Wu Z, Bernard J K, Taylor S J
Department of Animal and Dairy Science, University of Georgia, Tifton 31793.
Department of Animal and Dairy Science, University of Georgia, Tifton 31793.
J Dairy Sci. 2015 Jul;98(7):4629-39. doi: 10.3168/jds.2014-8711. Epub 2015 Apr 29.
Thirty-six multiparous Holstein cows and 12 springing heifers were used in a 9-wk randomized design trial to determine the response of cows fed calcareous marine algae (CMA) beginning 3wk prepartum or after parturition through 6wk postpartum on dry matter intake (DMI), blood and urine metabolites, and milk yield and composition. Within parity and expected calving date, cows were assigned randomly to 1 of 4 treatments with a 2×2 factorial arrangement. Prepartum diets were supplemented with calcium carbonate (CON) or 50g/d of CMA with a resulting dietary cation-anion difference of -5.17 and -3.99mEq/100g, respectively. Postpartum diets were formulated to provide either 317g/d of sodium bicarbonate and calcium carbonate (NBC) or 100g/d of CMA, providing a dietary cation-anion difference of 35.58 and 15.64mEq/100g, based on 25kg/d of DMI, respectively. No differences were observed in prepartum DMI or postpartum DMI, milk yield, percentage of milk fat, protein, lactose, and solids-not fat among treatments. Milk protein yield was higher for cows fed CMA prepartum compared with CON. Interactions of prepartum treatment and week were observed for yield of milk fat and energy-corrected milk because of higher yields for cows fed CMA during wk 2 and 6 compared with CON. Serum Na concentrations were greater for cows fed CON prepartum or NBC postpartum compared with CMA. Postpartum urinary concentrations of Na exhibited an interaction among treatments and were higher for CON-NBC and CMA-NBC compared with CON-CMA and CMA-CMA. Similar interactions of treatments were also observed for serum urea N and creatinine postpartum. Postpartum urinary K concentrations were higher for cows fed CMA postpartum compared with NBC. Results of this trial indicate that feeding cows CMA prepartum does not affect DMI or serum metabolites prepartum, but does support higher milk protein yield. Performance and serum metabolite concentrations of cows fed CMA postpartum were comparable with that of cows fed NBC, except for changes in serum and urinary concentration of Na, which was a function of dietary Na intake.
36头经产荷斯坦奶牛和12头初产青年母牛被用于一项为期9周的随机设计试验，以确定在产前3周或产后开始至产后6周饲喂钙质海藻（CMA）的奶牛对干物质摄入量（DMI）、血液和尿液代谢物以及产奶量和组成的反应。在相同胎次和预期产犊日期内，奶牛按2×2析因设计随机分配到4种处理中的1种。产前日粮分别添加碳酸钙（CON）或50g/d的CMA，日粮阴阳离子差分别为-5.17和-3.99mEq/100g。产后日粮配制为分别提供317g/d的碳酸氢钠和碳酸钙（NBC）或100g/d的CMA，基于25kg/d的DMI，日粮阴阳离子差分别为35.58和15.64mEq/100g。各处理间产前DMI、产后DMI、产奶量、乳脂率、蛋白质率、乳糖率和非脂固形物率均无差异。与CON组相比产前饲喂CMA的奶牛乳蛋白产量更高。由于在第2周和第6周饲喂CMA的奶牛比CON组产量更高，因此观察到产前处理与周数对乳脂产量和能量校正乳产量存在交互作用。与CMA组相比，产前饲喂CON或产后饲喂NBC的奶牛血清Na浓度更高。产后尿液中Na浓度在处理间存在交互作用，CON-NBC和CMA-NBC组高于CON-CMA和CMA-CMA组。产后血清尿素氮和肌酐在处理间也观察到类似的交互作用。与NBC组相比，产后饲喂CMA的奶牛尿液K浓度更高。本试验结果表明，产前饲喂奶牛CMA不影响产前DMI或血清代谢物，但能提高乳蛋白产量。产后饲喂CMA的奶牛的生产性能和血清代谢物浓度与饲喂NBC的奶牛相当，除了血清和尿液中Na浓度的变化，这是日粮Na摄入量的函数。
