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

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.

scholarly journals Effect of genotype and lactation on milk urea nitrogen, blood urea nitrogen and milk composition of dairy cows

2016 ◽  
Vol 19 (1-2) ◽  
pp. 74-84 ◽  
Author(s):  
MSK Sarker ◽  
MA Islam ◽  
KS Huque ◽  
NR Sarker ◽  
MM Hossain ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Blood Urea Nitrogen ◽  
Strong Correlation ◽  
Winter Season ◽  
Live Weight ◽  
Urea Nitrogen ◽  
Crossbred Cows ◽  
Significant Difference ◽  
Milk Urea ◽  
Milk Urea Nitrogen

This study was aimed to evaluate milk urea nitrogen (MUN) of cows considering variations in dietary nutrition, genetic quality and lactation yield which will be helpful to develop practical feeding guidelines for dairy cows based on MUN. A total of forty dairy cows consisting 20 native and 20 crossbred milking cows were selected in Sonaimuri, Noakhali in winter season to know the daily feed availability to cows. Feed, milk and blood samples were collected and analyzed. The dry matter intake of the local and crossbred cows were 2.58 and 2.74 (g/100 kg live weight respectively) and they did not show statistical variation (p<0.05). Metabolizable energy (ME) and protein intake showed significantly higher values in crossbred (85 MJ/day and 815 g/day) compared to local (40 MJ/day and 395 g/day) cows in winter season (p>0.05). Live weight, body condition score and milk yield and MUN varied significantly between genotypes although blood urea nitrogen (BUN) value did not differ significantly. Strong correlation between lactose and protein percentage was observed in both the lactations in local cows. Milk minerals are negatively correlated with protein, SnF and minerals in first lactation whereas moderate to strong relation was observed in second lactation with those parameters. Milk constituents didn’t show any difference between local & crossbred cows. Strong correlation between milk protein and lactose with SnF were observed in both local and crossbred cows in first lactation stage. BUN value showed a moderate correlation between milk yields of local cows. The results revealed that genotype and lactation have no effect on BUN although MUN value showed significant difference between local and crossbred cows.Bangladesh J. of Livestock Res. 19(1-2): 74-84, Jan-Dec 2012

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

2007 ◽  
Vol 82 (1-2) ◽  
pp. 42-50 ◽  
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

scholarly journals Corn supplementation on milk urea nitrogen content of dairy cows grazing on temperate annual pasture

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Aline Cristina Dall-Orsoletta ◽  
João Gabriel Rossini Almeida ◽  
Márcia Maria Oziemblowski ◽  
Henrique Mendonça Nunes Ribeiro-Filho
Keyword(s):  
Dairy Cows ◽  
Protein Production ◽  
Milk Protein ◽  
Live Weight ◽  
Corn Silage ◽  
Utilization Efficiency ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Lactation Stage ◽  
Milk Urea

ABSTRACT: The excretion of urinary nitrogen (N), one of the most important environmental contaminants from livestock systems, is highly correlated with milk urea N content. The objective of this research was to evaluate the use of different types of corn supplementation on milk urea N in grazing dairy cows. Twelve Holstein × Jersey lactating dairy cows were divided into six uniform groups according to milk production, lactation stage and live weight. Treatments were compared according to a 3 × 3 replicated Latin square experimental design, with three periods of seventeen days (twelve days to adaptation and five to measurements). The experimental treatments were exclusively grazing (G); grazing + supplementation with 4.2 kg DM of corn silage (CS) and grazing + supplementation with 3.2 kg DM of ground corn (GC). The pasture used was annual ryegrass (Lolium multiflorum L.) and white oats (Avena sativa L.). The milk protein production increased 65 g/day in the GC treatment group compared to the G and CS groups. The supplemented dairy cows showed lower milk urea N (-2.8 mg/dL) than unsupplemented cows, but the N utilization efficiency (g N output in milk/ g N intake) did not change between treatments (average = 0.26). Additionally, there was a relationship between milk and plasma urea nitrogen concentrations (R2 = 0.64). In conclusion, for dairy cows grazing annual temperate pastures, corn ground supplementation increased milk protein production and reduced the excretion of milk urea N, whereas corn silage reduced the excretion of milk urea N without affecting milk protein production.

scholarly journals Animal as the Solution: Searching for Environmentally Friendly Dairy Cows

2021 ◽  
Vol 13 (18) ◽  
pp. 10451
Author(s):  
Cameron J. Marshall ◽  
Pablo Gregorini
Keyword(s):  
Dairy Cows ◽  
Selective Breeding ◽  
Production Systems ◽  
Environmentally Friendly ◽  
Methane Emissions ◽  
Potential Solution ◽  
Urea Nitrogen ◽  
Breeding Values ◽  
Milk Urea ◽  
Milk Urea Nitrogen

There is increasing societal concern surrounding the environmental externalities generated from ruminant production systems. Traditional responses to address these externalities have often been system-based. While these approaches have had promising results, they have served to view the animal as a problem that needs solving, rather than as a potential solution. This review attempts to answer the question: can we breed animals that are more environmentally friendly to address environmental outcomes and satisfy consumer demand? This was done by exploring the literature of examples where animals have been specifically bred to reduce their environmental impact. The use of milk urea nitrogen breeding values has been demonstrated as a tool allowing for selective breeding of dairy cows to reduce nitrogen losses. Low milk urea nitrogen breeding values have been documented to result in reduced urinary nitrogen concentrations per urination event, which ultimately reduces the level of nitrogen that will be lost from the system. The ability to breed for low methane emissions has also shown positive results, with several studies demonstrating the heritability and subsequent reductions in methane emissions via selective breeding programs. Several avenues also exist where animals can be selectively bred to increase the nutrient density of their final product, and thus help to address the growing demand for nutrient-dense food for a growing human population. Animal-based solutions are permanent, cumulative, and often more cost-effective than system-based approaches. With continuing research and interest in breeding for more positive environmental outcomes, the animal can now start to be viewed as a potential solution to many of the issues faced by ruminant production systems, rather than simply being seen as a problem.

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