„ai“ 348 výsledků

Milk is considered not only a source of nutrient for the offspring but also a font of immunoregulatory compounds capable to predispose the naïve intestinal immune system of the new-born to react to the external environment. In the present study we evaluated the composition of milk microbiome from cows classified according to milk total and differential somatic cell counts. A total of 34, 13 and 13 milk samples of healthy, at risk and subclinical or chronic cows, respectively, were collected during the same milking from a local dairy herd. Through Next Generation Sequencing (NGS) of bacterial 16S rRNA gene, the differences of taxa in terms of relative abundances (RA) and alpha and beta biodiversity were analysed. The RA of several genera were statistically significant in the three groups, such as Arcanobacterium (p=0.001), Rhodococccus (p<0.05) and Rubrobacter (p<0.05), while at species level the presence of Propionibacterium granulosum, Pseudomonas alcaligenes and Prosthecobacter debontii were found. Shannon and Evenness indices computed at the genus level were not significant, while beta biodiversity showed a clear clusterization between groups. The results highlighted that milk microbiome is associated to a different cellular response at udder level, although more specific studies are needed to assess the source of bacteria species identified in milk microbial population of healthy animals.

Farrowing records of the Duroc, Hampshire and Pietrain breed were analysed by means of a three-trait repeatability animal model. The examined traits were number of piglets born alive (NBA), number of weaned piglets (NWE) and litter weight at weaning (LWWE). Heritability estimates were 0.10, 0.08 and 0.12 for NBA, NWE and LWWE, respectively. The ratios of the permanent environmental variance to the phenotypic variance were 0.08, 0.05 and 0.03 for NBA, NWE and LWWE, respectively. Using the estimated breeding values a desired index was constructed in order to improve each trait by one additive genetic standard deviation. NWE and NBA have a high correlation and range within breeds from 0.87 to 0.91, but LWWE had poor to moderate correlation with NBA and NWE (0.13 to 0.59). Animals ranking based on index showed better genetic merit for Duroc breed and the index scores ranged from 49.77 to 186.56. In the case of Hampshire and Pietrain breeds somewhat lower index scores (30.92 to 165.97) were observed. The estimated genetic trend for NBA was highest for the Pietrain breed (0.02), but for Duroc and Hampshire breeds the estimates were zero and negative (-0.01). For NWE the estimated genetic trends were practically zero for Duroc and Pietrain breeds and it was 0.02 for Pietrain. LWWE showed highest genetic trend for Duroc breed (0.17) but it was lower (0.09) for Pietrain and and negative (-0.24) for Hampshire.

Somatic cell count (SCC) has been extensively used as indicator of udder health and milk quality. Recent developments in milk-testing technology have led to cell differentiation in milk in a high throughput manner. Information on the proportion of the different cell types in milk would represent a valuable asset for a more precise definition of udder health status. The aim of the present study was to apply receiver-operating characteristic curve analysis to define the most accurate thresholds of milk differential somatic cell count (DSCC), which represents the percentage of neutrophils plus lymphocytes in the total SCC. The dataset accounted for 117,482 test-day records of 60,009 Holstein Friesian, Brown Swiss and Simmental cows. Different thresholds were defined so that DSCC trends were analysed throughout the lactation, considering also the classification factors of breed and parity. Finally, cows were classified as healthy, susceptible, mastitic or chronic on the basis of their health status, which was defined combining the information of SCC (below or above 200,000 cells/mL) and DSCC (below or above the specific cut-off). Our findings offered new insights for a practical use of DSCC to screen for mastitis, in order to help farmers make decisions to reduce the use of antimicrobials in the herd.

