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Moore SS, Costa A, Penasa M, Callegaro S, De Marchi M. How heat stress conditions affect milk yield, composition, and price in Italian Holstein herds. J Dairy Sci 2023; 106:4042-4058. [PMID: 37080787 DOI: 10.3168/jds.2022-22640] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 12/21/2022] [Indexed: 04/22/2023]
Abstract
An edited data set of 700 bulk and 46,338 test-day records collected between 2019 and 2021 in 42 Holstein-dominated farms in the Veneto Region (North of Italy) was available for the present study. Information on protein, fat and lactose content, somatic cell count, and somatic cell score was available in bulk milk as well as individual test-day records, whereas urea concentration (mg/dL), differential somatic cell count (%), and milk yield (kg/d) were available for test-day records only. Milk features were merged with meteorological data retrieved from 8 weather stations located maximum 10 km from the farms. The daily and weekly temperature-humidity index (THI; wTHI) and maximum daily (MTHI) and weekly temperature-humidity index were associated with each record to evaluate the effect of heat stress conditions on milk-related traits through linear mixed models. Least squares means were estimated to evaluate the effect of THI and, separately, of MTHI on milk characteristics correcting for conventional systematic factors. Overall, heat stress conditions lowered the quality of both bulk milk and test-day records, with fat and protein content being greatly reduced, and somatic cell score and differential somatic cell count augmented. Milk yield was not affected by either THI or MTHI in this data set, but the effect of elevated THI and MTHI was in general stronger on test-day records than on bulk milk. Farm-level economic losses of reduced milk quality rather than reduced yield as consequence of elevated THI or MTHI was estimated to be between $23.57 and $43.98 per farmer per day, which is of comparable magnitude to losses resulting from reduced production. Furthermore, MTHI was found to be a more accurate indicator of heat stress experienced by a cow, explaining more variability of traits compared with THI. The negative effect of heat stress conditions on quality traits commences at lower THI/MTHI values compared with milk yield. Thus, a progressive farmers' income loss due to climatic changes is already a reality and it is mainly due to deterioration of milk quality rather than quantity in the studied area.
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Affiliation(s)
- S Sterup Moore
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | - A Costa
- Department of Veterinary Medical Sciences (DIMEVET), Alma Mater University of Bologna, 40064 Ozzano dell'Emilia, Italy.
| | - M Penasa
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | - S Callegaro
- Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Firenze, 50144 Florence, Italy
| | - M De Marchi
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
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The Influence of Rotational Length, along with Pre- and Post-Grazing Measures on Nutritional Composition of Pasture during Winter and Spring on New Zealand Dairy Farms. Animals (Basel) 2022; 12:ani12151934. [PMID: 35953923 PMCID: PMC9367542 DOI: 10.3390/ani12151934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022] Open
Abstract
The quality of ryegrass−clover pasture was investigated between August (winter: start of calving) and November (spring: end of breeding) on pasture-based dairy farms (>85% of total feed from pasture) that had short (n = 2, Farms A and B; winter ~30 days, spring ~20−25 days) or long (n = 2, Farms C and D; winter ~35 days, spring ~25−30 days) grazing rotations to determine whether quality was affected by grazing rotation length (RT). Weekly assessments of pasture growth and herbage quality were made using a standardised electronic rising plate meter, and near-infrared spectroscopy, respectively. Data were subjected to repeated measure mixed model analysis, in which herbage quality was the outcome variable. The highest pre-grazing dry matter (PGDM) and height, post-grazing dry matter (DM) and height, and number of live leaves per tiller (leaf regrowth stage, LS) were present in late spring. Neutral detergent fibre (NDF), acid detergent fibre (ADF), metabolisable energy (ME), and organic matter digestibility (OMD) were positively correlated to each other (r2 ≥ 0.8) whilst ADF and lipid, and ADF and OMD were negatively correlated (r2 ≥ −0.8; p < 0.01). Metabolisable energy content was negatively correlated with ADF and NDF (r2 = −0.7, −0.8, respectively), and was inversely related to PGDM. Metabolisable energy was higher (p < 0.05) in farms with shorter (overall mean: 11.2 MJ/kg DM) than longer (10.9 MJ/kg DM) RT. Crude protein was also inversely related to PGDM and was higher with shorter (23.2% DM) than longer (18.3% DM; p < 0.05) RT. Pre-grazing DM affected the amount of pasture that was grazed and, hence, the amount of DM remaining after grazing (post-grazing DM or residual), so that PGDM was correlated with post-grazing height and residual DM (r2 = 0.88 and 0.51, respectively; both p < 0.001). In conclusion, RT, LS, and PGDM during winter and spring influenced the herbage quality, therefore, better management of pastures may enhance the productivity of dairy cows.
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Malacco V, Beckett L, Hilger S, Doane P, Reis R, Donkin S. Effects of increased doses of lysine in a rumen-protected form on plasma amino acid concentration and lactational performance of dairy cows fed a lysine-deficient diet. J Dairy Sci 2022; 105:3064-3077. [DOI: 10.3168/jds.2021-20823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/29/2021] [Indexed: 11/19/2022]
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Application of Optical Quality Control Technologies in the Dairy Industry: An Overview. PHOTONICS 2021. [DOI: 10.3390/photonics8120551] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sustainable development of the agricultural industry, in particular, the production of milk and feed for farm animals, requires accurate, fast, and non-invasive diagnostic tools. Currently, there is a rapid development of a number of analytical methods and approaches that meet these requirements. Infrared spectrometry in the near and mid-IR range is especially widespread. Progress has been made not only in the physical methods of carrying out measurements, but significant advances have also been achieved in the development of mathematical processing of the received signals. This review is devoted to the comparison of modern methods and devices used to control the quality of milk and feed for farm animals.
