外源睪固酮處理對新母豬與母豬生殖性能之效應

本研究旨在探討睪固酮分別處理斷乳母豬與進行週期中新母豬後對其繁殖性能之影響。在試驗1中選用66頭哺乳中母豬分成三組，在斷乳前3日連續每日給予0 mg、1 mg或2 mg睪固酮直到發情時人工授精兩次。在試驗2中選用8月齡已發身新母豬共14頭，在動情週期第13日起每日注射佐劑（n=5）、1mg（n=5）或2 mg（n=4）睪固酮直到發情時配種兩次。由試驗1結果顯示，接受2mg睪固酮母豬在開始處理十日內之發情率，比接受1 mg睪固酮或佐劑母豬者有較高之趨勢（95.3％ vs 85.7％或818％），且斷乳至發情日距亦短（4.1日 vs 4.4日或4.2日），惟均未呈顯著差異（P＞0.05）。雖然0、1與2 mg組母豬的分娩時總或活窩仔數以及分娩3週時窩仔數，均未呈組間差異；惟有隨著睪固酮處理劑量的增加而呈遞減的趨勢。再者，由試驗2結果顯示，新母豬接受1或2mg睪固酮較接受佐劑處理者，可提高其發情配種率（100％或100％ vs 60%，P＜0.05），且有縮短處理至發情日距的趨勢（6.2日或8.3日 vs 8.7日，P＞0.05）。新母豬於配種後6日的黃體數、總胚數及其回收率，均無組間差異（P＞0.05），而與試驗1母豬呈相似的劑量反應型式。綜合此等結果提示，睪固酮處理可提高母豬或新母豬之發情性能，惟未能有效改善其繁殖性能。

關鍵字

母豬；新母豬；睪固酮；黃體；囊胚；每窩仔豬數

並列摘要

The study was to investigate the effect of exogenous testosterone on the reproductive performances in weaned sows and cycling gilts. In Exp. 1, sixty-six lactating sows were assigned randomly to three groups and given 0 (vehicle, corn oil), 1, and 2 mg of testosterone per animal, respectively, per day from 3 days before weaning until estrus within 10 days after weaning. All sows were inseminated artificially twice after estrus check. In Exp. 2, fourteen pubertal gilts, 8 months of age, were selected and allocated to receive 0 (vehicle, n = 5), 1 ( n = 5), or 2 mg (n = 4) of testosterone daily from day 13 (day 0 is denoted as the first day of estrus) to estrus and then gilts were naturally mated. Results from Exp. 1 showed a tendency that sows receiving 2 mg of testosterone had highter percentage of estrus (95.3 vs 85.7 or 81.8%) and lower treatment-to-estrus interval (4.1 vs 4.4 or 4.2 days) in 10 days of treatment than those receiving 1 mg of testosterone or vehicle; however, there were no significant differences among these treatments. Although no significant differences existed in total or live litter size at farrowing and number of piglets at 3 weeks of age among the three treatments, the litter size showed a decreasing tendency with the increasing dosage of testosterone treated in the sows. In addition, results form Exp. 2 showed that gilts receiving 1 or 2 mg of testosterone had higher percentage of estrus (100 or 100 vs 60%, P ＜ 0.05) ; and shorter treatment-to-estrus interval (6.2 or 8.3 vs 8.7 days, P ＞ 0.05) than those receiving vehicle. However, the number of corpora lutea, and the number and recovery rate of blastocysts had no significant differences among the treatments evaluated on day 6 after mating in gilts; and showed the same dose-response pattern as sows in Exp. 1. In conclusion, these data suggested that testosterone treatment increase the estrus characteristics but do not effectively improve the reproductive performances in both sows and gilts.

並列關鍵字

Sow ； Gilt ； Testosterone ； Corpora lutea ； Blastocyst ； Litter size

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