本試驗的研究目的是評估后備母豬青春期日糧蛋白質水平及限飼對母豬乳腺發育的影響。 Crossbred gilts were fed a commercial diet until 90 d of age and then divided into four nutritional regimens based on two pelleted diets (as-fed basis): a high-protein diet (HP = 13.8 MJ of ME, 1.0% total lysine, 18.7% CP) and a low-protein diet (LP = 13.8 MJ of ME, 0.7% total lysine, 14.4% CP). 90日齡雜交母豬。兩種顆粒料分別為：高蛋白日糧（ME13.8MJ/kg，總賴氨酸1.0%，CP18.7%）；低蛋白日糧（ME13.8MJ/kg，總賴氨酸0.7%，CP14.4%）。 Nutritional regimens were as follows:1) HP ad libitum until slaughter (n = 22, T1); 2)HP ad libitum until 150 d of age followed by LP untilslaughter (n = 20, T2); 3) LP ad libitum until slaughter(n = 21, T3); and 4) HP with a 20% feed restriction untilslaughter (n = 19, T4). 4種處理分別為：自由采食高蛋白日糧至屠宰（n=22，T1）；自由采食高蛋白日糧至150日齡，后自由采食低蛋白日糧至屠宰（n=20，T2）；自由采食低蛋白日糧至屠宰（n=21，T3）；20%限飼高蛋白日糧至屠宰（n=19，T4）。 Gilts were weighed, their backfat thickness was measured, and jugular blood samples were obtained on d 90, 150, and at slaughter to determine concentrations of prolactin, IGF-I, leptin, and glucose. Gilts were slaughtered 8 ± 1 d after their first or second estrus (202.7 ± 14.5 d of age). Mammary glands were excised, parenchymal and extraparenchymal tissues were dissected, and composition of parenchymal tissue (protein, fat, DM, DNA, protein/DNA) was determined. 試驗母豬于第1次或第2次發情后的8±1天（202.7 ± 14.5日齡）屠宰。記錄母豬第90日齡、150日齡、屠宰時的體重、背膘厚，并同時收集頸靜脈血液用于檢測其中激素水平。屠宰時切割乳腺組織，分析乳腺外周、實質組織中蛋白質、脂肪、干物質、DNA、蛋白質/DNA。 The T4 gilts weighed less (P < 0.01) and had less backfat (P < 0.01) than did gilts on other treatments on d 150 and at slaughter. T4組母豬150日齡、屠宰時體重、背膘厚顯著低于其它3組。 Treatments had no significant effects on prolactin, IGF-I, or glucose concentrations, but there was a treatment × day interaction (P< 0.01) for leptin, with concentrations being lower at slaughter in restricted-fed (T4) vs. LP (T3) gilts (P <0.05). 各組母豬屠宰時血液催乳素、IGF-I、葡萄糖濃度均無顯著差異，但T4組母豬血液leptin水平顯著低于T3組。 There was less extraparenchymal mammary tissue (P < 0.01) in T4 gilts than in gilts from the other groups and a tendency (P = 0.13) for the amount of parenchymal tissue to be lower in T4 gilts. T4組母豬乳腺外周組織重量顯著低于其它3組，導致乳腺實質組織重量也低于其它3組，但差異不顯著。 In conclusion,a lower lysine intake during prepuberty did not hinder mammary development of gilts, but a 20% feed restriction decreased mass of parenchymal and extraparenchymaltissues. The effect of feed restriction on extraparenchymal tissue is most likely associated with the lower fat deposition. 總結：后備母豬青春期飼喂低蛋白日糧并不會影響母豬的乳腺發育，但20%的限飼將降低乳腺組織的外周組織、實質組織的重量。且乳腺外周組織重量的下降極可能與脂肪沉積減少有關。 戶啟蔚翻譯 畜牧人網站原創文章，轉載請注明作者和出處！ |
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