The present study aimed to evaluate the performances of Fourier transform near-infrared spectroscopy technique to determine the chemical and the fatty acid composition of different types of cheeses. A total of 95 cheeses from sheep and goat raw milk were produced in small local dairies of Siena province (Tuscany). For each cheese, spectrum was collected in intact slices of the sample and fatty acid profile was determined in ground samples. Outliers were identified and different mathematical pre-processing treatments (SNV, MSC, baseline correction and de-trending) were applied when necessary. Considering traditional chemical analysis and raw cheese spectral data, calibration and cross-validation models were carried out using partial least squares regression (PLS). The best results were evaluated in terms of coefficient of determination in calibration and cross-validation (R2cv), and root mean square error in calibration and cross-validation, and residual prediction deviation (RPD). Moisture, protein and ash showed the best R2cv (0.89, 0.74 and 0.72, respectively) and RPD values (3.0, 2.6 and 2.1, respectively). Saturated, monounsaturated and polyunsaturated fatty acids showed R2cv which ranged from 0.75 to 0.67, and RPD <2.0. Intermediate results in terms of R2cv (0.62 as mean) were obtained for medium chain saturated fatty acids (C8:0 to C14:0), whereas for C18 series only oleic acid reached good accuracy of prediction (R2cv >0.70). Obtained results are promising and additional samples could strongly increase the predictive ability for small dairy farms.

The by-products of olive oil production are not traditional feed ingredients in poultry nutrition. Despite their low nutritional value, they can be used not only as a source of energy and nutrients, but also as bioactive substances in nutrition of broiler chickens. The aim of the study was to determine whether the use of olive leaves and cake in feed mixtures for broilers affects their growth performance and bone mineralisation. In the feeding experiment 120 male Ross 308 broilers were used. At the age of 21 days the chickens were randomly assigned to 5 experimental groups each with two pens (replicates) of 12 animals and fed with 5 different feed mixtures without (Control) or supplemented with 5% or 10% olive leaves (OLeave5, OLeave10) or cake (OCake5, OCake10). Live weight and feed intake per pen were recorded weekly. At the end of the feeding experiment (42 days), 12 chickens per group were randomly selected and slaughtered. At the slaughter line, bone samples (femur, tibia and humerus) were taken from each chicken. The supplementation of olive leaves and cake had no significant effect on the growth performance and mineral content in femur, tibia and humerus of the broilers. The addition of 5 and 10% olive leaves to the feed resulted in higher Cu content in the humerus, but bone mineralisation did not change. In conclusion olive leaves and cake did not modify bone mineralisation but could be supplemented in the feed mixtures for broilers without negative effects on growth performance.

Chianina, Marchigiana, Maremmana, Podolica and Romagnola are the main Italian beef cattle breeds, and the quality of their products is largely recognized worldwide. This paper aims to determine the genetic variability and population differentiation by heterozygosity and fixation indices using SNPs data. The dataset was composed of 3,581 animals (Chianina, n = 909; Marchigiana, n = 879; Maremmana, n = 334; Podolica, n = 555; Romagnola, n = 904). The blood samples were collected in ANABIC performance testing station from 1985 to 2019. All the animals were genotyped with the GeneSeek GGP-LDv4 33k SNP chip containing 30,111 SNPs. The genotype quality control for each breed was conducted separately, and SNPs with call rate smaller than 0.95 and minor allele frequency larger than 5% were used for further analysis. Heterozygosity and FIS index were estimated in PLINK v1.9, and FST index was estimated using the hierstat package of R 4.0.1 software. The genetic analysis highlighted low values of heterozygosity in the improved beef breeds compared to the heritage breeds; moreover, the low values of FIS indicated a positive effect of controlled genetic inbreeding in the studied breeds. The FST; analysis confirmed the historical origin of Marchigiana breed and the values are consistent with their common breeding programmes. In this study, the importance of monitoring genetic variability of Italian beef cattle breeds was emphasized in order to maintain breed identity and genetic diversity in the selection process.

The aim of this paper was to evaluate the influence of birth weight and weaning weight on selected fattening, carcass, physical technological parameters and proximate composition of Longissimus thoracis et lumborum muscle from forty-five Holstein bull calves. Effect of birth weight: group1 (mean 36.98 kg), group 2 (mean 38.61 kg), group 3 (mean 41.11 kg) and weaning weight: group A (mean 88.54 kg), group B (mean 97.56 kg), group C (mean 116.09 kg) on parameters of Holstein veal production were examined. Each group was consisted of 15 animals. Slaughter weight, weight gains, body measurements, carcass conformation, retail yield (meat, trimmed fat, bones), and meat characteristics 24 hours and 7 days post mortem (pH, drip loss, shear force, colour, chemical composition) were studied. Calves of group 2 had highest lifetime average daily gains. Among monitored groups, significant effect of birth weight and weaning weight on hip height and heart girth were revealed. Dressing percentage (P<0.05) and carcass weight differed (P>0.05) little due to weaning weight. Calves of lighter birth weight had the least retail meat yield, but the most bones in carcass. Little effect of weaning weight on protein content (P<0.05) and energy value (P<0.01) or birth weight on energy value (P<0.05) of Longissimus muscle was revealed. Effect of birth weight or weaning weight on worsening or improving of physical technological traits of veal Longissimus muscle was not clear. Significantly different pH 24 hours post mortem was found in higher birth weight (P<0.01) and lower weaning weight (P<0.05). Parameters of meat colour – lightness and redness were not influenced by birth weight, but significantly affected by weaning weight (P<0.05). Content of palmitic acid was affected by both – birth weight and weaning weight (P<0.01). No interactions between birth weight or weaning weight were evident for resulted fattening, carcass, yield, physical technological and qualitative traits of calves.

