Resumo O objetivo deste estudo foi caracterizar a dinâmica de alguns parâmetros hematológicos em cordeiros recém-nascidos sadios, antes e após a ingestão de colostro. Foram coletadas amostras sanguíneas de 28 cordeiros recém-nascidos, determinando-se o eritroleucograma, as concentrações de proteína plasmática total (PPT) e de fibrinogênio nos momentos pré e pós-colostro. Os dados foram analisados comparando-se a variabilidade dos parâmetros entre os dois momentos. O hematócrito (P<0,001), a concentração de hemoglobina (P<0,05) e o volume globular médio (VGM) (P<0,05) diminuíram após a ingestão de colostro, enquanto a concentração de hemoglobina globular média (CHGM) aumentou (P<0,01) no momento pós-colostro. Houve aumento no número de leucócitos totais (P<0,001) e nas contagens absolutas de neutrófilos segmentados (P<0,05) e de linfócitos (P<0,01) após a ingestão de colostro. As concentrações de PPT e de fibrinogênio também aumentaram no momento pós-colostro (P<0,001 e P<0,01, respectivamente). O eritroleucograma, as concentrações de PPT e de fibrinogênio variam consideravelmente antes e após a ingestão de colostro, sendo modificados em função da própria ingestão do colostro e/ou da adaptação dos processos fisiológicos do animal à vida extrauterina. Portanto, recomenda-se que a interpretação de hemogramas realizados em cordeiros recém-nascidos seja feita com base em intervalos de referência específicos para o período neonatal.

Abstract The aim of this study was to characterize the dynamics of some hematological parameters in healthy newborn lambs before and after colostrum intake. Blood samples of 28 newborn lambs were collected, determining the erythro-leukogram, the total plasma protein (TPP) and fibrinogen concentrations in pre and post-colostrum moments. The data were analyzed comparing the variability of the parameters between the two moments. The packed cell volume (P<0.001), the hemoglobin concentration (P<0.05) and the mean corpuscular volume (MCV) (P<0.05) decreased after colostrum intake, while the mean corpuscular hemoglobin concentration (MCHC) increased (P<0.01) at the post-colostrum moment. There was an increase in the total white blood cell count (P<0.001) and in the absolute counts of segmented neutrophils (P<0.05) and lymphocytes (P<0.01) after colostrum intake. The TPP and fibrinogen concentrations also increased at the post-colostrum moment (P<0.001 and P<0.01, respectively). The erythro-leukogram, the TPP and fibrinogen concentrations vary considerably before and after colostrum intake, being modified according to the own colostrum intake and/or the adaptation of the physiological processes of the animal to the extrauterine life. Therefore, it is recommended that the interpretation of complete blood cell counts performed in newborn lambs be made based on the specific reference intervals for the neonatal period.

O objetivo deste estudo foi verificar a influência do colostro nos parâmetros bioquímicos séricos em cordeiros recém-nascidos. Foram colhidas amostras sanguíneas de 28 cordeiros, determinando-se os indicadores proteicos, energéticos, de função renal, bilirrubinas e as enzimas aspartato aminotransferase (AST), gama-glutamiltransferase (GGT) e creatina quinase (CK), nos momentos pré e pós-colostro. Os dados foram analisados comparando-se a variabilidade dos parâmetros entre os dois momentos. Houve elevação (P<0,001) das concentrações de proteínas totais, em resposta ao forte aumento (P<0,01) dos teores de globulinas totais e ao leve decréscimo (P<0,05) da concentração de albumina, após a ingestão colostral. Também foram observados maiores valores de bilirrubinas total e direta (P<0,001), e variação dos metabólitos renais, com elevação dos níveis de ureia (P<0,01) concomitante à redução dos valores de creatinina (P<0,001), no momento pós-colostro. Houve aumento (P<0,001) da glicemia, de colesterol total e triglicerídeos, bem como das atividades enzimáticas (P<0,001) de AST e GGT, entre os momentos avaliados. Conclui-se que a dinâmica do perfil bioquímico em cordeiros recém-nascidos sofre o efeito da ingestão de colostro e da adaptação das funções fisiológicas à vida extra-uterina. Os valores dos parâmetros variam marcadamente no período pós-natal, sendo recomendável a utilização de valores de referência próprios para esta fase.

This study aimed to verify the influence of colostrum in serum biochemical parameters in newborn lambs. Blood samples were taken of 28 lambs, determining the protein, energy and kidney function indicators, bilirrubins and the enzymes aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT) and creatine kinase (CK), in pre and post-colostrum moments. The data were analyzed comparing the variability of the parameters between the two moments. There was an elevation (P<0.001) in total protein concentrations, in response to substantial increase (P<0.01) in total globulin levels, and a slight decrease (P<0.05) in albumin concentration, after colostral intake. We also observed higher values of total and conjugated bilirubins (P<0.001), and variation of kidney metabolites, with an elevation of urea levels (P<0.01) concomitant to decrease of creatinine values (P<0.001) in the post-colostrum moment. There was an increase (P<0.001) in glycemia, total cholesterol and triglycerides, as well as of the enzymatic activities (P<0.001) of AST and GGT, between the moments evaluated. In conclusion, the dynamics of biochemical profile in newborn lambs suffers the effect of colostrum intake and of adaptations of physiological functions to extrauterine life. The parameters values vary markedly in the postnatal period, being recommended to use proper reference values for this phase.

The objectives of this study were to estimate the phenotypic correlations of residual feed intake (RFI) and gross feed efficiency (GFE) with hematological and metabolic blood profiles of lambs and to determine the differences for these traits in animals of different RFI classes. Twenty Ile de France male lambs, 115±8 days of age and 31.3±4.1 kg of body weight (means ± SD), were individually housed and their dry matter intake was measured over 65 days. They were weighed every 13 days to determine the average daily weight gain and two blood samples were collected at the last two weighings (at 07h30) for analysis of blood variables. The animals were divided into two classes: negative RFI (most efficient: <0.5 SD below the mean; n = 6) and positive RFI (least efficient: >0.5 SD above the mean; n=8). There were associations among RFI and the serum metabolic variables for albumin (rRFI = 0.74) and creatinine (rRFI = -0.45) and between GFE and serum albumin (rGFE = -0.70). Less efficient animals as measured by RFI had higher serum albumin and lower creatinine levels and showed a tendency to have a greater concentration of total plasma protein. Other serum biochemical parameters were not correlated with GFE and RFI, and no differences between RFI classes were found. There was a correlation between the percentage of eosinophils and RFI (rRFI = -0.65), and such more efficient animals had a higher proportion of these cells and a trend to have a lower percentage of monocytes. This study provided evidence indicating associations between RFI and protein metabolism, as reflected by the serum albumin and creatinine. The hematological findings suggest that RFI is related to susceptibility of lambs to stressand should provide a basis for further research in this regard.