Victoria C. Kennedy，James J. Gaspers，Bethany R. Mordhorst，Gerald L. Stokka，Kendall C. Swanson，Marc L. Bauer，Kimberly A. Vonnahme

翻譯：劉素利                   校對：上海亙泰實業集團

       給妊娠后期肉牛飼喂添加玉米干酒糟及其可溶物（DDGS）的飼糧，探討其妊娠后期和泌乳早期流向乳腺的動脈血流量、初乳和產奶量及難產、免疫力和牛犢出生體重（BW）的變化。飼喂兩種試驗日糧，對照組（CON，n=15，5.1% CP、36.2% ADF）包含90%玉米秸稈+10%青貯玉米的干飼糧；試驗組（SUP，n=12，DDGS添加量為牛只體重的0.3%）；妊娠246d時，青貯玉米增加到20%（妊娠日糧2：4.7% CP）；妊娠260d時，青貯玉米增加到30%（妊娠日糧3：5.5% CP）；妊娠270d，接近分娩時，所有試驗母牛飼喂同一種日糧（48%玉米秸稈、30%青貯玉米和22% DDGS、干物質基礎的10.8% CP），自由采食持續10周。妊娠第245d測定乳腺血流量；分娩時，評估分娩母牛和牛犢參數；采集初乳和頸靜脈血，母牛也被稱重；檢測泌乳44d時乳腺血流量和產奶量，牛犢每兩周（共持續8周）和斷奶時稱重。

       試驗數據表明，與對照組相比，試驗組：初乳有增高的趨勢（837 vs 614±95g，P=0.10），牛犢出生和出生24h時體重增加（0 h：43.2 vs. 39.8 ± 1.0 kg，P = 0.02；24 h：44.0 vs 40.4 ± 1.1 kg，P = 0.02），牛犢出生時血液二氧化碳分壓升高（6.82 vs. 6.00 ± 0.41 kPa，P = 0.04），牛犢出生24h時血清IgG無差異（P = 0.21），同側乳腺血流量增加（2.76 vs. 1.76 ± 0.30 L/min；P = 0.03）；然而，與對側乳腺匯總比較時，兩組間無顯著差異（P = 0.33）。泌乳44d時兩組間血液動力學檢測結果相似（P ≥ 0.32），試驗組產奶量與對照組比較有增加的趨勢（13.5 vs. 10.2 ± 1.2 kg/d，P = 0.07）；在泌乳56d時兩組間牛犢BW無差異，但斷奶時試驗組牛犢BW顯著升高（309.7 vs. 292.0 ± 6.0 kg，P = 0.04）。

       結果顯示，試驗驗證了在肉牛妊娠期日糧中添加DDGS能夠影響其乳腺血流量、產奶量和產犢BW的假設。這些發現暗示了母體營養對牛犢早期營養和被動免疫的影響，以及對其長期表現的潛在優勢。

Late Gestation Supplementation of Corn Dried Distiller’s Grains Plus Solubles to Beef Cows Fed A Low-Quality Forage: III. Effects on Mammary Gland Blood Flow, Colostrum and Milk Production, and Calf Body Weights

Objectives were to investigate the effects of supplementation with corn dried distiller’s grains plus solubles (DDGS) to late gestating beef cows on arterial blood flow to the mammary glands during late gestation and early lactation; colostrum and milk production; dystocia and immunity; and calf BW. Cows were fed a control (CON; n = 15; 5.1% CP; 36.2% ADF) diet consisting of 90% corn stover and 10% corn silage on a dry basis offered ad libitum or CON diet with supplementation of DDGS (0.30% of BW; SUP n = 12). Mammary gland blood flow was assessed on d 245 of gestation. At parturition, maternal and calving parameters were assessed; colostrum and jugular blood was sampled; and dams were weighed. Mammary gland blood flow and milk production was measured on d 44 of lactation. Calves were weighed fortnightly for 8 wk and at weaning. Colostrum production tended to be greater in SUP dams than in CON dams (837 vs. 614 ± 95 g, P = 0.10). Calves of SUP dams were heavier at birth and 24 h (0 h, 43.2 vs. 39.8 ± 1.0 kg, P = 0.02; 24 h, 44.0 vs 40.4 ± 1.1 kg, P = 0.02). At birth and 24 h, blood pCO2 was greater in calves born to SUP dams (6.82 vs. 6.00 ± 0.41 kPa, P = 0.04). Serum IgG did not differ (P = 0.21) at 24 h. Ipsilateral mammary gland blood flow of SUP cows was greater than CON cows (2.76 vs. 1.76 ± 0.30 L/min; P = 0.03); however, when summed with contralateral, total blood flow was similar (P = 0.33). Hemodynamic measures on d 44 of lactation were similar (P ≥ 0.32). Milk production tended to be increased (13.5 vs. 10.2 ± 1.2 kg/d, P = 0.07) in SUP vs. CON cows. Despite similar BW through 56 d, calves from SUP cows were heavier (P = 0.04) at weaning (309.7 vs. 292.0 ± 6.0 kg). In conclusion, we accept our hypothesis that DDGS supplementation during gestation influenced mammary blood flow, milk production and calf weights. These findings implicate maternal nutrition’s leverage on both nutrient and passive immunity delivery to the calf early in life as well as potential advantages on long term performance.（轉自：豬營養國際論壇）