Effect of rearing techniques and feed composition on productive traits, bird welfare and quality of poultry products

The PhD project was focused on the study of the poultry welfare conditions and improvements. The project work was divided into 3 main research activities. A) Field evaluation of chicken meat rearing conditions kept in intensive farms. Considering the lack of published reports concerning the overall Italian rearing conditions of broiler chickens, a survey was carried out to assess the welfare conditions of broiler reared in the most important poultry companies in Italy to verify if they are in accordance with the advices given in the European proposal COM (2005) 221 final. Chicken farm conditions, carcass lesions and meat quality were investigated. 1. The densities currently used in Italy are in accordance with the European proposal COM 221 final (2005) which suggests to keep broilers at a density lower than 30-32 kg live weight/m2 and to not exceed 38-40 kg live weight/m2. 2. The mortality rates in summer and winter agree with the mortality score calculated following the formula reported in the EU Proposal COM 221 final (2005). 3. The incidence of damaged carcasses was very low and did not seem related to the stocking density. 4. The FPD scores were generally above the maximum limit advised by the EU proposal COM 221 final (2005), although the stocking densities were lower than 30-32 kg live weight per m2. 5. It can be stated that the control of the environmental conditions, particularly litter quality, appears a key issue to control the onset of foot dermatitis. B) Manipulation of several farm parameters, such litter material and depth, stocking density and light regimen to improve the chicken welfare conditions, in winter season. 1. Even though 2 different stocking densities were established in this study, the performances achieved from the chickens were almost identical among groups. 2. The FCR was significantly better in Standard conditions contrarily to birds reared in Welfare conditions with lower stocking density, more litter material and with a light program of 16 hours light and 8 hours dark. 3. In our trial, in Standard groups we observed a higher content of moisture, nitrogen and ammonia released from the litter. Therefore it can be assumed that the environmental characteristics have been positively changed by the improvements of the rearing conditions adopted for Welfare groups. 4. In Welfare groups the exhausted litters of the pens were dryer and broilers showed a lower occurrence of FPD. 5. The prevalence of hock burn lesions, like FPD, is high with poor litter quality conditions. 6. The combined effect of a lower stocking density, a greater amount of litter material and a photoperiod similar to the natural one, have positively influenced the chickens welfare status, as a matter of fact the occurrence of FPD in Welfare groups was the lowest keeping the score under the European threshold of the proposal COM 221 final(2005). C) The purpose of the third research was to study the effect of high or low stocking density of broiler chickens, different types of litter and the adoption of short or long lighting regimen on broiler welfare through the evaluation of their productivity and incidence of foot pad dermatitis during the hot season. 1. The feed efficiency was better for the Low Density than for High Density broilers. 2. The appearance of FPD was not influenced by stocking density. 3. The foot examination revealed that the lesions occurred more in birds maintained on chopped wheat straw than on wood shaving. 4. In conclusion, the adoptions of a short light regimen similar to that occurring in nature during summer reduces the feed intake without modify the growth rate thus improving the feed efficiency. Foot pad lesion were not affected neither by stocking densities nor by light regimens whereas wood shavings exerted a favourable effect in preserving foot pad in good condition. D) A study was carried out to investigate more widely the possible role of 25-hydroxycholecalciferol supplemented in the diet of a laying hen commercial strain (Lohmann brown) in comparison of diets supplemented with D3 or with D3 + 25- hydroxycholecalciferol. Egg traits during a productive cycle as well as the bone characteristics of the layers have been as well evaluated to determine if there the vitamin D3 may enhance the welfare status of the birds. 1. The weight of the egg and of its components is often greater in hens fed a diet enriched with 25-hydroxycholecalciferol. 2. Since eggs of treated groups are heavier and a larger amount of shell is needed, a direct effect on shell strength is observed. 3. At 30 and at 50 wk of age hens fed 25 hydroxycholecalciferol exhibited greater values of bone breaking force. 4. Radiographic density values obtained in the trial are always higher in hens fed with 25-hydroxycholecalciferol of both treatments: supplemented for the whole laying cycle (25D3) or from 40 weeks of age onward (D3+25D3).

Effect of training systems and pruning methods on fruit quality in apple

The introduction of dwarfed rootstocks in apple crop has led to a new concept of intensive planting systems with the aim of producing early high yield and with returns of the initial high investment. Although yield is an important aspect to the grower, the consumer has become demanding regards fruit quality and is generally attracted by appearance. To fulfil the consumer’s expectations the grower may need to choose a proper training system along with an ideal pruning technique, which ensure a good light distribution in different parts of the canopy and a marketable fruit quality in terms of size and skin colour. Although these aspects are important, these fruits might not reach the proper ripening stage within the canopy because they are often heterogeneous. To describe the variability present in a tree, a software (PlantToon®), was used to recreate the tree architecture in 3D in the two training systems. The ripening stage of each of the fruits was determined using a non-destructive device (DA-Meter), thus allowing to estimate the fruit ripening variability. This study deals with some of the main parameters that can influence fruit quality and ripening stage within the canopy and orchard management techniques that can ameliorate a ripening fruit homogeneity. Significant differences in fruit quality were found within the canopies due to their position, flowering time and bud wood age. Bi-axis appeared to be suitable for high density planting, even though the fruit quality traits resulted often similar to those obtained with a Slender Spindle, suggesting similar fruit light availability within the canopies. Crop load confirmed to be an important factor that influenced fruit quality as much as the interesting innovative pruning method “Click”, in intensive planting systems.

