Department of Animal Sciences, University of Illinois, Urbana 61801.
Department of Animal Sciences, University of Illinois, Urbana 61801.
J Dairy Sci. 2018 Sep;101(9):8532-8543. doi: 10.3168/jds.2018-14447. Epub 2018 Jun 21.
Trace minerals are vital in the antioxidant response during oxidative stress; however, limited research is available on the effects of trace mineral supplementation during an aflatoxin (AF) challenge. The objective of the study was to determine the effects of 2 subcutaneous injections of 15 mg/mL of Cu, 5 mg/mL of Se, 60 mg/mL of Zn, and 10 mg/mL of Mn (Multimin 90, Multimin North America, Fort Collins, CO) given at 1 mL/90.7 kg of average body weight in response to an AF challenge. Fifty-eight Holstein cows [body weight (mean ± SD) = 734 ± 6 0kg; days in milk = 191 ± 93] were assigned to 1 of 3 treatments in a randomized complete block design. The experimental period (63 d) was divided into an adaptation phase (d 1-56) and a measurement phase (d 57-63). From d 57 to 59, cows received an AF challenge that consisted of 100 μg of aflatoxin B/kg of dietary dry matter intake (DMI) administered orally via balling gun. Treatments were saline injection and no AF challenge (NEG), saline injection and AF challenge (POS), and trace mineral injection and AF challenge (MM). Injections were performed subcutaneously on d 1 and 29. Milk was sampled 3 times daily from d 56 to 63, blood was sampled on d 0, 56, 60, and 63, and liver samples were taken on d 0 and 60. Two treatment orthogonal contrasts [CONT1 (NEG vs. POS) and CONT2 (POS vs. MM)] were made. Cows in NEG had lower AF excretion in milk and greater 3.5% fat-corrected milk (32.1 ± 1.37 kg/d) compared with cows in POS (28.6 ± 1.43 kg/d). Feed efficiencies (3.5% fat-corrected milk/DMI, energy-corrected milk/DMI, and milk/DMI) were greater for cows in NEG (1.42 ± 0.07, 1.46 ± 0.07, and 1.45 ± 0.07, respectively) than cows in POS (1.16 ± 0.08, 1.18 ± 0.08, and 1.22 ± 0.07, respectively). Cows in POS had greater milk urea nitrogen and blood urea nitrogen than cows in MM. Liver concentrations of Se and Fe were greater for cows in MM compared with cows in POS. Cows in MM tended to have greater plasma glutathione peroxidase activity compared with cows in POS. An upregulation of liver GPX1 was observed for cows in POS compared with cows in MM. In conclusion, subcutaneous injection of trace minerals maintained an adequate antioxidant response when an AF challenge was present.
痕量矿物质在氧化应激期间的抗氧化反应中至关重要；然而，关于在黄曲霉毒素（AF）挑战期间补充痕量矿物质的影响的研究有限。本研究的目的是确定在 AF 挑战期间，每头 90.7 千克平均体重皮下注射 2 次 15 毫克/毫升的铜、5 毫克/毫升的硒、60 毫克/毫升的锌和 10 毫克/毫升的锰（Multimin 90，Multimin North America，柯林斯堡，CO）的效果。58 头荷斯坦奶牛[体重（均值±SD）=734±60 千克；泌乳天数=191±93]按随机完全区组设计分为 3 种处理之一。实验期（63 天）分为适应期（d1-56）和测量期（d57-63）。从 d57 到 59，奶牛接受了黄曲霉毒素 B 挑战，即通过球枪口服给予 100μg 黄曲霉毒素 B/千克饲料干物质摄入量（DMI）。处理方式为盐水注射和无黄曲霉毒素 B 挑战（NEG）、盐水注射和黄曲霉毒素 B 挑战（POS）以及痕量矿物质注射和黄曲霉毒素 B 挑战（MM）。注射于 d1 和 d29 进行。从 d56 到 63，每天采集 3 次牛奶，于 d0、56、60 和 63 采集血液，于 d0 和 60 采集肝脏样本。进行了 2 个处理正交对比[CONT1（NEG 与 POS）和 CONT2（POS 与 MM）]。与 POS 组（28.6±1.43kg/d）相比，NEG 组奶牛的牛奶中黄曲霉毒素 B 排泄量更低，3.5%乳脂校正奶（32.1±1.37kg/d）更高。NEG 组奶牛的饲料效率（3.5%乳脂校正奶/DMI、能量校正奶/DMI 和奶/DMI）高于 POS 组（1.42±0.07、1.46±0.07 和 1.45±0.07，分别）。与 MM 组奶牛相比，POS 组奶牛的牛奶尿素氮和血液尿素氮更高。与 POS 组奶牛相比，MM 组奶牛的肝脏硒和铁浓度更高。与 POS 组奶牛相比，MM 组奶牛的血浆谷胱甘肽过氧化物酶活性呈上升趋势。与 MM 组奶牛相比，POS 组奶牛的肝脏 GPX1 呈上调趋势。总之，当存在黄曲霉毒素 B 挑战时，痕量矿物质的皮下注射维持了充足的抗氧化反应。
