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Large 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.

Male reproductive performances are often ignored in cattle breeding programmes, although semen traits might be used to improve bull breeding soundness. Effects of genetic and environmental factors on semen production and quality traits were estimated in 693 Piemontese bulls with the aim of providing the first estimates of genetic parameters for semen traits for this breed. Volume and concentrations of individual ejaculates (up to three per each test-day), and volume, concentration, total number of spermatozoa and post-thawing progressive motility of within test-day pooled semen were available for 19 060 ejaculates. Bulls reached the maximum amount of daily semen production after their third year of age, with concentration rapidly increasing until 23 months of age, and then slowly decreasing. Semen volume was at its highest when collection days were at least 15 days apart, whereas the maximum concentration was reached when the interval was 6 days. Heritability estimates were generally moderate (0.14–0.26), and low for progressive motility (0.08). Estimates of genetic correlation among the volumes of the individual ejaculates were high and positive (≥0.79), as were the genetic correlations among their concentrations (≥0.46). Genetic correlations among volume and concentration traits varied from −0.47 (with a 95% high posterior density interval ranging from −0.65 to −0.23) to −0.32 (with a 95% high posterior density interval ranging from −0.55 to −0.09). Progressive motility was unrelated with the other traits, but moderately positively correlated with volumes of the second and third ejaculates. The magnitude of heritabilities showed that selection for semen traits is possible. However, the unfavourable relationship between volume and concentration must be taken into account if a future selection programme is to be established.

The quality of subcutaneous fat of raw hams is a trait of interest in selective breeding programs for pig lines used in dry-cured ham production, and rapid, non-invasive methods for its assessment are available. However, the efficacy of such methods to provide indicator traits for breeding programs needs to be proven. The study investigated the accuracy of on-site visible–near IR spectroscopy predictions of iodine number and fatty acid (FA) composition of raw ham subcutaneous fat, and it evaluated their effectiveness as indicator traits of ham fat quality in a pig breeding program. Prediction equations were developed using visible–near IR spectra acquired at the slaughterhouse from five sites in subcutaneous fat of raw hams of 1025 crossbred pigs. Pigs were raised, under standardized rearing and feeding conditions, in the sib-testing program of the Goland C21 boar line and slaughtered at nine months of age and average body weight of 166 ± 15 kg. Accuracy was generally relatively poor, but R2 in external validation was >0.7 for iodine number and concentration of C18:2n-6, polyunsaturated FAs and omega-6 FAs. To assess the effectiveness of the on-site predictions as indicator traits in a breeding program, (co)variance components of the measured traits (OBS) and of their predictions using in-lab (in-lab-PR) or on-site (on-site-PR) spectrometers were estimated. Available records for OBS were 6814 and 2048, for iodine number and FA composition, respectively. Predictions using in-lab were available for pigs slaughtered between 2006 and 2014, for a total of 10 153 records. Predictions using on-site were obtained from spectra collected since 2011, for a total of 10 296 records. The estimated heritabilities for the investigated traits ranged from 0.34 to 0.50 and were greater for on-site-PR than for OBS. Genetic correlations between OBS and in-lab-PR were very close to 1.00 for all the investigated traits, whereas those between OBS and on-site-PRED ranged from 0.86 to 0.94. On-site visible-IR predictions are accurate enough to support the use of this technique for large-scale phenotyping of raw ham fat quality, even when dealing with animals of a single genetic line raised in standardized conditions, and may be implemented as indicator traits in breeding programs.

In recent years, test day models (TDm) have been proposed for genetic evaluation programs of dairy cattle. Advantages due to the use of TDm are known (Jensen, 2001). TDms differ for the (co)variance structure among observations: the first proposed model was a single trait repeatability model, whereas later studies investigated multitrait (MT) and random regression (RR) models (Swalve, 1999). RR assume that the shape of the lactation curve is influenced by random genetic and permanent environmental effects and differ for the number of parameters of the function used for fitting the shape of the individual lactation curve (Jamrozik et al., 1997). TDm are commonly considered in terms of accuracy of estimated breeding values but effects due to constraints on the observational structure of data, which result from the application of different models, are not considered. Such constraints are expected to affect the effective number of herds and cows providing records and, as a consequence, time at first evaluation of young bulls. Application of some TDm to a population with small average herd size might be troublesome because of the loss of herds involved in the genetic evaluation program, as reported by Dalzotto (2000) for the Italian Brown population.........

