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Frequency of diet delivery to dairy cows: Effect on nutrient digestion, rumen fermentation, methane production, nitrogen utilization, and milk production.
Journal of Dairy Science ( IF 3.5 ) Pub Date : 2020-06-10 , DOI: 10.3168/jds.2020-18199
C Benchaar 1 , F Hassanat 1
Affiliation  

The objective of this study was to examine the effect of frequency of diet delivery to dairy cows on nutrient digestion, rumen fermentation, milk production, nitrogen utilization, enteric methane emission, and manure methane production potential. Twelve lactating cows were used in a replicated 3 × 3 Latin square design (35-d period) and offered a TMR ad libitum [56:44 ratio of forage to concentrate, dry matter (DM) basis] once (0930 h), twice (0930 and 2130 h), or 4 times daily (0930, 1300, 1630, and 2130 h). Frequency of diet delivery did not affect intake or apparent total-tract digestibility of DM and nutrients. Likewise, milk production, milk composition (fat, protein, and lactose), and milk production efficiency (kg of milk/kg of DM intake or g of milk N/g of N intake) were not changed by frequency of diet delivery. Although diurnal variation of ruminal pH, total VFA, and acetate molar proportion were influenced by frequency of diet delivery, daily average ruminal pH, total VFA, and acetate and propionate molar proportions were not affected by frequency of diet delivery. Daily enteric CH4 emission averaged 534 g/d and was not changed by frequency of diet delivery. Methane energy losses (on gross energy intake basis) were lower when cows received the diet once daily (5.8%) versus twice or 4 times daily (6.1%). Urinary N excretion was higher for cows receiving the diet 4 times daily compared with cows receiving the diet once or twice daily (36 vs. 34% of N intake). Frequency of diet delivery had no influence on manure volatile solids excretion or maximal CH4 production potential. Results from this study show that delivering the diet once daily reduces enteric CH4 energy losses compared with twice or 4 times daily, whereas urinary N losses increased by delivering the diet 4 times daily compared with once or twice daily. However, milk production and maximal manure CH4 emission potential were not affected by frequency of diet delivery.



中文翻译:

日粮向奶牛的输送频率:对营养物质消化,瘤胃发酵,甲烷产生,氮利用和牛奶产生的影响。

这项研究的目的是检验饲喂日粮频率对奶牛的养分消化,瘤胃发酵,产奶量,氮利用量,肠内甲烷排放和粪便甲烷生产潜力的影响。将十二头泌乳牛用于3×3拉丁方格重复设计(35天周期),并提供任意TMR [饲草与浓缩物,干物质(DM)的比例为56:44]一次(0930小时),两次(0930和2130小时),或每天4次(0930、1300、1630和2130小时)。饮食分娩的频率不影响DM和营养素的摄入或表观总消化率。同样,产奶量,产奶量(脂肪,蛋白质和乳糖)和产奶效率(kg牛奶/ kg DM摄入量或g牛奶N / g氮摄入量)不会因饲喂频率而改变。尽管瘤胃pH,总VFA和乙酸盐摩尔比的日变化受饲喂频率的影响,但日平均瘤胃pH,总VFA和乙酸根和丙酸摩尔比不受饲喂频率的影响。每日肠溶性4排放量平均为534 g / d,并且不因饮食分娩频率而改变。当奶牛每天接受一次饮食(5.8%)时,甲烷能量损失(以总能量摄入为基础)较低,而每天两次或四次(6.1%)。与每天饲喂一次或两次的母牛相比,每天饲喂4次的母牛的尿N排泄更高(36和32%的氮摄入)。饲喂频率对粪便中挥发性固体的排泄或最大的CH 4产生潜能没有影响。这项研究的结果表明,每天饮食一次可以减少肠内CH 4与每天两次或四次相比,能量损失减少了,而每天摄入四次饮食使尿中的氮损失增加了。然而,产奶频率不影响产奶量和最大肥料CH 4排放潜能。

更新日期:2020-07-18
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