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Ayers A, Ziegler SE, Darby HM, Bosworth S, Alvez JP, Colby J, Kraft J, Greenwood SL. Assessment of dietary protein supplementation on milk productivity of commercial organic dairy farms during the grazing season. J Dairy Sci 2021; 105:1099-1114. [PMID: 34799110 DOI: 10.3168/jds.2021-20355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/25/2021] [Indexed: 11/19/2022]
Abstract
Variability of protein and energy supply from pasture during the grazing season is a primary factor that can influence milk production of grazing organic dairy herds in the Northeast United States. This study evaluated the effects of altering the crude protein (CP) content of dietary supplements included in dairy rations fed to grazing organic dairy herds, on milk production and composition. Six commercial organic farms participated in a 6-wk trial, consisting of a 2-wk baseline period and 4-wk experimental period. Farms were paired by their summer 2017 milk urea nitrogen profile, and farms within each pair were assigned by restricted randomization to (1) continuation of their regular supplements (n = 3, control group, CON), or (2) supplement with altered CP as percentage of dry matter, formulated using an organic barley and roasted soybean mix (n = 3, treatment group, TRT). Throughout the 6-wk trial, individual milk samples were collected at 2 consecutive milkings weekly, while pasture and supplement samples, pasture measurements, and management information were collected twice weekly per farm. Data were statistically analyzed using the MIXED procedure of SAS (version 9.4, SAS Institute Inc.) for all parameters, and effects of treatment, week, and their interaction (treatment × week) were determined. The supplement CP (percentage of dry matter) during the baseline period was 13.5% for CON and 15.3% for TRT and 14.8% for CON and 19.3% for TRT during the experimental period. Milk production was 21% higher during the experimental period for TRT compared with CON (24.1 vs. 19.9 kg of milk per day, respectively). Milk production decreased for CON from wk 1 to wk 6 (23.6 vs. 20.4 kg of milk per day), whereas TRT maintained milked production from wk 1 to wk 6 (22.8 vs. 22.7 kg of milk per day). Milk composition was different between groups, with CON having higher fat percent (4.21 vs. 3.73%, respectively) and protein percent (3.15 vs. 3.05%, respectively) compared with TRT for the 6 wk. The milk urea nitrogen concentrations were similar between TRT and CON for the baseline period (11.9 vs. 12.1 mg/dL) and the final week of the experimental period (14.5 vs. 14.2 mg/dL). Although the effects of different diet CP fractions, particularly rumen undegradable protein and soluble protein, must be further delineated, these results indicate that altering the CP content of dietary supplements fed to grazing organic dairy cattle during the summer period in the Northeast US could be a useful mechanism to maintain milk production.
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Affiliation(s)
- A Ayers
- Department of Animal and Veterinary Sciences, University of Vermont, Burlington 05405
| | - S E Ziegler
- University of Vermont Extension, University of Vermont, St. Albans 05478
| | - H M Darby
- University of Vermont Extension, University of Vermont, St. Albans 05478
| | - S Bosworth
- University of Vermont Extension, University of Vermont, St. Albans 05478
| | - J P Alvez
- Center for Sustainable Agriculture, University of Vermont, Burlington 05405
| | - J Colby
- Center for Sustainable Agriculture, University of Vermont, Burlington 05405
| | - J Kraft
- Department of Animal and Veterinary Sciences, University of Vermont, Burlington 05405
| | - S L Greenwood
- Department of Animal and Veterinary Sciences, University of Vermont, Burlington 05405.
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Müller CBM, Görs S, Derno M, Tuchscherer A, Wimmers K, Zeyner A, Kuhla B. Differences between Holstein dairy cows in renal clearance rate of urea affect milk urea concentration and the relationship between milk urea and urinary nitrogen excretion. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:143198. [PMID: 33162136 DOI: 10.1016/j.scitotenv.2020.143198] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/13/2020] [Accepted: 10/16/2020] [Indexed: 06/11/2023]
Abstract
Urine and fecal excretions from cattle contribute to global nitrogen (N) emissions. The milk urea nitrogen (MUN) concentration in dairy cows is positively correlated with urinary urea N (UUN) emissions, and both decline with the reduction in crude protein intake. However, MUN concentration may differ between individual cows despite feeding the same ration. Thus, we hypothesized that due to differences in endogenous N utilization cows with high MUN concentration excrete more UUN than cows with a low MUN concentration. The objective of the present study was to elucidate N partitioning and urea metabolism in dairy cows with divergent MUN concentrations fed two planes of crude protein. Twenty Holstein dairy cows with high (HMU; n = 10) and low (LMU; n = 10) milk urea concentrations were fed two isocaloric diets with a low (LP) and normal (NP) crude protein level. Methane and ammonia emissions were recorded in respiration chambers. Feed intake, feces and urine excretions and milk yield were recorded for four days and subsamples were analyzed for total N and N-metabolites. A carbon-13 labeled urea bolus was administered intravenously followed by a series of plasma samplings. Total N and UUN excretions and ammonia emissions from excreta were lower on the LP diet, however, methane emissions, urinary N excretions and ammonia emissions were comparable between groups. Although plasma and salivary urea concentrations, urea pool size and urea turnover were higher, HMU cows had lower renal urea clearance rates. Additionally, HMU cows had lower renal clearance rates for creatinine, uric acid and creatine and excreted less uric acid (on the LP diet only) and creatine with urine. In conclusion, contrary to our hypothesis, HMU cows did not excrete more UUN than LMU cows. The lower urinary creatine excretion of HMU cows suggests that these animals have a lower environmental nitrogen footprint.
