Acute phase proteins in cattle and swine : A review

Altres ajuts: acords transformatius de la UABThe major acute phase proteins (APPs) in cattle are haptoglobin (Hp) and serum amyloid A (SAA), and in swine, are Hp, SAA, C-reactive protein (CRP), and Pig major acute phase protein (Pig-MAP). Many methodologic assays are presently available to measure these parameters, which are still being improved to increase their specificity, sensitivity, user-friendliness, and economic availability. In cattle, the main applications are the diagnosis and monitoring of frequent diseases such as mastitis and metritis in dairy cows and respiratory problems in young calves. In pigs, APPs are useful in the control of bacterial and viral infections, and they may be used at the slaughterhouse to monitor subclinical pathologies and improve food safety. The utility of APP in animal production must not be forgotten; optimization of protocols to improve performance, welfare, and nutrition may benefit from the use of APPs. Other sample types besides serum or plasma have potential uses; APP determination in milk is a powerful tool in the control of mastitis, saliva is a non-invasive sample type, and meat juice is easily obtained at the slaughterhouse. Increasing our knowledge of reference intervals and the influence of variables such as age, breed, sex, and the season is important. Finally, worldwide harmonization and standardization of analytical procedures will help to expand the use of APPs

Serum haptoglobin dynamics in pigs vaccinated or not vaccinated against porcine circovirus type 2

The present work describes the serum haptoglobin (Hp) dynamics in piglets vaccinated and non-vaccinated with a commercial porcine circovirus type 2 (PCV2) vaccine at 3 weeks of age, and its relationship with the average daily weight gain (ADWG). The field study was carried out on two farms (A and B) with a previous clinical history of PCV2-systemic disease (PCV2-SD). The aim of the study was to assess whether Hp could be used as a surrogate marker of PCV2 vaccine efficacy. PCV2 infection was confirmed by quantitative real time PCR (qPCR) in pigs from both farms, but PCV2-SD was only diagnosed in farm A. No statistically significant relation was found between serum Hp concentration and the percentage of qPCR positive animals and the treatment applied (PCV2 vaccination) in both farms. On the other hand, using linear regression analysis, a significant negative correlation between the area under the curve of Hp (AUC) and ADWG was observed for farm A (p < 0.00001) and B (p = 0.01). Based on the obtained determination coefficient (R 2) values, AUC explained 20.0 and 11.6% of the observed ADWG for farms A and B, respectively. The present study supports that the measurement of acute phase proteins may be an indicator of ADWG in pig farms, but it was not apparently feasible to use the serum Hp concentration as a surrogate marker of PCV2 vaccine efficacy

Association between plasma metabolites and gene expression profiles in five porcine endocrine tissues

Background: Endocrine tissues play a fundamental role in maintaining homeostasis of plasma metabolites such as non-esterified fatty acids and glucose, the levels of which reflect the energy balance or the health status of animals. However, the relationship between the transcriptome of endocrine tissues and plasma metabolites has been poorly studied. Methods: We determined the blood levels of 12 plasma metabolites in 27 pigs belonging to five breeds, each breed consisting of both females and males. The transcriptome of five endocrine tissues i.e. hypothalamus, adenohypophysis, thyroid gland, gonads and backfat tissues from 16 out of the 27 pigs was also determined. Sex and breed effects on the 12 plasma metabolites were investigated and associations between genes expressed in the five endocrine tissues and the 12 plasma metabolites measured were analyzed. A probeset was defined as a quantitative trait transcript (QTT) when its association with a particular metabolic trait achieved a nominal P value < 0.01. Results: A larger than expected number of QTT was found for non-esterified fatty acids and alanine aminotransferase in at least two tissues. The associations were highly tissue-specific. The QTT within the tissues were divided into co-expression network modules enriched for genes in Kyoto Encyclopedia of Genes and Genomes or gene ontology categories that are related to the physiological functions of the corresponding tissues. We also explored a multi-tissue co-expression network using QTT for non-esterified fatty acids from the five tissues and found that a module, enriched in hypothalamus QTT, was positioned at the centre of the entire multi-tissue network. Conclusions: These results emphasize the relationships between endocrine tissues and plasma metabolites in terms of gene expression. Highly tissue-specific association patterns suggest that candidate genes or gene pathways should be investigated in the context of specific tissues