Dry cured ham is the most valuable product of the pig industry in Italy and quality of fat covering in fresh hams affects qualitative properties of the final product (Mordenti et al., 1992). High content of unsaturated fatty acids is a predisposing factor for fat with inadequate consistence and for oxydative processes during curing (Chizzolini et al., 1995). Iodine number and linoleic acid content are measures related to the degree of fat unsaturation and can be used to evaluate objectively quality aspects of fat covering of fresh hams (Bellati et al., 1996)...

The aim of this study was to estimate heritability of beef quality traits in Piemontese cattle. A total of 804 young bulls, progeny of 109 AI sires, were sampled from 124 fattening farms (FF) and slaughtered in different days at the same commercial abattoir. At slaughter, bulls were 523±73 d old and average carcasses weight (CW) was 417±45 kg. Carcasses were scored for fleshiness (EUS) and fatness. An individual beef sample was collected from Longissimus Thoracis 24 h after slaughter and held refrigerated at 4 °C for 8 d. Measured traits were pH at ageing (pH8d), beef colour (L*, a*, b*, Hue and Chroma), shear force (SF), drip (DL) and cooking loss (CL). A REML linear animal model including the fixed effects of FF, slaughter age and CW class and the random effect of the bull was used. The estimated heritability for EUS, SF, DL, Hue, L* and a* was of intermediate magnitude (from 0.22 to 0.49) whereas heritabilities for all other traits were low (from 0.04 to 0.16).

Survival analysis methodology was applied in order to analyse sources of variation of preweaning survival time and to estimate variance components using data from a crossbred piglets population. A frailty sire model was used with the litter effect treated as an additional random source of variation. All the variables considered had a significant effect on survivability: sex, cross-fostering, parity of the nurse-sow and litter size. The variance estimates of sire and litter were closed to 0.08 and 2 respectively and the heritability of pre-weaning survival was 0.03.

Pig breeding in Italy aims to obtain heavy pigs for production of typical cured end products. Detailed guidelines related to animals, weight, age, feeding regime, carcass and fresh ham traits impose constraints on this type of production.

Subaortic and pulmonic stenosis are congenital cardiac defects affecting several dog breeds (Jacobs, 1990; Buchanan, 1992; Tidholm, 1997). Subaortic stenosis (SAS) is characterized by a fibrous ring of tissue placed immediately below the aortic valve.

Alternative milk recording schemes, as alternate a.m.-p.m. (AT) procedures, have been proposed in order to reducerecording costs per cow thereby increasing the number of cows and young bulls that can be tested. The objective of thispaper is to compare predicted breeding values using alternative recording schemes for estimating lactation yields, specificallyfor dams of sires. Over 4 million test day records for milk yield of 306,148 Italian Friesian cows collected in 649herds in the province of Milan (Italy) between 1990 and 1997 were used. The simulation of alternative testing schemeswas carried out using A4 single milking data. The alternative schemes to estimate daily milk yield from AM and PM data,were: a) alternate scheme using a doubling; b) alternate scheme using a correction for milking interval applying (MI)direct or inverse factors; c) non-alternate scheme using a correction for MI applying inverse factors; d) random schemeusing a correction for MI applying inverse factors. A mixed model procedure to estimate breeding values was used. Therank correlation between EBV with A4 method and other testing schemes resulted around 99% at the population leveland around 89% with regard to the top 1% of cows. About 10% of cows ranked with A4 method were excluded from thelist of the top 1% when alternative testing schemes were applied. A negligible effect on the reduction of selection intensityfor the dams of sires path was found.

