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

翻译：刘素利                   校对：上海亘泰实业集团

       给妊娠后期肉牛饲喂添加玉米干酒糟及其可溶物（DDGS）的饲粮，探讨其妊娠后期和泌乳早期流向乳腺的动脉血流量、初乳和产奶量及难产、免疫力和牛犊出生体重（BW）的变化。饲喂两种试验日粮，对照组（CON，n=15，5.1% CP、36.2% ADF）包含90%玉米秸秆+10%青贮玉米的干饲粮；试验组（SUP，n=12，DDGS添加量为牛只体重的0.3%）；妊娠246d时，青贮玉米增加到20%（妊娠日粮2：4.7% CP）；妊娠260d时，青贮玉米增加到30%（妊娠日粮3：5.5% CP）；妊娠270d，接近分娩时，所有试验母牛饲喂同一种日粮（48%玉米秸秆、30%青贮玉米和22% DDGS、干物质基础的10.8% CP），自由采食持续10周。妊娠第245d测定乳腺血流量；分娩时，评估分娩母牛和牛犊参数；采集初乳和颈静脉血，母牛也被称重；检测泌乳44d时乳腺血流量和产奶量，牛犊每两周（共持续8周）和断奶时称重。

       试验数据表明，与对照组相比，试验组：初乳有增高的趋势（837 vs 614±95g，P=0.10），牛犊出生和出生24h时体重增加（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），牛犊出生时血液二氧化碳分压升高（6.82 vs. 6.00 ± 0.41 kPa，P = 0.04），牛犊出生24h时血清IgG无差异（P = 0.21），同侧乳腺血流量增加（2.76 vs. 1.76 ± 0.30 L/min；P = 0.03）；然而，与对侧乳腺汇总比较时，两组间无显著差异（P = 0.33）。泌乳44d时两组间血液动力学检测结果相似（P ≥ 0.32），试验组产奶量与对照组比较有增加的趋势（13.5 vs. 10.2 ± 1.2 kg/d，P = 0.07）；在泌乳56d时两组间牛犊BW无差异，但断奶时试验组牛犊BW显著升高（309.7 vs. 292.0 ± 6.0 kg，P = 0.04）。

       结果显示，试验验证了在肉牛妊娠期日粮中添加DDGS能够影响其乳腺血流量、产奶量和产犊BW的假设。这些发现暗示了母体营养对牛犊早期营养和被动免疫的影响，以及对其长期表现的潜在优势。

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.（转自：猪营养国际论坛）