Effect of increasing dietary protein with constant lysine:methionine ratio on production and omasal flow of nonammonia nitrogen in lactating dairy cows.

التفاصيل البيبلوغرافية
العنوان:	Effect of increasing dietary protein with constant lysine:methionine ratio on production and omasal flow of nonammonia nitrogen in lactating dairy cows.
المؤلفون:	Gonzalez Ronquillo M; Universidad Autonoma del Estado de Mexico, Facultad de Medicina Veterinaria y Zootecnia, Instituto Literario 100, Toluca, Mexico 50000., Faciola AP; Department of Animal Sciences, University of Florida, Gainesville 32611., Nursoy H; Department of Animal Nutrition, Veterinary Faculty, Bingol University, 12000, Bingol, Turkey., Broderick GA; US Dairy Forage Research Center, USDA Agricultural Research Service, Madison, WI 53726; Department of Dairy Science, University of Wisconsin, Madison 53706. Electronic address: gbroderi@wisc.edu.
المصدر:	Journal of dairy science [J Dairy Sci] 2021 May; Vol. 104 (5), pp. 5319-5331. Date of Electronic Publication: 2021 Mar 02.
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:	Lysine* , Omasum*, Animals ; Cattle ; Diet/veterinary ; Dietary Proteins ; Digestion ; Female ; Lactation ; Methionine ; Milk ; Nitrogen ; Rumen
مستخلص:	Eight lactating cows were fed 4 diets in which dietary crude protein (CP) was increased in steps of approximately 2 percentage units from 11 to 17% of DM by replacing high-moisture corn with soybean meal supplemented with rumen-protected Met to maintain a Lys:Met ratio of 3:1 in metabolizable protein. Trial design was a replicated 4 × 4 Latin square; experimental periods lasted 28 d, with data and sample collection being performed during wk 3 and 4 of each period. Digesta samples were collected from the rumen as well as the omasum to measure metabolite concentrations and ruminal outflow of N fractions using infusion of ¹⁵ N-enriched ammonia to quantify microbial nonammonia N (NAN) and nonmicrobial NAN. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.). There were linear increases in the yields of milk and true protein and concentration of milk urea N, and a linear decrease in N efficiency, with increasing dietary CP. Apparent ruminal and total-tract N digestibility increased linearly with increasing dietary CP, but estimated true total-tract N digestibility was not affected. Apparent digestibility of the other macronutrients was not influenced by diet. Ruminal ammonia, total AA and peptides, and branched-chain VFA also increased linearly with dietary CP. The ¹⁵ N enrichment of liquid- and particle-associated microbes linearly declined with increasing dietary CP due to decreasing ¹⁵ N enrichment of the ammonia pool. Although no effect of dietary CP on nonmicrobial NAN flow was detected, total NAN flow increased linearly from 525 g/d at 11% CP to 637 g/d at 17% CP due to the linear increase in microbial NAN flow from 406 g/d at 11% CP to 482 g/d at 17% CP. Under the conditions of this study, when dietary CP was increased by adding soybean meal supplemented with rumen-protected Met, improved milk and protein yields were driven not by RUP supply but by increased ruminal outflow of microbial protein. (Copyright © 2021 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
فهرسة مساهمة:	Keywords: dietary crude protein; lysine:methionine ratio; omasal flow of microbial protein
المشرفين على المادة:	0 (Dietary Proteins) AE28F7PNPL (Methionine) K3Z4F929H6 (Lysine) N762921K75 (Nitrogen)
تواريخ الأحداث:	Date Created: 20210305 Date Completed: 20210426 Latest Revision: 20210426
رمز التحديث:	20231215
DOI:	10.3168/jds.2020-19541
PMID:	33663832
قاعدة البيانات:	MEDLINE

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تدمد:	1525-3198
DOI:	10.3168/jds.2020-19541