CORRELATION BETWEEN INADEQUATE TRANSFER OF PASSIVE IMMUNITY AND NEONATAL CALF DIARRHEA: DIAGNOSTIC, PROGNOSTIC AND TREATMENT ASPECTS
Tesi di Dottorato
Data di Pubblicazione:
2020
Citazione:
CORRELATION BETWEEN INADEQUATE TRANSFER OF PASSIVE IMMUNITY AND NEONATAL CALF DIARRHEA: DIAGNOSTIC, PROGNOSTIC AND TREATMENT ASPECTS / G. Sala ; tutor: D. Pravettoni ; coordinatore: V. Grieco. DIPARTIMENTO DI MEDICINA VETERINARIA, 2020 Feb 06. 32. ciclo, Anno Accademico 2019. [10.13130/sala-giulia_phd2020-02-06].
Abstract:
Calves at birth have a naïve immunity system and their immune protection is almost exclusively ensured by the maternal immunity transferred by the ingestion of colostrum in the first hours of life2. Inadequate transfer of passive immunity (ITPI) has been related to increased morbidity and mortality in calves3. Furthermore, calves with ITPI have a 24 times greater risk of developing. Neonatal Calf Diarrhea (NCD) and are more likely to be bacteremic. NCD is a multifactorial disease that causes severe economic losses due to mortality, treatment cost, and poor growth. The clinical presentation of NCD is characterized by liquid feces, dehydration, metabolic acidosis, alterations in posture, behavior and hypovolemic shock.
This first study of this research project aims to compare serum total protein (sTP) and gamma-glutamyl-transferase (GGT) activity in calves affected by NCD to discriminate calves with or without adequate transfer of passive immunity (ITPI). Forty-three Holstein Friesian calves admitted to the Clinic for Ruminant and Swine (CTS)-Veterinary Teaching Hospital of the University of Milan for neonatal calf diarrhea (NCD) were enrolled from May 2018 to May 2019. For each calf, age, dehydration degree, hematocrit, sTP, GGT activity and immunoglobulin G (IgG) were measured and recorded. The results underline the influence of the dehydration degree (p 0.02) on sTP concentration and the association between age and GGT activity concentration (p 0.01). The ROC curve analysis, considering the influence of dehydration degree and age of calves, showed different cut-off points for sTP in normohydrated calves (52 g/L) and dehydrated animals (56 g/L), with high sensibility (1 and 0.8 respectively), but low sensitivity (0.6 and 0.58 respectively). The cut-off points of GGT activity, based on the age of the calves, resulted from 295 UI/L in calves with 5 days or more and 100,5 UI/L in calves oldest than 5 days, with high sensitivity (1 and 0.85 respectively) and good sensibility (0.75 and 0.77 respectively). GGT is an interesting test to use in the case of NCD because the variability of results appears to be associated only with the age of the animals and not with the effects of diarrhea. Therefore, the results suggest that the GGT activity is a more accurate test for detecting ITPI in calves affected by NCD compared to the sTP.
The second aim of this research project was to identify the major risk factors associated with case fatality in diarrheic calves undergoing a standard therapeutic protocol. Clinical and laboratory findings were reviewed in 225 Holstein Friesian diarrheic calves over a 2 year period. Calves were treated according to a fluid therapy protocol using an oral electrolyte solution or an IV infusion. After therapy, 159 calves were discharged in a healthy state, whereas 66 calves died. Logistic regression analysis showed that serum total protein (STP) concentration (odds ratio, OR, 0.51; 95% confidence interval, CI 0.31–0.84; P < 0.01) and the strength of suckle reflex (OR 4.83; CI 1.17–19.88; P < 0.05) were the major risk factors associated with case fatality in diarrheic calves. These results could help to distinguish between diarrheic calves with a good prognosis and those with a major risk of treatment failure.
During NCD, the aim of the treatment is to correct hydration and acid-base imbalance with fluid therapy. Antibiotic treatment is commonly recommended regardless of the pathogen involved, but the real efficacy of its use is controversial. The third study of this research project investigates the efficiency of antibiotics during NCD and their influence on gut microbiota, considering the immunity status of the calf. Forty-two Holstein Friesian calves with NCD, aged from 1 to 28 days were enrolled, ex
Tipologia IRIS:
Tesi di dottorato
Elenco autori:
G. Sala
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