Haptoglobin and serum amyloid-A concentrations and their relationship with oocyst count in neonatal lambs experimentally infected with Cryptosporidium parvum

Acute phase biomarkers, oxidants, antioxidants, and trace minerals of mobile sheep flocks naturally infected with brucellosis

This study assayed the acute phase responses of sheep seropositive to Brucella. Sera collected from ewes (n=160) were subjected to serological tests of Brucella, Rose Bengal plate agglutination test (RBPAT), buffer acidified plate agglutination test (BAPAT), and complement fixation test (CFT). Results revealed that CFT was the most predictive test of brucellosis followed by BAPAT then RBPAT. The moderate predictive blood biochemical parameters were zinc and ascorbic acid. Ewes with low CFT titre (chronic) had low fibrinogen, copper, NO, and GPx. Seropositive animals had high blood concentrations of ascorbic acid and zinc.

Use of procalcitonin, neopterin, haptoglobin, serum amyloid A and proinflammatory cytokines in diagnosis and prognosis of bovine respiratory disease in feedlot calves under field conditions

Bovine respiratory diseases (BRD) have long been considered a serious problem that causes major economic losses in feedlot calves (FC). This study aimed to determine the diagnostic and prognostic effect of selected biological markers including, procalcitonin (PCT), neopterin (NP), proinflammatory cytokines (IL-1β, IL-8, TNF-α, IF-γ), haptoglobin (HP) and serum amyloid A (SAA) on FC with BRD under field conditions. Sixty-nine FC that were identified to be infected with Mannheimia haemolytica and Histophilus somni and had different clinical respiratory signs (diseased group) were selected for this study. In addition, 20 healthy FC have been selected as a control group. We have detected higher serum levels of PCT, NP, HP, SAA, IL-1β, IL-8, TNF-α and IF-γ in diseased FC group compared with the control group. All tested markers revealed a high level of discrimination between BRD infected FC and healthy ones (AUC > 0.90). Moreover, the obtained data showed a high degree of prognostic accuracy for PCT, NP, IL-8, HP, IF-γ and IL-1β in predicting treatment response of FC with BRD at the selected thresholds (AUC = 0.99, 0.99, 0.97, 0.93, 0.88 and 0.82, respectively). Significant inhibition was observed for the selected biochemical markers in treated FC 7 days post-treatment. In conclusion, this study showed that BRD in FC was associated with significant alterations in serum APPs, proinflammatory cytokines, PCT and NPT levels. Furthermore, it demonstrated that these serum biomarkers are much higher in FC with BRD compared to recovered ones. Our data suggest that the measurement of PCT, NPT, APPs and cytokines together with the clinical examination may be a useful diagnostic and prognostic tool for assessment of FC naturally infected with M. haemolytica and H. somni.

Acute phase response in organic lambs associated with colostrum serum amyloid A, weight gain, and Cryptosporidium and Giardia infections

In neonatal period, lamb's immune system goes through rapid adaptation to the extra-uterine environment. Success of this process can influence the animal's future performance and, thus, the quantitative assessment of it would greatly benefit sheep producers. The current study was conducted to investigate the acute phase response (APR) (measured through serum amyloid A (SAA), haptoglobin (Hp) and albumin (ALB)) in relation to later life growth (measured at 122 days of age), and naturally occurring Cryptosporidium and Giardia infections in neonatal lambs grown in organic farm. Serum (n = 692) and faecal (n = 141) samples were collected from 269 lambs in their first 3 weeks of life. The ewes' colostrum (n = 181) SAA concentrations were positively associated with the lambs' serum SAA and Hp concentrations at 2 to 4 days of age. Hp and ALB concentrations at the second week of age were positively associated with the growth rate at 122 days of age. Lamb serum globulin (GLOB) concentrations and Cryptosporidium-positive faecal samples were negatively associated at the second and third weeks of life. These findings suggest the importance of interactions between the immune system and environmental factors at the second week of the lambs' lives and its association with future performance.

Haptoglobin and serum amyloid A as putative biomarker candidates of naturally occurring bovine respiratory disease in dairy calves

Bovine respiratory disease (BRD) is one of the leading causes of morbidity and mortality in dairy calves. Identification of reliable biomarkers of naturally occurring BRD is essential for ensuring early diagnosis and treatment of calves and monitoring treatment efficacy. This need is punctuated, especially in mild to moderate cases that would greatly help to decrease recurrence and the overall prevalence of BRD. The present study was conducted to investigate the changes in serum concentrations of haptoglobin (Hpt) and serum amyloid A (SAA) and association between oxidative stress and acute phase proteins (APPs) in BRD. Hpt and SAA levels significantly increased (P < .01) in BRD stressed calves as compared to healthy subjects. There was a significant decrease (P < .01) in serum albumin (Alb) concentration of infected calves as compared to controls. The oxidative stress markers revealed a significant (P < .01) increase in lipid peroxidation (LPO) and a concurrent decrease in activities of superoxide dismutase (SOD), reduced glutathione (R-GSH) and catalase (CAT) in BRD. A significant correlation among APPs, extent of oxidative stress and clinical score (CS) of calves was depicted. A stepwise decrease in Hpt and SAA and increase in Alb was observed in infected calves post-treatment. These results suggest implication of oxidative stress in enhancing APPs and monitoring of APPs as a potential complement to clinical assessment of treatment in calves with naturally occurring BRD. Hpt may be useful as the most sensitive biomarker in BRD. However, the combined use of Hpt and oxidative stress biomarkers would greatly improve the diagnostic accuracy.