Genetic Variability and Management in Nero di Parma Swine Breed to Preserve Local Diversity

Nero di Parma is an endangered swine breed reared in the North of Italy which nowadays counts 1603 alive pigs. The aims of this study were (i) to explore the genetic diversity of the breed at pedigree level to determine the actual genetic structure, (ii) to evaluate the effectiveness of the breeding recovery project and (iii) to potentially propose breeding strategies for the coming generations. The pedigree dataset contained 14,485 animals and was used to estimate demographic and genetic parameters. The mean equivalent complete generations was equal to 6.47 in the whole population, and it reached a mean value of 7.94 in the live animals, highlighting the quality of the available data. Average inbreeding was 0.28 in the total population, whereas it reached 0.31 in the alive animals and it decreased to 0.27 if only breeding animals were considered. The rate of inbreeding based on the individual increase in inbreeding was equal to 7%. This study showed the effectiveness of the recovery project of the breed. Nevertheless, we found that inbreeding and genetic diversity have reached alarming levels, therefore novel breeding strategies must be applied to ensure long-term survival of this breed

Body weight estimation from body measures in Cornigliese sheep breed

The aim of this research is to propose equations to estimate body weight (BW) from body measures (BMs) in the Cornigliese sheep, an endangered breed reared in Italy for meat purpose. BW and BMs were submitted to correlation and multiple regression analyses. Two datasets were used: (i) 303 animals (178 females, 125 males, BW 4.00–117.80 kg), on which BW, height at withers (HW), chest circumference (ChC) and body length (BL) were measured; (ii) 156 animals (109 females, 47 males, BW 5.15–117.80 kg) out of 303 on which croup height (HCr), chest width (ChW), chest depth (ChD) and croup width (CrW) were also considered. On each dataset, two regression models were applied, one containing all variables (models 1 and 3, respectively, for datasets 1 and 2) and the other one comprising groups of variables, selected by means of the stepwise procedure (models 2 and 4, respectively, for datasets 1 and 2). BW resulted correlated with all BMs (from 0.852 for ChW to 0.950 for ChC; p < .001). Models 1 and 3 fitted the data better than models 2 and 4, both for all animals and for females and males separately. We concluded that BW could be predicted from BMs also in Cornigliese sheep breed. The best fits were obtained when the highest number of measures was included in the model (models 1 and 3). Nevertheless, models 2 and 4 could be used more easily in extensive sheep breeding than models 1 and 3, since they require less parameters.Highlights The estimation of body weight is important in a meat type sheep breed for choosing the optimal slaughter time. A reduction of work for farmer is positive, mainly in field conditions of extensive rearing, where scales are not easily available. Body weight could be predicted from body measures in Cornigliese sheep breed with good precision and accuracy

Effect of Duroc genes proportion on growth performance and on carcass and meat quality characteristics in heavy pigs

By means of the application of covariance models, the linear effects of the proportion of Duroc genes were evaluated with respect to growth (from 6 to 170 kg live weight) and feed/gain ratios, as well as carcass (lean cuts, adipose cuts, linear measures, backfat thickness, loin area and lean percentage) and meat quality (L* a* b* colour, reflectance, electrical conductivity, pH) in 167 heavy pigs (87 castrated males, 80 females) from different crosses of Duroc (D), Large White (LW) and Landrace (L) breeds, from 25 to approximately 300 d of age. The pigs were weighed at 25, 105, 170, 235 d and at the end of the trial (298 ± 6 d of age), and were raised under the same conditions. The proportion of Duroc genes was 0% (LWxL; no. 33), 25% [(LWx(DxL); n. 31 and Lx(DxLW); n. 35)] and 50% [Dx(LWx(LWxL)); n. 68]. The increase in the proportion of Duroc genes negatively affected the live weight at the different ages (P0.10). In fact, during the final phase (from 120 to 170 kg l.w.) the effect of the Duroc breed on daily gain became positive (P=0.08), and the feed/gain ratios were significantly lower (P=0.02). The carcass composition was not significantly influenced by the increase in the proportion of Duroc genes, with the exception of a rise in the weight of neck (P<0.01) and flare fat (P=0.02) and a reduction of ham (P=0.09). Carcass length resulted lower as the proportion of Duroc genes increased (P<0.01); at 24 h from slaughtering, meat colour showed lower values for lightness (P=0.08), redness (P=0.02) and yellowness (P=0.03)

Monitoring blood plasma leptin and lactogenic hormones in pregnant sows.

