PMID- 15653524
OWN - NLM
STAT- MEDLINE
DCOM- 20050329
LR  - 20131121
IS  - 0022-0302 (Print)
IS  - 0022-0302 (Linking)
VI  - 88
IP  - 2
DP  - 2005 Feb
TI  - Association between live body weight and milk urea concentration in Holstein 
      cows.
PG  - 580-4
AB  - Use of milk urea (MU) concentration as a parameter for detection of nutritional 
      imbalances requires identification and quantification of nutritional and 
      nonnutritional factors that influence it. The objective of this study was to 
      assess the relationship between live body weight (BW) and MU concentration in 
      Holstein cows. Results for the test-day measurements at 7 dairy farms were 
      obtained from the Israeli Dairy Herd Improvement Center and concomitant cow 
      weights were registered in local computerized weighing systems. A total of 1996 
      cows and 25,485 records were studied. The overall unadjusted per-cow mean MU 
      nitrogen concentration and BW were 15.3 mg/dL (SD = 3.8) and 593 kg (SD = 84), 
      respectively. The linear association between BW and MU was negative and highly 
      significant and the quadratic component of BW had a highly significant positive 
      association with MU. There was a significant interaction between the association 
      of MU and BW with lactation number. Sampling month, milk yield, milk fat 
      percentage, and somatic cell count accounted for significant variation in MU. 
      Predicted MU concentrations at different BW values were calculated for each 
      parity group, by setting equations that included the estimates of the variables 
      associated with MU and constant values (lactation averages) for the independent 
      variables, with the exception of BW. Plotting of results showed exponential 
      characteristics for the relationship between BW and predicted MU concentrations. 
      At any of the considered BW, predicted MU concentrations were lower for 
      first-parity cows. The trends and interactions found in the present study may 
      contribute to improving accuracy of models designed to calculate urinary nitrogen 
      excretion rates and normative milk urea concentrations.
FAU - Hojman, D
AU  - Hojman D
AD  - Dairy Cattle Department-Extension Service, Ministry of Agriculture and Rural 
      Development, Bet Dagan 50150, Israel. danhoj@shaham.moag.gov.il
FAU - Gips, M
AU  - Gips M
FAU - Ezra, E
AU  - Ezra E
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - United States
TA  - J Dairy Sci
JT  - Journal of dairy science
JID - 2985126R
RN  - 0 (Lipids)
RN  - 0 (Milk Proteins)
RN  - 8W8T17847W (Urea)
SB  - IM
MH  - Animals
MH  - *Body Weight
MH  - Cattle/*physiology
MH  - Cell Count
MH  - Female
MH  - Lactation
MH  - Lipids/analysis
MH  - Milk/*chemistry/cytology
MH  - Milk Proteins/analysis
MH  - Parity
MH  - Urea/*analysis
EDAT- 2005/01/18 09:00
MHDA- 2005/03/30 09:00
CRDT- 2005/01/18 09:00
PHST- 2005/01/18 09:00 [pubmed]
PHST- 2005/03/30 09:00 [medline]
PHST- 2005/01/18 09:00 [entrez]
AID - S0022-0302(05)72721-1 [pii]
AID - 10.3168/jds.S0022-0302(05)72721-1 [doi]
PST - ppublish
SO  - J Dairy Sci. 2005 Feb;88(2):580-4. doi: 10.3168/jds.S0022-0302(05)72721-1.