Correlação entre lipidose hepática, variação da condição corporal e analitos hepáticos em bovinos leiteiros

Liver lipidosis is a metabolic disorder mostly observed in high yielding dairy cattle, especially during the transition period. The aim of this study was to determine the correlation between hepatic lipid infiltration, biochemical indicators of liver function, and body condition score (BCS) variation in dairy cows. Fifty-one multiparous Holstein cows raised in a confined system were evaluated. Liver biopsies and blood samples were collected, and BCS was measured on days 3 and 28 postpartum. Lipid infiltration was determined by histologic examination. The plasma activity of aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase and concentration of beta-hydroxybutyrate, non-esterified fatty acids, albumin, total bilirubin, and cholesterol were determined. BCS was measured using objective (camera) and subjective (visual) methods. Mild lipid infiltration was found in 3.92% of cows sampled on day 3 and 5.88% on day 28. Bilirubin was significantly higher on day 3 than on day 28 postpartum, and cholesterol was significantly higher on day 28 than on day 3 in all cows. There was no difference in biochemical analytes between cows with and without lipidosis. On day 3, mean subjective BCS was 3.10 and objective BCS was 3.16, while on day 28, these scores were 2.91 and 2.99, respectively. The calculated liver function index (LFI) was found to be a more sensitive indicator of liver function than the hepatic analytes evaluated. No correlation between BCS variation and lipid infiltration was found. Cholesterol and bilirubin levels showed the most remarkable changes during the early postpartum period. LFI is a potential indicator of postpartum liver function.A lipidose hepática é um distúrbio metabólico principalmente observado nos bovinos de leite de alto rendimento, especialmente no período de transição. O objetivo deste estudo foi determinar a correlação entre infiltração lipídica hepática, indicadores bioquímicos de função hepática e variação da condição corporal em bovinos leiteiros. Foram avaliadas cinquenta e um vacas multíparas de raça Holandesa em confinamento. Coletaram-se biopsias de fígado e amostras de sangue, e a condição corporal (BCS) aferiu-se nos dias 3 e 28 pós-parto. A infiltração lipídica determinou-se mediante avaliação histológica. Mensuraram-se a atividade da aspartato aminotransferase, fosfatase alcalina e da gama-glutamil transferase, concentração de beta-hidroxibutirato, ácidos graxos não esterificados, albumina, bilirrubina total e colesterol. A BCS mediu-se utilizando método objetivo (câmera) e subjetivo (visualmente). Observou-se discreta infiltração lipídica em 3,92% dos bovinos amostrados no dia 3 e 5,88% no dia 28. Em todos os bovinos a bilirrubina foi significativamente mais alta no dia 3 do que no dia 28 e o colesterol foi superior no dia 28 do que no dia 3. Não houve diferença nos analitos bioquímicos dos bovinos com e sem lipidose. No dia 3, a média subjetiva da BCS foi 3,10 e a objetiva 3,16, enquanto no dia 28, obtiveram-se valores de 2,91, e 2,99 respectivamente. O índice calculado de função hepática mostrou ser um indicador mais sensível da função hepática do que os analitos avaliados individualmente. Não houve correlação entre a variação do BCS e infiltração lipídica

Relation between Liver Lipid Content and Plasma Biochemical Indicators in Dairy Cows

