Indicators of undernutrition in cattle

Potential biochemical indicators of long-term undernutrition in cattle, which could be used objectively, reliably and routinely, were investigated by evaluating frequently analysed metabolites in cattle. In an initial study, a meta-regression of literature data for glucose, urea, non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) against body condition score (BCS), body weight (BW) and its change (BWC) was conducted. The credible intervals of the gradients included zero for all regressions, showing that there were no significant relationships between any of the blood metabolites and BCS, BW or BWC across the 13 included studies. In a second study, fresh field samples from nine herds of adequately-nourished suckler cows and stored samples from two herds of suckler cows, which had experienced severe undernutrition, were analysed for serum albumin, total protein, urea, BHB, NEFA, creatinine, fructosomine and globulin. Positive regressions with BCS were obtained for albumin and creatinine, and a negative regression with fructosamine/albumin ratio. With the threshold for detecting undernutrition set at >= 10.75 mu mol g(-1), the fructosamine/albumin ratio gave sensitivity and specificity of 100%. Therefore, it is probably necessary to combine several blood measures to obtain a valid assessment of the nutritional state of ruminants, and we advise against the use of a single plasma metabolite concentration in assessing the nutritional state and welfare of individual cows

Utilização de óleo de soja em rações para vacas leiteiras no período de transição: consumo, produção e composição do leite Use of soybean oil for dairy cows during transition period: Intake, milk yield and composition

O objetivo neste estudo foi avaliar o desempenho produtivo de vacas leiteiras sob suplementação com óleo de soja durante o período de transição. Foram utilizadas 20 vacas da raça Holandesa, multíparas e gestantes, distribuídas aleatoriamente em duas rações: controle, com 2,5% de extrato etéreo (EE) na matéria seca (MS); e gordura, com adição de 3,0% de óleo de soja e 5,5% de EE na MS. Os valores médios de consumo de MS e nutrientes não diferiram no período pré e pós-parto nas vacas das dietas controle e com óleo de soja, exceto no maior consumo de EE, em decorrência da maior concentração desse nutriente na dieta com óleo. Em virtude da maior densidade energética da ração com óleo de soja, as vacas apresentaram maior consumo de nutrientes digestíveis totais e energia líquida no pós-parto. Não foi observada alteração nas produções de leite e gordura, no entanto, observou-se redução do teor de gordura do leite nas vacas da ração com óleo de soja em relação àquelas da ração controle. As rações utilizadas não influenciaram o consumo, mas a dieta com óleo de soja aumentou a ingestão de energia líquida e melhorou o balanço de nutrientes no início da lactação. Foi observado aumento não-significativo (+ 2,53 kg/dia) na produção de leite das vacas da dieta com óleo de soja.<br>The objective of this study was to evaluate the productivity of dairy cows supplemented with soybean oil during the transition period. Twenty multiparous and pregnant Holstein cows were randomly allocated to two diets: control (C), 2.5% ether extract (EE) in the dry matter (DM); and fat (G), with the addition of 3% soybean oil, and 5.5% EE in the dry matter. The average values for intake were not different in the pre- and post-partum for cows on the control and fat diets except for an increase in EE intake due to great concentration of this nutrient in the soybean oil diet. Due to the higher energy density of the fat diet, cows had higher intake of total digestible nutrients and net lactation energy during the post-partum. There was no alteration in milk and fat yield, but a reduction in the milk fat content was observed for cows fed fat diet compared with the control diet. The diets used had no influence on the intake, and the fat diet resulted in an increased net energy intake and improvement in the nutrient balance during the initial phase of lactation. A non-significant increase in milk yield (+ 2.53 kg/d) was observed when using the fat diet