894 research outputs found
Diamond detector based microdosimetry: key solution in the determination of the radiobiological effectiveness?
No full textHadron therapy offers a higher dose conformity and potential increase of radiobiological effectiveness (RBE), compared to conventional radiation therapy. The arrival of proton therapy in Belgium emphasises the importance of developing a way that could not only accurately represent the dose delivered to the patient, but that could also address the problem of RBE in clinical conditions. We think that microdosimetry, the measurement of stochastic energy deposition distributions in a micrometre size sensitive volume, could provide an efficient tool for assessing these differences in radiation quality. Although tissue-equivalent proportional counters remain the gold standard for experimental microdosimetry, diamond has promising properties to be operated as radiation detector, due to its radiation hardness, chemical stability and absolute nontoxicity. Furthermore, diamond is tissue equivalent. This research aims to investigate the possibilities of a prototype high-purity single crystal diamond detector as microdosimeter. Based on the lab experiments, it is concluded that this diamond microdosimeter has excellent capabilities: a resolution of 10 keV/μm and a lower detection limit of 10 keV/μm are obtained
Health and welfare problems of finishing beef cattle: lameness and possible preventing solutions
Get PDFThe general purpose of this PhD thesis was to analyse the impact on beef cattle health and welfare of some housing and flooring solutions mainly adopted in the intensive rearing systems. In particular, it aimed at investigating claws health status of intensively finished beef cattle belonged to different breeds (Charolaise, Limousine and Holsteins) and housed on different flooring systems (deep litter, fully concrete slatted floor and rubber covered slatted floor). A further aim was the testing of possible preventing solutions against lameness. The thesis was divided in 6 chapters:
A general introductive chapter (Chapter 1) focused on the beef cattle production system in Europe, and in Italy in particular way. Moreover, it identified the most relevant housing and management factors that could impair the welfare of finishing beef cattle.
In the light of the rare published research concerning the claw disorder distribution in finishing beef cattle, the first step consisted in a post mortem inspection at the slaughterhouse that allowed to assess the claw condition of a large number of finishing beef cattle batches (Chapter 2). In particular, we assessed after trimming the prevalence of specific claw disorders and their location on the sole in hind feet of beef cattle which arrived at slaughter with no signs of impaired locomotion. Non-infectious disorders resulted the most common diagnoses among batches, mainly on the lateral claws and in the heel-sole junction area.
The second research aimed at assessing the prevalence of lameness, its severity degree (mild or severe) and its time of onset during finishing. This study focused the most prevalent intensive beef production system operating in Italy that consists of Charolais bulls fattened in deep litter or fully slatted floor pens (Chapter 3). Severe lameness events were always recorded in the last part of the fattening. Fully slatted floor increased the prevalence of severe lameness and the relative risk of early culling compared to deep litter. An increased space allowance for bulls in fully slatted floor acted as preventive measure against both mild and severe lameness.
Considering alternative housing solutions to the concrete fully slatted floor, the third study aimed to assess whether growth performance, health, behaviour and claw condition of finishing bulls belonging to two beef breeds with different slaughter weight like Charolaise and Limousine, would be affected by their housing on a concrete or on a rubber covered slatted floor (Chapter 4). On a perspective of the development of welfare friendly flooring systems tailor-made for specific beef cattle breeds, the use of rubber covered floor as an alternative to the concrete slatted floor should be advised only for bulls like Limousine that are finished at a final body weight (BW) around 600 kg. Despite the positive growth performance, health and welfare of Charolais bulls finished at a final BW above 700 kg were impaired by their housing on both concrete or rubberized slatted floors.
In order to prevent the negative impact of the new rubberized surfaces on the cleanliness of the animals, the last research was addressed to investigate the effects of an increased drainage area on hygiene, body condition, behaviour, claw- and leg health of fattening bulls kept in fully slatted pens equipped with rubber mats (Chapter 5). This 4%-unit increase was not enough to improve the hygiene of the floor, and thus of the animals even if it reduced the number of carcasses penalised at the slaughter for unacceptable hygiene. However, regardless of drainage area, several signs of good comfort on rubberized surfaces were recorded in any group of bulls such as few abnormal locomotor and transition movements, frequent social interactions and relaxing lying postures.
