Yuan K, Vargas-Rodriguez C F, Mamedova L K, Muckey M B, Vaughn M A, Burnett D D, Gonzalez J M, Titgemeyer E C, Griswold K E, Bradford B J
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
Kemin Industries, Des Moines, IA 50317.
J Dairy Sci. 2014;97(6):3822-31. doi: 10.3168/jds.2013-7770. Epub 2014 Apr 14.
The objective of this study was to evaluate effects of chromium propionate (CrPr), rumen-protected lysine and methionine (RPLM), or both on metabolism, neutrophil function, and adipocyte size in lactating dairy cows (38 ± 15 d in milk). Forty-eight individually fed Holstein cows (21 primiparous, 27 multiparous) were stratified by calving date in 12 blocks and randomly assigned to 1 of 4 treatments within block. Treatments were control, CrPr (8 mg/d of Cr, KemTRACE brand chromium propionate 0.04%, Kemin Industries Inc., Des Moines, IA), RPLM (10 g/d lysine and 5 g/d methionine intestinally available, from LysiPEARL and MetiPEARL, Kemin Industries Inc.), or CrPr plus RPLM. Treatments were fed for 35 d; blood plasma samples were collected ond 21 and 35 of treatment, and blood neutrophils were isolated from 24 cows for analysis of tumor necrosis factor α (TNFα) and interleukin 1β (IL-1β) transcript abundance in the basal state and after 12h of lipopolysaccharide (LPS) activation. Tailhead subcutaneous adipose tissue samples were collected ond 35 for measurement of adipocyte size. Plasma glucose, nonesterified fatty acids, and glucagon concentrations were unaffected by treatments, whereas plasma insulin concentration was increased by RPLM. Basal TNFα transcript abundance in neutrophils was not affected by treatment, but basal IL-1β transcript abundance was decreased by RPLM and tended to be increased by CrPr. After LPS activation, CrPr increased neutrophil TNFα transcript abundance. In addition, RPLM×parity interactions were detected for both TNFα and IL-1β abundance after LPS activation, reflecting enhanced responses in primiparous cows and attenuated responses in multiparous cows supplemented with RPLM. Adipocyte size was not affected by treatment. Supplemental CrPr and RPLM had minimal effects on metabolism when fed for 35 d near peak lactation but may modulate innate immune function in lactating dairy cows.
本研究的目的是评估丙酸铬（CrPr）、瘤胃保护性赖氨酸和蛋氨酸（RPLM）或二者对泌乳奶牛（产奶38±15天）代谢、中性粒细胞功能和脂肪细胞大小的影响。48头单独饲养的荷斯坦奶牛（21头初产牛，27头经产牛）按产犊日期分为12个区组，并在每个区组内随机分配到4种处理中的1种。处理方式为对照组、CrPr（8毫克/天的铬，KemTRACE牌丙酸铬0.04%，Kemin Industries Inc.，得梅因，爱荷华州）、RPLM（10克/天可利用的赖氨酸和5克/天可利用的蛋氨酸，来自LysiPEARL和MetiPEARL，Kemin Industries Inc.），或CrPr加RPLM。处理持续35天；在处理的第21天和第35天采集血浆样本，并从24头奶牛中分离出血液中性粒细胞，用于分析基础状态下以及脂多糖（LPS）激活12小时后肿瘤坏死因子α（TNFα）和白细胞介素1β（IL-1β）的转录丰度。在第35天采集尾根皮下脂肪组织样本用于测量脂肪细胞大小。血浆葡萄糖、非酯化脂肪酸和胰高血糖素浓度不受处理影响，而血浆胰岛素浓度因RPLM而升高。中性粒细胞中基础TNFα转录丰度不受处理影响，但基础IL-1β转录丰度因RPLM而降低，且有因CrPr而升高的趋势。LPS激活后，CrPr增加了中性粒细胞TNFα转录丰度。此外，在LPS激活后，检测到RPLM×胎次对TNFα和IL-1β丰度均有交互作用，这反映出在补充RPLM的初产奶牛中反应增强，而经产奶牛中反应减弱。脂肪细胞大小不受处理影响。在泌乳高峰期附近饲喂35天时，补充CrPr和RPLM对代谢的影响最小，但可能调节泌乳奶牛的先天免疫功能。