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Affiliation(s)
- Carolin Beatrix Maria Müller
- Institute of Nutritional Physiology 'Oskar Kellner', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 1, 18196 Dummerstorf, Germany
| | - Solvig Görs
- Institute of Nutritional Physiology 'Oskar Kellner', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 1, 18196 Dummerstorf, Germany
| | - Michael Derno
- Institute of Nutritional Physiology 'Oskar Kellner', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 1, 18196 Dummerstorf, Germany
| | - Armin Tuchscherer
- Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 1, 18196 Dummerstorf, Germany
| | - Klaus Wimmers
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Annette Zeyner
- Institute of Agricultural and Nutritional Sciences, Group Animal Nutrition, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Björn Kuhla
- Institute of Nutritional Physiology 'Oskar Kellner', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 1, 18196 Dummerstorf, Germany.
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Atsbeha DM, Flaten O, Olsen HF, Kjos NP, Kidane A, Skugor A, Prestløkken E, Øverland M. Technical and economic performance of alternative feeds in dairy and pig production. Livest Sci 2020. [DOI: 10.1016/j.livsci.2020.104123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Association of bulk tank milk urea nitrogen concentration with elevated individual cow values and investigation of sampling frequency for accurate assessment. Trop Anim Health Prod 2019; 51:2431-2436. [PMID: 31187407 DOI: 10.1007/s11250-019-01959-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 05/29/2019] [Indexed: 10/26/2022]
Abstract
Individual milk urea nitrogen (MUN) levels ≥ 19.63 mg/dL have been recently reported to significantly affect fertility. The objectives of the present study were to (a) predict the percentage of cows with elevated MUN within a herd using bulk tank (BTMUN) levels, in the absence of individual MUN records, and (b) establish a sampling frequency protocol for the assessment of actual BTMUN levels. A database of 17,687 monthly individual MUN and concurrent 229 monthly BTMUN records from 24 dairy herds was used. A ROC analysis was performed to determine the BTMUN threshold over which cows in the herd have elevated MUN concentrations that, based on literature, affect fertility. Moreover, a regression was run to predict the percentage of cows with elevated MUN within a herd from BTMUN values. A second database of 10,687 daily BTMUN records from 29 herds was used to identify an appropriate sampling frequency to assess the actual BTMUN levels. Eleven different sampling frequencies ranging from once to 8 times per month were assessed. A BTMUN value of 15.76 mg/dL was the optimum threshold over which cows with elevated MUN concentrations are included in a herd. The percentage of cows with elevated MUN values can be accurately predicted using BTMUN values (R2 = 0.872; P < 0.001). A bulk tank sampling frequency of once per week seems appropriate for most herds in order to assess the actual BTMUN levels, in case daily BTMUN values are not available from milk processors.
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Cecchinato A, Bobbo T, Ruegg PL, Gallo L, Bittante G, Pegolo S. Genetic variation in serum protein pattern and blood β-hydroxybutyrate and their relationships with udder health traits, protein profile, and cheese-making properties in Holstein cows. J Dairy Sci 2018; 101:11108-11119. [PMID: 30316608 DOI: 10.3168/jds.2018-14907] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/24/2018] [Indexed: 12/15/2022]
Abstract
The aim of this study was to investigate in Holstein cows the genetic basis of blood serum metabolites [i.e., total protein, albumin, globulin, albumin:globulin ratio (A:G), and blood β-hydroxybutyrate (BHB)], a set of milk phenotypes related to udder health, milk quality technological characteristics, and genetic relationships among them. Samples of milk were collected from 498 Holstein cows belonging to 28 herds. All animal welfare and milk phenotypes were assessed using standard analytical methodology. A set of Bayesian univariate and bivariate animal models was implemented via Gibbs sampling, and statistical inference was based on the marginal posterior distributions of parameters of concern. We observed a small additive genetic influence for serum albumin concentrations, moderate heritability (≥0.20) for total proteins, globulins, and A:G, and high heritability (0.37) for blood BHB. Udder health traits (somatic cell score, milk lactose, and milk pH) showed low or moderate heritabilities (0.15-0.20), whereas variations in milk protein fraction concentrations were confirmed as mostly under genetic control (heritability: 0.21-0.71). The moderate and high heritabilities observed for milk coagulation properties and curd firming modeling parameters provided confirmation that genetic background exerts a strong influence on the cheese-making ability of milk, largely due to genetic polymorphisms in the major milk protein genes. Blood BHB showed strong negative genetic correlations with globulins (-0.619) but positive correlations with serum albumin (0.629) and A:G (0.717), which suggests that alterations in the serum protein pattern and BHB blood levels are likely to be genetically related. Strong relationships were found between albumin and fat percentages (-0.894), between globulin and αS2-CN (-0.610), and, to a lesser extent, between serum protein pattern and milk technological characteristics. Genetic relationships between blood BHB and traits related to udder health and milk quality and technological characteristics were mostly weak. This study provides evidence that there is exploitable additive genetic variation for traits related to animal health and welfare and throws light on the shared genetic basis of these traits and the phenotypes related to the quality and cheese-making ability of milk.
