Department of Large Animal Clinical Sciences, University of Florida, Gainesville, FL 32610, USA.
North Florida Research and Education Center, Department of Animal Sciences, University of Florida, Marianna, FL 32443, USA.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae326.
This study aimed to evaluate embryo yield in Holstein heifers superovulated with a single injection of recombinant, long-acting human follicle-stimulating hormone (rFSH) vs. multiple injections of pituitary-derived follicle-stimulating hormone (FSH). In experiment 1, heifers were assigned randomly to one of four experimental groups: Control (280 mg of pituitary-derived FSH; six injections of 40 mg and two injections of 20 mg, each ~12 h apart, n = 16); rFSH1 (50 µg of FSH analog protein, n = 16); rFSH2 (75 µg of FSH analog protein, n = 16); or rFSH3 (100 µg of FSH analog protein, n = 16). The rFSH was administered as a single injection. Estrous cycles were presynchronized with gonadorelin acetate (GnRH) and an intravaginal progesterone insert (CIDR) on day 8, followed by cloprostenol sodium (PGF2α) on day 3 and day 2 with removal of the CIDR, and GnRH on day 0. On day 5, ovarian follicles ≥ 5 mm in diameter were ablated by transvaginal ultrasound-guided aspiration. On day 6.5, the heifers received a CIDR and the first injection of either rFSH or pituitary-derived FSH. On day 9, the heifers received two injections of PGF2α, 12 h apart. On day 10.5, the CIDR was removed, and on day 11, the heifers received a GnRH injection. Heifers were AI-inseminated 12- and 24-h post-GnRH injection, and uterine contents were flushed transcervically on day 18 (7 d after the GnRH injection). Ovarian follicles ≥ 5 mm and corpora lutea (CL) were counted via ultrasound on days 5, 9, and 18. In experiment 1, group did not affect (P = 0.52) the number of follicles ≥ 5 mm (Control = 15.9 ± 1.2; rFSH1 = 17.5 ± 1.3; rFSH2 = 17.1 ± 1.3; rFHS 3 = 18.6 ± 1.4 follicles) or the number of CL (P = 0.96) on day 9 (Control = 1.1 ± 0.3; rFSH1 = 1.1 ± 0.3; rFSH2 = 1.1 ± 0.3; rFSH3 = 0.9 ± 0.2). Furthermore, there was no effect (P = 0.28) of rFSH dose on freezable embryos (grade 1 and 2 embryos) collected on day 18 (Control = 4.7 ± 1.1; rFSH1 = 4.7 ± 1.2; rFSH2 = 4.4 ± 1.1; rFSH3 = 2.6 ± 0.7 embryos). In experiment 2, Control (n = 8) and rFSH1 (n = 16) groups were repeated in three replicates using the same protocols as experiment 1. Consequently, Results showed that rFSH produced fewer total number of ova/embryos (Control = 9.9 ± 1.5 vs. rFHS1 = 5.9 ± 0.9, P = 0.04) and fewer freezable embryos (Control = 5.3 ± 1.0 vs. rFSH1 = 1.4 ± 0.3, P < 0.01). In conclusion, the single rFSH injection effectively induced superovulation; however, its repeated use reduced embryo production.
本研究旨在评估荷斯坦小母牛单次注射重组长效人促卵泡激素（rFSH）与多次注射垂体源性促卵泡激素（FSH）的胚胎产量。在实验 1 中，小母牛被随机分配到四个实验组之一：对照组（280mg 垂体源性 FSH；六次注射 40mg 和两次注射 20mg，每次间隔约 12 小时，n=16）；rFSH1（50μg FSH 类似物蛋白，n=16）；rFSH2（75μg FSH 类似物蛋白，n=16）；或 rFSH3（100μg FSH 类似物蛋白，n=16）。rFSH 作为单次注射给药。发情周期通过 GnRH 乙酸盐（GnRH）和阴道内孕酮插入物（CIDR）同步化于第 8 天，然后在第 3 天和第 2 天注射氯前列醇钠（PGF2α），同时取出 CIDR，并在第 0 天注射 GnRH。第 5 天，通过经阴道超声引导抽吸切除直径≥5mm 的卵巢卵泡。第 6.5 天，小母牛接受 CIDR 和 rFSH 或垂体源性 FSH 的第一次注射。第 9 天，小母牛接受两次 PGF2α 注射，间隔 12 小时。第 10.5 天，取出 CIDR，第 11 天，小母牛注射 GnRH。小母牛在 GnRH 注射后 12 小时和 24 小时进行人工授精，在 GnRH 注射后第 18 天（注射后 7 天）经宫颈冲洗子宫内容物。在第 5、9 和 18 天通过超声检查计数直径≥5mm 的卵泡和黄体（CL）的数量。在实验 1 中，组间对直径≥5mm 的卵泡数量（对照组=15.9±1.2；rFSH1=17.5±1.3；rFSH2=17.1±1.3；rFHS3=18.6±1.4 个卵泡）或第 9 天的黄体数量（对照组=1.1±0.3；rFSH1=1.1±0.3；rFSH2=1.1±0.3；rFSH3=0.9±0.2）无影响（P=0.52）。此外，rFSH 剂量对第 18 天收集的可冷冻胚胎（1 级和 2 级胚胎）数量（对照组=4.7±1.1；rFSH1=4.7±1.2；rFSH2=4.4±1.1；rFSH3=2.6±0.7 个胚胎）无影响（P=0.28）。在实验 2 中，对照组（n=8）和 rFSH1 组（n=16）重复进行了三次实验，使用与实验 1 相同的方案。结果表明，rFSH 产生的总卵子/胚胎数量较少（对照组=9.9±1.5 vs. rFHS1=5.9±0.9，P=0.04）和可冷冻胚胎数量较少（对照组=5.3±1.0 vs. rFSH1=1.4±0.3，P<0.01）。总之，单次 rFSH 注射能有效诱导超排卵；然而，其重复使用会降低胚胎产量。
