scholarly journals Investigation of milk urea nitrogen concentration and factors affecting its variation in Greek Holstein herds

2018 ◽  
Vol 68 (3) ◽  
pp. 423 ◽  
Author(s):  
N. SIACHOS (Ν. ΣΙΑΧΟΣ) ◽  
N. PANOUSIS (Ν. ΠΑΝΟΥΣΗΣ) ◽  
G. ARSENOS (Γ. ΑΡΣΕΝΟΣ) ◽  
G. E. VALERGAKIS (Γ.Ε. ΒΑΛΕΡΓΑΚΗΣ)
Keyword(s):  
Milk Fat ◽  
Nitrogen Concentration ◽  
Multiple Regression Model ◽  
Milk Traits ◽  
Protein Ratio ◽  
Urea Nitrogen ◽  
Factors Affecting ◽  
Target Values ◽  
Milk Urea ◽  
Milk Urea Nitrogen

Milk urea nitrogen (MUN) is an important tool in dairy cow nutrition, as it reflects the amount of nitrogen in the diet which is not used for production. The objective of this study was to evaluate MUN values in Greek dairy herds, for the first time, and to investigate the source of its possible variation. For this purpose, a dataset of 23,266 milk records from 24 Holstein herds in the region of Thessaly (Greece) was used. Descriptive statistics, analysis of variance and a multiple regression model were used for statistical analysis. Significant differences were observed among farms (P<0.05). Mean MUN concentration was 15.54 mg/dL. More than 90% of the measurements were above the upper limit of reference herd target-values. In contrast with previous observations, lower MUN values (P<0.05) were observed during the summer and autumn. A positive relationship between milk yield and MUN was observed, but only up to MUN values of 16 mg/dL. Milk fat content and fat/protein ratio were negatively related to MUN, while cows with higher protein content had lower MUN values (P<0.05). Most milk traits and sampling month explained only 25.8% of the variation in MUN concentration (P<0.05). In conclusion, MUN values in Greek dairy farms were greater than target-values suggested for most herds, indicating systematic nutritional errors that could affect health and reproductive performance of dairy cows.

Factors affecting the milk urea nitrogen concentration in Chinese Holstein cows

2018 ◽  
Vol 68 (2) ◽  
pp. 193-211 ◽  
Author(s):  
Huimin Zhang ◽  
Mengqi Wang ◽  
Hongrui Jiang ◽  
Yan Cui ◽  
Hailei Xia ◽  
...  
Keyword(s):  
Protein Content ◽  
Nitrogen Concentration ◽  
Dairy Farm ◽  
Urea Nitrogen ◽  
Factors Affecting ◽  
Chinese Holstein ◽  
Chinese Holstein Cows ◽  
Milk Urea ◽  
Positive Correlations ◽  
Milk Urea Nitrogen

AbstractIn order to investigate the factors affecting milk urea nitrogen in Chinese Holstein cows, a large commercial dairy farm participated in a 30-month study. In this study, the mean milk urea nitrogen concentration was 11.75 mg/dl. The milk urea nitrogen reached its maximum value on day 90 of lactation for the first parity and the third or higher parities, but it peaked at the end of lactation for the second parity. The milk urea nitrogen of the first parity was lower than that of other parities. The milk urea nitrogen showed its minimum level in January, and reached its maximum in July. The milk urea nitrogen at the first month of lactation in cows calving in summer was higher than other seasons, while at the fourth month of lactation, the milk urea nitrogen of cows calving in autumn was significantly lower than in cows calving in other seasons. Positive correlations were observed between daily milk yield, net energy for lactation, crude protein and milk urea nitrogen for the first and third parities, but negative correlations were observed in the second parity. The milk urea nitrogen showed significantly positive correlations with fat content, total solid content and daily matter intake for all parities. A negative correlation was observed between milk urea nitrogen and protein content, with the exception of the second parity. For all data, as milk urea nitrogen concentration increased, milk protein content decreased. It has been recommended that milk urea nitrogen concentration should be evaluated in combination with parity, days in milk, season (or month), daily matter intake and dietary nutritional components, in order to improve the management and economic benefits of dairy farm.

scholarly journals Milk Urea Nitrogen Concentration: Heritability and Genetic Correlations with Reproductive Performance and Disease

2005 ◽  
Vol 88 (12) ◽  
pp. 4434-4440 ◽  
Author(s):  
R.G. Mitchell ◽  
G.W. Rogers ◽  
C.D. Dechow ◽  
J.E. Vallimont ◽  
J.B. Cooper ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Nitrogen Concentration ◽  
Genetic Correlations ◽  
Urea Nitrogen ◽  
Milk Urea ◽  
Milk Urea Nitrogen

Factors affecting milk urea nitrogen and protein concentrations in Quebec dairy cows

1999 ◽  
Vol 39 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Richard Eicher ◽  
Emile Bouchard ◽  
Michel Bigras-Poulin
Keyword(s):  
Dairy Cows ◽  
Urea Nitrogen ◽  
Factors Affecting ◽  
Milk Urea ◽  
Milk Urea Nitrogen

scholarly journals Milk Urea Concentration to the Evaluation of Nitrogen Efficiency Transformation on Dairy Farms