Proteínas de fase aguda como biomarcadores en medicina y producción porcina

El objetivo fundamental de esta tesis fue valorar la utilidad de las concentraciones plasmáticas de las proteínas de fase aguda (PFAs) como biomarcadores de enfermedades e indicadores de los parámetros productivos en la especie porcina. Las PFAs son parámetros bioquímicos que incrementan su concentración en respuesta a diferentes tipos de agresiones que afectan al organismo. En la especie porcina las tres PFAs más importantes son: haptoglobina (Hp), Pig Major Acute Phase Protein (Pig-MAP) y Proteína C-reactiva (CRP). En el estudio 1 se realizó la validación de un método inmunoturbidimétrico utilizado para la determinación de CRP humana para su uso con muestras porcinas. Se concluyó que el método de humana debido a su buena precisión, al empleo de calibrador trazable y a que es fácilmente automatizable, se puede utilizar con muestras porcinas mientras no existan métodos específicos de referencia ni materiales de referencia específicos de especie. En el estudio 2 se evaluó la cinética de las concentraciones plasmáticas de Hp, CRP y Pig-MAP a lo largo de todo el ciclo productivo en una explotación porcina de engorde. No se detectaron diferencias en la concentración de estas proteínas en función del sexo y se observó que la concentración de Pig-MAP disminuye con la edad. A la semana 8 de vida se detectó una infección subclínica producida por el virus del síndrome reproductivo y respiratorio porcino (PRRSV) que no causó incremento de la concentración de PFAs. En cambio, al final del período de este estudio, las tres PFA incrementaron considerablemente debido a un brote clínico con problemas respiratorios graves. En el estudio 3 se determinaron los niveles de Hp y Pig-MAP en cerdos de la misma granja comercial del estudio 2 en donde a un grupo de animales se les incorporó en su dieta un inmunomodulador, los cerdos del estudio 2 sirvieron de grupo control. Los animales que recibieron en la dieta este aditivo mostraron niveles más bajos de Hp tras tres semanas de tratamiento y presentaron un mayor incremento de peso y de ganancia media diaria. Por el contrario, las concentraciones de Pig-MAP no mostraron cambios a lo largo del estudio. Las concentraciones de Hp se incrementaron en ambos grupos tras la administración de la vacuna de Aujeszky. En conclusión, este estudio demuestra que la haptoglobina en un buen biomarcador para monitorizar los parámetros productivos y la respuesta a la vacuna de Aujeszky. En el estudio 4 se llevó a cabo una infección experimental con seis cepas diferentes del virus del síndrome reproductivo y respiratorio porcino (PRRSV), cuatro de ellas pertenecientes al genotipo I y dos al genotipo II. Hp y CRP resultaron ser las PFAs que se incrementaron de forma más acusada tras la infección, en cambio, la concentración sérica de Pig-MAP no se alteró de forma significativa. Por último, en el estudio 5 se investigó la relación entre la presencia de lesiones pulmonares y la concentración sérica de Hp, CRP y Pig-MAP en cerdos de matadero. Los cerdos procedían de 24 granjas clasificadas en función del grado de lesión característica de pleuritis (pleuritis negativa: P-, o pleuritis positiva: P+) y de consolidación pulmonar cráneo-ventral (CVPC negativa: M- y CVPC positiva: M+) observadas en matadero. Se obtuvieron muestras de suero de 20 animales de cada granja en las que se analizaron las concentraciones de las tres PFAs. Las tres proteínas incrementaron claramente en las granjas M+, pero sólo Hp y Pig-MAP incrementaron significativamente en las P+. Los análisis ROC realizados concluyeron que la PFA que mejor discriminaba entre los grupos P+/P- y M+/M- era la Pig-MAP.The main goal of this thesis was to evaluate the usefulness of serum concentrations of acute phase proteins (APPs) as biomarkers of disease and indicators of growth performance in pigs. The APPs are plasma protein that increase its concentration in response to different types of attacks that affect the organism. In pigs the three major APPs are: haptoglobin (Hp), Pig Major Acute Phase Protein (Pig-MAP) and C-reactive protein (CRP). Study 1 was conducted to validate an immunoturbidimetric method used for the determination of human CRP for use with porcine samples. It was concluded that the human method due to its good precision, traceable calibrator and satisfactory overlap performance, can be used with porcine samples meanwhile there is neither a reference method nor a reference material for determination of CRP in pig. In study 2, the kinetic profile of haptoglobin, C-reactive protein (CRP) and Pig-MAP were evaluated in pigs throughout the productive cycle in a fattening farm. No significant differences were observed in haptoglobin, Pig-MAP and CRP concentrations between males and females. The concentration of Pig-MAP decreased progressively until 13 weeks of age. At week 8, a PRRS virus recirculation took place but the serum concentration of any APPs did not increase. By contrast, at the end of the period of this study, all three proteins increased concomitantly to a clinical outbreak with severe respiratory problems. In study 3, the serum concentration of Hp and Pig-MAP were analyzed in a group of pigs receiving a feed additive with immunomodulatory properties. These animals were from the same commercial farm than those in study 2 and raised in parallel. For this reason, pigs of Study 2 were used as control group. Animals receiving this additive in the diet showed lower levels of Hp after three weeks of treatment and had an improvement in total body weight and average daily gain. By contrast, the concentrations of Pig-MAP were unchanged throughout the study. Hp concentrations increased in both groups after administration of Aujeszky vaccine. In conclusion, this study shows that the haptoglobin in a good biomarker to monitorize production parameters and for monitoring Aujeszky vaccine in pigs reared under standard commercial conditions. In study 4, an experimental infection was performed with six different strains of porcine reproductive and respiratory syndrome virus (PRRSV), four of them belonging to genotype I and two to genotype II. Hp and CRP were found to be the APPs which increased more markedly after infection, however, the serum concentration of Pig-MAP did not change significantly. Finally, study 5 investigated the relationship between the presence of lung lesions in pigs at the slaughterhouse and serum concentration of Hp, CRP and Pig-MAP. The pigs came from 24 farms classified according to the level of pleuritis lesions (pleuritis negative: P-, or pleuritis positive: P+) and cranio-ventral pulmonary consolidation (CPVC negative: M-and CPVC positive: M+) observed in slaughterhouse. Serum samples from 20 pigs from each farm were collected and testedfor APPs. All three proteins clearly increased on farms M+, but only Hp and Pig-MAP increased significantly in the P+. ROC analysis concluded that the best APP to discriminate between groups P+ / P- and M+ / M-was Pig-MAP

