Nonprotein Nitrogen and Protein Distribution in the Milk of Cows

DePeters, E.J.; Ferguson, James D.

doi:10.3168/jds.s0022-0302(92)78085-0

Cited by 192 publications

(120 citation statements)

References 68 publications

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“…Some authors found that high environment temperatures reduced the total protein content and decreased the consistency of milk clots of four different breeds, which was lower in summer and higher in winter (DePeters and Cant, 1992;DePeters and Ferguson, 1992).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of raw milk quality in different production systems and periods of the year

et al. 2014

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-The objective of this study was to evaluate the quality of raw milk in different production systems and its variation throughout the year. The data were collected from 943 dairy farms in the South, Central-West and Central regions of the state of Minas Gerais, and in Vale do Paraíba, in the state of São Paulo, Brazil. The data were collected in the period from January 2009 to September 2011, in a total of 18,206 samples. The properties were divided into confinement, semi-confinement and extensive production systems. The evaluated factors were somatic cell count (SCC), total bacterial count (TBC) and protein and fat contents. There was no effect of production system on the contents of protein, fat and SCC. Total bacterial count, however, was affected by production. Seasonal variations were found for SCC, TBC, protein and fat; the highest protein values were found from March to June; the highest fat contents were obtained from May to August; and TBC and SCC, from December to March. The production system does not interfere with the percentage of fat and protein and SCC of the milk. However, confinement systems present a better TBC content. Both month and year are factors that interfere with TBC, SCC, protein and milk fat, and the best patterns are found in the coldest periods of the year.

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Section: Discussionmentioning

confidence: 99%

Evaluation of raw milk quality in different production systems and periods of the year

et al. 2014

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“…Milk urea nitrogen is primarily derived from BUN because urea equilibrates with water in the body. This equilibrium explains the high correlation between MUN and BUN concentrations (Depeters and Ferguson, 1992). Blood urea nitrogen derives from at least 2 sources: the liver detoxification of ammonia diffused from the rumen and the catabolism of AA in the liver (Depeters and Ferguson, 1992).…”

Section: Introductionmentioning

confidence: 91%

“…This equilibrium explains the high correlation between MUN and BUN concentrations (Depeters and Ferguson, 1992). Blood urea nitrogen derives from at least 2 sources: the liver detoxification of ammonia diffused from the rumen and the catabolism of AA in the liver (Depeters and Ferguson, 1992). Thereby, MU concentration could reflect protein metabolism in the cow and could be related to the diet.…”

Section: Introductionmentioning

confidence: 91%

Modeling milk urea of Walloon dairy cows in management perspectives

Bastin

Laloux

Gillon

et al. 2009

Journal of Dairy Science

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The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management purposes. Data included 607,416 MU test-day records of firstlactation cows from 632 dairy herds in the Walloon Region of Belgium. Several advanced features were used. First, to detect the herd influence, the classical herd × test-day effect was split into 3 new effects: a fixed herd × year effect, a fixed herd × month-period effect, and a random herd test-day effect. A fixed time period regression was added in the model to take into account the yearly oscillations of MU on a population scale. Moreover, first autoregressive processes were introduced and allowed us to consider the link between successive test-day records. The variance component estimation indicated that large variance was associated with the random herd × test-day effect (48% of the total variance), suggesting the strong influence of herd management on the MU level. The heritability estimate was 0.13. By comparing observed and predicted MU levels at both the individual and herd levels, target ranges for MU concentrations were defined to take into account features of each cow and each herd. At the cow level, an MU record was considered as deviant if it was <200 or >400 mg/L (target range used in the field) and if the prediction error was >50 mg/L (indicating a significant deviation from the expected level). Approximately 7.5% of the MU records collected between June 2007 and May 2008 were beyond these thresholds. This combination allowed for the detection of potentially suspicious cows. At the herd level, the expected MU level was considered as the sum of the solutions for specific herd effects. A herd was considered as deviant from its target range when the prediction error was greater than the standard deviation of MU averaged by herd test day. Results showed that 6.7% of the herd test-day MU levels between June 2007 and May 2008 were considered deviant. These deviations seemed to occur more often during the grazing period. Although theoretical considerations developed in this study should be validated in the field, this research showed the potential use of a test-day model for analyzing functional traits to advise dairy farmers.

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“…In this study, the numeric increase in BUN which cows fed with alfalfa hay was expected because alfalfa hay has more rumen degradable protein (RDP) than corn silage (NRC, 2001) but the BUN might be compensated by similar starch and fermentable energy content of diets. DePeters and Ferguson (1992) reported that concentrations of ruminal NH 3 and BUN are highly correlated. In this study, the concentrations of ruminal NH 3 was not affected by the dietary treatments and ranged from 17.4 to 20.7 mg/dl (Gencoglu and Turkmen, 2006).…”

Section: Resultsmentioning

confidence: 99%

The effects of partial replacement of corn silage on biochemical blood parameters in lactating primiparous dairy cows

Polat¹,

Gencoglu²,

Turkmen³

2009

Vet. Med. - Czech

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ABSTRACT:The aim of this experiment was to investigate the effects of partial replacement of corn silage with long alfalfa hay and/or coarse chopped wheat straw on biochemical parameters in late lactating Holstein primiparous dairy cows. Twelve late lactating Holstein primiparous cows including four cows equipped with a rumen cannula, averaging 210 ± 20 days in milk and weighing 575 ± 50 kg were randomly assigned in a 4 × 4 Latin square design. During each of four 21-days periods, cows were fed four total mixed diets that were varied in the forage sources:(1) 50% corn silage (CS), (2) 35% corn silage + 15% wheat straw (CSW), (3) 35% corn silage + 15% alfalfa hay (CSA), (4) 25% corn silage + 10% wheat straw + 15% alfalfa hay (CSWA). At the end of the feeding period, blood samples were taken from jugular vein. Serum glucose, total protein, albumin/globulin, creatinine, creatinin kinase, urea and uric acid levels were determined by using Auto Technicon DAX 72 autoanalyzer. While serum glucose, albumin, globulin, urea, uric acid and creatinine kinase activity were not found significantly different among groups, serum total protein (between CS and CSA, CS and CSWA) and creatinine (between CSA and CSWA) levels had statistical significance at the levels of P < 0.05. It is concluded that rumen propionate and ammonia levels may be good indicator for glucose and BUN, respectively.

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Nonprotein Nitrogen and Protein Distribution in the Milk of Cows

Cited by 192 publications

References 68 publications

Evaluation of raw milk quality in different production systems and periods of the year

Evaluation of raw milk quality in different production systems and periods of the year

Modeling milk urea of Walloon dairy cows in management perspectives

The effects of partial replacement of corn silage on biochemical blood parameters in lactating primiparous dairy cows

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