This research studied the relevance of potential sources of variation for dry period length in Italian Holstein cows reared in northern Italy and investigated the effect of days dry (DD) on milk production and calving interval in the subsequent lactation. Field data of individual cow DD were merged: a) with information from the previous lactation (6832 lactations, 87 herds) and analysed to investigate factors influencing DD; b) with milk yield (MY) and calving interval (CI) of the subsequent lactation (≈4000 lactations, >80 herds) and analysed to investigate the effect of DD on subsequent lactation performance. Individual cow DD averaged 67±27d, with a median of 62d; nearly 20% of DD were greater than 80 d. Herd had the greatest impact on DD; average herd DD was 71 d and >50% of herds had a mean dry period length >70d. Longer DD were associated with second or later parity cows, lower daily MY at dryoff, and extremes in the length of the previous lactation, either short or long. After an adjustment for MY genetic merit, dry periods 80d resulted in a 100kg increase in subsequent MY. However, yield lost in the subsequent lactation caused by average DD

Abstract In this study, a hierarchical threshold mixed model based on a cumulative t-link specification for the analysis of ordinal data or more, specifically, calving ease scores, was developed. The validation of this model and the Markov chain Monte Carlo (MCMC) algorithm was carried out on simulated data from normally and t4 (i.e. a t-distribution with four degrees of freedom) distributed populations using the deviance information criterion (DIC) and a pseudo Bayes factor (PBF) measure to validate recently proposed model choice criteria. The simulation study indicated that although inference on the degrees of freedom parameter is possible, MCMC mixing was problematic. Nevertheless, the DIC and PBF were validated to be satisfactory measures of model fit to data. A sire and maternal grandsire cumulative t-link model was applied to a calving ease dataset from 8847 Italian Piemontese first parity dams. The cumulative t-link model was shown to lead to posterior means of direct and maternal heritabilities (0.40 ± 0.06, 0.11 ± 0.04) and a direct maternal genetic correlation (-0.58 ± 0.15) that were not different from the corresponding posterior means of the heritabilities (0.42 ± 0.07, 0.14 ± 0.04) and the genetic correlation (-0.55 ± 0.14) inferred under the conventional cumulative probit link threshold model. Furthermore, the correlation (> 0.99) between posterior means of sire progeny merit from the two models suggested no meaningful rerankings. Nevertheless, the cumulative t-link model was decisively chosen as the better fitting model for this calving ease data using DIC and PBF.

This study aimed to investigate the relationship between cathepsin B activity and muscle firmness of dry cured hams. A total of 988 samples of semimembranosus muscle were collected from raw hams of heavy pigs and cathepsin B activity was determined using fluorimetric method. Raw hams were cured following San Daniele guidelines. Dry-cured hams were deboned and cross-sectioned. On the cross section firmness was measured at three muscular sites (M. semimembranosus, semitendinosus and biceps femoris) using a Hardness Meter MK2. This study did not evidence any significant relationship between cathepsin activity and firmness of dry cured hams.