Polymeric membranes for CO2 separation: effect of aging, humidity and facilitated transport

Polymeric membranes represent a promising technology for gas separation processes, thanks to low costs, reduced energy consumption and limited waste production. The present thesis aims at studying the transport properties of two membrane materials, suitable for CO2 purification applications. In the first part, a polyimide, Matrimid 5218, has been throughout investigated, with particular reference to the effect of thermal treatment, aging and the presence of water vapor in the gas transport process. Permeability measurements showed that thermal history affects relevantly the diffusion of gas molecules across the membrane, influencing also the stability of the separation performances. Subsequently, the effect of water on Matrimid transport properties has been characterized for a wide set of incondensable penetrants. A monotonous reduction of permeability took place at increasing the water concentration within the polymer matrix, affecting the investigated gaseous species to the same extent, despite the different thermodynamic and kinetic features. In this view, a novel empirical model, based on the Free Volume Theory, has been proposed to qualitatively describe the phenomenon. Moreover, according to the accurate representation of the experimental data, the suggested approach has been combined with a more rigorous thermodynamic tool (NELF Model), allowing an exhaustive description of water influence on the single parameters contributing to the gas permeation across the membrane. In the second part, the study has focused on the synthesis and characterization of facilitated transport membranes, able to achieving outstanding separation performances thanks to the chemical enhancement of CO2 permeability. In particular, the transport properties have been investigated for high pressure CO2 separation applications and specific solutions have been proposed to solve stability issues, frequently arising under such severe conditions. Finally, the effect of different process parameters have been investigated, aiming at the identification of the optimal conditions capable to maximize the separation performance.

Effect of host genotype and prion strain on the phenotypic heterogeneity of Creutzfeldt-Jakob disease: the peripheral nervous system involvement and the spectrum of the genetic form

The first study was designed to assess whether the involvement of the peripheral nervous system (PNS) belongs to the phenotypic spectrum of sporadic Creutzfeldt-Jakob disease (sCJD). To this aim, we reviewed medical records of 117 sCJDVV2, 65 sCJDMV2K, and 121 sCJDMM(V)1 subjects for symptoms/signs and neurophysiological data. We looked for the presence of PrPSc in postmortem PNS samples from 14 subjects by western blotting and real-time quaking-induced conversion (RT-QuIC) assay. Seventy-five (41.2%) VV2-MV2K patients, but only 11 (9.1%) MM(V)1, had symptoms/signs suggestive of PNS involvement and neuropathy was documented in half of the VV2-MV2K patients tested. RT-QuIC was positive in all PNS samples, whereas western blotting detected PrPSc in the sciatic nerve in only one VV2 and one MV2K. These results support the conclusion that peripheral neuropathy, likely related to PrPSc deposition, belongs to the phenotypic spectrum of sCJDMV2K and VV2, the two variants linked to the V2 strain. The second study aimed to characterize the genetic/molecular determinants of phenotypic variability in genetic CJD (gCJD). To this purpose, we compared 157 cases of gCJD to 300 of sCJD. We analyzed: demographic aspects, neurological symptoms/signs, histopathologic features and biochemical characteristics of PrPSc. The results strongly indicated that the clinicopathological phenotypes of gCJD largely overlap with those of sCJD and that the genotype at codon 129 in cis with the mutation (i.e. haplotype) contributes more than the latter to the disease phenotype. Some mutations, however, cause phenotypic variations including haplotype-specific patterns of PrPSc deposition such as the “dense” synaptic pattern (E200K-129M), the intraneuronal dots (E200K-129V), and the linear stripes perpendicular to the surface in the molecular layer of cerebellum (OPRIs-129M). Overall, these results suggest that in gCJD PRNP mutations do not cause the emergence of novel prion strains, but rather confer increased susceptibility to the disease in conjunction with “minor” clinicopathological variations.

Sinus rhythm restoration with electrical cardioversion: acute effect of shock configuration and subsequent modifications in peripheral flow and sleep.