The mechanism of action of leptin in pregnant breeding sows, in which hyperphagia is managed through dietary strategies, is yet to be clarified. The aim of this study was to monitor leptin concentrations and their interactions with lactogenic hormones in Large White×Landrace breeding multiparous sows (n=15). All sows showed a normal body condition (mean body condition score: 2.96). Blood samples were collected the day after weaning the litters, at insemination, every 15 days up to day 45 of pregnancy and every 7 days from day 46 to farrowing. At delivery, the placenta was collected for the analysis of leptin and leptin receptor expressions. Plasma leptin levels increased from the end of mid gestation (day 72) and remained high until farrowing (P<0.05). As expected, plasma prolactin (PRL), low during most of pregnancy, increased during the 2 weeks before farrowing (P<0.05), whereas progesterone levels reached plateau at 30 days of gestation and decreased at farrowing (P<0.05). Cortisol levels peaked close to farrowing (P<0.05). Leptin was expressed in the placenta, where the receptor expression analysis showed the presence of the short form but not of the long form. A positive correlation was found between leptin and PRL concentrations during mid (r=0.430; P<0.001) and late (r=0.687; P<0.001) pregnancy, and with progesterone in early pregnancy (r=0.462; P<0.05). During late gestation, a positive correlation was observed between leptin and cortisol (r=0.585; P<0.001). Our results suggested that, in restrictively fed pregnant sows, the leptin levels increased from the end of mid pregnancy to delivery, confirming the presence of leptin resistance. We showed a correlation between leptin and lactogenic hormones during different stages of pregnancy in sows. Lactogenic hormones show pregnancy-specific changes in their secretion and all may become involved in modulating leptin signal

Effect of the proportion of Duroc genes in crosses with Large White and Landrace pigs on the characteristics of seasoned Parma ham

The aim of this study was to estimate the linear and quadratic effects of the proportion of Duroc genes on the characteristicsof seasoned Parma hams by means of a covariance model. The study was carried out on 167 pigs (87 castratedmales, 80 females) from different crosses among Duroc (D), Large White (LW) and Landrace (L) breeds, slaughteredat 300 d of age (live weight 170 kg). All pigs were raised under similar conditions. The curing period was 380 days. Theproportion of Duroc genes was 0% (LWxL; n. 33), 25% [(LWx(DxL); n. 31 and Lx(DxLW); n. 35)] and 50%[Dx(LWx(LWxL)); n. 68]. The increase in the proportion of Duroc genes had a positive linear effect (P<0.01) and a negativequadratic effect (P=0.01) on the yield of deboned ham while ham fat thickness decreased linearly (P=0.07) andincreased quadratically (P<0.01). A higher proportion of Duroc genes was also linearly associated with a lower lightness(P<0.01) and a less yellow color (P=0.09) of the biceps femoris muscle; positive quadratic coefficients have been shownfor lightness (P<0.01), yellowness (P=0.01) and hue (P=0.03). The chemical composition of the semitendinosus musclefeatured a linear increase in moisture (P<0.01) and decrease in fat (P=0.03) and non protein nitrogen (P=0.01) content,in addition to significant quadratic effects with an increase in the proportion of Duroc genes. In conclusion, crossbreedingwith the Duroc breed (up to 50%) makes it possible to obtain positive quality characteristics of cured Parma ham

Carcass and meat parameters in Cornigliese sheep breed as affected by sex and age-class