Abstract Background The gilthead sea bream (Sparus aurata) has long been considered resistant to viral nervous necrosis (VNN), until recently, when significant mortalities caused by a reassortant nervous necrosis virus (NNV) strain were reported. Selective breeding to enhance resistance against NNV might be a preventive action. In this study, 972 sea bream larvae were subjected to a NNV challenge test and the symptomatology was recorded. All the experimental fish and their parents were genotyped using a genome-wide single nucleotide polymorphism (SNP) array consisting of over 26,000 markers. Results Estimates of pedigree-based and genomic heritabilities of VNN symptomatology were consistent with each other (0.21, highest posterior density interval at 95% (HPD95%): 0.1–0.4; 0.19, HPD95%: 0.1–0.3, respectively). The genome-wide association study suggested one genomic region, i.e., in linkage group (LG) 23 that might be involved in sea bream VNN resistance, although it was far from the genome-wide significance threshold. The accuracies (r) of the predicted estimated breeding values (EBV) provided by three Bayesian genomic regression models (Bayes B, Bayes C, and Ridge Regression) were consistent and on average were equal to 0.90 when assessed in a set of cross-validation (CV) procedures. When genomic relationships between training and testing sets were minimized, accuracy decreased greatly (r = 0.53 for a validation based on genomic clustering, r = 0.12 for a validation based on a leave-one-family-out approach focused on the parents of the challenged fish). Classification of the phenotype using the genomic predictions of the phenotype or using the genomic predictions of the pedigree-based, all data included, EBV as classifiers was moderately accurate (area under the ROC curve 0.60 and 0.66, respectively). Conclusions The estimate of the heritability for VNN symptomatology indicates that it is feasible to implement selective breeding programs for increased resistance to VNN of sea bream larvae/juveniles. Exploiting genomic information offers the opportunity of developing prediction tools for VNN resistance, and genomic models can be trained on EBV using all data or phenotypes, with minimal differences in classification performance of the trait phenotype. In a long-term view, the weakening of the genomic ties between animals in the training and test sets leads to decreased genomic prediction accuracies, thus periodical update of the reference population with new data is mandatory.

Abstract Background Susceptibility of European sea bass (Dicentrarchus labrax L.) to viral nervous necrosis (VNN) is well-known. Interest towards selective breeding as a tool to enhance genetic resistance in this species has increased sharply due to the major threat represented by VNN for farmed sea bass and limitations concerning specific therapeutical measures. A sea bass experimental population (N = 650) was challenged with nervous necrosis virus (NNV) to investigate genetic variation in VNN mortality. In addition, relationships of this trait with serum cortisol concentration after stress exposure, antibody titer against NNV antigens, and body weight at a fixed age were studied to identify potential indicator traits of VNN resistance. Results The estimate of heritability for VNN mortality was moderate and ranged from 0.15 (HPD95%, 95% highest posterior density interval: 0.02, 0.31) to 0.23 (HPD95%: 0.06, 0.47). Heritability estimates for cortisol concentration, antibody titer, and body weight were 0.19 (HPD95%: 0.07, 0.34), 0.36 (HPD95%: 0.16, 0.59) and 0.57 (HPD95%: 0.33, 0.84), respectively. Phenotypic relationships between traits were trivial and not statistically significant, except for the estimated correlation between antibody titer and body weight (0.24). Genetic correlations of mortality with body weight or antibody titer (− 0.39) exhibited a 0.89 probability of being negative. A negligible genetic correlation between mortality and cortisol concentration was detected. Antibody titer was estimated to be positively correlated with body weight (0.49). Conclusions Antibody titer against NNV offers the opportunity to use indirect selection to enhance resistance, while the use of cortisol concentration as an indicator trait in breeding programs for VNN resistance is questionable. The estimate of heritability for VNN mortality indicates the feasibility of selective breeding to enhance resistance to NNV and raises attention to the development of genomic prediction tools to simplify testing procedures for selection candidates.

