دورية أكاديمية
Rumen metabolism, omasal flow of nutrients, and microbial dynamics in lactating dairy cows fed fresh perennial ryegrass (Lolium perenne L.) not supplemented or supplemented with rolled barley grain.
| العنوان: | Rumen metabolism, omasal flow of nutrients, and microbial dynamics in lactating dairy cows fed fresh perennial ryegrass (Lolium perenne L.) not supplemented or supplemented with rolled barley grain. |
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| المؤلفون: | Dineen M; Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland P61 C996; Department of Animal Science, Cornell University, Ithaca, NY 14853., McCarthy B; Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland P61 C996., Dillon P; Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland P61 C996., LaPierre PA; Department of Animal Science, Cornell University, Ithaca, NY 14853., Fessenden S; Department of Animal Science, Cornell University, Ithaca, NY 14853., Matthews C; Teagasc, Moorepark Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland P61 C996., Galvin N; Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland P61 C996., Van Amburgh ME; Department of Animal Science, Cornell University, Ithaca, NY 14853. Electronic address: mev1@cornell.edu. |
| المصدر: | Journal of dairy science [J Dairy Sci] 2020 Dec; Vol. 103 (12), pp. 11332-11348. Date of Electronic Publication: 2020 Oct 15. |
| نوع المنشور: | Journal Article |
| اللغة: | English |
| بيانات الدورية: | Publisher: American Dairy Science Association Country of Publication: United States NLM ID: 2985126R Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1525-3198 (Electronic) Linking ISSN: 00220302 NLM ISO Abbreviation: J Dairy Sci Subsets: MEDLINE |
| أسماء مطبوعة: | Publication: Champaign, IL : American Dairy Science Association Original Publication: Lancaster, Pa. [etc.] |
| مواضيع طبية MeSH: | Hordeum* , Lolium*, Cattle/*physiology , Dietary Supplements/*analysis , Milk/*metabolism, Animals ; Body Weight ; Cattle/microbiology ; Diet/veterinary ; Dietary Fiber/metabolism ; Digestion ; Edible Grain ; Female ; Fermentation ; Lactation ; Milk/chemistry ; Nutrients/metabolism ; Omasum/metabolism ; Rumen/metabolism ; Rumen/microbiology ; Urea/metabolism |
| مستخلص: | The objective of this study was to evaluate the effect of rolled barley grain (RB) supplementation on rumen metabolism, omasal flow of nutrients, and microbial dynamics in lactating dairy cows fed fresh perennial ryegrass (Lolium perenne L.; PRG)-based diets. Ten ruminally cannulated Holstein cows averaging (mean ± standard deviation) 49 ± 23 d in milk and 513 ± 36 kg of body weight were assigned to 1 of 2 treatments in a switchback design. The treatment diets were PRG only (G) or PRG plus 3.5 kg of dry matter RB (G+RB). The study consisted of three 29-d periods where each period consisted of 21 d of diet adaptation and 8 d of data and sample collection. A double marker system was used to quantify nutrient flow entering the omasal canal along with labeled 15 N-ammonium sulfate to measure bacterial, protozoal, and nonmicrobial N flow. Rumen evacuation techniques were used to determine nutrient and microbial pool size, allowing the calculation of fractional rates of digestion and microbial growth. There was no difference in daily milk yield or energy-corrected milk yield between treatments. Milk fat concentration and milk urea N decreased, whereas milk protein concentration increased in cows fed the G+RB diet. During the omasal sampling phase, dry matter intake was higher in cows fed the G+RB diet. Ruminal and total-tract neutral detergent fiber digestibility was lower in G+RB cows; however, no difference was observed in reticulorumen pH. The rumen pool size of fermentable carbohydrate was increased in cows fed the G+RB diet; however, the fractional rate of digestion was decreased. Flow of nonammonia N and bacterial N at the omasal canal increased in cows fed the G+RB diet compared with the G diet. Protozoa N flow was not different between diets; however, protozoa appeared to supply a much larger amount of microbial N and exhibited shorter generation time than previously considered. Feed N ruminal digestibility, corrected for microbial contribution, was similar for both treatments (88.4 and 89.0% for G and G+RB, respectively). In conclusion, RB supplementation did not benefit overall animal performance; however, it reduced ruminal neutral detergent fiber digestibility and increased bacterial N flow. The results demonstrate the large dependence of cows consuming PRG-based diets on microbial N as the main source of nonammonia N supply. Additional quantitative research is required to further describe the supply of nutrients and microbial dynamics in cows consuming PRG-based diets in an effort to determine most limiting nutrients. (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.) |
| فهرسة مساهمة: | Keywords: fermentable carbohydrate; omasal flow; pasture; protozoa |
| المشرفين على المادة: | 0 (Dietary Fiber) 8W8T17847W (Urea) |
| تواريخ الأحداث: | Date Created: 20201018 Date Completed: 20210210 Latest Revision: 20210210 |
| رمز التحديث: | 20240628 |
| DOI: | 10.3168/jds.2020-18437 |
| PMID: | 33069418 |
| قاعدة البيانات: | MEDLINE |
Full Text Finder | تدمد: | 1525-3198 |
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| DOI: | 10.3168/jds.2020-18437 |