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Affiliation(s)
- Alessio Cecchinato
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Padova, Italy.
| | - Tania Bobbo
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Padova, Italy
| | - Pamela L Ruegg
- Department of Animal Science, Michigan State University, East Lansing 48824
| | - Luigi Gallo
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Padova, Italy
| | - Giovanni Bittante
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Padova, Italy
| | - Sara Pegolo
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Padova, Italy
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Kidane A, Øverland M, Mydland LT, Prestløkken E. Milk production of Norwegian Red dairy cows on silages presumed either low or optimal in dietary crude protein content. Livest Sci 2018. [DOI: 10.1016/j.livsci.2018.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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12
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Zhao F, Wu T, Wang H, Ding L, Ahmed G, Li H, Tian W, Shen Y. Jugular arginine infusion relieves lipopolysaccharide-triggered inflammatory stress and improves immunity status of lactating dairy cows. J Dairy Sci 2018; 101:5961-5970. [DOI: 10.3168/jds.2017-13850] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 02/24/2018] [Indexed: 01/08/2023]
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13
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Zhang H, Wang M, Jiang H, Cui Y, Xia H, Ni W, Li M, Karrow NA, Yang Z, Mao Y. Factors affecting the milk urea nitrogen concentration in Chinese Holstein cows. ANIM BIOL 2018. [DOI: 10.1163/15707563-17000099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
In 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.
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Affiliation(s)
- Huimin Zhang
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Mengqi Wang
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Hongrui Jiang
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Yan Cui
- 2Institute of Agricultural Products Processing, Ningbo Academy of Agricultural Sciences, Ningbo 315040, China
| | - Hailei Xia
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Wei Ni
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Mingxun Li
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Niel A. Karrow
- 3Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, N1G 2W1, Canada
| | - Zhangping Yang
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Yongjiang Mao
- 1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
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Suarez WT, de Alvarenga Junior BR, de Oliveira Krambeck Franco M, Gabriel WL, de Oliveira DM, dos Santos VB. In Situ Determination of Urea in Milk Employing a Portable and Low-Cost LED Photometer. FOOD ANAL METHOD 2017. [DOI: 10.1007/s12161-017-1087-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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15
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Barros T, Quaassdorff M, Aguerre M, Colmenero JO, Bertics S, Crump P, Wattiaux M. Effects of dietary crude protein concentration on late-lactation dairy cow performance and indicators of nitrogen utilization. J Dairy Sci 2017; 100:5434-5448. [DOI: 10.3168/jds.2016-11917] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/14/2017] [Indexed: 11/19/2022]
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16
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Corea E, Aguilar J, Alas N, Alas E, Flores J, Broderick G. Effects of dietary cowpea (Vigna sinensis) hay and protein level on milk yield, milk composition, N efficiency and profitability of dairy cows. Anim Feed Sci Technol 2017. [DOI: 10.1016/j.anifeedsci.2017.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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17
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Duplessis M, Pellerin D, Cue RI, Girard CL. Short communication: Factors affecting vitamin B12 concentration in milk of commercial dairy herds: An exploratory study. J Dairy Sci 2016; 99:4886-4892. [PMID: 27040783 DOI: 10.3168/jds.2015-10416] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/18/2016] [Indexed: 11/19/2022]
Abstract
Only bacteria can synthesize vitamin B12, and this requires adequate Co supply. The natural source of vitamin B12 in human diets comes from animal products, especially those from ruminants. This study aimed to describe variability regarding vitamin B12 concentration in milk among and within commercial dairy herds in early lactation. A secondary objective was to explore potential causes for this variability such as genetic variation and diet characteristics. In total, 399 dairy cows (135 primiparous and 264 multiparous; 386 Holstein and 13 Jersey cows) in 15 commercial herds were involved. Milk samples were taken at 27.4±4.1 and 55.4±4.1d in milk. Neither parity (primiparous vs. multiparous) nor sampling time affected milk concentrations of vitamin B12. Nevertheless, vitamin B12 concentration in milk was highly variable among and within dairy herds. The lowest vitamin B12 concentration in milk of cows was observed in the Jersey herd. Among herds, vitamin B12 concentration in milk ranged from 2,309 to 3,878 pg/mL; one glass (250mL) of milk from those herds would provide between 23 and 40% of the vitamin B12 recommended daily allowance. Among individual cows, however, this provision varied between 16 and 57% of the recommendation. In spite of the limited size of the studied population, the heritability value was 0.23, suggesting that genetic selection could modify milk vitamin B12 concentration. We observed a positive relationship between milk vitamin B12 concentration and dietary acid detergent fiber content and a negative relationship between milk concentration of vitamin B12 and dietary crude protein content.
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Affiliation(s)
- M Duplessis
- Département des Sciences Animales, Université Laval, Québec, G1V 0A6, Canada; Agriculture et Agroalimentaire Canada, Centre de Recherche et Développement de Sherbrooke, Sherbrooke, Québec, J1M 1Z3, Canada
| | - D Pellerin
- Département des Sciences Animales, Université Laval, Québec, G1V 0A6, Canada
| | - R I Cue
- Department of Animal Science, McGill University, Ste-Anne-de-Bellevue, Québec, H9X 3V9, Canada
| | - C L Girard
- Agriculture et Agroalimentaire Canada, Centre de Recherche et Développement de Sherbrooke, Sherbrooke, Québec, J1M 1Z3, Canada.