This study aimed to analyse the sources of variation of milking speed assessed through automatic computerised devices included in milking machines, to study the relationships between this trait and milking speed assessed through stopwatch and to develop statistical procedures useful for converting automatic device milking time into stopwatch milking time in order to obtain a fast, simple and cheap collection of milking time records for genetic evaluation purposes. A total of 571 records of stopwatch milking time (SMT), device milking time (DMT) and milk yield at milking were collected in 23 herds of the Trentino Alto Adige region in Italy equipped with two types of automatic milking devices. After log-transformation of SMT (lnSMT) and DMT (lnDMT) and a preliminary analysis of sources of variation of lnDMT, dataset was partitioned into two mutually exclusive subsets: a calibration one, used for statistical analysis, and a validation one, used as test set to validate the prediction models. This procedure was replicated 6 times in order to repeat the cross validation accordingly. Three conversion models have been compared, based on different combinations of the effects of lnDMT, milking device and herd within milking device on lnSMT. Solutions of the models have been applied for each replicate to the validation dataset for estimating lnSMT and the soundness of conversion equations have been evaluated considering the correlation between estimated and actual lnSMT and bias and precision of estimates. Milking time assessed through different procedures resulted in differences between methods for both mean and distribution, and these suggested the need of developing statistical procedures aimed to the conversion of DMT into SMT before their use in sire evaulation. The soundness of the models tended to slightly increase with the increase in the number of effects considered. The correlation between estimated and actual SMT was in the range of 0.80 to 0.86, the estimated bias was close to 0 for all models and the precision, i.e. the average standard deviation of the difference between estimated and actual SMT, in the range of 8-9% of the mean of actual SMT. In conclusion, conversion equations proposed for joining the two sources of information performed satisfactorily, giving rise to SMT accurate estimates, which were not distorted and fairly precise. The use of such equations can support the integration of automatically acquired milking time records into breeding schemes, which is advisable for increasing the number of sires progeny tested and the accuracy of breeding values estimated.

This paper aimed to present the first results of an explorative screening program currently running in Italy and focussing on the prevalence of a specific orthopaedic disorder, elbow dysplasia (ED), in some breeds of dogs commonly reared in Italy. Data consisted of radiographic findings taken on 1370 dogs (758 females and 612 males) of 6 breeds (Bernese Mountain dog, Cane Corso, German Shepherd , Golden Retriever, Labrador Retriever and Rottweiler) screened at an age of 20.6 ± 11.6 months. Radiographs were graded for both ED and hip dysplasia (HD) according to a four- (0 to 3) or a five-grade (A to E) linear system, respectively. Logistic regression analysis was used for studying the relationships between breed, sex, age of dogs at screening and HD diagnosis with the outcome of the diagnosis for ED. Prevalence of ED (ED score ≥ 1) for the pool of breeds involved was 25%, and Labrador Retriever (17%) and Rottweiler (40%) showed, respectively, the lowest and the highest prevalence of ED among breeds in the study. Prevalence of HD (grades C or high- er) approached 15%. When compared to other breeds, Rottweiler and Bernese Mountain dogs showed significantly high- er risk to be affected by ED (odds ratio 3.2 and 3.0, respectively). Conversely, sex did not significantly affect the onset of ED. When compared to the youngest group of dogs at screening (average: 14 months), the oldest group of screened dogs (average: 40 months) exhibited a significantly higher risk of being diagnosed as affected by ED (odds ratio: 1.9). A negative status of hip joints appeared positively associated with a negative status of elbow joints, and dogs diagnosed as affected by HD had a 40% increased risk of being diagnosed as affected by ED. In conclusion, results from this study demonstrated that ED has a noticeable prevalence in some Italian dog populations, particularly in heavy breeds. Screening of dogs for ED appeared feasible and should be performed at a standard age. Phenotypic association between hip and elbow dysplasia observed in this study suggests that the genetic relationships between these skeletal disorders should be investigated.

The purpose of this study was to estimate the effects of herd origin of bull, AI stud and sire identification number (ID) on official estimated breeding values (EBV) for production traits of Holstein Friesian proven bulls. The data included 1,005 Italian Holstein-Friesian bulls, sons of 76 sires, born in 100 herds and progeny tested by 10 AI studs. Bulls were required to have date of first proof between September 1992 and September 1997, to be born in a herd with at least one other bull and to have sire and dam with official EBV when bull was selected for progeny testing. Records of sires with only one son were also discarded. The dependent variable analyzed was the official genetic evaluation for a “quantity and quality of milk” index (ILQ). The linear model to predict breeding values of bulls included the fixed class effects of herd origin of bull, AI testing organization, birth year of bull, and estimated breeding values of sire and dam, both as linear covariates. The R2of the model was 45% and a significant effect was found for genetic merit of sire (P < 0.001) and dam (P < 0.014), for herd origin of bull (P < 0.01) and for birth year of bull (P < 0.001). The effect of AI testing organization was not sig- nificant. The range of herd origin effect was 872 kg of ILQ. However, in this study, the causes of this result were not clear; it may be due to numerous factors, one of which may be preferential treatment on dams of bulls. Analyses of resid- uals on breeding value of proven bulls for ILQ showed a non significant effect of sire ID, after adjusting for parent aver- age, herd origin effect and birth year effect. Although the presence of bias in genetic evaluation of dairy bulls is not evi- dent, further research is recommended firstly to understand the reasons of the significant herd origin effect, secondly to monitor and guarantee the greatest accuracy and reliability of genetic evaluation procedures.

