Acute phase proteins in healthy and sick dairy and beef calves and their association with growth
Year: 2018
Type: dissertation
Abstract: The acute phase response (APR) is a component of the innate immune system, a general and non-specific response that limits the spread of infection and removes factors potentially harmful to the body. Infection, neoplasm or tissue trauma initiates an acute phase response, resulting in visible systemic signs of illness, fever, reduction of appetite and depression. APR also induces a variety of less discernible changes. One measurable sign of APR is the increased synthesis of acute phase proteins (APP) by the liver, mediated by cytokines. In bovine medicine, increased concentrations of the APPs haptoglobin (Hp), serum amyloid A (SAA) and fibrinogen (Fb) have been associated with several diseases, including respiratory tract infections in calves, metritis, mastitis, and hoof diseases. The aim of this thesis was to explore further the associations between APPs and common diseases in calves and assess the ability of APPs to differentiate between severities of disease during different stages. The studies also addressed the possibility of using the variation in APP concentrations in apparently healthy animals to predict the growth. The thesis is based on four individual studies, performed as field studies on commercial Finnish farms. APP measurements and collection of data for explanatory variables were got from dairy calves on dairy farms, beef calves in suckler herds and calves on a calf-rearing farm. The reference values for Hp, SAA and Fb were established from the healthy population of dairy calves (Study I). The association between the diseases and APPs were assessed in different calf populations, and increased concentrations of Hp, SAA and Fb were recorded in calves with respiratory tract infection and umbilical inflammation (Studies I, II, III). Fb, Hp and SAA differed between surgically confirmed diagnoses of local umbilical inflammation and severe umbilical inflammation reaching the abdominal cavity (Study I). Decreased haptoglobin concentrations were associated with weak signs of eimeriosis (diarrhoea or low oocyst count or presence of non-pathogenic Eimeria spp.; Study II). Increased albumin concentrations at around two weeks of age were associated with better growth rate over the first 30 days of life (Study III) in a population of beef calves. However, a longer-term effect was recorded for SAA concentrations around two to three weeks of age (Studies III and IV). A negative association between increased SAA and growth rate was evident for beef calves over the period 30–200 days of age in (III). A similar association between SAA and growth was apparent in rearing dairy calves over two months, seven months and even at slaughter, at 15–18 months (Study IV). The results support the concept that APPs are suitable markers for inflammation and several calf diseases. The novel finding of an association between SAA and growth rate represents opportunities for purposes other than aiding clinical work. The increase in non-specific markers of inflammation can indicate general disturbance in animal health.
Source: Työväentutkimus Vuosikirja
Author: Leena Seppä‐Lassila
Language: English
Topic: Animal health and immunology
Subfield: Animal Science and Zoology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2897780527