Successively, general discussion and conclusions focused the main outcomes (Chapter 6). Although our findings provide new insights about the relevant impact of lameness in beef cattle farms, additional investigations are need to identify other potential predisposing factors on farms for specific claw disorders and consequently the best housing, flooring and management solutions for bulls during their finishing
Physiological and productive response of lactating dairy cows to the alpine transhumance at the end of the summer grazing
No full textThe study aimed at verifying if the prolonged walking and fasting of the driving down transhumance from an alpine pasture to the farm of origin at the end of the summer grazing may impair health and productive response of lactating cows belonging to two specialised dairy breeds. The study considered a herd of 380 dairy cows and heifers of Italian Holstein and Italian Brown breeds that faced a driving down transhumance with a vertical drop of about 1050 m. The animals walked for about 40 km completing the journey in 23 h, including three resting periods. Ten Holstein and nine Brown lactating cows were selected and monitored before and after the driving down transhumance taking individual blood samples and recording milk yield. The prolonged physical exercise and the limited water and energy intake during the driving down transhumance impaired cows’ metabolic profile resembling a status of ketosis. A significant drop in milk yield was observed in all the monitored animals regardless of the breed. The production loss was more severe (49.4%) in cows with high milk yield and less days in milk. These animals required also a prolonged time to recover from the milk drop due to the driving down transhumance and, based on these findings, they should be excluded from this practise
Individual antimicrobial treatments in veal calves: Effect on the net carcasses weight at the slaughterhouse and relationship with the serostatus of the calves upon arrival to the fattening unit
Get PDFIn recent years, the scientific community, institutions, and public opinion have shown a growing awareness towards the problem of antimicrobial resistance. Guidelines from the European Union aim at significantly reducing (even avoiding) the antimicrobial use for prophylactic and metaphylactic purposes in veterinary medicine and this represents an important issue for several intensive farming systems, such as the veal industry. This retrospective observational cohort study analyzed net carcass weight data at the slaughter of 618 veal calves belonging to 6 batches of animals fattened in an Italian commercial farm according to the number of individual antimicrobial treatments administered during the fattening cycle. Sixty-eight percent (419 animals) of the overall sample of calves received at least one individual antimicrobial treatment due to a disease event during the fattening, and 280 of these (45 % of the overall sample) had more than one treatment. On average, the net carcass weight of calves individually treated more than once was about 10 kg lower than that of untreated calves or treated only once. Moreover, the carcasses of calves that received more than one treatment were 16 times more at risk of being severely penalized in payment at the slaughterhouse due to a net weight below 110 kg than those of untreated calves. Serum analysis data of a subsample of 105 calves belonging to 3 out of the 6 batches collected within 5 days after their arrival to the veal farm identified 3 persistently infected animals by bovine viral diarrhea (BVD) virus and a prevalence of calves with serum immunoglobulin concentration below 7.5 g/L of 37 %. The presence of specific antibodies against infectious bovine rhinotracheitis (IBR) and bovine respiratory syncytial virus (BRSV) and a serum immunoglobulin level above 7.5 g/L at the onset of the fattening were the most important factors associated with a decreased risk of multiple individual antimicrobial treatments (and thus, disease development) or with a delay in disease onset during the fattening, thus leading to better performances at the slaughter. The outcomes of this study suggested that a relationship could exist between calf serostatus upon arrival to the veal farm and the possibility to avoid multiple individual antimicrobial treatments during fattening. Further research is needed to deeply study this association, as such knowledge would allow for planning effective preventing strategies to reduce the antimicrobial use in veal calves
Effetto della transumanza di fine alpeggio sul comportamento e sulla produzione di latte di bovine di razza Frisona e Bruna
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Comparison between cow milk and a high-energy whey-based milk replacer for the weaning of Holstein dairy heifers.
No full textAssociation between gastrointestinal tract, claw disorders, on-farm mortality and feeding management in veal calves
Get PDFFine morphology of the myrmecophilous larva of Paussus kannegieteri (Coleoptera: Carabidae: Paussinae: Paussini). Corresponding author
No full textFIGURES 13–18. Paussus kannegieteri third instar larva: 13, thorax, left lateral view; 14, thorax, dorsal view; 15, mesothoracic spiracle; 16, metathoracic spiracle-like structure; 17, mesothoracic leg, anterolateral view; 18, apex of metathoracic leg with lanceolate setae, posterolateral view. CO = coxa, ls = lanceolate setae, m = membrane, ME = mesonotum, MT = metanotum, pe = peritreme, PR = pronotum, un = claw. Scale bars: Figs. 13–14 = 500 µm; Fig. 15 = 10 µm; Fig. 16 = 20 µm; Fig. 17 = 200 µm; Fig. 18 = 50 µm.Published as part of Giulio, Andrea Di, 2008, Fine morphology of the myrmecophilous larva of Paussus kannegieteri (Coleoptera: Carabidae: Paussinae: Paussini), pp. 37-50 in Zootaxa 1741 on page 44, DOI: 10.5281/zenodo.18152
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