Karimi Reza, Towhidi Armin, Ganjkhanlou Mahdi, Ghasemzadeh-Nava Hamid, Khoee Sepideh, Kastelic John
Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Reprod Domest Anim. 2023 Apr;58(4):511-518. doi: 10.1111/rda.14319. Epub 2023 Jan 29.
The primary objectives were to investigate the effects of feeding a new rumen-protected glucose (RPG) on uterine involution and ovarian follicular dynamics in recently calved dairy cattle. From 4 to 30 days after calving, 16 Holsteins (first to third lactation, mean parity 1.75) were randomly assigned to be fed either a basal diet top-dressed with either 600 g RPG (RPG group) or 600 g of the coating material and glucose (CONT group). Based on transrectal ultrasonography, conducted every 3 days starting 20 days after calving, the interval from calving to complete uterine involution was shorter in RPG versus CONT (27.1 vs. 30.4 days, p < .01). Furthermore, based on transrectal ultrasonography conducted every 2 days, cattle fed RPG had smaller (3.0-4.9 mm) ovarian follicles (2.96 vs. 0.9, p < .001) and more total follicles (5.26 vs. 2.85, p < .01). Feeding RPG had increased serum insulin concentrations (4.59 ± 0.54 vs. 3.13 ± 0.57, p < .05), but had no significant effects on serum glucose concentrations, dry matter intake or milk yield. In conclusion, we inferred that cattle fed RPG had increased glucose turnover that was responsible for higher insulin concentrations, faster uterine involution, and more ovarian follicles.
主要目的是研究饲喂一种新型瘤胃保护性葡萄糖（RPG）对近期产犊奶牛子宫复旧和卵巢卵泡动态的影响。在产犊后4至30天，将16头荷斯坦奶牛（头胎至第三胎泌乳，平均胎次1.75）随机分为两组，分别饲喂添加600克RPG的基础日粮（RPG组）或600克包膜材料和葡萄糖的基础日粮（对照组）。基于产后20天开始每3天进行一次的经直肠超声检查，RPG组从产犊到子宫完全复旧的间隔时间比对照组短（27.1天对30.4天，p<0.01）。此外，基于每2天进行一次的经直肠超声检查，饲喂RPG的奶牛卵巢卵泡较小（3.0 - 4.9毫米）（2.96对0.9，p<0.001）且卵泡总数更多（5.26对2.85，p<0.01）。饲喂RPG可提高血清胰岛素浓度（4.59±0.54对3.13±0.57，p<0.05），但对血清葡萄糖浓度、干物质采食量或产奶量无显著影响。总之，我们推断饲喂RPG的奶牛葡萄糖周转率增加，这导致了更高的胰岛素浓度、更快的子宫复旧和更多的卵巢卵泡。