A total of 72 animals from Cornigliese sheep breed were reared under homogeneous conditions, with the aim to assess the effect of sex (males, females) and age-class (heavy lambs, adults) on carcass and meat parameters. A model with fixed effects of herd, sex, slaughtering session, age-class and interaction (sex*age-class) was used; for slaughter data, the carcass weight was used as a covariate. The age-class effect was significant for most of the carcass measurements, indicating a late development in animals. Also, slaughter performance was significantly affected by age-class, with higher values (p<0.05) of hot carcass yield shown by heavy lambs than by adults. Carcass compactness index was lower in heavy lambs than in adults (p<0.001), and the lowest value (0.283; p<0.05) appeared in female heavy lambs. The percentage of fat trimmings in carcass and the tissue composition of sample cut were influenced by a significant interaction between age-class and sex (p<0.05): in males the age-class never affected the tissue composition of sample cut, as in females the muscle and fat percentages increased with age while the bone percentage decreased. The fat content of loin meat increased with age in females (p < 0.05) and decreased in males (p < 0.05). The poly-unsaturated fatty acids (FA) content of loin meat was higher in males than in females (p < 0.001), with saturated FA and mono-unsaturated FA revealing significant interactions between age-class and sex (p < 0.05). In conclusion, future implementation of genetic selection, oriented towards the improvement of meat production characteristics that are potentially present in the breed, is important

Exploring genetic diversity in an Italian horse native breed to develop strategies for preservation and management

Genetic diversity is a key factor for both adaptation and response to selection. The loss of genetic diversity causes a decrease in individual fitness, and it has a dramatically negative effect on population lifespan in the long term. This study aimed at exploring the genetic diversity at pedigree level of the Bardigiano horse breed, which is a native breed from Italy shaped for living in rural areas. In 1977, the Bardigiano studbook was founded to preserve the breed and for improving its use for riding and draft purposes. Pedigree data contained 9,469 horses, of which 3,416 were alive. Demographic and genetic parameters were estimated on subpopulations to evaluate potential genetic diversity differences among breeding and nonbreeding animals, and animals showing different breeding values (EBVs) for an index combining 18 conformation traits. Throughout the studied period, inbreeding steadily increased, reaching in the last birth year cohort a mean value equal to 0.10. The rate of inbreeding per generation, assuming a mean generation interval of 8.74 years, was equal to 1.64%. Moreover, significant differences on both average relatedness and inbreeding among horses with high and low EBVs were shown. Our study unravelled the state of genetic diversity in the Bardigiano breed, highlighting that breeding strategies for optimizing the contribution of breeding animals in the coming generations are needed to ensure long‐term survival of the Bardigiano horse breed

Effect of sex and season of birth on Gompertz growth curve parameters in "Nero di Parma" pigs

The growth curves of “Nero di Parma” pigs were studied by applying the Gompertz equation to 1069 body weight (BW) records from 285 pigs (156 females, 129 castrated males) born in 11 outdoor and 5 indoor herds; pigs were fed commercial complete feeds offered ad libitum and, on a limited basis in the outdoor system, diets were integrated with pasture. The parameters of the Gompertz equation were compared with reference to sex and season of birth. Mature BW for castrated males (229.0 kg) was 3.5% greater than that for females (221.3 kg) (P180 kg)

Application of different growth models to "Nero di Parma" pigs

The growth curves of 280 "Nero di Parma" pigs from birth to maturity were calculated by applying nine different models (regressions from 1st to 4th degree and nonlinear regressions following the Brody, Logistic, Janoschek, Bertalannfy and Gompertz models) to 1109 individual records of body weight (BW) from two different data sets. The goodness of fit of experimental data was calculated by means of Residual Variance, Akaike Information Criterion, Residual Standard Deviation and R2. The best fit was obtained by Gompertz equation, as follows: BW(kg)= 240.2±2.4 * esp (-exp (-0.0069±0.0001*(age(d)–213.5±3.1))). Regardless to the model, all correlations between actual and estimated BW were highly significant (P<0.001): the highest correlation (0.980) was obtained by the application of the Gompertz equation. In conclusion the growth of "Nero di Parma" pigs can be well described by applying the Gompertz model to field data