PMID- 26051314
OWN - NLM
STAT- MEDLINE
DCOM- 20160210
LR  - 20181202
IS  - 1525-3198 (Electronic)
IS  - 0022-0302 (Linking)
VI  - 98
IP  - 8
DP  - 2015 Aug
TI  - The effect of high and low levels of supplementation on milk production, nitrogen 
      utilization efficiency, and milk protein fractions in late-lactation dairy cows.
PG  - 5529-44
LID - S0022-0302(15)00371-9 [pii]
LID - 10.3168/jds.2014-9016 [doi]
AB  - To fill the feed deficit in the autumn/late lactation period in a seasonal 
      grazing system, supplementation is required. This study aimed to investigate the 
      use of baled grass silage or concentrate as supplementation to grazing dairy cows 
      in late lactation. Eighty-four grass-based spring-calving dairy cows, averaging 
      212d in milk, were allocated to 1 of 6 treatments [high grass allowance (HG), low 
      grass allowance (LG), grass with a low concentrate allocation (GCL), grass with a 
      low grass silage allocation (GSL), grass with a high concentrate allocation 
      (GCH), and grass with a high grass silage allocation (GSH)] to measure the 
      effects of using baled grass silage or concentrate as supplements to grazed 
      grass. Effects on intake, milk yield, milk composition and N fractions, and N 
      utilization efficiency were measured. Treatments HG and LG received 17 and 14kg 
      of dry matter (DM) grass/cow per d, respectively. Treatments GCL and GSL were 
      offered 14kg of DM grass/cow per d and 3kg of DM of supplementation/cow per d. 
      Treatments GCH and GSH were offered 11kg of DM grass/cow per d and 6kg of DM of 
      supplementation/cow per d. Milk yield was greatest in the GCH treatment and milk 
      solids yield was greatest in both concentrate-supplemented treatments. The HG and 
      LG treatments excreted a greater quantity of N as a proportion of N intake than 
      the supplemented treatments. The HG treatment also excreted the greatest total 
      quantity of N. This indicates an improvement in N utilization efficiency when 
      supplementation is offered compared with grazing only. Offering 6kg of DM of 
      either grass silage or concentrate as supplementation decreased milk true protein 
      concentration compared with offering a grass-only diet. This suggests that 
      increasing the proportion of supplementation relative to grass may negatively 
      affect milk processability, which is associated with milk true protein 
      concentration.
CI  - Copyright (c) 2015 American Dairy Science Association. Published by Elsevier Inc. 
      All rights reserved.
FAU - Reid, M
AU  - Reid M
AD  - Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, 
      Co. Cork, Ireland; Institute of Global Food Security, Queen's University Belfast, 
      Stranmillis Road, Belfast, BT9 5AY, UK.
FAU - O'Donovan, M
AU  - O'Donovan M
AD  - Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, 
      Co. Cork, Ireland.
FAU - Murphy, J P
AU  - Murphy JP
AD  - Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, 
      Co. Cork, Ireland.
FAU - Fleming, C
AU  - Fleming C
AD  - Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, 
      Co. Cork, Ireland.
FAU - Kennedy, E
AU  - Kennedy E
AD  - Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, 
      Co. Cork, Ireland.
FAU - Lewis, E
AU  - Lewis E
AD  - Teagasc, Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, 
      Co. Cork, Ireland. Electronic address: Eva.lewis@teagasc.ie.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20150604
PL  - United States
TA  - J Dairy Sci
JT  - Journal of dairy science
JID - 2985126R
RN  - 0 (Milk Proteins)
RN  - N762921K75 (Nitrogen)
SB  - IM
MH  - *Animal Nutritional Physiological Phenomena
MH  - Animals
MH  - Cattle
MH  - Diet/*veterinary
MH  - Dietary Supplements
MH  - Eating
MH  - Female
MH  - Lactation/*physiology
MH  - Milk/chemistry
MH  - Milk Proteins/*analysis
MH  - Nitrogen/*metabolism
MH  - Poaceae
MH  - Seasons
MH  - Silage
OTO - NOTNLM
OT  - concentrate
OT  - grass
OT  - grass silage
OT  - milk protein
OT  - nitrogen
OT  - nutrition
EDAT- 2015/06/09 06:00
MHDA- 2016/02/11 06:00
CRDT- 2015/06/09 06:00
PHST- 2014/10/25 00:00 [received]
PHST- 2015/04/12 00:00 [accepted]
PHST- 2015/06/09 06:00 [entrez]
PHST- 2015/06/09 06:00 [pubmed]
PHST- 2016/02/11 06:00 [medline]
AID - S0022-0302(15)00371-9 [pii]
AID - 10.3168/jds.2014-9016 [doi]
PST - ppublish
SO  - J Dairy Sci. 2015 Aug;98(8):5529-44. doi: 10.3168/jds.2014-9016. Epub 2015 Jun 4.