Logistic regression models were used for studying the relationships between milk yield, body condition score (BCS), somatic cell score and some disorders of periparturient cows (mammary edema and retained placenta) with the occur- rence of ovarian cysts, clinical mastitis and lameness. Data from milk recording (milk yield and somatic cell content) col- lected at nearly monthly intervals (time period: 35 ± 3 d) were merged with BCS recorded on the same dates of milk recording on periparturient heifers, lactating and dry cows, and with health disorders data (retained placenta, severe mammary edema, ovarian cysts and clinical mastitis and lameness) collected during regular herd activities over nearly 3.5 years. Data were from one commercial herd consisting of over 200 lactating dairy cows and exhibiting an average 305-d milk yield of nearly 10,000 kg. A total of 5,315 records from 728 lactations and 429 cows were used in the analy- ses. The time period incidence rate was 11.9%, 6.6% and 4.6% for ovarian cysts, lameness and mastitis, respectively, and the lactational incidence rate was 44.1%, 33.4% and 28.1% for ovarian cysts, lameness and mastitis, respectively. Occurrence of both ovarian cysts and mastitis was more common in the early lactation than afterwards, whereas lame- ness tended to occurr erratically during lactation. The risk of occurrence of mastitis and lameness was lower in primi- parous when compared to multiparous cows. The increase of milk yield increased the risk of occurrence of ovarian cysts (odds ratio: 1.32, P < 0.01) and of mastitis (odds ratio: 1.12, P < 0.10), whereas no significant relationship was found between milk yield and lameness. An increase of somatic cell score was found to be a risk factor for mastitis (odds ratio: 1.36, P ders was not related to BCS at calving, and monthly variation of BCS was related to the onset of mastitis only. Retained placenta did not appear to present a risk factor for the occurrence of diseases of concern, whereas the presence of severe mammary edema at calving increased the risk of mastitis occurrence by nearly 50%. Regular recording of herd health data seems advisable for a better understanding of the relationships between production and functional traits and the occurrence of health disorders.

This paper aimed to assess the prevalence of hip dysplasia (HD) in some breeds of dogs widely diffused in Italy and to estimate heritability of HD in German Shepherd and Boxer Italian populations. Data consisted of radiographic findings taken on 32,900 dogs (18,665 females and 14,225 males) of 7 breeds (German Shepherd; Boxer; Labrador Retriever; Golden Retriever; Rottweiler; Dobermann; Cane Corso) screened at an age of 17.9 ± 7.0 months. Radiographs of the coxofemoral joints, taken by 478 veterinarians, were scored for HD grade by a single veterinarian panelist according to a grading procedure based on a 5-class linear system (from A, no signs of dysplasia, to E, severe dysplastic hip changes). Logistic regression analysis was used for studying the relationships between selected explanatory variables with the out- come of the diagnosis for HD. Variance components, direct and maternal heritability have been estimated for German Shepherd and Boxer dogs using a REML animal model procedure. Prevalence of HD (hip joint graded C or worse) for the pool of breeds involved approached 22%, with large differences among breeds. In dogs diagnosed as dysplastic, the mild form (grade C) was largely prevalent for all breeds. When compared to the German Shepherd, the Cane Corso exhibit- ed a significantly higher risk, whereas the Dobermann, Labrador and Rottweiler showed a significantly lower risk of being affected by HD. The probability of being diagnosed as dysplastic increased with the increasing of the age of dogs at screening and with the decreasing of experience of x-raying veterinarians. The effect of birth year of dogs on the out- come of the HD diagnosis was significant, but evidenced an inconsistent trend through years. Heritability estimates approached 0.24 and 0.15 for Boxers and German Shepherds, respectively, whereas maternal heritability was close to 0.03 for both breeds. Results from this study demonstrated that HD is fairly prevalent in some breeds of dogs common- ly found in Italy, and its reduction should be a goal in breeding schemes of purebred dogs. Age at screening and expe- rience of the x-raying veterinarians are disturbance factors to be considered in screening programs for HD. Heritability estimates for HD was low, but additive genetic variance seems enough for conjecturing selection programs aimed to decrease hip joints disease. Given the low heritability values, current selection schemes based on phenotypic records seem ineffective, whereas the use of breeding values estimated under BLUP animal model procedures should be recom- mended for gaining genetic progress of Italian dog populations.

