The effect of nutritional management of the dairy cow on reproductive efficiency
The effect of nutritional management of the dairy cow on reproductive efficiency
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DOI：
10.1016/j.anireprosci.2006.08.007
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发表时间：
2006-12-01
影响因子：
2.2
通讯作者：
Roche, James F.
中科院分区：
文献类型：
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作者：
Roche, James F.
奶牛低生育力的原因是多方面的。干燥期和产后早期营养不良导致葡萄糖、胰岛素、胰岛素样生长因子（IGF-1）降低和LH脉冲频率降低，同时β-羟基丁酸、非酯化脂肪酸（NEFA）和三酰甘油增加。奶牛必须动员大量的脂肪，但也有一些蛋白质储备，因此增加了低钙血症，酸中毒，酮症，脂肪肝和皱胃移位等代谢紊乱的发病率。产乳热和酮病的发生影响子宫收缩，延迟产犊，并增加胎膜残留（RFM）和子宫内膜炎的风险。导致RFM的营养风险因素是低钙血症、产犊时高身体状况评分（BCS）以及维生素E和硒缺乏。腹膜炎的危险因素是低钙血症、RFM、高甘油三酯和NEFA。因此，代谢紊乱使奶牛易患妇科疾病，从而降低繁殖效率。在产犊时过度调理的奶牛或体重减轻过多的奶牛更可能与第一次发情间隔时间延长，从而延长开放日。营养诱导的产后不发情的特征是由于LH脉冲频率降低，优势卵泡不能产生足够的雌二醇以诱导排卵。高营养还可以增加类固醇激素如孕酮或雌二醇的代谢清除率。发情当天较低浓度的雌二醇与亚发情的发生高度相关，从而使高产奶牛的发情检测更加困难。营养也影响受孕率（CR）到AI。发生低钙血症、酮症、酸中毒或皱胃移位的奶牛具有较低的CR，并且需要更长的时间才能怀孕。过多的BCS损失和口粮中过量的蛋白质含量可以降低CR，而减少F2 α产生的补充脂肪可以提高CR。孕酮（P4）的代谢清除率增加，这降低了早期胚胎卵裂至囊胚阶段的血液浓度，与CRs降低有关。总之，奶牛的营养管理不良，特别是产犊前后，是不孕症的关键驱动因素。(c)2006 Elsevier B. V.保留所有权利。
The cause of low fertility in dairy cows is multifactorial. Poor nutrition during the dry and early postpartum periods results in reduced glucose, insulin, insulin-like growth factor (IGF-1) and low LH pulse frequency with concomitant increases in beta-hydroxy butyrate, non-esterified fatty acids (NEFA) and triacylglycerol. Cows must mobilize large lipid, but also some protein reserves, with a consequent increased incidence of such metabolic disorders as hypocalcaemia, acidosis, ketosis, fatty liver and displaced abomasums. The occurrence of milk fever and ketosis affects uterine contractions, delays calving and increases the risk of retained foetal membranes (RFM) and endometritis. The nutritional risk factors that cause RFM are hypocalcaemia, high body condition score (BCS) at calving and deficiencies in Vitamin E and selenium. The risk factors for endometritis are hypocalcaemia, RFM, high triacylglycerol and NEFA. Thus, metabolic disorders predispose cows to gynaecological disorders, thereby reducing reproductive efficiency. Cows that are overconditioned at calving or those that lose excess body weight are more likely to have a prolonged interval to first oestrus, thereby prolonging days open. Nutritionally induced postpartum anoestrus is characterized by turnover of dominant follicles incapable of producing sufficient oestradiol to induce ovulation due to reduced LH pulse frequency.High nutrition can also increase metabolic clearance rate of steroid hormones such as progesterone or oestradiol. Lower concentrations of oestradiol on the day of oestrus are highly correlated with the occurrence of suboestrus, thereby making the detection of oestrus in high yielding cows even more difficult. Nutrition also affects conception rate (CR) to AI. Cows that develop hypocalcaemia, ketosis, acidosis or displaced abomasums have lower CRs and take longer to become pregnant. Excessive loss of BCS and excess protein content of the ration can reduce CR while supplemental fats that attenuate the production of F2 alpha can improve CR. The increased metabolic clearance rate of progesterone (P4), which decreases blood concentrations during early embryo cleavage up to the blastocyst stage is associated with decreased CRs.In conclusion, poor nutritional management of the dairy cow, particularly before and after calving, is a key driver of infertility. (c) 2006 Elsevier B.V. All rights reserved.