Background: The incidence of metabolic disorders in dairy cows has increased as a result of intensive production practices and genetic selection for milk yield. Among such disorders, liver lipidosis is very frequently observed and has significant negative effects on cow health and milk yield. Severe energy supply deficit causes high fat mobilization, resulting in rapid body condition loss and liver lipid infiltration, which cannot always be detected by known blood biochemical indicators. The main objective of the study was to determine possible associations of blood biochemical parameters with liver lipid infiltration severity in high-yield multiparous Holstein cows along prepartum and postpartum periods.Materials, Methods & Results: Fifty-four high-yield Holstein cows from a herd managed in a free-stall system in the northwest region of the state of Rio Grande do Sul, Brazil were evaluated. Cows were divided in two groups according to their physiological status. Group 1 included 19 prepartum cows, with an average milk yield of 44.7 L/d in the previous lactation, and 2.8 average parity, and Group 2 included 35 postpartum cows, with an average milk yield of 46.8 L/d in the previous lactation, and 2.5 average parity. The farm produced 10,000 kg milk per year, containing 3.5% of fat, 3.2% of protein and 4.7% of lactose. Total cholesterol (CH), plasma triglycerides (TGp), beta-hydroxybutyrate (BHB), albumin (ALB), non-esterified free fatty acids (NEFA) levels, and aspartate aminotransferase (AST) and creatine kinase (CK) activities were analyzed in the plasma and liver triglycerides (TGl) levels were determined in liver tissue samples.The SPSS statistical software was used for the statistical analyses.  The obtained data were analyzed for normality by the Shapiro-Wilk test and for homoscedasticity by Bartlett test. Data were submitted to analysis of variance, and means were compared by the t-test (PROC TTEST). Pearson correlation test (PROC CORR) was used to compare the results between prepartum and postpartum cows, and between those with and without lipidosis.An overall incidence of 20% severe hepatic lipidosis was determined both in prepartum and postpartum cows. Positive significant correlations were obtained between days in milk (DIM) and AST (r= 0.43; P < 0.01), CH and TGp (r= 0.44; P < 0.01), TGl and AST (r=0.32; P < 0.05), NEFA and AST (r= 0.45; P < 0.01) and CK and AST (r= 0.447; P < 0.01). Negative significant correlations were detected between TGp and DIM (r= -0.45; P < 0.01), and between TGl and TGp (r= -0.30; P < 0.05).Discussion: Prepartum cows showed moderate fat infiltration in the liver, while 25.7% of postpartum cows presented severe lipidosis. AST values increased as lactation progressed, suggesting a greater tendency of liver damage, in early postpartum. The obtained CK values were within the reference range, except for the cows with hepatic lipidosis, indicating that the measured AST activity was originated from the liver and not from the muscle tissues. TGp, NEFA and AST values indicate the degree of fat mobilization and, possibly, liver infiltration, while TGl indicates fat infiltration in the liver. Although negative energy balance (NEB) may trigger lipolysis and some degree of hepatic lipidosis, plasma BHB values did not significantly increase. The obtained results show that the evaluated plasma parameters may be useful to establish guidelines for the identification of changes in the metabolic profile of dairy cows during different production stages, as well as measures for the prevention and control of metabolic disorders

Relation between liver lipid content and plasma biochemical indicators in dairy cows

