飼糧鈣含量或添加根黴菌發酵萃取物對公番鴨精液品質之影響

Abstract

本研究目的旨在探討飼糧中鈣含量或根黴菌發酵萃取物（Rhizopus fermentation extract, RE）添加對公番鴨精液品質的影響。 試驗使用28週齡公番鴨27隻，隨機分配至三處理組，分別為高鈣組（3% Ca）、對照組（1% Ca）及根黴菌發酵萃取物添加組（1% Ca + 0.2% RE，簡稱RE添加組），每組9隻。試驗分為兩部分探討，第一部分：高鈣組與對照組比較，探討飼糧中的高鈣濃度（高鈣組）對番鴨精液品質的影響。第二部分：對照組與RE添加組比較，探討根黴菌發酵萃取物添加（RE添加組）對公番鴨精液品質的影響。試驗開始於30週齡，直至52週齡結束，為期22週。試驗期間每週採精兩次並測量參試鴨隻之精液量、精子濃度、活力及總精子數等。每4週稱重一次，並採集血液及精液進行血液生化值、精子形態及存活率等檢測。於38週齡時採集精液，將各處理組9隻鴨子採集之精液混合成混合精液後，對36隻26週齡母改鴨進行人工授精，三組使用108隻母改鴨。於46和49週齡時，同樣使用混合精液對12隻36週齡母改鴨進行人工授精，三組使用36隻母改鴨。收集授精後隔天起七天之種蛋入孵，計算其受精率。 結果顯示，飼糧鈣含量不影響體增重、精液量、精子存活率及受精率。高鈣組精子濃度於試驗後期有較對照組為低之趨勢，且在47週齡時有顯著差異（P＜0.05）。高鈣組之總精子數於39週齡後皆低於對照組，惟未達到顯著差異。高鈣組之精子直線速度（straight line velocity, VSL）、精子曲線速度（curvilinear velocity, VCL）及精子平均路徑速度（average path velocity, VAP）顯著低於對照組，且高鈣組有較高的精子折頸率，但其畸形率與對照組間無顯著差異。 對照組與RE添加組在體增重、精子濃度、精子活力、畸形率、存活率及受精率上無顯著差異，RE添加組與對照組之精液量分別維持在1.4 mL以上與1.2-1.4 mL。除RE添加組於47週齡精液量及於36週齡之精液總精子數顯著高於對照組外，其它試驗期間兩組間之精液量及精液總精子數皆無顯著差異。 綜而論之，本試驗結果顯示高鈣飼糧（3%）對精子活力有不利影響，而根黴菌發酵萃取物添加並不影響精子活力、受精率、存活率以及畸形率，但可提高番鴨的精液量。因此，降低飼料鈣含量或根黴菌發酵萃取物添加之處理，可提高公番鴨之精子活力或精液量，有利於生產效率的提升。

The objective of this study was to understand the effects of dietary calcium level or Rhizopus fermentation extract (RE) on semen quality of the Muscovy duck. A total of number 27 28-week old male Muscovy ducks were used in this study and allocated randomly into three groups for different treatments: 3% Ca, 1% Ca and 1% Ca + 0.2% RE. The experiment was divided into two parts. The first part was to investigate the effect of calcium level on the semen quality of Muscovy duck and the second part was to understand the effect of Rhizopus fermentation extract on the semen quality of Muscovy duck. From 30 weeks of age, semen samples were collected twice every week until 52 weeks of age and semen volume, concentration, motility, and total number of spermatozoa were measured. During the experiment, ducks were weighed every four weeks. The blood and semen were also sampled for analysis of blood biochemistry value and sperm morphology. Semen was collected at 38, 46 and 49 weeks of age, and the 108 or 36 female Kaiya ducks at 26 or 36 weeks of age were randomly allocated into three groups for artificial insemination, and the eggs were collected for fertilization observation. The results indicate that there was no significant difference in body weight gain, semen volume, sperm viability and fertilization rate between the 3% Ca group and the 1% Ca group. The sperm concentration of the 1% Ca group was higher than that of the 3% Ca group at late stage of the study and there was significantly different at 47 weeks of age (P<0.05), but there was no significant difference for the overall sperm concentration. The total number of spermatozoa was higher in the 1% Ca group after 39 weeks of age, but there was no significantly different from 3% Ca group. In sperm motility, the 1% Ca group was significantly higher in straight line velocity (VSL), curvilinear velocity (VCL), and average path velocity (VAP) than the 3% Ca group. In sperm morphology, there was no significant difference in sperm viability, but the high calcium group has a higher sperm necking rate. However, the malformation rate was not significantly different between the two groups. There was no significant difference in body weight gain, sperm concentration, motility, morphology, viability and fertilization rate between the 1% Ca group and the 1% Ca + 0.2% RE group. In semen volume, 1% Ca + 0.2% RE group was maintained above 1.4 mL, while the 1% Ca group was maintained at 1.2-1.4 mL. However, except for the semen volume of 1% Ca + 0.2% RE group, it was significantly high than that of the 1% Ca group of 47 weeks of age. However, there was no significant difference in other weeks of age between these two groups. In total number of spermatozoa, there was no significant difference between the two groups except at 36 weeks of age the 1% Ca + 0.2% RE group was significantly higher than 1% Ca group. In conclusion, the dietary calcium level has an adverse effect on sperm motility. The addition of Rhizopus fermentation extract to the dietary does not affect sperm motility, viability, morphology and fertilization rate, but can increase the semen volume in Muscovy duck. Results of this study show that reducing the calcium level in the diet or the addition of the Rhizopus fermentation extract can improve the semen characteristics of the Muscovy duck, which is conducive to the improvement of production efficiency.