2021 ◽  
Vol 65 (3) ◽  
pp. 30-39
Author(s):  
I. Maskaľová ◽  
V. Vajda
Keyword(s):  
Multiple Regression ◽  
Nitrogen Concentration ◽  
Nutrient Content ◽  
Nitrogen Efficiency ◽  
Regression Equations ◽  
Urea Nitrogen ◽  
Regression Relationship ◽  
Milk Urea ◽  
Nutritional Effects ◽  
Milk Urea Nitrogen

Abstract The aim of this study was to evaluate the effects of nutrition on the milk urea nitrogen (MUN) concentration; on the transformation of N in the farm’s conditions; and there-by allow the milk urea nitrogen concentration to serve as a tool to maximize the protein nutrition and the metabolism of the cows. The relations evaluated by linear or multiple regression confirmed that the highest nutritional effects of the crude protein (CP) on the MUN concentration, which represented a 69.3 % variation in the MUN content. According to the CP content in the total mix ration (TMR) and MUN content (3150 milk samples) under farm conditions, a regression relationship was determined for the estimated of MUN (mg.dl–1) = –13.2 + 0.16 × CP (g.kg–1 dry matter). For multiple regression, the rate of variation expressed by this relationship increased to 72 for nutrient content and 78.3 % for nutrient intake in the TMR. The efficiency of nitrogen utilization (ENU) determined by calculations based on the MUN content according to the regression equations represented a negative correlation (P < 0.0001; R2 = 0.854) with respect to the CP content in the TMR and that the increased CP content by 1 % in the range of 14 to 18 % in the TMR decreased the ENU by 1.48 %. Validation of the models for prediction of nitrogen transformation (ENU) for practical application on the farms determined the best equation, which used the available data from the routine analysis of Breeding services of Slovakia. After taking into consideration of our breeding conditions, it was confirmed that the equation of ENU had taken into account the MUN, in addition to the amount of the milk produced.

scholarly journals Effects of herd, season and days in milk on milk urea nitrogen of crossbred dairy cows in Sylhet

2015 ◽  
Vol 2 (2) ◽  
pp. 287-292
Author(s):  
Nusrat Zahan Shoshe ◽  
Md Abdul Baset ◽  
Md Tariqul Islam ◽  
Shiekh MA Matin ◽  
Md Abdullah Al Mahmud
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Milk Fat ◽  
Wet Season ◽  
Urea Nitrogen ◽  
Lactation Stage ◽  
Milk Urea ◽  
Daily Milk Yield ◽  
Daily Milk ◽  
Milk Urea Nitrogen

The study included 724 crossbred cows (Local × Holstein Friesian) from 9 dairy farms of Sylhet district from July 2013 to June 2014 to determine the effect of herd, season, and days in milk in milk urea nitrogen and the effect of milk production and composition on milk urea nitrogen. According to the season, milk samples were divided into two groups: wet season (June - October) and dry season (November - February). Days in milk (DIM) were grouped into two lactation stages: Lactation 1 (?100 days in milk) and Lactation 2 (?100 days in milk). Milk urea nitrogen was grouped into five categories by increments of 5 mg/dl, started with those less than 10 mg/dl and finishing with concentration greater than 25 mg/dl. The daily milk yield was 6.78 kg ranged from 2.00 to 18.00 kg. The mean of milk urea nitrogen (MUN) concentration was 14.58 mg/dl. Mean values for milk fat and protein contents were 3.74 % and 3.72 %. Among the 9 herds, the highest content of milk urea (MU) was 16.37 mg/dl which was found in herd 2 and the second highest estimation of MU content were in herd 1, 3, 6 and 9 (15.58, 15.51, 15.12 and 14.45 mg/dl, respectively). In the district of Sylhet, the lowest MU content was estimated in herd 4, 5, 7 and 8 (13.59, 13.48, 13.16 and 13.60 mg/dl, respectively). Difference of MUN concentration was not significant between the dry and wet season. The MUN concentrations were 14.82 mg/dl and 14.90 mg/dl in dry and wet season respectively. The concentration of MUN in Lactation 1 was 13.61 mg/dl and in Lactation 2 was 16.26 mg/dl. Milk fat (%) were 3.56, 3.77, 3.64, 4.15 and 3.66 when MUN concentration were ?10.00, 10.01- 15.00, 15.01-20.00, 20.01-25.00 and ?24.01 mg/dl respectively. Daily milk yield did not increase with the increase of MUN concentration. Milk yield were 6.37, 7.21, 6.23, 7.31 and 7.00 Kg/d while MUN concentration were ?10.00, 10.01-15.00, 15.01-20.00, 20.01-25.00 and ?25.01 mg/dl. It may be concluded that herd category and lactation stage influence the milk urea nitrogen concentration of crossbred dairy cows in the Sylhet district.Res. Agric., Livest. Fish.2(2): 287-292, August 2015

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