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Dong LF, Zhang WB, Zhang NF, Tu Y, Diao QY. Feeding different dietary protein to energy ratios to Holstein heifers: effects on growth performance, blood metabolites and rumen fermentation parameters. J Anim Physiol Anim Nutr (Berl) 2016; 101:30-37. [DOI: 10.1111/jpn.12493] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/03/2016] [Indexed: 11/26/2022]
Affiliation(s)
- L. F. Dong
- Feed Research Institute; Chinese Academy of Agricultural Sciences; Beijing China
| | - W. B. Zhang
- Feed Research Institute; Chinese Academy of Agricultural Sciences; Beijing China
| | - N. F. Zhang
- Feed Research Institute; Chinese Academy of Agricultural Sciences; Beijing China
| | - Y. Tu
- Feed Research Institute; Chinese Academy of Agricultural Sciences; Beijing China
| | - Q. Y. Diao
- Feed Research Institute; Chinese Academy of Agricultural Sciences; Beijing China
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Moharrery A. Investigation of different levels of RDP in the rations of lactating cows and their effects on MUN, BUN and urinary N excretion. ITALIAN JOURNAL OF ANIMAL SCIENCE 2016. [DOI: 10.4081/ijas.2004.157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Bertoni G, Trevisi E, Lombardelli R. Some new aspects of nutrition, health conditions and fertility of intensively reared dairy cows. ITALIAN JOURNAL OF ANIMAL SCIENCE 2016. [DOI: 10.4081/ijas.2009.491] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Relationship between efficiency of nitrogen utilization and isotopic nitrogen fractionation in dairy cows: contribution of digestion v. metabolism? Animal 2016; 10:221-9. [DOI: 10.1017/s1751731115002025] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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22
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Cantalapiedra-Hijar G, Ortigues-Marty I, Lemosquet S. Diets rich in starch improve the efficiency of amino acids use by the mammary gland in lactating Jersey cows. J Dairy Sci 2015. [DOI: 10.3168/jds.2015-9518] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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23
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CASE STUDY: Reducing dietary protein decreased the ammonia emitting potential of manure from commercial dairy farms. ACTA ACUST UNITED AC 2015. [DOI: 10.15232/pas.2014-01360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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24
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Freitas D, Campos J, Marcondes M, Valadares Filho S, Franco M, Martins E, Rodrigues B, Oliveira A. Levedura seca integral na alimentação de vacas lactantes. ARQ BRAS MED VET ZOO 2015. [DOI: 10.1590/1678-7265] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Os efeitos da inclusão de levedura seca de cana-de-açúcar (Saccharomyces cerevisiae) na dieta de vacas lactantes foram avaliados com base no fornecimento de quatro dietas constituídas de diferentes níveis de substituição do farelo de soja pela levedura de cana-de-açúcar (0,00; 0,33; 0,67 e 1,00kg/kg de MS). O delineamento utilizado foi o quadrado latino 4 × 4. Não houve efeito dos tratamentos sobre o consumo de MS, MO, EE, FDNi e NDT, porém ocorreu redução linear no consumo de PB e FDNcp e aumento do consumo de CNF. Diferenças estatísticas não foram verificadas para os coeficientes de digestibilidade aparente da MS, MO, PB, CNF e NDT; no entanto os coeficientes do FDNcp e do EE decresceram linearmente. Não foi observado efeito sobre a produção e eficiência de síntese microbiana, utilização dos componentes nitrogenados e produção e composição do leite. Conclui-se que a levedura seca pode substituir 100% o farelo de soja na alimentação de vacas lactantes.
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Kristensen T, Jensen C, Østergaard S, Weisbjerg M, Aaes O, Nielsen N. Feeding, production, and efficiency of Holstein-Friesian, Jersey, and mixed-breed lactating dairy cows in commercial Danish herds. J Dairy Sci 2015; 98:263-74. [DOI: 10.3168/jds.2014-8532] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/20/2014] [Indexed: 11/19/2022]
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Zade S, Mani V, Deka RS, Kumar M, Kaur H, Kewalramani NJ, Tyagi AK. Energy metabolites, lipid variables and lactation performance of periparturient Murrah buffaloes (Bubalus bubalis) fed on diet supplemented with inorganic chromium. Biol Trace Elem Res 2014; 159:115-27. [PMID: 24833279 DOI: 10.1007/s12011-014-0010-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 05/07/2014] [Indexed: 10/25/2022]
Abstract
The aim of this study was to elucidate the effects of chromium (Cr) supplementation as inorganic Cr (CrCl3·6H2O) on energy balance, lipid peroxidation, and lactation performance in periparturient Murrah buffaloes. Twenty-four multiparous Murrah buffaloes according to lactation, parity, body mass, and expected calving date were divided equally. Experimental buffaloes were randomly assigned to four treatment diets: a control diet and three diets with an inorganic Cr supplementation at 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM), respectively from 60 days before expected calving date until 60 days of lactation. Milk productions of buffaloes were recorded every day until 60 days in milk. Blood samples were collected at days -60, -45, -30,-21, -15, -7, -3, 0, 7, 15, 21, 30, 45, and 60 days relative to actual calving for determination of plasma glucose, nonesterified fatty acid (NEFA), thiobarbituric acid reactive substance (TBARS), total cholesterol, total protein, albumin, blood urea nitrogen (BUN), and minerals. Adding inorganic Cr to the diet of Murrah buffaloes increased milk yield. Percentage of fat and total solid yield increased significantly through the experiment in the Cr-supplemented group. At the day of calving, buffaloes showed a decrease in dry matter intake (DMI), plasma glucose, and zinc (Zn) and Cr concentrations. In contrast, plasma NEFA, TBARS, and copper (Cu) levels were found highest at the day of calving among all groups. Cr supplementation increased peripheral blood glucose concentration while decreased level of NEFA and TBARS was recorded in Cr-fed buffaloes. Supplemental Cr had no effect on plasma cholesterol, total protein, albumin, and BUN in periparturient period. Dietary Cr supplementation had positive effect on plasma Cr concentration, but the plasma concentration of Cu, Zn, and iron (Fe) was not affected by different dietary Cr level supplementation. The results suggest that dietary inorganic Cr supplementation improved milk yield by reducing negative energy balance and lipid peroxidation in buffaloes during periparturient period.