Meat and fat of 24 Cinta Senese pigs were used to produce frankfurter-type sausages. The animals were raised in two rearing systems: i) fenced area with concentrate as exclusive feed (C, n=12) and ii) wood/pasture fenced area and grazing on natural available resources (acorn and herbaceous pasture) (P, n=12). Physicochemical characteristics, fatty acid composition and sensory attributes of the frankfurter-type sausages were assessed. Both sausages from C and P groups showed high fat content (> 23%) likely due to the high level of intramuscular fat of Cinta Senese meat. Frankfurter-type sausages obtained from P group had higher percentage of monounsaturated fatty acids and lower percentage of saturated fatty acids than the C group, probably due to the availability of grazing resources during the fattening period. However, in both types of sausages, the polyunsaturated to saturated fatty acids ratio was higher than the recommended lower limit of 0.40. Regarding the physical traits, differences between groups were found for the colour traits: P frankfurter-type sausages had lower lightness and higher redness and yellowness than C frankfurter-type sausages, likely due to the physical exercise associated to grazing activity of P animals. Texture parameters did not differ between groups for hardness and cohesiveness, whereas chewiness and springiness were higher in C than P samples. Feeding systems changed the perception of some sensorial properties, in particular taste and odour. Overall, Cinta Senese frankfurter-type sausages could represent an innovative product for local farms, allowing, in addition, the use of second-choice meat portions, once acquitted some improvements in the recipes.

According to census accomplished in 2001, only 9% of Italian poultry breeds are still widespread. This project aims to describe morphological variability and genetic background among 13 Italian autochthonous chicken breeds, 10 from Northern Italy and 3 from Central Italy. An updated biometrical measurement protocol was established starting from phenotypic characterization guidelines released by FAO. Six traits were registered on each animal: live body weight (LBW), body length (BL), shank length (SL), shank width (SW), breast width (BW), and wingspan (WS). Moreover, all breeds were genotyped using the Affymetrix 600 K Chicken SNP Array, in order to evaluate genetic variability and population structure. Means of BL and BW showed low variability among breeds, with the lowest value in Pepoi (BL = 32.29 ± 1.57 cm and BW = 28.92 ± 1.93 cm), and maximum in Robusta Lionata for BL (46.79 ± 1.66 cm) and in Robusta Maculata for BW (42.33 ± 3.60 cm). On the contrary, average LBW varied notably among breeds, with the highest value for Robusta Maculata (♂ 4,221.7 ± 450.6 g; ♀ 2,831.7 ± 253.2 g) and the lowest values for Modenese males (1,695.0 ± 128.1 g) and Pepoi females (1,293.3 ± 219.2 g). The lowest observed heterozygosity (Ho) and expected heterozygosity (He) were obtained for Padovana Argentata (Ho: 0.151 ± 0.198; He: 0.146 ± 0.185) and the highest for Millefiori di Lonigo (Ho: 0.293 ± 0.199; He: 0.291 ± 0.178). Furthermore, multidimensional scaling plot showed clear genetic identity for each breed, with clusters formed according to geographical and historical origin of the breeds, which were confirmed in neighbor networks. In conclusion, local breeds have conserved authentic genetic patterns and these results can help improve conservation strategies.