The paper provides a practical procedure to estimate the chemical composition of pigs, their compositional growth and the expected feed intake from measurements of body weight (BW) and backfat thickness (P2) serially performed in vivo. A farm data set provided information on 920 individuals including BW, measured at 71 ± 4 (t1), 126 ± 5 (t2) and 184 ± 5 (t3) days of age, of P2 at t2 and t3, and of voluntary daily feed intake (FI), recorded over the period from t2 to t3 by automated IVOG feeders. Body lipid mass was estimated as L= (9.17 + 0.70*P2) *BW/100 and the other chemical constituents were predicted from fat free empty body mass using Gompertz growth functions and allometry. Using individual changes of body composition from age t2 to t3, energy requirements for maintenance and growth and the corresponding predicted feed intakes (PFI) were estimated. Measured FI were analysed for the effects of month, batch (within month), BWt2, P2t2, average metabolic weight, average daily gain and variation of P2 from t2 to t3. The same model was run again replacing the direct simple body measurements (BW and P2) with the estimated values of PFI as source of variation. Results. The Gompertz estimates of mature protein mass (Pm), relative growth rate parameter (B) and lipid to protein ratio at maturity were 43.5 ± 5.8 kg, 0.0116 ± 0.0011 d-1 and 1.81 ± 0.30, respectively. The current protein mass averaged 18.5 + 1.6 kg and the daily retentions of protein and lipid were 177 ± 21 and 239 ± 62 g/d, respectively. FI and PFI averaged 2.824 ± 0.448 and 2.814 ± 0.393 kg/d, respectively. In the ANOVA of the FI data, the replacement of direct body measurements by PFI did not change the proportion of variance explained (83%) and the RSD (0.199 g/d). The two sets of residual feed intake values obtained from the two ANOVA were highly correlated (RSD = 0.043 kg/d; R2= 0.961). Agreement between predicted and determined feed intakes provided a reasonable guarantee to the estimated (based on BW and P2) changes of body composition. Thus, a scheduled protocol of measurement of BW and P2 over the course of growth, coupled with the use of allometry, can be proposed to estimate in vivo the change of the chemical status of pigs kept under non limiting conditions.

This study aimed to investigate the relationship between body condition score (BCS), calving interval (CI), angularity (ANG), strength (FV) and milk yield (MY) on Brown Swiss cattle using data collected in the alpine provinces of Bolzano- Bozen and Trentino. The data set consisted of 28,538 test day records of BCS and MY from 3,282 Brown Swiss cows in lactation reared in 109 herds; production traits were merged with 13,796 repeated individual calving interval records and 38,711 type traits records. A multi-traits REML animal model was used to estimate (co)variance components, with repeated observations. Heritability estimates for BCS, FV and ANG was 18%, 18% and 27%, respectively, while estimates for CI was very low (2%). Genetic correlations between CI and BCS was -0.44; between BCS and ANG was - 0.64; between BCS and MY was -0.35; between ANG and CI was 0.12. In conclusion, the selection for MY and ANG negatively affect fertility and average condition score of Brown cows. BCS recorded during lactation could be proposed as a useful trait for indirect selection aimed to improve fertility of cows.

