Palmitic acid increased yields of milk and milk fat and nutrient digestibility across production level of lactating cows.
Palmitic acid increased yields of milk and milk fat and nutrient digestibility across production level of lactating cows.
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棕榈酸提高了泌乳牛的牛奶和乳脂产量以及营养物质的消化率。
DOI：
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发表时间：
2013
影响因子：
3.5
通讯作者：
M. S. Allen
中科院分区：
文献类型：
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作者：
P. Piantoni;A. Lock;M. S. Allen
在具有协变量周期的交叉设计实验中，在不同产奶量（34.5 至 66.2 kg/d）的奶牛中评估了补充棕榈酸对采食量、消化率以及代谢和生产反应的影响。 32 头经产荷斯坦奶牛（产奶 151 ± 66 天）被随机分配到产奶水平内的治疗序列。治疗方法是在饮食中添加棕榈酸（PA；99% C16:0）或对照（SH；豆壳）（占饮食 DM 的 2%）。治疗期为 21 天，最后 4 天用于数据和样本收集。在第一个治疗期之前，给奶牛喂食对照饮食 21 天，并获得所有变量的基线值（协变量期）。在协变量期间测量的产奶量（初步产奶量）用作协变量。一般来说，对于测量的响应变量，没有检测到治疗和初步产奶量之间的相互作用。与 SH 相比，PA 处理提高了乳脂百分比（3.40 vs. 3.29%）、产奶量（46.0 vs. 44.9 kg/d）、乳脂（1.53 vs. 1.45 kg/d）和 3.5% 脂肪校正乳（44.6 vs. 42.9 kg/d）。蛋白质和乳糖的浓度和产量不受处理的影响。与 SH 相比，PA 处理不会影响干物质 (DM) 摄入量或体重，往往会降低身体状况评分（2.93 比 2.99），并提高饲料效率（3.5% 脂肪校正牛奶/DM 摄入量；1.60 比 1.54）。 PA 处理提高了中性洗涤纤维（39.0 vs. 35.7%）和有机物（67.9 vs. 66.2%）的全消化道消化率，但降低了脂肪酸（FA）消化率（61.2 vs. 71.3%）。随着总 FA 摄入量的增加，总 FA 消化率下降 (R(2) = 0.51)，总 FA 吸收量增加 (二次方 R(2) = 0.82)。脂肪酸产量响应（按每单位额外 FA 摄入量在牛奶中分泌的额外 FA 产量计算）总 FA 为 11.7%，C16:0 加 cis-9 C16:1 FA 为 16.5%。 PA处理增加了非酯化FA（101 vs. 90.0 μEq/L）和胆囊收缩素（19.7 vs. 17.6 pmol/L）的血浆浓度，并倾向于增加胰岛素的血浆浓度（10.7 vs. 9.57 μIU/mL）。结果表明，以日粮干物质的 2% 饲喂棕榈酸有可能提高牛奶和乳脂产量，与生产水平无关，且不会增加身体状况评分或体重。然而，一小部分补充的 FA 被分配到牛奶中。
The effects of palmitic acid supplementation on feed intake, digestibility, and metabolic and production responses were evaluated in dairy cows with a wide range of milk production (34.5 to 66.2 kg/d) in a crossover design experiment with a covariate period. Thirty-two multiparous Holstein cows (151 ± 66 d in milk) were randomly assigned to treatment sequence within level of milk production. Treatments were diets supplemented (2% of diet DM) with palmitic acid (PA; 99% C16:0) or control (SH; soyhulls). Treatment periods were 21 d, with the final 4 d used for data and sample collection. Immediately before the first treatment period, cows were fed the control diet for 21 d and baseline values were obtained for all variables (covariate period). Milk production measured during the covariate period (preliminary milk yield) was used as covariate. In general, no interactions were detected between treatment and preliminary milk yield for the response variables measured. The PA treatment increased milk fat percentage (3.40 vs. 3.29%) and yields of milk (46.0 vs. 44.9 kg/d), milk fat (1.53 vs. 1.45 kg/d), and 3.5% fat-corrected milk (44.6 vs. 42.9 kg/d), compared with SH. Concentrations and yields of protein and lactose were not affected by treatment. The PA treatment did not affect dry matter (DM) intake or body weight, tended to decrease body condition score (2.93 vs. 2.99), and increased feed efficiency (3.5% fat-corrected milk/DM intake; 1.60 vs. 1.54), compared with SH. The PA treatment increased total-tract digestibility of neutral detergent fiber (39.0 vs.35.7%) and organic matter (67.9 vs. 66.2%), but decreased fatty acid (FA) digestibility (61.2 vs. 71.3%). As total FA intake increased, total FA digestibility decreased (R(2) = 0.51) and total FA absorbed increased (quadratic R(2) = 0.82). Fatty acid yield response, calculated as the additional FA yield secreted in milk per unit of additional FA intake, was 11.7% for total FA and 16.5% for C16:0 plus cis-9 C16:1 FA. The PA treatment increased plasma concentration of nonesterified FA (101 vs. 90.0 μEq/L) and cholecystokinin (19.7 vs. 17.6 pmol/L), and tended to increase plasma concentration of insulin (10.7 vs. 9.57 μ IU/mL). Results show that palmitic acid fed at 2% of diet DM has the potential to increase yields of milk and milk fat, independent of production level without increasing body condition score or body weight. However, a small percentage of the supplemented FA was partitioned to milk.
影响因子：
15.9
作者：
Stein, DT;Stevenson, BE;McGarry, JD
通讯作者：
McGarry, JD