Background: The incidence of metabolic disorders in dairy cows has increased as a result of intensive production practices and genetic selection for milk yield. Among such disorders, liver lipidosis is very frequently observed and has significant negative effects on cow health and milk yield. Severe energy supply deficit causes high fat mobilization, resulting in rapid body condition loss and liver lipid infiltration, which cannot always be detected by known blood biochemical indicators. The main objective of the study was to determine possible associations of blood biochemical parameters with liver lipid infiltration severity in high-yield multiparous Holstein cows along prepartum and postpartum periods. Materials, Methods & Results: Fifty-four high-yield Holstein cows from a herd managed in a free-stall system in the northwest region of the state of Rio Grande do Sul, Brazil were evaluated. Cows were divided in two groups according to their physiological status. Group 1 included 19 prepartum cows, with an average milk yield of 44.7 L/d in the previous lactation, and 2.8 average parity, and Group 2 included 35 postpartum cows, with an average milk yield of 46.8 L/d in the previous lactation, and 2.5 average parity. The farm produced 10,000 kg milk per year, containing 3.5% of fat, 3.2% of protein and 4.7% of lactose. Total cholesterol (CH), plasma triglycerides (TGp), beta-hydroxybutyrate (BHB), albumin (ALB), non-esterified free fatty acids (NEFA) levels, and aspartate aminotransferase (AST) and creatine kinase (CK) ac-tivities were analyzed in the plasma and liver triglycerides (TGl) levels were determined in liver tissue samples. The SPSS statistical software was used for the statistical analyses. The obtained data were analyzed for normality by the Shapiro-Wilk test and for homoscedasticity by Bartlett test. Data were submitted to analysis of variance, and means were compared by the t-test (PROC TTEST). Pearson correlation test (PROC CORR) was used to compare the results between prepartum and postpartum cows, and between those with and without lipidosis. An overall incidence of 20% severe hepatic lipidosis was determined both in prepartum and postpartum cows. Positive significant correlations were obtained between days in milk (DIM) and AST (r= 0.43; P < 0.01), CH and TGp (r= 0.44; P < 0.01), TGl and AST (r=0.32; P < 0.05), NEFA and AST (r= 0.45; P < 0.01) and CK and AST (r= 0.447; P < 0.01). Negative significant correlations were detected between TGp and DIM (r= -0.45; P < 0.01), and between TGl and TGp (r= -0.30; P < 0.05). Discussion: Prepartum cows showed moderate fat infiltration in the liver, while 25.7% of postpartum cows presented severe lipidosis. AST values increased as lactation progressed, suggesting a greater tendency of liver damage, in early postpartum. The obtained CK values were within the reference range, except for the cows with hepatic lipidosis, indicat¬ing that the measured AST activity was originated from the liver and not from the muscle tissues. TGp, NEFA and AST values indicate the degree of fat mobilization and, possibly, liver infiltration, while TGl indicates fat infiltration in the liver. Although negative energy balance (NEB) may trigger lipolysis and some degree of hepatic lipidosis, plasma BHB values did not significantly increase. The obtained results show that the evaluated plasma parameters may be useful to establish guidelines for the identification of changes in the metabolic profile of dairy cows during different production stages, as well as measures for the prevention and control of metabolic disorders

Degree of liver lipid infiltration relative to blood indicators of liver function and variation of body condition score in dairy cows