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Affiliation(s)
- Satish Zade
- Dairy Cattle Nutrition Division, National Dairy Research Institute, Karnal, 132001, India
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27
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Application of osmometry in quality analysis of milk. Journal of Food Science and Technology 2013; 51:606-10. [PMID: 24587540 DOI: 10.1007/s13197-013-1216-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 11/08/2013] [Accepted: 11/17/2013] [Indexed: 10/26/2022]
Abstract
The aim of this study was to evaluate osmometry as a tool in quality analysis of milk. The osmolality of raw milk, sterilized milk, skimmed UHT (ultra-high temperature-treated) milk, pasteurized milk, standardized UHT milk and fermented milk (Lactococcus lactis culture) was determined by freezing point osmometry. The relationship between osmolality and pH of fermented milk was further investigated during spontaneous fermentation of UHT milk at 37 °C for 48 h. Average osmolality values (mean ± SD) were raw milk-290.2 ± 7.98, sterilized milk-290.2 ± 5.84, skimmed UHT milk-290.8 ± 3.31, pasteurized milk-283.6 ± 2.28, standardized UHT milk-281 ± 4.59 and fermented milk-466.0 ± 17.30 mOsmoles kg(-1). For fresh milk samples, 88 % showed normal osmolality, 8 % were hypo-osmotic and 4 % hyper-osmotic. Fermentation studies revealed a high negative correlation between osmolality and pH, with a correlation coefficient of -97.49 %. Hypo-osmotic milk shows mixing of milk with water along the production chain. Hyper-osmotic milk indicates fermentation of milk at high ambient temperatures or with prolonged storage. It may also reveal adulteration of fresh milk with a soluble substance. Osmolality was highest for fermented milk owing to production of lactic acid during fermentation. This was confirmed by the high negative correlation between osmolality and pH of milk in fermentation studies. Hence the osmolality of fermented milks may be used as an index of the extent of fermentation.
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Rzewuska K, Strabel T. Genetic parameters for milk urea concentration and milk traits in Polish Holstein-Friesian cows. J Appl Genet 2013; 54:473-82. [PMID: 23934506 PMCID: PMC3825602 DOI: 10.1007/s13353-013-0159-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/15/2013] [Accepted: 06/18/2013] [Indexed: 11/26/2022]
Abstract
Milk urea concentration (MU) used by dairy producers for management purposes can be affected by selection for milk traits. To assess this problem, genetic parameters for MU in Polish Holstein-Friesian cattle were estimated for the first three lactations. The genetic correlation of MU with milk production traits, lactose percentage, fat to protein ratio (FPR) and somatic cell score (SCS) were computed with two 5-trait random regression test-day models, separately for each lactation. Data used for estimation (159,044 daily observations) came from 50 randomly sampled herds. (Co)variance components were estimated with the Bayesian Gibbs sampling method. The coefficient of variation for MU in all three parities was high (40-41 %). Average daily heritabilities of MU were 0.22 for the first parity and 0.21 for the second and third lactations. Average genetic correlations for different days in milk in the first three lactations between MU and other traits varied. They were small and negative for protein percentage (from -0.24 to -0.11) and for SCS (from -0.14 to -0.09). The weakest genetic correlation between MU and fat percentage, and between MU and lactose percentage were observed (from -0.10 to 0.10). Negative average genetic correlation with the fat to protein ratio was observed only in the first lactation (-0.14). Genetic correlations with yield traits were positive and ranged from low to moderate for protein (from 0.09 to 0.33), fat (from 0.16 to 0.35) and milk yield (from 0.20 to 0.42). These results suggest that the selection on yield traits and SCS tends to increase MU slightly.