International evaluation models for beef cattle allow to compare animals’ estimated breeding values (EBV) across different countries, thanks to sires having offspring in more than one country. In this study we aimed to provide an up-to-date picture of the Interbeef international beef cattle evaluations from a national perspective, considering both large and small populations. Limousin age-adjusted weaning weight (AWW) phenotypes were available for 3,115,598 animals from 10 European countries, born between 1972 and 2017. EBV and reliabilities were obtained using a multi-trait animal model including maternal effects where AWW from different countries are modelled as different traits. We investigated the country of origin of the sires with internationally publishable EBV and, among them, the country of origin of the top 100 sires for each country scale. All countries had 20 to 28,557 domestic sires whose EBV were publishable, according to Interbeef’s rules, on the scale of other countries. All countries, except one, had domestic sires that ranked among the top 100 sires on other country scales. Across countries, inclusion of information from relatives recorded in other countries increased the reliability of EBV for domestic animals on average by 9.6 percentage points for direct EBV, and 8.3 percentage points for maternal EBV. In conclusion, international evaluations provide small countries access to a panel of elite foreign sires with EBV on their country scale and a more accurate estimation of EBV of domestic animals, while large countries obtain EBV for their sires on the scale of different countries which helps to better promote them.

A study was conducted on the effect of two different lamb production systems on the fatty acid (FA) composition of subcutaneous fat of 40 purebred Ile de France lambs. In the first production system, ewes and lambs grazed on pasture without concentrate (GS), whereas in the second production system, ewes and lambs were housed indoor and fed silage/hay and concentrate (IS). Twenty lambs (7 females and 13 males) were included in each group. Lambs were slaughtered at 28.75 ± 2.76 kg. The FA were determined by gas chromatography and analysed through ANOVA by considering the following fixed effects: production system, sex and the interaction between production system and sex. Subcutaneous fat of GS lambs had greater proportion of C18:3n-3 (P <0.001), C22:5n-3 (P <0.05) and C22:6n-3 (P <0.05) than IS lambs, which resulted in a higher sum of n-3 polyunsaturated FA in GS compared to IS lambs (2.00 vs. 1.15 g/100 g FAME, P <0.001). Moreover, subcutaneous fat of GS lambs had greater proportion of c9,t11-C18:2 (P <0.001) and sum of detected conjugated linoleic acid isomers than IS lambs (2.21 vs. 0.67 g/100 g FAME, P <0.001). Females had significantly greater proportion of C18:2n-6 (P <0.05) and C18:3n-6 (P <0.001) than males. We can conclude that the GS system where lambs are raised under grazing conditions may provide carcasses with a more acceptable subcutaneous fat, as far as a human health and nutrition perspective is concerned.

The African Chicken Genetic Gain (ACGG) project (https://africacgg.net/) aims at backyard poultry optimization by commercial dual-purpose breeds introduction into Africa. To measure benefits, genotype by environment interaction (GxE) analysis provides guidance while predicting environmental effects on production traits of breeds. A survey among Ethiopian poultry smallholders showed egg sale being the most important purpose of keeping village chickens in Oromia. Data was available about laying of 894 ACGG chickens in Oromia. Hence current research questions were: 1) Does GxE take place? 2) Which breed performs best regarding laying and in which environment within Oromia? Traits investigated were egg number and egg weight of five breeds (S-RIR, Sasso, Horro, Kuroiler and Koekoek) located in three zones (East Hararge, East and West Shoa) and 5 districts (Adami Tulu, Bako Tibe, Dano, Dugda and Haromaya) in Oromia. Observations were taken as group measure performing weighted analyses. GxE was only present for egg number with magnitude strongest for zone. S-RIR performed best for both traits in both environments, except Kuroiler performing better in East Shoa for egg number and Koekoek for egg weight. This indicates success of crossbreed S-RIR. Sasso and Horro performed worst supported by previous research for Horro but not Sasso. Low precipitation in East Shoa caused bigger distance in egg number predictions, being higher for S-RIR and lower for Horro and Sasso compared to West Shoa. Apart from these final conclusions, social context of breeding and data collection difficulties should not be forgotten. Just like relevance of other performance trait analyses.