The aims of this study were to predict beef quality traits (BQ: colour, shear force, drip and cooking losses) of Piemontese cattle using near-infrared spectroscopy (NIRS) and to estimate genetic parameters for measured BQ and their predictions by NIRS. Heritabilities and genetic correlations for measured BQ and their predictions based on NIRS were estimated through bivariate Bayesian analyses. Heritability estimates for measured BQ were of intermediate magnitude (from 0.10 to 0.63) and similar to those for NIRS predictions. The genetic correlations between BQ measures and their predictions by NIRS were very high for colour traits, high for drip loss, and nil for shear force and cooking loss. NIRS predictions can be proposed as indicator traits in breeding programs for enhancement of colour traits and drip loss.

Electrical conductivity (EC) of milk is defined as an indicator of the udder health. The EC is a low cost and easy recordable information in dairy herds with automatic milking systems. The heritability of EC showed to be higher than somatic cell count and for this reason might be an useful trait for indirect selection for mastitis resistance. The heritability for EC in Italian Brown cattle was equal to 0.23. Therefore, EC could be useful not only for dairy cows management but also for selection of dairy cows. The high correlation between breeding values for SCC and EC is promising in order for improving mastitis resistance and functional ability of dairy cows.

This study investigated the application of mid-infrared spectroscopy for the prediction of protein composition in individual milk samples (n=1,336) of Simmental cows. Protein fractions were quantified by RP-HPLC and MIR data were recorded over the spectral range from 4,000 to 900 cm-1. Models were developed by partial least squares regression using untreated spectra. The most successful predictions were for protein, casein, αS1-casein, whey protein, and β-lactoglobulin contents. The models could discriminate between high and low values of protein composition (R2=0.50 to 0.58). The root mean square errors of cross-validation were 3.11g/l for protein (range 39.91g/l), 2.76g/l for casein (range 35.16g/l), 1.07 g/l for αS1-casein (range 12.82g/l), 0.51 g/l for whey protein (range 4.97g/l), and 0.43 for β-lactoglobulin (range 4.37). Application of MIR spectroscopy is possible for the routinely assessment of protein, casein, αS1-casein, whey protein, and β-lactoglobulin and its implementation might be in future a tool for improving protein composition of bovine milk through breeding programs.

In the last years an increasing number of associations between single nucleotide polymorphisms (SNPs) in candidate genes and production traits have been reported in beef cattle, but very often the results were not validated and few studies considered breeds homozygous for the allele responsible for the muscular hypertrophy. Therefore, we analysed the variability of 19 previously reported SNPs in 12 genes (GH, GHR, GDF8, GHRL, IGF2, LEP, LEPR, MYF5, NPY, POMC, UCP2, UCP3) in the hypertrophic Piemontese breed and investigated the effects of the observed polymorphisms on growth and conformation. Fourteen SNPs were polymorphic and a significant linkage disequilibrium was observed between SNPs in GHR, LEP and NPY genes, for which both single-SNP and haplotype effects were estimated. Negligible effects on the investigated traits were observed for GHRL, MYF5, NPY, POMC, UCP2 and UCP3 genes. The GHR gene significantly affected daily gain and its effect was further increased when haplotypes were considered. The C allele at LEP-1 and LEP- 2 had moderate negative effects on the considered traits, whereas the C allele at LEP-3 mostly had positive effects; haplotypes in the LEP gene showed weaker but favourable associations with all the traits. The C allele at IGF2 and LEPR had favourable effects on daily gain and negative effects on meat conformation traits. The associations observed for GHR and LEP were consistent with those of previous studies, providing additional evidence of their usefulness as markers. Practical aspects of the applications to the breeding programme of the Piemontese breed need to be examined.