Changes in biomarkers of metabolic stress during late gestation of dairy cows associated with colostrum volume and immunoglobulin content.

The objective of this observational study was to compare the metabolic status of dairy cows during the last 6 wk of gestation based on colostrum volume and immunoglobulin content. For this, healthy Holstein cows were randomly selected from 3 commercial herds in Michigan. In each farm, 4 cohorts of 21 cows (1 per season), stratified by parity, were enrolled (n = 228). Cows were blood sampled weekly during the last 6 wk of gestation, and biomarkers related to nutrient utilization, oxidant status, and inflammation were quantified in serum. Cows were milked within 6 h of calving, and the volume of colostrum produced was recorded and an aliquot collected. Concentration of IgG, IgA, and IgM were measured by radial immunodiffusion. Cows were grouped into high or low colostrum producer, high or low IgG, high or low IgA, and high or low IgM. For volume category, we arbitrarily defined 6 L of colostrum (4 L for first and 2 L for second feeding of calves) as the cutoff point, whereas for IgG we used the industry standard of ≥50 g/L. To create groups of low and high IgM or IgA, we used the median of these immunoglobulin as the cutoff point. Colostrum volume was lowest in winter, but no differences were observed among parity groups. Conversely, colostrum IgG concentration was highest in fall and winter, but colostrum IgM was lowest at these seasons. However, colostrum immunoglobulin content only showed a negative weak correlation with volume (Spearman's correlation coefficient < -0.28). Compared with low colostrum producer, high colostrum producer cows had higher concentrations of antioxidant potential and ß-hydroxybutyrate, and lower cholesterol and oxidant status index. Cows with high IgG showed higher concentrations of glucose compared with low IgG. Cows with high IgA had higher concentrations of cholesterol, reactive oxygen and nitrogen species, oxidant status index, and total protein, whereas ß-hydroxybutyrate and glucose were lower compared with low IgA. Biomarkers of metabolic stress were not significantly different between high IgM and low IgM. Nevertheless, the differences observed did not result in differences in inflammatory status between animals in any of the colostrum variable categories analyzed, suggesting that physiological homeostasis was not disrupted during late gestation in association with the colostrum variables studied. Overall, the great variability observed in colostrum variables suggests that colostrogenesis is a complex and multifactorial process. However, our results suggest that greater availability of antioxidants during late gestation could support the production of higher volumes of colostrum, which needs to be explored in future trials.

Transferência de imunidade passiva e proteinograma sérico em bezerros das raças Crioula Lageana variedade Mocha e Aberdeen Angus (Red Angus) nos primeiros seis meses de vida / Transfer of passive immunity and serum proteinogram in calves of the Criollo Lageano hornless variety and Aberdeen Angus (Red Angus) breed in their first six months of life

