development (DOD) is large enough to be exploited in specific breeding programs.
The high prevalence of diseases and defects in pure dog breeds might be due to high selection intensities in genetically closed populations (Ubbink, 1998). Inbreeding affects mostly fitness traits and traits which are of qualitative inheritance but also quantitative traits (Klemetsdal, 1998). Mäki et al. (2001) reported estimates of inbreeding depression on hip and elbow dysplasia in six dog breeds in Finland, but no previous studies dealing with inbreeding depression on DOD in Boxer dogs are available. The aims of this study were to infer (co)variance component for DOD and to asses the effect of inbreeding depression on DOD in the Italian Boxer dog population. In conclusion The degree of osteophytes development shows exploitable additive genetic variation. Its extent in the area between the 11th and 13th thoracic vertebrae is of particular importance because it is strictly correlated to the degree of osteophytes development of all the other sites, and has a moderate heritability. A slightly detrimental effect have been noticed for the inbreeding, especially for group of dogs with F greater than 10%
Genetic Correlations between Boar Taint Compound Concentrations in Fat of Purebred Boars and Production and Ham Quality Traits in Crossbred Heavy Pigs
No full textSelecting pigs with reduced ability to accumulate boar taint (BT) compounds in their tissues is an alternative to male surgical castration. As the majority of slaughter pigs are crossbred, before selecting against BT in purebreds, it is essential to consider possible impacts on commercial traits in crossbreds. This study estimated the genetic correlations between BT compound levels measured in 1115 purebred pigs and carcass and ham quality traits collected in 26,577 crossbred Italian heavy pigs. Genetic correlations were estimated in bivariate Bayesian analyses including one BT trait and one production or ham quality trait at a time. Heritability of androstenone, skatole, and indole was 0.41, 0.49, and 0.37, respectively. A moderate negative correlation between skatole and carcass yield (−0.40), and between all BT compounds and backfat (from −0.26 to −0.55) was observed. Conversely, positive correlations (from 0.11 to 0.54) were found between skatole and ham fat thickness traits. Correlations between BT compounds and iodine number ranged from −0.07 (for androstenone) to −0.64 (for skatole), whereas those with PUFA ranged from −0.13 (for indole) to −0.33 (for skatole). Hence, reducing BT could decrease ham fat thickness and increase unsaturated fatty acids, with potential negative impacts on product quality
Indagine sulle attitudini produttive e sul miglioramento genetico della razza Pezzata Rossa derivata Simmental in Europa: produzione di latte.
No full text
Le combat permanent contre l’eau et la poussière: Cours de base pour la conservation des archives destiné aux collaboratrices et collaborateurs des archives de l’État
No full textM. CARNIER & M. PRENEEL (version française complétée par P.-A. TALLIER & R. DEPOORTERE)info:eu-repo/semantics/publishe
Breed and crossbreeding effects on weight, yield an quality of heavy Italian dry-cured hams
No full textThe aim of this study was to estimate direct heterosis and breed additive effects of Belgian Landrace (BL), Duroc (DU) and Spotted Poland (SP) in comparison with Italian Large White (LW) on weight, losses and percentage yields during processing, and qualitative traits of heavy dry-cured hams. Hams from 290 pigs of 16 genetic types, produced by LW, BL × LW, DU × LW and SP × LW gilts mated with LW, BL, DU and SP boars, were controlled during industrial processing; a sub-sample of 116 dry-cured hams were deboned and chemical composition, colour and organoleptic properties were assessed. Technological processing traits were slightly influenced by additive effects and the imported breeds gave yields of dry-cured hams comparable to those of LW. BL crossbred pigs reduced the incidence of bone on the weight of seasoned ham (P < 0.01), but tended to have a higher percentage of ham discarded during processing than LW and a lower ham flavour score (P < 0.05). These findings suggest a lesser dry-curing suitability of BL-derived hams, even though no pigs gave PSE meat. DU decreased the incidence of bone (P < 0.05), protein content (P < 0.05) and flavour score (P < 0.10) and increased dry matter and sodium chloride (P < 0.05) of dry-cured hams with respect to LW. SP gave lighter boned hams than LW (P < 0.01), but with higher trimming discards (P < 0.05), and did not exert any influence on quality traits of seasoned hams. Direct heterosis never affected weight, losses and quality traits of seasoned hams, suggesting a negligible effect of crossbreeding on processing traits of pork meat
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