Veterinary Medicine Teaching and Research Center, University of California, Davis, 18830 Road 112, Tulare 93274; Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis 95616.
Veterinary Medicine Teaching and Research Center, University of California, Davis, 18830 Road 112, Tulare 93274; Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis 95616.
J Dairy Sci. 2022 Mar;105(3):2315-2325. doi: 10.3168/jds.2021-21069. Epub 2022 Jan 5.
This observational study described first-milking colostrum mineral concentrations and total yields, and evaluated its associations with cow serum mineral concentrations, parity, and first postpartum milking yield in 100 multiparous Jersey cows from a single herd fed a negative dietary cation-anion difference diet prepartum. Additionally, first- and second-milking colostrum mineral concentrations and total yields were compared in a subset of 65 cows. Serum minerals (Ca, P, Mg, Na, K, Zn, Fe, Cu) were assessed before first milking. Cows were milked at 9 h and 4 min ± 3 h and 32 min and at 21 h and 11 min ± 3 h and 43 min postpartum (± standard deviation); yields were recorded and samples collected for mineral concentrations assessment (Ca, P, Mg, Na, K, Zn, Fe, Cu). Linear regression was used to evaluate the associations between first-milking colostrum mineral concentrations and total yields and cows' serum mineral concentrations, parity, first-milking colostrum yield, and calving-to-milking interval. The most abundant minerals in first-milking colostrum were (least squares mean ± standard error of the mean) Ca (55.71 ± 13.52 mmol/L; 8.75 ± 5.74 g) and P (41.91 ± 13.01 mmol/L; 5.26 ± 3.72 g), followed by Na (39.65 ± 13.23 mmol/L; 3.08 ± 1.77 g), K (36.47 ± 7.57 mmol/L; 5.79 ± 4.20 g), Mg (13.43 ± 3.09 mmol/L; 1.25 ± 0.78 g), Zn (272.12 ± 113.34 μmol/L; 71.98 ± 55.34 mg), Fe (12.51 ± 3.79 μmol/L; 2.56 ± 1.55 mg), and Cu (3.34 ± 1.22 μmol/L; 0.77 ± 0.56 mg). Higher concentrations of Ca, Mg, Na, Zn, Fe, and Cu, and total yields of Mg, Zn, Fe, and Cu were observed at first- compared with second-milking colostrum. Serum and first-milking colostrum Cu concentrations were positively associated, but no significant associations were observed between other minerals' serum and first-milking colostrum concentrations or total yields. Parity was associated with first-milking colostrum Ca, P, K, and Fe concentrations and yields; younger multiparous cows had higher concentrations and total yields of these minerals. Linear (Fe), quadratic (P, Na, and K), and cubic (Mg, Zn, and Cu) associations were observed between first-milking colostrum mineral concentrations and yield. In all cases, mineral total yields were linearly associated with first-milking colostrum yield. In conclusion, variation in first-milking colostrum mineral concentrations and total yields across cows could be partially explained by cow parity and colostrum yield. Further research including primiparous and cows under different management settings is needed to expand the knowledge and understanding of colostrum mineral concentrations and total yields in dairy cows.
这项观察性研究描述了第一次挤奶初乳的矿物质浓度和总产量，并评估了其与奶牛血清矿物质浓度、胎次和产后第一次挤奶产量的关系，研究对象为来自单个牛群的 100 头荷斯坦奶牛，这些奶牛在产前饲喂负钙阴离子差日粮。此外，在 65 头奶牛的亚组中比较了第一次和第二次挤奶初乳的矿物质浓度和总产量。在第一次挤奶前评估血清矿物质（Ca、P、Mg、Na、K、Zn、Fe、Cu）。奶牛在产后 9 小时 4 分钟 ± 3 小时 32 分钟和 21 小时 11 分钟 ± 3 小时 43 分钟时挤奶；记录产量并采集样本评估矿物质浓度（Ca、P、Mg、Na、K、Zn、Fe、Cu）。使用线性回归评估第一次挤奶初乳矿物质浓度和总产量与奶牛血清矿物质浓度、胎次、第一次挤奶初乳产量和产犊至挤奶间隔之间的关系。第一次挤奶初乳中最丰富的矿物质（均数 ± 标准误）为 Ca（55.71 ± 13.52 mmol/L；8.75 ± 5.74 g）和 P（41.91 ± 13.01 mmol/L；5.26 ± 3.72 g），其次是 Na（39.65 ± 13.23 mmol/L；3.08 ± 1.77 g）、K（36.47 ± 7.57 mmol/L；5.79 ± 4.20 g）、Mg（13.43 ± 3.09 mmol/L；1.25 ± 0.78 g）、Zn（272.12 ± 113.34 μmol/L；71.98 ± 55.34 mg）、Fe（12.51 ± 3.79 μmol/L；2.56 ± 1.55 mg）和 Cu（3.34 ± 1.22 μmol/L；0.77 ± 0.56 mg）。与第二次挤奶初乳相比，第一次挤奶初乳中的 Ca、Mg、Na、Zn、Fe 和 Cu 浓度以及 Mg、Zn、Fe 和 Cu 的总产量更高。血清和第一次挤奶初乳 Cu 浓度呈正相关，但其他矿物质血清和第一次挤奶初乳浓度或总产量之间没有显著相关性。胎次与第一次挤奶初乳 Ca、P、K 和 Fe 浓度和产量有关；年轻的多胎奶牛具有更高的这些矿物质浓度和总产量。第一次挤奶初乳矿物质浓度和产量之间呈线性（Fe）、二次方（P、Na 和 K）和三次方（Mg、Zn 和 Cu）关系。在所有情况下，矿物质总产量均与第一次挤奶初乳产量呈线性相关。总之，奶牛之间第一次挤奶初乳矿物质浓度和总产量的差异部分可以用胎次和初乳产量来解释。需要进一步研究包括初产奶牛和在不同管理环境下的奶牛，以扩大对奶牛初乳矿物质浓度和总产量的认识。