A baixa funcionalidade hepática tem se apresentado de forma incisiva nos rebanhos leiteiros, causando severas perdas diretas e indiretas ao desempenho dos animais. Geralmente afeta os animais no período final da gestação e o início da lactação, as quais são fases de intensa demanda energética em que geralmente as demandas não acompanham o consumo alimentar. Os principais problemas relacionados com ela são a baixa produção de leite, menor eficiência reprodutiva, aumento da incidência de outras doenças e descarte involuntário. Durante o período de transição, a diminuição no consumo de matéria seca e o aumento da demanda energética, promovem uma lipomobilização que incrementa as concentrações séricas dos ácidos graxos não esterificados (NEFA) e do beta-hidroxibutirato (BHB). O aumento destes parâmetros indica um maior grau de balanço energético negativo, que pode levar um acúmulo de triglicerídeos e lipídeos totais no fígado originando a lipidose hepática. O presente estudo teve como objetivos: (1) Associar os metabólitos com o grau de infiltração lipídica e com a perda de condição corporal avaliada de forma objetiva (câmera de escore) e subjetiva (escala visual de Ferguson), bem como comparar o grau de concordância dos dois métodos de avaliação; (2) Correlacionar o grau de infiltração lipídica com o índice de função hepática (IFH); (3) Comparar os valores dos indicadores bioquímicos com o grau de infiltração lipídica no pré e pós-parto. Para tanto foram realizados dois estudos. No primeiro estudo, foram utilizadas 51 vacas leiteiras multíparas da raça Holandesa, avaliadas durante os primeiros 28 dias de lactação. Foi determinado o grau de infiltração lipídica mediante histopatologia hepática. Simultaneamente foram realizadas amostragens de sangue para avaliação dos indicadores de lesão e função hepática (AST, GGT, FA, albumina, bilirrubina, colesterol) e a avaliação do escore de condição corporal. Diferentemente do esperado, as vacas de ambos os grupos de coleta não apresentaram grau de infiltração lipídica considerável, e somente alguns animais apresentaram grau leve de infiltração. A perda de condição corporal foi de 0,19 pontos para o método subjetivo e 0,17 pontos para o método objetivo entre o 3º e o 28º dia pós-parto. As concentrações de BHB, NEFA, GGT, AST, FA, e bilirrubina sofreram diminuição entre os dois períodos. No entanto, houve aumento dos valores de albumina e colesterol no mesmo período. Independente do grupo, todas as vacas apresentaram hipocolesterolemia no pós-parto imediato. Houve uma correlação positiva e significativa entre os métodos subjetivo e objetivo de avaliação do ECC. Comparação nos metabólitos de vacas com e sem lipidose (total) o único metabólito alterado foi o colesterol das vacas com lipidose hepática, os demais estavam dentro dos intervalos de referência. As vacas com lipidose hepática no pós-parto apresentaram índice de função hepática menor (-3,46), comparado com vacas sem lipidose (-1,02), podendo o IFH ser usado como teste indicativo de lipidose hepática. No segundo estudo foram utilizadas 54 vacas leiteiras multíparas da raça Holandesa, divididas em dois grupos (pré e pós-parto). Foi determinado a infiltração lipídica mediante a técnica de extração química de lipídeos hepáticos. Simultaneamente foram realizadas amostragens de sangue para avaliação dos indicadores bioquímicos. Ocorrência de lipidose sevara encontrada no estudo foi de 20% das vacas no pré e pós-parto. Foram encontradas correlações positivas entre os dias ao leite (DIM) e aspartato aminotranferase (AST), entre colesterol e triglicerídeos plasmáticos (TRp), entre triglicerídeos hepáticos (TG) e AST, entre NEFA e AST, e entre creatina quinase (CK) e AST, e correlações negativas entre TRp e DIM, assim como entre TG e TRp. Conclui-se que a incidência da lipidose hepática leve atinge as vacas leiteiras alterando o perfil bioquímico de forma discreta, tendo o controle do ECC das vacas um dos fatores chave para minimizar esta patologia e suas consequências.Impaired liver function is frequently observed in dairy herds, and directly and indirectly account for performance losses. It usually affects cows at the end of gestation and beginning of lactation. The high energy requirements of cows during this transition stage are often not met due to their low feed intake, resulting in low milk yield, poor reproductive efficiency, increased incidence of diseases, and involuntary culling. In order to cope with this energy deficit, body fat is mobilized, increasing serum levels of non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB). Increased NEFA and BHB levels indicate negative energy balance, which may result in the accumulation of triglycerides (TG) and total lipids in the liver leading to hepatic lipidosis. The objectives of the present study were: (1) to establish a possible association of blood metabolites with the degree of liver lipid infiltration and body condition score (BCS), evaluated both objectively (score camera) and subjective (Ferguson visual scale), as well as to compare the degree of agreement between these two BCS evaluation methods; (2) to correlate the degree of lipid infiltration with liver function index (LFI); (3) to compare biochemical indicator values with the degree of lipid infiltration during the pre- and postpartum periods. Two studies were carried out. In the first study, 51 Holstein multiparous dairy cows were evaluated during the first 28 days of lactation. Liver lipid infiltration degree was determined by histopathology. At the time of liver biopsy, blood samples were collected to evaluate liver lesion and function indicators (AST, GGT, AF, albumin, bilirubin, cholesterol) and BCS was evaluated. Unexpectedly, no significant liver lipid infiltration degree differences were detected between cows pre- or postpartum; only a few animals presented a slight degree of infiltration. Body condition losses of 0.19 and 0.17 points between 3 and 28 days postpartum were determined using the objective and subjective methods, respectively. Blood BHB, NEFA, GGT, AST, FA, and bilirubin levels were reduced between both periods, while albumin and cholesterol levels increased. Independently of the group, all cows presented hypocholesterolemia in the immediate postpartum period. There was a positive and significant correlation between the subjective and objective BCS evaluation methods. All evaluated metabolites of cows with and without lipidosis were within the reference intervals, except for the blood cholesterol of cows with hepatic lipidosis. Cows with hepatic lipidosis during postpartum period presented lower liver function index (-3.46) compared with those without lipidosis (-1.02), suggesting that this index may be used as an indicator of hepatic lipidosis. In the second study, 54 multiparous Holstein dairy cows were divided into two groups (prepartum and postpartum). Liver lipid infiltration was determined by the chemical extraction of liver lipids. Blood samples were collected at the time of liver biopsy to evaluate the biochemical indicators. The overall incidence of severe liver lipidosis was 20%. Positive correlations between days in milk (DIM) and aspartate aminotransferase activity (AST), between plasma cholesterol and plasma triglyceride (TGp) levels, between liver triglyceride (TGl) levels and AST, between NEFA and AST, and between creatine kinase (CK) and AST activities were determined, whereas negative correlations between TGp and DIM, and between TGl and TGp were detected. It is concluded that mild hepatic lipidosis in dairy cows promotes moderate changes in their biochemical profile, and the control of BCS is one of the key factors to minimize this disorder and its consequences

