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.

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 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

scholarly journals Using Milk Urea Nitrogen to Evaluate Diet Formulation and Environmental Impact on Dairy Farms

2001 ◽  
Vol 1 ◽  
pp. 852-859 ◽  
Author(s):  
J.S. Jonker ◽  
R.A. Kohn
Keyword(s):  
Environmental Impact ◽  
Dairy Cattle ◽  
Dairy Cows ◽  
Chesapeake Bay ◽  
Dairy Farms ◽  
Utilization Efficiency ◽  
Urea Nitrogen ◽  
Lactating Dairy Cows ◽  
Milk Urea ◽  
Lactating Dairy Cattle

Reducing nitrogen (N) excretion by dairy cattle is the most effective means to reduce N losses (runoff, volatilization, and leaching) from dairy farms. The objectives of this review are to examine the use of milk urea nitrogen (MUN) to measure N excretion and utilization efficiency in lactating dairy cows and to examine impacts of overfeeding N to dairy cows in the Chesapeake Bay drainage basin. A mathematical model was developed and evaluated with an independent literature data set to integrate MUN and milk composition to predict urinary and fecal excretion, intake, and utilization efficiency for N in lactating dairy cows. This model was subsequently used to develop target MUN concentrations for lactating dairy cattle fed according to National Research Council (NRC) recommendations. Target values calculated in this manner were 8 to 14 mg/dl for a typical lactation and were most sensitive to change in milk production and crude protein intake. Routine use of MUN to monitor dairy cattle diets was introduced to dairy farms (n = 1156) in the Chesapeake Bay watershed. Participating farmers (n = 454) were provided with the results of their MUN analyses and interpretive information monthly for a period of 6 months. The average MUN across all farms in the study increased in the spring, but the increase was 0.52 mg/dl lower for farmers receiving MUN results compared to those who did not participate in the program. This change indicated that participating farmers reduced N feeding compared to nonparticipants. Average efficiency of feed N utilization (N in milk / N in feed x 100) was 24.5% (SD = 4.5). On average, farmers fed 6.6% more N than recommended by the NRC, resulting in a 16% increase in urinary N and a 2.7% increase in fecal N compared to feeding to requirement. N loading to the Chesapeake Bay from overfeeding protein to lactating dairy cattle was estimated to be 7.6 million kg/year. MUN is a useful tool to measure diet adequacy and environmental impact from dairy farms.

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

scholarly journals PSVII-6 Effects of heat stress on proteolysis in dairy cattle skeletal muscle

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 168-168
Author(s):  
Melissa S Roths ◽  
Megan A Abeyta ◽  
Tori Rudolph ◽  
Brittany Wilson ◽  
Matthew B Hudson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Heat Stress ◽  
Dairy Cattle ◽  
Electric Heating ◽  
Economic Loss ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
E3 Ligases ◽  
Acclimation Period ◽  
Milk Urea

Abstract Heat stress (HS) occurs when internal body temperatures are elevated above a thermoneutral zone in response to extreme environmental temperatures. In the U.S. dairy industry, HS results in economic loss due to decreased feed intake, milk quality, and milk yield. Previous work has demonstrated increased plasma urea nitrogen in heat stressed dairy cattle which is thought to originate from increased skeletal muscle proteolysis, however this has not been empirically established. The objective of this investigation was to determine the extent to which HS promotes proteolysis in skeletal muscle of dairy cattle. We hypothesized HS would increase activation of the calpain and proteasome systems in skeletal muscle. To test this hypothesis, following a 3-d acclimation period in individual box stalls, all lactating dairy cows were held under thermoneutral (TN) conditions for 4-d for collection of baseline measures and then exposed to TN or HS conditions for 7-d followed by a biopsy of semitendinosus (n=8/group). To induce HS, cattle were fitted with electric heating blankets, which they wore for the duration of the heating period. This approach increased rectal temperature 1.1°C (P&lt; 0.05), respiratory rate by 33 bpm (P&lt; 0.05), plasma urea nitrogen by 19% (P=0.08) and milk urea nitrogen by 26% (P&lt; 0.05), and decreased dry matter intake by 32% (P&lt; 0.05) and milk production by 26% (P&lt; 0.05) confirming HS. Contrary to our expectations, we discovered that calpain I and II abundance and activation, and calpain activity were similar between groups. Likewise, protein expression of E3 ligases, MafBx and Murf1, were similar between groups as was total ubiquitinated proteins and proteasome activity. Collectively, and counter to our hypothesis, these results suggest skeletal muscle proteolysis is not increased following 7-d of HS. These data question the presumed dogma that increased blood urea nitrogen is due to elevated proteolysis in skeletal muscle.

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
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