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Affiliation(s)
- Katarzyna Rzewuska
- Department of Genetics and Animal Breeding, Faculty of Animal Breeding and Biology, Poznan University of Life Sciences, Wołyńska 33, 60-637 Poznań, Poland
| | - Tomasz Strabel
- Department of Genetics and Animal Breeding, Faculty of Animal Breeding and Biology, Poznan University of Life Sciences, Wołyńska 33, 60-637 Poznań, Poland
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Aguilar M, Hanigan MD, Tucker HA, Jones BL, Garbade SK, McGilliard ML, Stallings CC, Knowlton KF, James RE. Cow and herd variation in milk urea nitrogen concentrations in lactating dairy cattle. J Dairy Sci 2012; 95:7261-8. [PMID: 23040023 DOI: 10.3168/jds.2012-5582] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 08/19/2012] [Indexed: 11/19/2022]
Abstract
Milk urea nitrogen (MUN) is correlated with N balance, N intake, and dietary N content, and thus is a good indicator of proper feeding management with respect to protein. It is commonly used to monitor feeding programs to achieve environmental goals; however, genetic diversity also exists among cows. It was hypothesized that phenotypic diversity among cows could bias feed management decisions when monitoring tools do not consider genetic diversity associated with MUN. The objective of the work was to evaluate the effect of cow and herd variation on MUN. Data from 2 previously published research trials and a field trial were subjected to multivariate regression analyses using a mixed model. Analyses of the research trial data showed that MUN concentrations could be predicted equally well from diet composition, milk yield, and milk components regardless of whether dry matter intake was included in the regression model. This indicated that cow and herd variation could be accurately estimated from field trial data when feed intake was not known. Milk urea N was correlated with dietary protein and neutral detergent fiber content, milk yield, milk protein content, and days in milk for both data sets. Cow was a highly significant determinant of MUN regardless of the data set used, and herd trended to significance for the field trial data. When all other variables were held constant, a percentage unit change in dietary protein concentration resulted in a 1.1mg/dL change in MUN. Least squares means estimates of MUN concentrations across herds ranged from a low of 13.6 mg/dL to a high of 17.3 mg/dL. If the observed MUN for the high herd were caused solely by high crude protein feeding, then the herd would have to reduce dietary protein to a concentration of 12.8% of dry matter to achieve a MUN concentration of 12 mg/dL, likely resulting in lost milk production. If the observed phenotypic variation is due to genetic differences among cows, genetic choices could result in herds that exceed target values for MUN when adhering to best management practices, which is consistent with the trend for differences in MUN among herds.
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Affiliation(s)
- M Aguilar
- Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
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Meyer PM, Machado PF, Coldebella A, Cassoli LD, Coelho KO, Rodrigues PHM. Validação de modelos de predição das concentrações de nitrogênio ureico no leite do rebanho de vacas holandesas. REVISTA BRASILEIRA DE SAÚDE E PRODUÇÃO ANIMAL 2012. [DOI: 10.1590/s1519-99402012000300023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Objetivou-se, no presente trabalho, validar modelos de predição de nitrogênio ureico no leite no intuito de contribuir para avaliação da adequação nutricional de dietas de rebanhos de vacas leiteiras. Foram utilizadas 8.833 observações de vacas da raça Holandesa de um rebanho comercial, registraram-se produção de leite, peso corporal, número de dias em lactação e número de lactações. Dos dados coletados, foram tiradas médias mensais a fim de se estudar o rebanho. O modelo 1 foi desenvolvido por Jonker et al. (1998) e os modelos 2 e 3 por Kauffman & St-Pierre (2001). Para a avaliação dos modelos, foram medidas a acurácia, a precisão e a robustez. Notou-se falta de acurácia para os modelos 1 (viés=2,60mg/dL) e 2 (viés=-1,95mg/dL), enquanto o modelo 3 foi acurado (-0,89mg/dL). Contudo, os modelos 1, 2 e 3 não diferiram entre si quanto à precisão (erro residual=3,72, 2,68 e 2,64mg/dL, respectivamente). Os modelos 1 e 2 não apresentaram robustez para o número de dias em lactação, tampouco o modelo 1 para a concentração de gordura. O modelo 3 foi o melhor avaliado, quando se desejou estimar as concentrações de nitrogênio ureico no leite de um rebanho de vacas Holandesas nas condições de campo estudadas.
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Fatehi F, Zali A, Honarvar M, Dehghan-banadaky M, Young A, Ghiasvand M, Eftekhari M. Review of the relationship between milk urea nitrogen and days in milk, parity, and monthly temperature mean in Iranian Holstein cows. J Dairy Sci 2012; 95:5156-5163. [DOI: 10.3168/jds.2011-4349] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 04/09/2012] [Indexed: 11/19/2022]
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Genetic relationship between milk urea nitrogen and reproductive performance in Holstein dairy cows. Animal 2012; 5:26-32. [PMID: 22440698 DOI: 10.1017/s1751731110001606] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The objective of this study was to describe the genetic and phenotypic relationship between milk urea nitrogen (MUN) and reproductive traits in Iranian Holstein dairy cows. Test-day MUN data obtained from 57 301 dairy cows on 20 large dairy herds in Iran between January 2005 and June 2009. Genetic parameters for MUN and reproductive traits were estimated with a five-trait model using ASREML program. Random regression test-day models were used to estimate heritabilities separately for MUN from first, second and third lactations. Regression curves were modeled using Legendre polynomials of order 3. Herd-year-season along with age at calving was included as fixed effects in all models for reproductive traits. Heritabilities for MUN and reproductive traits were estimated separately for first lactation, second lactation and third lactation. The estimated heritabilities for MUN varied from 0.18 to 0.22. The heritability estimate was low for reproductive traits, which ranged from 0.02 to 0.06 for different traits and across parities. Except for days open, phenotypic and genetic correlations of MUN with reproductive performance traits were close to zero. Genetic correlations between MUN and days open were 0.23, 0.35 and 0.45 in first, second and third lactation, respectively. However, the phenotypic correlation between MUN at different parities was moderate (0.28 to 0.35), but the genetic correlation between MUN at different parities was high and ranged from 0.84 to 0.97. This study shows a limited application of MUN for use in selection programs to improve reproductive performance.