Relation between Liver Lipid Content and Plasma Biochemical Indicators in Dairy Cows

Background: The incidence of metabolic disorders in dairy cows has increased as a result of intensive production practices and genetic selection for milk yield. Among such disorders, liver lipidosis is very frequently observed and has significant negative effects on cow health and milk yield. Severe energy supply deficit causes high fat mobilization, resulting in rapid body condition loss and liver lipid infiltration, which cannot always be detected by known blood biochemical indicators. The main objective of the study was to determine possible associations of blood biochemical parameters with liver lipid infiltration severity in high-yield multiparous Holstein cows along prepartum and postpartum periods.Materials, Methods & Results: Fifty-four high-yield Holstein cows from a herd managed in a free-stall system in the northwest region of the state of Rio Grande do Sul, Brazil were evaluated. Cows were divided in two groups according to their physiological status. Group 1 included 19 prepartum cows, with an average milk yield of 44.7 L/d in the previous lactation, and 2.8 average parity, and Group 2 included 35 postpartum cows, with an average milk yield of 46.8 L/d in the previous lactation, and 2.5 average parity. The farm produced 10,000 kg milk per year, containing 3.5% of fat, 3.2% of protein and 4.7% of lactose. Total cholesterol (CH), plasma triglycerides (TGp), beta-hydroxybutyrate (BHB), albumin (ALB), non-esterified free fatty acids (NEFA) levels, and aspartate aminotransferase (AST) and creatine kinase (CK) activities were analyzed in the plasma and liver triglycerides (TGl) levels were determined in liver tissue samples.The SPSS statistical software was used for the statistical analyses.  The obtained data were analyzed for normality by the Shapiro-Wilk test and for homoscedasticity by Bartlett test. Data were submitted to analysis of variance, and means were compared by the t-test (PROC TTEST). Pearson correlation test (PROC CORR) was used to compare the results between prepartum and postpartum cows, and between those with and without lipidosis.An overall incidence of 20% severe hepatic lipidosis was determined both in prepartum and postpartum cows. Positive significant correlations were obtained between days in milk (DIM) and AST (r= 0.43; P < 0.01), CH and TGp (r= 0.44; P < 0.01), TGl and AST (r=0.32; P < 0.05), NEFA and AST (r= 0.45; P < 0.01) and CK and AST (r= 0.447; P < 0.01). Negative significant correlations were detected between TGp and DIM (r= -0.45; P < 0.01), and between TGl and TGp (r= -0.30; P < 0.05).Discussion: Prepartum cows showed moderate fat infiltration in the liver, while 25.7% of postpartum cows presented severe lipidosis. AST values increased as lactation progressed, suggesting a greater tendency of liver damage, in early postpartum. The obtained CK values were within the reference range, except for the cows with hepatic lipidosis, indicating that the measured AST activity was originated from the liver and not from the muscle tissues. TGp, NEFA and AST values indicate the degree of fat mobilization and, possibly, liver infiltration, while TGl indicates fat infiltration in the liver. Although negative energy balance (NEB) may trigger lipolysis and some degree of hepatic lipidosis, plasma BHB values did not significantly increase. The obtained results show that the evaluated plasma parameters may be useful to establish guidelines for the identification of changes in the metabolic profile of dairy cows during different production stages, as well as measures for the prevention and control of metabolic disorders

