臺灣博碩士論文加值系統

本試驗之目的旨在了解季節之變化對乳用公山羊精液性狀之影響。試驗共使用7頭健康、性成熟之乳用公山羊，飼養於自然光照下，每週測量其陰囊周長，同時以人工陰道採集精液樣品，測定其精液量、精子泳動波、精子活力、死精子率、精子畸形率，精子濃度及每次射精之總精子數等，並在試驗期間每兩週選取精子泳動波3分以上（包含3分）之精液，以10﹪脫脂乳粉稀釋液製作冷凍精液一次，然後分別冷凍保存一週及三個月後，再解凍觀察冷凍精液之精子活力及精子存活率。全部試驗為期一年，並將試驗期間區分為長日照期（日照時間大於12小時）與短日照期（日照時間小於12小時）及春、夏、秋、冬四個季節，分別比較各種精液性狀之變化與差異性。
試驗結果顯示，乳用公山羊之陰囊周長、精液量、精子泳動波、精子活力及死精子率等，在長日照及短日照期間之差異皆不顯著（P＞0.05）；而精子畸形率（7.18±0.28 vs.5.81± 0.26％）、精子濃度（4.11±0.07 vs.3.65±0.06 ×109sperms /ml）及每次射精之總精子數（4.67±0.09 vs.4.16±0.10 ×109 sperms）則以長日照期顯著較短日照期為高（P＜0.05）。
在季節性變化方面，乳用公山羊之陰囊周長以秋季之30.27±0.08公分為最大，春季之29.63±0.06公分為最小，且與其他季節均呈顯著差異（P＜0.05）。在精液性狀上，精液量以秋季之1.30±0.03 mL 為最高，春季之1.03±0.02mL為最低，呈顯著之季節性變化（P＜0.05）。精子泳動波以春季（3.90±0.07）顯著較其他季節為低（P＜0.05），而以秋季（4.40±0.12）為最高，但與夏、冬兩季並無顯著差異（P＞0.05）。精子活力評分以春季（2.87±0.07）顯著較其他季節為低（P＜0.05），而冬季（3.35±0.06）為最高，並顯著高於春、夏（3.02±0.06）兩季。死精子率以春季之25.54±1.41％顯著高於夏季之21.10±0.64％及冬季之21.12±1.10％（P＜0.05），但與秋季之23.14±1.33％間並無顯著差異。精子畸形率以秋季顯著較其他季節為高，而冬季則顯著較其他季節為低（P＜0.05）。精子濃度以冬季之3.46±0.06×109 sperms /mL為最低，且顯著其他季節為低（P＜0.05），而夏季為4.19±0.06×109 sperms /mL，且顯著較秋季（3.69±0.08×109 sperms /mL）及冬季（P＜0.05）為高。每次射精之總精子數則以秋季之4.77±0.12×109 sperms為最高，且以夏季（4.76±0.12×109 sperms）及秋季顯著高於春季（4.18±0.09×109 sperms）及冬季（3.93±0.14×109 sperms）（P＜0.05）。
冷凍保存一週之乳用山羊精液，在解凍後精子活力評分以長日照期間之1.83±0.0l顯著較短日照期間之2.07±0.25為低（P＜0.05），而解凍後之精子存活率在不同日照期間並無顯著差異（P＞0.05）。在一年中不同季節製作並冷凍保存一週之精液，解凍後其精子活力之數值以春季之1.67±0.05顯著較其他季節為低（P＜0.05），而精子之存活率在不同季節間則無顯著差異（P＞0.05）。冷凍保存三個月之乳用公山羊精液，其解凍後精子活力之數值亦以長日照期顯著較短日照期為低（P＜0.05），而精子存活率在不同日照期間則無顯著差異；在一年中不同季節製作並冷凍保存三個月之精液，其解凍後精子活力評分以春季（1.53±0.08）及夏季（1.69±0.07）顯著較秋季（2.04±0.09）及冬季（1.98±0.06）為低（P＜0.05），而解凍後精子之存活率在不同季節間則無顯著差異（P＞0.05）。
綜合本試驗之結果，顯示在台灣中部地區之乳用公山羊，其陰囊周長及精液性狀具有明顯之季節性變化，且其冷凍精液之精子活力亦受不同季節精液來源之影響。
關鍵詞：乳用公山羊、精液性狀、冷凍精液、季節