Age-Related Serum Biochemical Reference Intervals Established for Unweaned Calves and Piglets in the Post-weaning Period

The purpose of the present study is to establish the influence of age on serum biochemistry reference intervals (RIs) for unweaned calves and recently-weaned piglets using large number of animals sampled at different ages from populations under different season trials. Specifically, milk replacer (MR)-fed calves from April-July 2017 (n = 60); from December 2016-March 2017 (n = 76) and from April-August 2018 (n = 57) and one group of healthy weaned piglets (n = 72) were subjected to the study. Serum enzymes and metabolites of calves at age of 24 h (24 h after colostrum intake), 2, 5, and 7 weeks from merged trials and piglets at 0, 7, and 14 days post-weaning (at 21, 28, and 35 days of age) were studied. The main variable is age whereas no major trial- or sex-biased differences were noticed. In calves, ALT, AST, GGT, GPx, SOD, NEFAs, triglycerides, glucose, creatinine, total protein, and urea were greatly elevated (p 0.1) during the study. In comparison with the adult RIs, creatinine from 24 h, NEFAs from 2 w, GGT from 5 w, and urea from 7 w are fully comparable with RIs or lie within RIs determined for adult. In piglets, no changes were noticed on glucose (p > 0.1) and haptoglobin (p > 0.1) and there were no major changes on hepatic enzymes (ALT, AST, and GGT), total protein, creatinine and urea even though several statistical differences were noticed on 7 days post-weaning. Cholesterol, triglycerides, NEFAs, cortisol and PigMAP were found increased (p < 0.05) while TNF-alpha was found less concentrated (p < 0.001) at 0 days post-weaning compared with other times. Moreover, the RIs of creatinine and GGT are fully comparable with RIs or lie within RIs determined for adult. In conclusion, clinical biochemistry analytes RIs were established for unweaned calves and recently-weaned piglets and among them some can vary at different ages