Data di Pubblicazione:
2016
Citazione:
CLINICAL PATHOLOGICAL MONITORING OF DAIRY COWS IN THE TRANSITION PERIOD / P. Moretti ; supervisor: A. Giordano ; coordinator: G. Sironi. DIPARTIMENTO DI SCIENZE VETERINARIE E SANITA' PUBBLICA, 2016 Jan 19. 28. ciclo, Anno Accademico 2015. [10.13130/moretti-pierangelo_phd2016-01-19].
Abstract:
Ideally, due to the variation in methods, procedures, sampling sites and population of animals sampled among different laboratories, each diagnostic laboratory should establish a set of reference intervals for all the parameters and all the species analysed. Even if the transference of existing RIs may be possible in some circumstances, this may be not applicable when all the information concerning possible sources of variation are not available. In accordance to the guidelines recently published by the American Society for Veterinary Clinical Pathology (ASVCP) (Friedrichs et al., 2012), reference intervals for healthy high producing dairy cows around 3 and 30 days after calving were established as shown in the study presented in chapter 5. The adoption of separated RIs for these two different moments of lactation was mandatory due to the remarkable metabolic, hormonal, and immune changes occurring during the post-partum period but was also supported by the statistical analysis as shown in the study. The statistical analysis confirmed also some known differences concerning the variation occurring in the early post-partum period, such as the higher degree of negative energy balance (higher NEFA and BOHB), increased inflammatory status (higher ceruloplasmin and haptoglobin, and lower paraoxonase-1), and the increased oxidative stress (higher dROMs) near parturition. The establishment of RIs may be based on an a priori study, characterized by the determination of inclusion and exclusion criteria preceding the sampling or, as happened in this case, through the selection of data from an existing database, with an a posteriori method (Friedrichs et al. 2012). In the present case, the availability of a database derived from a large field study allowed us to select a sufficient number of reference values (results obtained from a selected reference individuals selected according to the inclusion and exclusion criteria) belonging to cows that were clinically healthy for the whole lactation period and that had production and fertility consistent with the normal standard of dairy herds of our geographical area. This allowed also to reduce the variability of results, leading to the establishment of narrower reference intervals compared to the previously adopted reference intervals in many cases. According to the aims, in the same work, the possible effects of herd, days of sampling and parity were evaluated, evidencing only rare variations mainly regarding the samples obtained 30 days post-partum. Even if the low number of samples in each subgroup did not allow to establish specific RIs for the affected variables, some important information can be derived from these results. In particular, the differences observed among the herds one month after parturition highlighted that during a period less influenced by huge metabolic and hormonal variations as occurs one month after parturition, also slight differences in dietary and management strategy may reflect in changes of some metabolic and inflammatory variables, with a higher magnitude compared to the peri-parturient period.
Moreover, the metabolic, hormonal, and inflammatory variations occurring during transition, point out the importance to find possible markers that early indicate the presence of a subclinical condition in cows. Based on the published literature available, this is the first time that RIs for the main acute phase proteins (APPs) in cows (paraoxonase-1, haptoglobin, ceruloplasmin) (Giordano et al., 2004; Eckersall and Bell, 2010) and for some markers of oxidative stress (dROM and thiol groups) were provided. APPs are promising early markers of inflammation due to their rapid increase or decrease during this condition (Bertoni et al., 2008; Huzzey et al., 2011). Markers of ox
Tipologia IRIS:
Tesi di dottorato
Elenco autori:
P. Moretti
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