Rómulo Campos

Relationship among blood indicators of lipomobilization and hepatic function during early lactation in high-yielding dairy cows

Blood indicators are used as a tool to diagnose metabolic disorders. The present work was conducted to study the relationships among blood indicators of lipomobilization and hepatic function in high-yielding dairy cows. Two groups of Holstein cows were studied: 27 early lactation cows and 14 mid lactation cows from four different herds with similar husbandry characteristics in Galicia, Spain. Blood samples were obtained to measure beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), triglycerides (TG), and the activity of aspartate transaminase (AST) and gamma-glutamyl transferase. Cows in early lactation had higher levels of BHB and NEFA than mid lactation cows. High lipomobilization (NEFA > 400 µmol/L) was detected in 67% and 7% of early lactation and mid lactation cows, respectively, while subclinical ketosis (BHB > 1.2 mmol/L) was detected in 41% and 28% of the early lactation and lactation cows, respectively. TG concentrations were low in all cows suffering subclinical ketosis and in 61% of the cows with high lipomobilization. During early lactation, 30% of cows suffered hepatic lipidosis as detected by levels of AST. Compromised hepatic function was observed in early lactation cows as shown by lower concentrations of glucose, total protein, and urea.

Composição do sangue e do leite em ovinos leiteiros do sul do Brasil: variações na gestação e na lactação

Dairy sheep industry has increased intensively in southern Brazil, however, without the corresponding knowledge of variations on metabolic and hematological parameters and on milk composition, with application in research and clinical activities. This work was carried out on Lacaune sheep, intensively grazed in the county of Bento Goncalves (RS), in southern Brazil. Blood samples were collected from the jugular vein for metabolic profiles and hematology. Samples were taken randomly from 14 sheep in each of the following periods: nonpregnant ewes; at 60, 90 and 120 of pregnancy and at 7, 30, 60 and 140 days of lactation. During the lactation period, milk samples were also taken to assay the physico-chemical composition. Milk acidity, protein and fat levels were different from reference levels in another countries. The most relevant changes on metabolic profile were noticed at the end of gestation and at the beginning of lactation. Urea values showed variation (P<0.05) during the gestation and lactation periods. The levels of glucose and fructosamine decreased and the BHB increased significantly at the end of gestation period (P<0.05). During the lactation period glucose level lowered and cholesterol level increased significantly (P<0.05). Phosphorus level lowered, specially at 30 days post parturition (P<0.05). Hematologic parameters did not show variation during the physiologic periods studied. An exception was the segmented neutrophils that increased with the advance of the gestation (P<0.05). The data presented here may help for further nutrition and metabolic studies on dairy sheep and milk quality.

Association of canine obesity with reduced serum levels of C-reactive protein

The prevalence of obesity is increasing in dogs as well as in humans. C-reactive protein (CRP) is an important tool for the detection of inflammation and/or early tissue damage and is linked to obesity in humans. The objective of the present study was to determine if serum CRP levels are altered in obese dogs. Fifteen lean (control group) and 16 overweight (obese group) dogs were examined. Blood samples were collected under fasted conditions for serum determination of CRP, glucose, insulin, cholesterol, triglyceride, and fructosamine. Results indicated that obese dogs were insulin resistant because serum insulin and insulin/glucose ratios were higher than in lean dogs (P ≤ 0.05). Serum CRP concentrations were lower in obese dogs than in controls (P ≤ 0.001). C-reactive protein was negatively correlated with insulin/glucose ratio (R = −0.42) and cholesterol (R = −0.39; P ≤ 0.05). Furthermore, levels of cholesterol, triglycerides, and fructosamine were increased in the obese group compared with the control group. Based on these results, it can be postulated that CRP production is inhibited by obesity and insulin resistance in dogs.

Fatores ambientais que afetam a produção e a composição do leite em rebanhos assistidos por cooperativas no Rio Grande do Sul

Neste estudo, avaliaram-se os efeitos de alguns fatores ambientais sobre a producao, a composicao quimica e a contagem de celulas somaticas do leite em rebanhos vinculados as cooperativas no Rio Grande do Sul. Foram utilizados dados de um programa de controle leiteiro durante cinco anos, totalizando 165.311 observacoes, para analisar os seguintes efeitos ambientais: ano e mes do controle leiteiro, idade ao parto, tempo em controle leiteiro e estadio da lactacao. A producao media de leite foi de 19,36 L/vaca/dia. Foi encontrada maior producao de leite em vacas de 5 a 6 anos de idade ao parto, nos primeiros 60 dias de lactacao, nos meses de inverno e em rebanhos com mais tempo em controle leiteiro. Maior numero de celulas somaticas foi relacionado a reducao na producao de leite. Houve menor teor de gordura e de proteina no leite nos primeiros 60 dias de lactacao e aumento desses componentes com o aumento no numero de celulas somaticas. A concentracao de lactose no leite diminuiu significativamente a medida que aumentaram as celulas somaticas e a idade ao parto. A contagem de celulas somaticas aumentou com a idade da vaca e a medida que avancou a lactacao. Nos meses de inverno, verificaram-se valores mais elevados de proteina, gordura e lactose, possivelmente como consequencia da alimentacao com gramineas temperadas. Os resultados revelam a importância das variacoes ambientais no estudo da composicao do leite.

