Willenburg K L, Miller G M, Rodriguez-Zas S L, Knox R V
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 2003 Jan;81(1):9-15. doi: 10.2527/2003.8119.
The effect of boar exposure during artificial insemination (AI) on semen backflow, fertilization, and embryo quality was evaluated. Gilts (approximately 170 d) were induced into estrus with PG600, and ovulation was synchronized using hCG 72 h later. Estrus detection was initiated after PG600 and continued at 12-h intervals. At estrus, gilts were allotted to receive boar exposure (BE, n = 20) or no boar exposure (NBE, n = 20) during AI. Gilts receiving NBE were identified to be in estrus prior to AI and the boar was then removed for 1 h, whereas gilts in the BE group received 15 min of exposure during AI. Insemination occurred in crates at 12 and 24 h after onset of estrus with 3 x 10(9) sperm/80 mL. Backflow was collected continuously with samples taken at time 0, (during AI), and at 0.25, 0.5, 0.75, 1, 2, 4, and 8 h after first and second AI. The effect of treatment was evaluated for time of insemination (min), backflow (mL), and sperm in backflow samples. Oviducts were flushed 2 d after first AI to evaluate the effect oftreatment on fertilization rate, accessory sperm numbers on embryos (scored 1 to 5), and embryo quality. There was no effect of first or second AI; therefore, data were pooled. Average duration of AI was 3.7 +/- 0.2 min and was not influenced by BE (P < 0.10). However, during the initial stage of AI, BE reduced the volume of semen (18.6 vs 32.4 +/- 3 mL) and the number of sperm lost (0.8 vs 1.3 +/- 0.15 x 10(9) sperm) compared to NBE (P < 0.05). There was a treatment x time effect (P < 0.05) for volume of backflow. By 45 min, the BE gilts lost more volume (9.0 vs 3.6 mL) compared to the NBE group, but sperm loss did not differ. Between 1 and 8 h after AI, neither volume nor sperm loss was influenced by treatment. By 8 h, total leakage (65 vs 63 mL) and total sperm loss (1.6 x 10(9) vs 1.8 x 10(9) sperm) were not influenced by BE (P > 0.10). However, more accessory sperm (P < 0.01) were found on embryos for the NBE (> or = 11 sperm/embryo) compared to BE embryos (< or = 10 sperm/embryo). Despite this observation, percentages of fertilized embryos (99.5 +/- 0.5 %) and number of embryos (11.5 +/- 0.1) were not different (P > 0.10). In conclusion, AI in the presence of a mature boar did not affect total semen leakage, sperm loss, fertilized embryos, or embryo quality. The importance of boar exposure during insemination was evident from less leakage during insemination, but had no effect on fertility; this suggests that the elimination of boar exposure during AI may not be deleterious to reproductive performance.
评估了人工授精（AI）期间公猪接触对精液回流、受精和胚胎质量的影响。用PG600诱导约170日龄的后备母猪发情，72小时后使用hCG使排卵同步。在注射PG600后开始发情检测，并以12小时的间隔持续进行。发情时，将后备母猪分为两组，一组在人工授精期间接受公猪接触（BE组，n = 20），另一组不接受公猪接触（NBE组，n = 20）。接受NBE的后备母猪在人工授精前被确定处于发情期，然后将公猪移开1小时，而BE组的后备母猪在人工授精期间接受15分钟的公猪接触。在发情开始后的12小时和24小时，在产箱中进行人工授精，输精量为3×10⁹精子/80 mL。在时间0（人工授精期间）、首次和第二次人工授精后0.25、0.5、0.75、1、2、4和8小时连续收集回流精液。评估处理对人工授精时间（分钟）、回流精液量（mL）和回流精液样本中精子数量的影响。在首次人工授精后2天冲洗输卵管，以评估处理对受精率、胚胎上附属精子数量（评分1至5）和胚胎质量的影响。首次或第二次人工授精没有影响；因此，将数据合并。人工授精的平均持续时间为3.7±0.2分钟，不受公猪接触的影响（P < 0.10）。然而，在人工授精的初始阶段，与NBE组相比，BE组减少了精液量（18.6对32.4±3 mL）和损失的精子数量（0.8对1.3±0.15×10⁹精子）（P < 0.05）。回流精液量存在处理×时间效应（P < 0.05）。到45分钟时，与NBE组相比，BE组的后备母猪损失了更多的精液量（9.0对3.6 mL），但精子损失没有差异。在人工授精后1至8小时，处理对精液量和精子损失均无影响。到8小时时，总漏出量（65对63 mL）和总精子损失（1.6×10⁹对1.8×10⁹精子）不受公猪接触的影响（P > 0.10）。然而，与BE组胚胎（≤10个精子/胚胎）相比NBE组胚胎（≥11个精子/胚胎）上发现了更多的附属精子（P < 0.01）。尽管有此观察结果，但受精胚胎的百分比（99.5±0.5%）和胚胎数量（11.5±0.1）没有差异（P > 0.10）。总之，在成熟公猪在场的情况下进行人工授精不会影响精液总漏出量、精子损失、受精胚胎或胚胎质量。人工授精期间公猪接触的重要性在人工授精期间较少的漏出量中很明显，但对生育力没有影响；这表明在人工授精期间消除公猪接触可能不会对繁殖性能有害。
