Natural antibodies related to metabolic and mammary health in dairy cows     

van Knegsel AT  Hostens M  de Vries Reilingh G  Lammers A  Kemp B  Opsomer G  Parmentier HK 《Preventive veterinary medicine》2012,103(4):287-297

Natural antibodies (NAb) are defined as antibodies that circulate in normal healthy individuals under the absence of deliberate antigenic stimulation. Two types of NAb are distinguished: NAb towards exogenous antigens and NAb towards autoantigens (N(A)Ab). The objectives of the current study were threefold. First, we studied the relation between metabolic health and concentrations of NAb binding keyhole limpet hemocyanin (KLH) or lipopolysaccharide (LPS) in milk and plasma of dairy cows in early lactation. Second, we determined the presence of N(A)Ab binding transferrin, myosin and thyroglobulin in bovine milk. Third, we studied the relation between N(A)Ab in bovine milk and mammary health. For the first objective, dairy cows were either fed a control (C) (n = 8) or a diet where 2 kg of concentrates were replaced by an iso-energetic concentrate containing marine algae (ALG) from week −3 till 8 postpartum (experiment 1). Plasma and milk samples were analyzed weekly for NAb binding either KLH or LPS. Plasma was analyzed for glucose, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA). For the second and third objective, milk samples were collected weekly from 96 dairy cows from week 2 till 9 postpartum and analyzed for milk composition and N(A)Ab binding myosin, transferrin and thyroglobulin (experiment 2). For both datasets, N(A)Ab titers are expressed as ²log values of the highest dilution giving a positive reaction. Data are expressed as means ± SEM. Repeated observations were analyzed in a mixed model. In experiment 1, no diet effect (P > 0.05) was observed on NAb binding LPS in plasma or milk, NAb binding KLH in milk was greater (P = 0.05) for cows fed the control diet. Concentration of NAb binding KLH and LPS in plasma was negatively related to plasma NEFA concentration (P < 0.05). In experiment 2, NAb binding myosin (5.66 ± 0.06), thyroglobulin (4.85 ± 0.06), and transferrin (5.76 ± 0.07) were identified in milk. Clinical mastitis incidence (9%) tended to be positively related to concentration of NAb binding myosin (P = 0.06) and negatively related to Nab binding transferrin (P = 0.08). In conclusion, NAb binding KLH and LPS in plasma and milk are related to metabolic health, as indicated by plasma NEFA concentration. Furthermore, this study demonstrates the presence of N(A)Ab in bovine milk and shows trends for a relation between N(A)Ab binding auto-antigens and mastitis. Future studies should confirm these trends and shed light on the predictive value of N(A)Ab in bovine milk for mammary health.  相似文献   

奶牛泌乳早期日粮能量类型对机体代谢物和代谢激素的影响     

梁松 《中国畜牧兽医》2007,34(4):152-152

通过对泌乳早期能量负平衡与机体代谢失调的研究表明,有效生脂和生糖能量源之间的平衡在奶牛日粮中扮演着重要角色。所以本研究目的在于比较奶牛泌乳早期生糖和生脂日粮对肝脏甘油三酯、代谢物及其代谢激素的影响,并研究分析了代谢物浓度与能量蓄积之间的相关性。试验选用16头奶牛,从产前3周至产后9周分别饲喂生脂和生糖日粮(两种日粮净能相等),且产后第2周到第9周于环控仓中饲养。产后饲喂生脂日粮的奶牛NEFA浓度较高(0.46±0.04 vs 0.37±0.04mmol/L),而胰岛素较低(4.0±0.5 vs 5.5±0.6μIU/ml);血浆中葡萄糖、β-羟基丁酸、IGF-Ⅰ、甲状腺素在两种日粮中没有较为明显差异。两种日粮处理奶牛产前和产后2周肝脏甘油三酯浓度相一致;饲喂生糖日粮奶牛产后4周肝脏TAG含量较低,但无显著的日粮差异。本试验也发现能量蓄积和乳脂以及能量蓄积与NEFA呈负相关,而能量蓄积与胰岛素浓度呈正相关。总之,试验结果显示,胰岛素调控着奶牛泌乳早期产奶和机体组织之间的能量分配。与饲喂生脂日粮相比,泌乳奶牛早期饲喂生糖日粮能减低机体体脂动员;当饲喂生脂日粮时,可提高乳中的生脂营养素,降低血浆胰岛素和增加NEFA浓度。  相似文献   

Nutrient Prioritization in Dairy Cows Early Postpartum: Mismatch Between Metabolism and Fertility?     

JLMR Leroy  T Vanholder  ATM Van Knegsel  I Garcia-Ispierto  PEJ Bols 《Reproduction in domestic animals》2008,43(S2):96-103

For several decades, researchers worldwide report a decrease in fertility in high-yielding dairy cows, most probably based on conflicting metabolic and reproductive needs. The dairy herd manager's success at improving milk production has been accompanied by a negative trend for the most visible reproductive parameters such as calving intervals, number of days open and number of inseminations needed per pregnancy. In parallel, many research groups studied the metabolic and endocrine factors that influence follicular growth and the developmental competence of oocytes and embryos. In the past, herd managers and reproductive biologists each tried to tackle the same problems with limited consultation. More recently, the situation has improved significantly and theriogenologists, nutritionists and veterinarians now conduct research in multidisciplinary teams. This review paper starts in a general way by discussing nutrient prioritization towards the udder to guarantee milk production and by describing interactions between the somatotropic and gonadotropic axis. It then focuses on the consequences of the negative energy balance on follicular growth and environment, oocyte and embryo quality, not only by summarizing the currently accepted hypotheses but also based on clear scientific evidence at the follicular level. All this, with one question in mind: is there a mismatch between metabolism and fertility and what can the dairy manager learn from research to tackle the problem of reduced fertility?  相似文献