Hematological, biochemical and ruminant parameters for diagnosis of left displacement of the abomasum in dairy cows from Southern Brazil

O objetivo deste trabalho foi avaliar indicadores hematologicos, bioquimicos e ruminais no diagnostico e tratamento do deslocamento de abomaso a esquerda (DAE) em vacas leiteiras, na Regiao do Planalto do Rio Grande do Sul, Brasil. Foram coletadas amostras de liquido ruminal, sangue e urina de 40 animais, dos quais 20 vacas com DAE e 20 vacas clinicamente sadias utilizadas como grupo controle. Os animais com DAE, quando comparados ao grupo controle, apresentaram diminuicao da producao de leite diaria, do peso corporal e do escore condicao corporal. A utilizacao de fitas reagentes para medicao do pH ruminal demonstrou-se eficaz em campo, em comparacao ao potenciometro digital. A dinâmica ruminal apresentou-se prejudicada nos animais com DAE, o que foi evidenciado pelos valores aumentados do tempo de reducao de azul de metileno. Os valores sericos de lactato, beta-hidroxibutirato, ureia, albumina, acidos graxos livres e colesterol apresentam-se como ferramentas auxiliares na caracterizacao da doenca.

Metabolic evaluation of dairy cows submitted to three different strategies to decrease the effects of negative energy balance in early postpartum

Durante o inicio da lactacao as vacas leiteiras sofrem transtornos metabolicos causados pelo balanco energetico negativo, o que predispoe a infiltracao gordurosa hepatica e cetose. O objetivo deste estudo foi avaliar o status metabolico de vacas leiteiras de alta producao submetidas a tres tratamentos para prevenir severa lipomobilizacao e cetose no inicio da lactacao. Cinquenta e quatro vacas de raca Holandesa multiparas produzindo >30 L/dia foram divididas em quatro grupos: controle (CN= sem tratamento), precursor de glicose (PG= propileno-glicol), protetor hepatico (Mp= Mercepton®) e suplementacao com sais de acidos linolenico e linoleico (Mg-E= Megalac-E®). Amostras de sangue foram coletadas nos dias 1, 7, 14, 21, 28, 35, 42 e 49 do pos-parto. A condicao corporal foi avaliada nos mesmos periodos e a producao de leite foi registrada nas semanas 2, 4, 5, 6, 7 e 8 de lactacao. As concentracoes de acidos graxos nao esterificados (AGNE), albumina, AST, s-hidroxibutirato (BHB), colesterol, glicose, proteina total, ureia e triglicerideos foram determinadas nas amostras de sangue. Pontos de corte para diagnosticar cetose subclinica foram definidos quando BHB >1,4mmol/L e AGNE >0,7mmol/L. A ocorrencia geral de cetose subclinica foi de 24% durante o periodo. Uma curva ascendente de colesterol e de glicose foi observada desde a 1a ate a 8a semana de lactacao, enquanto que nenhuma tendencia foi observada com BHB e AGNE, embora diferencas entre os tratamentos foram detectadas (p<0,05). A condicao corporal diminuiu de uma media de 3,85 na 1a semana ate 2,53 na 8a semana de lactacao (p=0,001). A producao de leite foi superior no grupo de Mg-E comparado com os demais tratamentos. Comparado com o grupo CN, os tratamentos de Mp e PG nao mostraram diferencas significativas na bioquimica sanguinea nem na producao de leite (p<0,05) As vacas que receberam PG e Mg-E mostraram maiores valores de AGNE, indicando uma acentuada lipomobilizacao. A suplementacao com Mg-E tambem resultou em maiores concentracoes de colesterol, BHB, ureia, AST e menores valores de glicemia. Este resultado pode ser explicado pela maior producao de leite observada com este tratamento. Os tratamentos com PG e Mp nao melhoraram a producao de leite, comparados ao grupo CN, mas tambem nao mostraram evidencias metabolicas de cetose, alta lipomobilizacao nem infiltracao gordurosa hepatica. Os resultados sugerem que o tratamento com Mg-E melhora a producao de leite, mas induz um balance energetico negativo maior levando a moderada lipomobilizacao e producao de corpos cetonicos, aumentando o risco de figado gorduroso.

Indicadores do ambiente ruminal e suas relações com a composição do leite e células somáticas em diferentes períodos da primeira fase da lactação em vacas de alta produção

In the current international milk payment system, where the quality is the main factor; two fundamental aspects have acquired great importance: the somatic cells count and the amount of total solids. The first one depends on the health of the mammary gland and the second factor, which has more economic impact for the dairy industry, is directly related to feeding management and the cattle breed. The environment of the rumen can modify the composition of the milk, specially the fat percentage. The main source of protein in the ruminants depends on the synthesis of protein in the rumen. The current feeding systems used in high-yielding dairy cows, predispose them to the outcome of metabolic syndromes that directly or indirectly affect the milk production. The purpose of this study was to establish a relation between the index of the rumen environment (Methylene blue reduction time and pH) and urinary pH with the composition of the milk and the somatic cells count. None statistical relation was found among the parameters evaluated. The average values of non fat solids in this study were below the official values approved in Brazil.