This study aims to genetically evaluate clinical mastitis (CM) in Holstein cattle using a two-trait repeatability animal model with the average lactation somatic cell score (LSCS) as an indicator trait of mastitis. The data set included 21,786 Holsteins with 29,110 lactations in 59 herds and with a calving date between 2015 and 2019. CM was considered as an all-or-none trait (values 0 or 1) in the period from calving to 305 days in milk, and the LSCS was obtained by logarithmic transformation of the average of the individual test-day records for somatic cell count over lactation. Heritability of CM was estimated using a single-trait repeatability animal model, whereas the genetic correlation between CM and LSCS was assessed through a two-trait repeatability animal model. Fixed effects included in the analyses were parity-age and herd-year-season, and the random effects were the permanent environment and the animal. The (co)variance matrix was employed in breeding values estimation for both single-trait (only CM) and bivariate models (CM and LSCS) including genomic prediction. Only genotyped sires formed the reference population for the single-step genomic evaluation. The heritability for CM was 0.04 in the single-trait and 0.05 in the two-trait analysis. Genetic correlation between CM and LSCS was 0.80. The employment of the two-trait model had a considerably strong influence on reliability. The reliability increased for cows with records as well as for the genotyped sires. This study indicates that the two-trait analysis of CM and LSCS is feasible and improves the reliability of the estimated breeding values.

The aim of the study was to investigate the genetic differentiation of the Black Slavonian pig population. Two parallel analyses were performed using genealogical records and molecular data. Pedigree information of 6,099 pigs of the Black Slavonian breed was used to evaluate genetic variability and population structure. Additionally, 70 pigs were genotyped using 23 microsatellite markers. Genealogical data showed shrinkage in genetic diversity parameters with effective population size of 23.58 and inbreeding of 3.26%. Expected and observed heterozygosity were 0.685 and 0.625, respectively, and the average number of alleles per locus was 7.826. Bayesian clustering algorithm method and obtained dendrograms based on pedigree information and molecular data revealed the existence of four genetic clusters within the Black Slavonian pig. Wright’s FIS, FST and FIT from pedigree records were 0.017, 0.006, and 0.024, respectively, and did not prove significant population differentiation based on the geographical location of herds, despite the natural mating system. Obtained results indicate that despite the increased number of animals in the population, genetic diversity of Black Slavonian pig is low and conservation programme should focus on strategies aimed at avoiding further loss of genetic variability. Simultaneous use of genealogical and molecular data can be useful in conservation management of Black Slavonian pig breed.

This study aimed to evaluate the score for subclinical ketosis risk, which is routinely monitored in Czech Holstein cows. The score is based on milk recording indicator traits which include fat-to-protein ratio, fat-to-lactose ratio, citric acid, β-hydroxybutyrate, and acetone concentrations. The score was significantly (P <0.001) affected by the age of cow at calving, days in milk (DIM) and season of test-day recording. Variance components were estimated with a univariate linear animal model for the score on the first test-day and with a multivariate linear animal model for the score in 3 successive test-days (6-40, 30-70, 60-100 DIM). The heritability estimate was lower at the beginning of lactation (0.08) and increased gradually to 0.11 at the end of the recorded period. Genetic correlations between the score at the first and the other two test-days were lower than 1 indicating that they are genetically different traits. Estimated breeding values were normally distributed with mean 0.20 and reliabilities up to 0.66 in females and 0.98 in males. Breeding values were negatively correlated with most of other routinely evaluated traits, with the strongest correlations with milk fat percentage (0.39), body condition score (-0.26) and fertility of cows (-0.25). The score for subclinical ketosis risk showed sufficient genetic variability and had the potential to be used in genetic improvement of resistance to (sub)clinical ketosis of Czech Holstein cows.

The dichotomy between developed and developing countries was observed not only in asymmetric human population growth, but also in increasing demand for animal products revolving around poultry and pigs in developing World. Modern livestock industry has adopted innovative technologies to improve the biological efficiency of animal production and feeding, and for this purpose different mathematical models have been applied. In this review, the authors summarize the growth models, briefly introduce the principles of precision feeding and provide evidence that models are key elements of these systems. Modelling is an excellent tool to help in understanding and to predict the animal’s response to different farm conditions. Models comprise of equations set describing nutrient flows and animal response. They are essential elements of precision livestock farming system being the basis of the decision support tool since, from yesterday’s data, they provide today what happens tomorrow. Precision farming adopts real-time monitoring systems collecting serial data about individual or group of animals. However, without a well-defined goal-oriented data process, data by itself are not useful to farmers. Available and newly recorded data can be converted to valuable information for management purposes through models applied in farming systems. Nutritional models are integrated part of those systems; therefore, growth modelling is a key tool to improve the efficiency and sustainability of livestock production systems.