Atrial fibrillation (AF) is a widespread arrhythmia, associated with higher risk of stroke, sleep disorders and dementia. In some conditions, electrical cardioversion (ECV) represents the best choice for rhythm control. Nowadays, there is a growing interest in developing new devices for screening and monitoring of AF patients. We aimed to improve acute efficacy of ECV procedure and to explore the feasibility of the use of new wearable devices for monitoring in candidates to AF ECV. We compared antero-apical pads vs antero-posterior patches approach for AF ECV, and we elaborated a decision algorithm to improve acute efficacy. After, we evaluated the feasibility of the use of new wearable devices for monitoring of candidates to AF ECV. In particular, we analysed the effect of AF ECV on heart rate variability and vascular age parameters derived from PPG signals registered with Empatica (CE 1876/MDD 93/42/EEC), and on EEG pattern registered with Neurosteer (Israel). From December 2005 to September 2019, 492 patients were enrolled. We evaluated acute efficacy of the two approaches for AF ECV and we elaborated a decision algorithm based on body surface area, weight, and height. The decision algorithm improved first shock efficacy (93.2% vs. 87.2%, p=0.025). From 1st November 2021 to 1st April 2022, 24 patients were enrolled in PPEEG-AF pilot study. Considering vascular age parameters, a significant reduction in TPR and a wave was observed (p<0.001). Considering sleep patterns, a tendency to higher coherence was observed in registrations acquired during AF, or considering signals registered for each patient independently from AF. The new decision algorithm improved acute efficacy and reduced costs associated with adhesive patches. Significant modifications were observed on vascular age parameters measured before and after ECV, and a possible AF effect on sleep pattern was noticed. More data are necessary to confirm these preliminary results.

Effect of season and cryopreservation on oxidative status of stallion spermatozoa

The aim of this study was to investigate 1) the effect of different ROS and lipid peroxidation on sperm quality, and 2) differences in ROS between non-breeding and breeding seasons. Eighteen ejaculates from six stallions were collected in January and July (N = 36), processed for freezing. After 90’ of cooling, some straws were not frozen (unfrozen), some were frozen (frozen). Rapid sperm (RAP, CASA), membrane-acrosome integrity (MAI), high mitochondrial membrane potential (Mpos), intracellular Ca2+ (Fneg), lipid peroxidation (BODIPY), ROS (DCFH, MitoSOX) and chromatin fragmentation (DFI%) were evaluated by flow cytometry during incubation at +37°C at T0 (after 90 min at +4°C and after thawing), 3, 6, 12 and 24h. In winter, ROS and BODIPY were higher and faster (P < 0.0001) in frozen than unfrozen; DFI% was similar at 0h (P > 0.05) but higher in frozen after 3h of incubation (P < 0.0001). RAP, PMAI, Mpos and Fneg were lower in frozen compared to unfrozen (P < 0.0001). Summer and winter data were compared. Overall, ROS concentrations and BODIPY were higher and faster (P < 0.001) in winter, DFI% was lower in winter (P < 0.001), but similar between the two groups within seasons after thawing. Differences were found at 3h and 12h for DFI%, and for DCFH and MitoSOX at 0h and 12h of incubation in winter and summer respectively. A moderate positive correlations was found between DFI% and MitoSOX, DCFH, BODIPY, whereas a negative correlation, stronger in winter, between RAP, PMAI, Mpos, Fneg and BODIPY, DCFH, MitoSOX. DFI was not different in unfrozen and frozen, despite a significant higher ROS level in winter, and incubation allowed to asses differences in DFI, suggesting that incubation should be included when evaluating stallion frozen semen. Higher level of ROS and BODIPY in winter was less detrimental than freezing-thawing.

Assessment of molecular sequences and enzyme activity of amylase trypsin inhibitors (ATIs) from a selection of ancient and modern grains

Wheat amylase-trypsin inhibitors (ATIs) are a family of wheat proteins, which play an important role in plant defence against pest attacks. ATIs are also of great interest for their impact on human health and recently ATIs have been identified as major stimulators of innate immune cells. In this study, ten selected wheat samples with different ploidy level and year of release were used for the agronomic trial, for in vitro enzymatic assays and for ATIs gene sequencing. Wheat samples were grown under organic farming management during three consecutive cropping years at two growing areas (Italy and USA). The PCA analysis performed on the deduced amino acid sequences of four representative ATIs genes (WMAI, WDAI, WTAI-CM3, CMx) evidenced that the ten wheat varieties can be differentiated on the basis of their ploidy level, but not with respect to ancient or recently developed wheat genotypes. The results from in vitro alpha-amylase and trypsin inhibitory activities showed high variability among the ten wheat genotypes and the contribution of the genotype and the cropping year was significant for both inhibitory activities. The hexaploid wheat genotypes showed the highest inhibitory activities. Einkorn showed a very low or even absent alpha-amylase inhibitory activity and the highest trypsin inhibitory activity. It was not possible to differentiate ancient and recently developed wheat genotypes on the basis of their ATIs activity. The weather conditions differently affected the two inhibitory activities. In both cultivation areas, higher precipitation and lower high mean temperatures correlated with lower alpha-amylase inhibitory activities, while there were different correlations considering trypsin inhibitory activity for the two growing areas. The protein content negatively correlated with both inhibitory activities in USA and Italy. This information can be important in the understanding of plant defence mechanisms in relation to the effect of both genotype and abiotic and biotic stress.