Production, milk iodine, and nutrient utilization in Jersey cows supplemented with the brown seaweed Ascophyllum nodosum (kelp meal) during the grazing season
Production, milk iodine, and nutrient utilization in Jersey cows supplemented with the brown seaweed Ascophyllum nodosum (kelp meal) during the grazing season
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DOI：
10.3168/jds.2019-16478
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发表时间：
2019-09-01
影响因子：
3.5
通讯作者：
Brito, A. F.
中科院分区：
文献类型：
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作者：
Antaya, N. T.;Ghelichkhan, M.;Brito, A. F.
海带粉（KM）是一种由棕色海藻Ascophyllum nodosum制成的补充剂，已知它可以生物积累碘（I），并且是最丰富的根皮单宁来源，可以抑制瘤胃蛋白质水解和微生物生长。本研究的目的是调查KM对放牧奶牛的生产，牛奶I，血液代谢产物的浓度，营养物质的表观全消化道消化率和CH 4排放量的影响。在研究开始时，将8头经产泽西奶牛（平均值+/- SD）和12头经产泽西奶牛（平均值142 +/- 47天）分配至0 g/d KM（对照饲料，CTRL）或113 g/d KM（褐藻饲料，BSW）组，采用随机完全区组设计。饮食制定产生一个70：30的粗精比，并包括（干物质基础）：48%的冷季型多年生牧草和52%的部分TMR（pTMR）。每个实验周期（n = 3）持续28天，数据和样品收集发生在每个周期的最后7天。奶牛每天有大约16.5小时的牧场使用时间。牧草干物质摄入量增加，总干物质摄入量往往增加奶牛饲喂BSW与CTRL饮食。产奶量和乳成分的浓度和产量不受日粮的影响。同样，皮质醇，葡萄糖，脂肪酸和甲状腺素的血液浓度没有改变喂养CTRL或BSW。然而，观察到牛奶I浓度的饮食x周期相互作用;提供BSW饮食的奶牛在周期1、2和3期间具有更高的牛奶I浓度，但在周期2中观察到BSW和CTRL之间的最大差异（分别为579和111 μ g/L）。除第2阶段外，饲喂KM的奶牛中牛奶I的浓度未超过推荐用于人类消费的500 μ g/L阈值。饮食x期间的相互作用也被发现血清三碘甲状腺原氨酸浓度，粗蛋白质和酸性洗涤剂纤维，CH 4的生产，尿排泄嘌呤衍生物的总消化道消化率。总体而言，缺乏KM对牛奶产量和牛奶成分的浓度和产量的影响表明，乳制品生产商在放牧季节做出KM补充决策之前应考虑成本。未来的研究是必要的，以评估零售有机牛奶中的浓度，因为在美国东北部和中西部的有机奶制品，并可能在该国的其他地区的KM补充剂的高流行率。
Kelp meal (KM) is a supplement made from the brown seaweed Ascophyllum nodosum, known to bio-accumulate iodine (I) and to be the richest source of phlorotannins, which can inhibit ruminal proteolysis and microbial growth. The objective of this study was to investigate the effects of KM on production, milk I, concentrations of blood metabolites, apparent total-tract digestibility of nutrients, and CH4 emissions in grazing dairy cows. Eight multiparous Jersey cows averaging (mean +/- SD) 175 +/- 60 d in milk and 12 primiparous Jersey cows averaging 142 +/- 47 d in milk at the beginning of the study were assigned to either 0 g/d of KM (control diet, CTRL) or 113 g/d of KM (brown seaweed diet, BSW) in a randomized complete block design. Diets were formulated to yield a 70: 30 forage-to-concentrate ratio and consisted of (dry matter basis): 48% cool-season perennial herbage and 52% partial TMR (pTMR). Each experimental period (n = 3) lasted 28 d, with data and sample collection taking place during the last 7 d of each period. Cows had approximately 16.5 h of access to pasture daily. Herbage dry matter intake increased, and total dry matter intake tended to increase in cows fed BSW versus the CTRL diet. Milk yield and concentrations and yields of milk components were not affected by diets. Similarly, blood concentrations of cortisol, glucose, fatty acids, and thyroxine did not change with feeding CTRL or BSW. However, a diet x period interaction was observed for milk I concentration; cows offered the BSW diet had greater milk I concentration during periods 1, 2, and 3, but the largest difference between BSW and CTRL was observed in period 2 (579 vs. 111 mu g/L, respectively). Except for period 2, the concentration of milk I in cows fed KM did not exceed the 500 mu g/L threshold recommended for human consumption. Diet x period interactions were also found for serum triiodothyronine concentration, total-tract digestibilities of crude protein and acid detergent fiber, CH4 production, and urinary excretion of purine derivatives. Overall, the lack of KM effects on milk yield and concentrations and yields of milk components indicate that dairy producers should consider costs before making KM supplementation decisions during the grazing season. Future research is needed to evaluate the concentration of I in retail organic milk because of the high prevalence of KM supplementation in northeastern and midwestern US organic dairies and possibly in other regions of the country.