The study was performed on 136 pig carcasses representing the Croatian pig population with regards to the breed structure. The carcasses were dissected according to the EU reference method and lean meat percentage was estimated using the Hennessy Grading Probe (HGP7) device and the “Two points” (ZP) method. Comparison of lean meat percentage obtained by dissection and two prediction methods showed significant differences in estimating the lean meat percentage of pig carcasses (P <0.05). The distribution of carcasses according to SEUROP system showed a difference in the classification depending on the applied method, indicating a need for adjustment of current formulae for lean meat percentage estimation in Croatia.

Yield performance and external and internal quality traits of eggs laid by two Italian purebreds, Ermellinata di Rovigo (ER) and Pepoi (PP) were studied at 36 and 50 weeks of age. Daily egg production and egg traits were evaluated by a factorial model (2 x 2) with genotype and age as main effects and their interaction. The daily laying rate was similar between the breeds and the hen-day egg mass was higher (p<0.01) for ER than for PP. The ER eggs differed (p<0.01) from PP eggs with higher egg weight, yolk and albumen weight, and a more coloured eggshell with lower L, higher a* and b*, and lower eggshell thickness. PP showed more (p<0.05) inclusion of albumen than yolk in comparison to ER. With increased hen age, egg weight, eggshell lenght, width, lightness and thickness increased (p<0.01), whereas shape index and a* and b* did not change. Throughout the laying period, the eggs were classified as small (PP) and medium size (ER). With increased hen age, PP eggs were more spherical, ER eggs were more ovoid; yolk and albumen weight increased (p<0.01) in ER, whereas yolk and eggshell weight increased (p<0.01) in PP. The yolk:albumen ratio increased (p<0.01) along with hen‘s age and the Haugh Units and egg inclusions decreased (p<0.01). The ER and PP eggs differed for many egg external traits, which allow to distinguish the eggs by weight, shape, and eggshell colour and for the eggshell thickness and the albumen traits.

The agricultural models put in place to meet food demand in the 1950s are now showing their limits. Strong impacts on the environment or animal welfare issues require a change in the agricultural model. Agroecology is a response to these ecological and societal crises. The theoretical definition of this agricultural model is explained in literature. However, it remains important to clarify what is an agroecological farm in the field: how does the farming system work? Which indicators are used? What are the worldviews of the farmers? For that, systemic approach can be useful. The aim of this article is to advance a fuller understanding of the management of agroecological systems in the field through a new systemic approach. A new definition of the systemic approach is proposed with three pillars (functioning system, decision-making system and thinking system) to allow a more detailed analysis of production systems by using a specific method, crossing biotechnical sciences, humanities and social sciences. Consideration of all three pillars can explain what an agroecological system is in practice, with identification of specific indicators and worldview.

Feed efficiency has a major influence on farm profitability and environmental stewardship in the dairy industry. The aim of this study was to describe a new selection index adopted by the Italian Holstein and Jersey Association (ANAFIJ, Cremona, Italy) to improve feed efficiency using data recorded by the official dairy recording system. Predicted dry matter intake (pDMI) was derived from milk yield, fat content, and estimated cow body weight. Fat-protein corrected milk (FPCM) was derived from milk yield corrected for fat, protein, and a fixed coefficient for lactose content (4.80%). Therefore, the predicted feed efficiency (pFE) was estimated as ratio between FPCM and pDMI. Average pFE was 1.27±0.18 (kg.d-1) with heritability of 0.32. Predicted Feed Efficiency index (pFEi), traditional and genomic, has been implemented in the Italian Holstein Friesian evaluation system. Results suggest that pFEi may be a new breeding objective for Italian Friesians. The official selection index (PFT), in use since 2002, is positively correlated with pFEi. However, the introduction of pFEi will improve the positive feed efficiency trend. This approach will permit the Italian Holstein Friesian breeders to improve feed efficiency, without increasing costs of recording system. However, to avoid the risk of selecting animals with an excessive negative energy balance after calving, it would be useful to include in the pFE a correction for body condition score and reproductive performances. Meanwhile, in order to increase the accuracy of the predicted phenotype, an Italian consortium is creating a consistent phenotypic critical mass of individual data for dry matter intake in cows, heifers and young bulls.