Seasonal Changes of Semen Characteristics in Dairy Goat Bucks
Shao-Chih Chang
Abstract
The purpose of this study was to investigate the effect of photoperiod and season on fresh semen characteristics and frozen semen quality of dairy goat bucks. Seven healthy and sexually matured dairy goat bucks were used in this study. Scrotal circumference were measured and semen samples were collected with an artificial vagina once weekly during a year. Semen volume, mass activity score and motility score of sperm, percentage of abnormal sperm and dead sperm, sperm concentration and total sperms per ejaculation were measured respectively. Semen with 3.0 or higher score of mass activity of sperm were diluted with 10％ skim milk extender biweekly and cryopreserved for one week and three months respectively. Afterward, the post-thawed motility score and viability of sperm in frozen semen were evaluated. The natural photoperiod was divided into long-daylight period（＞12 hrs）and short-daylight period（＜12 hrs）groups, and the year was divided into：spring, summer, autumn and winter seasons. The result showed that the percentage of abnormal sperm（7.18±0.28 vs.5.81± 0.26％）, sperm concentration（4.11±0.07 vs.3.65±0.06 ×109 sperms/ml）and total sperms per ejaculation（4.67±0.09 vs.4.16±0.10 ×109 sperms）of long-daylight period group were higher than those in short-daylight period group（P＜0.05）.There were no significant difference（P＞0.05）in scrotal circumference, semen volume, mass activity score and motility score of sperm and the percentage of dead sperm between two photoperiods groups.
The maximal scrotal circumference of dairy goat bucks occurred in autumn（30.27±0.08 cm）and was significantly higher than those in other seasons（P＜0.05）. Semen volume was higher in autumn（1.30±0.03 ml）, lower in spring（1.03±0.02ml）and it showed significantly seasonal difference
（P＜0.05）. The mass activity and motility score of sperms in spring
（3.90±0.07 and 2.87±0.07）were significantly lower than those in the other seasons（P＜0.05）. The highest percentage of dead sperms presented in spring
（25.54±1.41％）and it was significantly higher than those in the summer
（21.10±0.64％）and winter（21.12±1.10％），but there were no significantly difference between spring and autumn（P＞0.05）. The percentage of abnormal sperms was highest in the autumn and lowest in the winter. Sperm concentration in winter（3.46±0.06×109 sperm/ml）was significantly lower than those in other seasons（P＜0.05）. Total sperms per ejaculation in summer
（4.76±0.12×109 sperms）and autumn（4.77±0.12×109 sperms）were significantly higher than those in the spring（4.18±0.09×109 sperms） and winter（3.93±0.14×109 sperms）（P＜0.05）。
Post-thawed motility score of sperm in frozen semen cryopreservated for one week was significantly higher in short-daylight period group（2.07±0.25）than those in long-daylight period group（1.83±0.0l）（P＜0.05）,and it was lower in spring（1.67±0.05）than those in other seasons. There were no significantly difference in viability of sperms between two daylight period groups and between seasons. Semen cryopreservated for three months showed significant difference on post-thawed motility score of sperms between different daylight period groups（P＜0.05）,and it also showed significantly seasonal difference（P＜0.05）, But there was no significantly difference in viability of sperms between two daylight period groups and seasons.
It was concluded that, the semen characteristics of dairy goat bucks in central Taiwan showed significantly seasonal variation, and the frozen semen quality was in accordance with the seasonal variation of fresh semen.
Keyword：Dairy goat bucks, semen characteristics, frozen semen, season.

目錄 頁次
壹、中文摘要 1
貳、前言 3
叁、文獻檢討 5
一、台灣地區乳用山羊簡介 5
二、公羊之生殖生理 5
（一） 公羊之生殖系統 6
（二） 精子之生成 8
（三） 影響公畜生殖之原因 14
1.環境溫度 14
2.營養 14
3.季節 15
三、公羊生殖性能之季節性變化 16
（一） 季節性生殖之機制…………………………………………………..16
（二） 生殖內分泌系統之季節性變化…………………………………......21
（三） 生殖器官形態學之季節性變化……………………………………..22
（四） 精液性狀之季節性變化……………………………………………..24
（五） 山羊季節性生殖之人工調節………………………………………..25
四、山羊精液之冷凍保存......................................................................................27
（一） 精漿存在與否對山羊精液冷凍保存之影響………………………....28
（二） 影響山羊冷凍精液品質之其他因素………………………………....30
1. 季節…………………………………………………………………..30
2. 精液之稀釋比例及步驟……………………………………………..31
3. 冷凍步驟及解凍溫度………………………………………………..32
4. 冷凍稀釋液之添加劑………………………………………………..33
肆、試驗材料與方法 35
一、試驗動物 35
二、飼養與管理 35
三、樣品之採集及處理 36
四、日照長度及季節之分組 44
五、試驗結果之統計分析 44
伍、結果與討論 46
一、陰囊周長 46
二、新鮮精液性狀 50
（一）精液量 50
（二）精子泳動波 53
（三）精子活力 55
（四）死精子率 58
（五）精子之畸形率 61
（六）精子之濃度 65
（七）每次射精之總精子數 68
三、冷凍精液性狀 71
（一）解凍後精子之活力 71
（二）精子之存活率 75
陸、結論 80
柒、參考文獻 82
捌、附表 92
玖、英文摘要 101

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