Department of Animal Science, Cornell University, Ithaca, NY 14853.
Protekta Inc., Lucknow, ON, Canada N0G 2H0.
J Dairy Sci. 2019 Jun;102(6):5191-5207. doi: 10.3168/jds.2019-16272. Epub 2019 Apr 17.
The objective of this study was to determine the effects of feeding synthetic zeolite A for 3 wk before expected calving on peripartal serum mineral concentrations, hypocalcemia, oxidant status, and performance. Holstein cows (n = 55) entering their second or greater lactations were assigned randomly to 1 of 2 dietary treatments starting 21 d before expected calving: control (CON: 40% corn silage, 33% wheat straw, and 27% concentrate; n = 29) or experimental [EXP: CON plus zeolite A (X-Zelit, Protekta Inc., Lucknow, ON, Canada/Vilofoss, Graasten, Denmark; n = 26) at an inclusion rate of 3.3% of dry matter, targeting 500 g/d as-fed]. Cows were fed the same postpartum diet and housed in individual tiestalls through 28 d in milk. Cows fed EXP had higher serum Ca concentrations as parturition approached and during the immediate postpartum period. Serum P concentrations were lower for the EXP-fed cows during the prepartum period and the first 2 d of lactation, whereas serum Mg concentrations were lower than those of the CON-fed cows only during the immediate periparturient period. Cows fed EXP had decreased prevalence of subclinical hypocalcemia (SCH) from d -1 through 3 relative to day of parturition, with the largest difference occurring within the first day postpartum. Prepartum dry matter intake tended to be decreased and rumination was decreased in cows fed EXP; however; postpartum dry matter intake, rumination, milk yield, milk component yield, and colostrum measurements did not differ between treatments. Cows fed EXP tended to have increased hazard of pregnancy by 150 d in milk when controlling for parity compared with CON-fed cows; potential reproductive benefits merit further study. This study demonstrated that zeolite A supplementation during the prepartum period results in markedly improved serum Ca concentrations around parturition and similar postpartum performance compared with controls and is effective at decreasing hypocalcemia in multiparous Holstein cows.
本研究旨在确定在预计分娩前 3 周饲喂合成沸石 A 对围产期血清矿物质浓度、低血钙、氧化应激状态和生产性能的影响。进入第二次或以上泌乳期的荷斯坦奶牛（n = 55）在预计分娩前 21 天随机分配到 2 种日粮处理之一：对照组（CON：40%玉米青贮、33%小麦秸秆和 27%精料；n = 29）或实验组[EXP：CON 加沸石 A（X-Zelit，Protekta Inc.，Lucknow，ON，加拿大/Vilofoss，Graasten，丹麦；n = 26），添加量为干物质的 3.3%，目标为每头奶牛每天摄入 500 g]。奶牛产后饲喂相同的日粮，并在 28 天泌乳期内单独饲养在牛舍中。随着接近分娩和产后立即，饲喂 EXP 的奶牛血清 Ca 浓度更高。在围产期前期和泌乳期前 2 天，EXP 组奶牛血清 P 浓度较低，而仅在围产期立即期间，EXP 组奶牛血清 Mg 浓度低于 CON 组。与分娩当天相比，从分娩前 1 天到第 3 天，饲喂 EXP 的奶牛亚临床低钙血症（SCH）的患病率降低，产后第一天的差异最大。与对照组相比，围产期前期干物质采食量有下降趋势，EXP 组奶牛反刍减少；然而，产后干物质采食量、反刍、产奶量、乳成分产量和初乳测量值在处理之间没有差异。与对照组相比，控制胎次时，饲喂 EXP 的奶牛在泌乳 150 天时有增加妊娠的趋势；这可能是因为 EXP 具有生殖益处，值得进一步研究。本研究表明，在围产期前期补充沸石 A 可显著提高分娩前后的血清 Ca 浓度，与对照组相比，产后表现相似，并且有效降低了高产荷斯坦奶牛的低血钙症。