A raça Crioula Lageana apresenta-se como uma alternativa para a pecuária moderna, devido a sua grande variabilidade genética, rusticidade e adaptação às condições ambientais do Planalto Catarinense. Estas características podem influenciar importantes eventos fisiológicos, os quais deveriam ser investigados, pois podem auxiliar no desenvolvimento de futuros programas de melhoramento animal. Sabe-se que a falha da transferência de imunidade passiva (TIP) constitui um importante fator para a elevação dos índices de mortalidade neonatal na espécie bovina. Desta forma, torna-se indispensável à avaliação dos aspectos relacionados à TIP em bezerros da raça Crioula Lageana variedade mocha e a sua comparação com outras raças de corte criadas no Planalto Serrano Catarinense. Com o objetivo de avaliar e comparar a TIP e o proteinograma sérico foram selecionados dois grupos experimentais compostos por 11 bezerros da raça Crioula Lageana variedade mocha e 14 bezerros da raça Aberdeen Angus (Red Angus). Amostras de sangue foram colhidas por meio da venopunção jugular para a mensuração da proteína total sérica (PTS), eletroforese das proteínas séricas em gel de agarose, atividade da gamaglutamiltransferase (GGT) e concentração de imunoglobulinas G (IgG) por meio do método de turvação pelo sulfato de zinco nos períodos entre 24 e 36 horas, 15, 30, 60, 90, 120, 150 e 180 dias de vida. A análise estatística dos dados foi realizada por meio da análise de variância de medidas repetidas (ANOVA), teste de Tukey para a comparação entre médias (P<0,05) e correlação entre as variáveis. Ao analisar os valores de PTS, globulinas, gamaglobulinas, IgG e atividade sérica de GGT ao nascimento (24 a 36 horas) pode se afirmar que houve adequada TIP não havendo diferença significativa entre as raças, exceto para a atividade sérica da GGT. Observaram-se variações fisiológicas na curva de proteínas séricas do nascimento até os 180 dias de idade. Forte correlação positiva foi observada entre os valores de gamaglobulina e IgG (r=0,814 para CL e r=0,877 para AA), PTS (r=0,783 para CL e r=0,947 para AA), globulinas (r=0,945 para CL e r=0,985 para AA), evidenciando que estas variáveis foram bons indicadores da TIP em bezerros ao segundo dia de vida (24-36 horas). A correlação entre gamaglobulinas e atividade da GGT foi fracamente positiva (r=0,251) para bovinos da raça Crioula Lageana variedade mocha e fortemente positiva (r=0,815) para a raça Aberdeen Angus (Red Angus), o qual foi admitido a grande variação nos valores da GGT após 24 horas de vida do bezerro. Não houve diferença na TIP entre as raças Crioula Lageana variedade mocha e Aberdeen Angus (Red Angus), ocorrendo de maneira bem-sucedida em ambas as raças. Pode-se sugerir que a raça Crioula Lageana variedade mocha seja mais tardia na síntese ativa de anticorpos, ressaltando a precocidade dos taurinos evidenciada na raça Aberdeen Angus (Red Angus).(AU)

The Criollo Lageano breed is an alternative for modern farming, due to its high genetic variability, rusticity and adaptation to environmental conditions of the Plateau of Santa Catarina, Brazil. These characteristics can influence important physiological events which should be investigated, because they can assist in developing future programs of animal breeding. It is known that failure of passive transfer (FPT) is an important factor for the increase in neonatal mortality in cattle. Thus, it is essential to evaluate aspects related to FPT in Criollo Lageano calves and the comparison with other beef breed created in the Plateau of Santa Catarina. Aiming to evaluate and to compare the passive transfer of immunity and serum protein concentrations, two experimental groups of 11 calves of Criollo Lageano (CL) hornless variety and 14 Aberdeen Angus (Red Angus) calves were selected. Blood samples were collected by jugular venipuncture for the measurement of total serum protein (TSP) by serum protein electrophoresis in agarose gel and the activity of gamma glutamyl transferase (GGT) and concentration of immunoglobulin G (IgG) by the method of the turbidity zinc sulphate, between 24 and 36 hours, 15, 30, 60, 90, 120, 150 and 180 days. Statistical analysis of data was performed by analysis of variance (ANOVA), Tukey test for comparison of means (P<0.05) and correlation between variables. Values of TSP, globulins, immunoglobulins, IgG and serum GGT activity at birth (24-36 hours) confirmed that there was adequate TIP with no significant difference between the races, except for the serum GGT activity. Physiological variations in the curve of serum proteins from birth to 180 days of age were identified. Strong positive correlation was found between the values of gamma globulin and IgG (r=0.814 and r=0.877 for CL to AA), PTS (r=0.783 and r=0.947 for CL to AA), globulins (r=0.945 and r=0.985 for CL to AA), indicating that these variables will be good indicators of TIP in calves at the second day of life (24-36 hours). The correlation between gamma globulin and activity of GGT was weakly positive (r=0.251) for CL and strongly positive (r=0.815) for the Aberdeen Angus (Red Angus), in which a wide variation in GGT values after 24 hours of life of the calf were noticed. No difference was found in FPT between Criollo Lageano hornless variety and Aberdeen Angus (Red Angus), and was successful way in both breeds. It can be suggested that Criollo Lageano hornless variety breed is later in active antibody synthesis, highlighting the precocity of taurine evident in Aberdeen Angus (Red Angus) breed.(AU)