Genetic and Phenotypic Relationships Among Milk Urea Nitrogen, Fertility, and Milk Yield in Holstein Cows

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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Lactose and milk urea nitrogen: fluctuations during lactation in Holstein cows

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982014000900004 ◽

2014 ◽

Vol 43 (9) ◽

pp. 479-484 ◽

Cited By ~ 14

Author(s):

Andrés F. Henao-Velásquez ◽

Oscar David Múnera-Bedoya ◽

Ana Cristina Herrera ◽

Jorge H. Agudelo-Trujillo ◽

Mario Fernando Cerón-Muñoz

Keyword(s):

Holstein Cows ◽

Urea Nitrogen ◽

Milk Urea ◽

Milk Urea Nitrogen

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AGPAT3 Gene polymorphisms are associated with milk production traits in Chinese Holstein cows

Journal of Dairy Research ◽

10.1017/s0022029921000546 ◽

2021 ◽

pp. 1-6

Author(s):

Xiaomei Sun ◽

Yan Liang ◽

Qisong Gao ◽

Jiahe Guo ◽

Cheng Tang ◽

...

Keyword(s):

Milk Production ◽

Milk Yield ◽

Nucleotide Polymorphisms ◽

Production Traits ◽

Milk Production Traits ◽

Fat Percentage ◽

Urea Nitrogen ◽

Protein Percentage ◽

Milk Urea ◽

Milk Urea Nitrogen

Abstract The current study reports the identification of previously undiscovered single-nucleotide polymorphisms (SNPs) in the bovine AGPAT3 gene and further investigates their associations with milk production traits. Our results demonstrate that the major allele C of the SNP g.12264 C > T is positively correlated with test-day milk yield, protein percentage and 305-day milk yield. Importantly, in silico analysis showed that the C/T transition at this locus gives rise to two new transcription factor binding sites (TFBS), E2F1 and Nkx3-2. Polymorphism g.18658 G > A was the only SNP associated with milk urea nitrogen (MUN) with the G allele related to an increase in milk urea nitrogen as well as fat percentage. The GG genotype of SNP g.28731 A > G was associated with the highest fat and protein percentage and lowest 305-day milk yield and somatic cell score (SCS). The association between AGPAT3 locus and milk production traits could be utilized in marker-assisted selection for the genetic improvement of milk production traits and, probably in conjunction with other traits, for selection to improve fitness of dairy cattle.

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1184 Trends in milk urea nitrogen, milk composition, and milk yield in dairy farms in the Northeast U.S

Journal of Animal Science ◽

10.2527/jam2016-1184 ◽

2016 ◽

Vol 94 (suppl_5) ◽

pp. 568-568

Author(s):

A. N. Hristov ◽

M. T. Harper ◽

J. Oh ◽

F. Giallongo ◽

J. C. Lopes ◽

...

Keyword(s):

Milk Yield ◽

Dairy Farms ◽

Milk Composition ◽

Urea Nitrogen ◽

Milk Urea ◽

Milk Urea Nitrogen

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Predicting urinary nitrogen excretion by milk urea nitrogen in lactating Chinese Holstein cows

Animal Science Journal ◽

10.1111/j.1740-0929.2007.00452.x ◽

2007 ◽

Vol 78 (4) ◽

pp. 395-399 ◽

Cited By ~ 6

Author(s):

Shaowei ZHAI ◽

Jianxin LIU ◽

Yueming WU ◽

Junan YE

Keyword(s):

Nitrogen Excretion ◽

Holstein Cows ◽

Urea Nitrogen ◽

Chinese Holstein ◽

Chinese Holstein Cows ◽

Milk Urea ◽

Urinary Nitrogen Excretion ◽

Urinary Nitrogen ◽

Milk Urea Nitrogen

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Milk urea-nitrogen negatively affected first-service breeding success in commercial dairy cows in Prince Edward Island, Canada

Preventive Veterinary Medicine ◽

10.1016/j.prevetmed.2007.05.005 ◽

2007 ◽

Vol 82 (1-2) ◽

pp. 42-50 ◽

Cited By ~ 3

Author(s):

P. Arunvipas ◽

J.A. VanLeeuwen ◽

I.R. Dohoo ◽

E.R. Leger ◽

G.P. Keefe ◽

...

Keyword(s):

Dairy Cows ◽

Breeding Success ◽

Prince Edward Island ◽

Urea Nitrogen ◽

Milk Urea ◽

Milk Urea Nitrogen

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319 Predicting Urinary Nitrogen Excretion from Milk Urea Nitrogen of Fresh Forage or Total Mixed Ration Fed Dairy Cows: A Meta-analysis

Journal of Animal Science ◽

10.1093/jas/skab235.315 ◽

2021 ◽

Vol 99 (Supplement_3) ◽

pp. 171-171

Author(s):

Matthew R Beck ◽

Cameron Marshall ◽

Konagh Garrett ◽

Andrew P Foote ◽

Ronaldo Vibart ◽

...

Keyword(s):

Dairy Cows ◽

Meta Analysis ◽

Live Weight ◽

Predictive Ability ◽

Nitrogen Excretion ◽

Good Precision ◽

Urea Nitrogen ◽

Total Mixed Ration ◽

Milk Urea ◽

Milk Urea Nitrogen

Abstract Urine nitrogen excretion (g/d; UN) represent a significant environmental impact for both confinement feeding and pastoral based dairy systems. It is difficult to measure UN directly due to animal handling and labor requirements, especially in forage based production systems. The currently available milk urea nitrogen (MUN) equations have been shown to overestimate UN excretion of grazing dairy cows compared with an equation using urinary creatinine and UN concentration, indicating that diet may alter the relationship between MUN and UN. This potential was explored using data retrieved (treatment means: n = 69 and 27 for fresh forage [FF] and total mixed ration [TMR] fed cattle, respectively) from the literature and new data obtained from dairy cows fed FF (n = 15) in metabolism crates was used to test the new equations. The TMR data from literature was further split into a training set (to develop the model; n = 53) and a test set (to validate the model; n = 16). There was an interaction for diet type (P < 0.01) where UN (g/d) = 0.023 × MUN (mg/dL) × live-weight (kg, LW) for TMR fed cattle, (similar to a pre-established equation); however, UN (g/d) = 0.015 × MUN × LW for FF fed cattle. For FF based equations, the New MUN equation and the creatinine equation showed good precision and accuracy (Lin’s CCC = 0.79 and 0.74, respectively) and adequate predictive ability (RMSEP = 29.8 and 35.9, respectively). The new MUN equation for TMR fed cattle showed excellent accuracy and precision (Lin’s CCC = 0.87) with good predictive ability (RMSEP = 24.3) for UN excretion (observed mean = 216.5 g/d). The new equations generated during this meta-analysis provide promising predictive ability of UN excretion, which can be used for management considerations, future research, and policy making.

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