Abstract:
Shortly after weaning, piglets generally eat dry feed poorly; but nevertheless, a phenomenal gain-to-feed ratio is achieved as they gain about as much weight as they eat (150-200 g/d). The high gain-to-feed ratio, though, cannot be explained by their nutrient intake or nutrient repartitioning. Analyses based on tissue composition and bio-electrical impedance data showed that newly weaned piglets lose fat, maintain protein, and gain large amounts of water because of edema. This edema, which may well contribute up to one kg of BW, seems to be triggered by refeeding syndrome. Refeeding syndrome in adult humans occurs when subjects fast for an extended period of time (weeks) that results in downshifts in metabolic activity and concomitant shedding of phosphate (PO4), magnesium (Mg), and potassium (K) in urine. If food is abruptly reintroduced, thus, resulting in strong insulin spikes, metabolism is triggered but hampered by a lack of PO4, Mg, K, and thiamine, causing hypophosphatemia, metabolic stress, and edema. In piglets, the same process appears to happen immediately after weaning but in hours rather than weeks, possibly linked to their high metabolic rate. Refeeding syndrome can be lethal in humans but does not appear to be directly lethal in piglets. Our attempts to prevent it through altered diet composition and/or controlled feeding programs have not resulted in better performance at the end of the nursery phase. A practical ramification of weaning-induced edema is that growth and gain-to-feed ratio data immediately after weaning should be interpreted with caution. In addition, diets arguably should be formulated to not strongly trigger insulin release, while high lysine levels are not needed as the gain is not based on protein accretion.
摘要:
断奶后不久,仔猪通常吃干饲料差;但尽管如此,当它们增加与它们吃的一样多的重量(150-200g/d)时,实现了惊人的增食比。高增益-进料比,虽然,不能用他们的营养摄入量或营养再分配来解释。基于组织组成和生物电阻抗数据的分析表明,新断奶仔猪减脂,维持蛋白质,并因水肿而获得大量水分。这个水肿,这很可能会导致高达一公斤的BW,似乎是由再喂养综合征引发的。当受试者长时间禁食(数周)导致代谢活动下降并伴随磷酸盐(PO4)脱落时,就会发生成年人的再摄食综合征。镁(Mg),和尿中的钾(K)。如果食物突然被重新引入,因此,导致强烈的胰岛素峰值,新陈代谢被触发,但由于缺乏PO4,Mg,K,还有硫胺素,导致低磷酸盐血症,代谢应激,和水肿。在仔猪中,同样的过程似乎在断奶后立即发生,但在数小时而不是数周内发生,可能与它们的高代谢率有关.再摄食综合征在人类中可能是致命的,但在仔猪中似乎并不直接致命。我们试图通过改变饮食组成和/或控制喂养计划来预防它,并没有在苗圃阶段结束时获得更好的表现。断奶引起的水肿的实际分支是断奶后立即应谨慎解释生长和增食比数据。此外,可以说,饮食应该被配制成不会强烈触发胰岛素释放,而高赖氨酸水平是不需要的,因为增益不是基于蛋白质的增加。