Relation between liver lipid content and plasma biochemical indicators in dairy cows

Background: The incidence of metabolic disorders in dairy cows has increased as a result of intensive production practices and genetic selection for milk yield. Among such disorders, liver lipidosis is very frequently observed and has significant negative effects on cow health and milk yield. Severe energy supply deficit causes high fat mobilization, resulting in rapid body condition loss and liver lipid infiltration, which cannot always be detected by known blood biochemical indicators. The main objective of the study was to determine possible associations of blood biochemical parameters with liver lipid infiltration severity in high-yield multiparous Holstein cows along prepartum and postpartum periods. Materials, Methods & Results: Fifty-four high-yield Holstein cows from a herd managed in a free-stall system in the northwest region of the state of Rio Grande do Sul, Brazil were evaluated. Cows were divided in two groups according to their physiological status. Group 1 included 19 prepartum cows, with an average milk yield of 44.7 L/d in the previous lactation, and 2.8 average parity, and Group 2 included 35 postpartum cows, with an average milk yield of 46.8 L/d in the previous lactation, and 2.5 average parity. The farm produced 10,000 kg milk per year, containing 3.5% of fat, 3.2% of protein and 4.7% of lactose. Total cholesterol (CH), plasma triglycerides (TGp), beta-hydroxybutyrate (BHB), albumin (ALB), non-esterified free fatty acids (NEFA) levels, and aspartate aminotransferase (AST) and creatine kinase (CK) ac-tivities were analyzed in the plasma and liver triglycerides (TGl) levels were determined in liver tissue samples. The SPSS statistical software was used for the statistical analyses. The obtained data were analyzed for normality by the Shapiro-Wilk test and for homoscedasticity by Bartlett test. Data were submitted to analysis of variance, and means were compared by the t-test (PROC TTEST). Pearson correlation test (PROC CORR) was used to compare the results between prepartum and postpartum cows, and between those with and without lipidosis. An overall incidence of 20% severe hepatic lipidosis was determined both in prepartum and postpartum cows. Positive significant correlations were obtained between days in milk (DIM) and AST (r= 0.43; P < 0.01), CH and TGp (r= 0.44; P < 0.01), TGl and AST (r=0.32; P < 0.05), NEFA and AST (r= 0.45; P < 0.01) and CK and AST (r= 0.447; P < 0.01). Negative significant correlations were detected between TGp and DIM (r= -0.45; P < 0.01), and between TGl and TGp (r= -0.30; P < 0.05). Discussion: Prepartum cows showed moderate fat infiltration in the liver, while 25.7% of postpartum cows presented severe lipidosis. AST values increased as lactation progressed, suggesting a greater tendency of liver damage, in early postpartum. The obtained CK values were within the reference range, except for the cows with hepatic lipidosis, indicat¬ing that the measured AST activity was originated from the liver and not from the muscle tissues. TGp, NEFA and AST values indicate the degree of fat mobilization and, possibly, liver infiltration, while TGl indicates fat infiltration in the liver. Although negative energy balance (NEB) may trigger lipolysis and some degree of hepatic lipidosis, plasma BHB values did not significantly increase. The obtained results show that the evaluated plasma parameters may be useful to establish guidelines for the identification of changes in the metabolic profile of dairy cows during different production stages, as well as measures for the prevention and control of metabolic disorders