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Morning versus afternoon cutting time of Berseem clover (Trifolium alexandrinum L.) affects feed intake, milk yield and composition in Girgentana goats. J DAIRY RES 2011; 78:500-4. [DOI: 10.1017/s0022029911000719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Twenty lactating Girgentana goats were used to evaluate the effect of morning v. afternoon cutting time of Berseem clover (Trifolium alexandrinum L.) on feed intake, milk yield and milk composition. Goats were randomly divided into two groups of ten animals, receiving 10 kg of fresh Berseem clover cut at 9.00 (AM group) or 16.00 (PM group), respectively; 500 g of concentrate was given individually to goats before offering forage. Feed intake increased (P<0·01) in the PM group (30·5 v. 25·3 g dry matter/kg body weight), associated with the different nutrient content of diets: lower crude protein but higher dry matter, neutral detergent fibre, water soluble carbohydrates (WSC) and total fatty acids in the PM-harvested forage. Milk production, protein and casein content were higher (P<0·05) in the PM group (1415 g/d, 3·25% and 2·42% v. 1277 g/d, 3·15% and 2·33%, respectively), whereas no differences between groups were detected for milk fat, lactose or urea content. Body weight slowly decreased from the start to the end of the experiment, without differences between groups. This study showed an important milk yield responses in Girgentana goats offered afternoon-cut compared with morning-cut Berseem clover, due to a marked increase in WSC in the afternoon-cut forage.
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Appuhamy JADRN, Knapp JR, Becvar O, Escobar J, Hanigan MD. Effects of jugular-infused lysine, methionine, and branched-chain amino acids on milk protein synthesis in high-producing dairy cows. J Dairy Sci 2011; 94:1952-60. [PMID: 21426986 DOI: 10.3168/jds.2010-3442] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Accepted: 12/13/2010] [Indexed: 01/28/2023]
Abstract
In addition to lysine and methionine, current ration-balancing programs suggest that branched-chain amino acid (BCAA) supply may also be limiting in dairy cows. The objective of this study was to investigate whether BCAA, leucine, isoleucine, and valine become limiting for milk protein synthesis when methionine and lysine supply were not limiting. Nine multiparous Holstein cows with an average milk production of 53.5±7.1 kg/d were randomly assigned to 7-d continuous jugular infusions of saline (CTL), methionine and lysine (ML; 12 g and 21 g/d, respectively), or ML plus leucine, isoleucine, and valine (ML+BCAA; 35 g, 15 g, and 15 g/d, respectively) in a 3×3 Latin square design with 3 infusion periods separated by 7-d noninfusion periods. The basal diet consisted of 40% corn silage, 14% alfalfa hay, and a concentrate mix, and respectively supplied lysine, methionine, isoleucine, leucine, and valine as 6.1, 1.8, 4.7, 8.9, and 5.3% of metabolizable protein. Dry matter intake (23.9 kg/d), milk yield (52.8 kg/d), fat content (2.55%), fat yield (1.33 kg/d), lactose content (4.77%), lactose yield (2.51 kg/d), and milk protein efficiency (0.38) were similar across treatments. Protein yield and protein content were not significantly different between ML (1.52 kg/d and 2.88%, respectively) and ML+BCAA (1.51 kg/d and 2.83%, respectively), but they were significantly greater than that of CTL (1.39 kg/d and 2.71%). Cows that received ML+BCAA had less milk urea nitrogen content (10.9 mg/dL) compared with milk of CTL cows (12.4 mg/dL) and ML cows (11.8 mg/dL). Whereas high-producing cows responded positively to methionine and lysine supplementation, no apparent benefits of BCAA supplementation in milk protein synthesis were found. Infusion of BCAA may have stimulated synthesis of other body proteins, probably muscle proteins, as evidenced by decreased milk urea nitrogen.
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Affiliation(s)
- J A D R N Appuhamy
- Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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Hossein-Zadeh NG, Ardalan M. Estimation of genetic parameters for milk urea nitrogen and its relationship with milk constituents in Iranian Holsteins. Livest Sci 2011. [DOI: 10.1016/j.livsci.2010.07.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Faye B, Konuspayeva G, Loiseau G. Variability of urea concentration in camel milk in Kazakhstan. ACTA ACUST UNITED AC 2010. [DOI: 10.1051/dst/2010025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Bach A, Valls N, Solans A, Torrent T. Associations Between Nondietary Factors and Dairy Herd Performance. J Dairy Sci 2008; 91:3259-67. [DOI: 10.3168/jds.2008-1030] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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A method for estimation of urea using ammonia electrode and its applicability to milk samples. J DAIRY RES 2008; 75:466-70. [DOI: 10.1017/s0022029908003488] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A method for the estimation of urea in milk using ammonia electrode is described. Urea is first degraded by urease enzyme into ammonium ion and carbon dioxide at neutral pH. The ammonium ion is then converted into ammonia at alkaline pH. A linear inverse relationship was observed between logarithmic concentration of ammonia or urea and electrode response. Repeatability, expressed as a coefficient of variation, was 1·77% at a level of 8·92 mm-urea in milk. The method was validated in milk samples spiked with between 2×10−3 and 10×10−3 m-urea and recovery of added urea was quantitative. Whereas, preservative sodium azide at 0·5 g/l or 2 g/l level did not affect results, lower values of urea concentration in presence of Bronopol at 0·5 g/l were observed. Urea levels in milk samples estimated by this method were comparable to standard enzymatic method. The method is simple, fast and is not prone to interference from other milk constituents.
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Lehloenya KV, Stein DR, Allen DT, Selk GE, Jones DA, Aleman MM, Rehberger TG, Mertz KJ, Spicer LJ. Effects of feeding yeast and propionibacteria to dairy cows on milk yield and components, and reproduction. J Anim Physiol Anim Nutr (Berl) 2008; 92:190-202. [DOI: 10.1111/j.1439-0396.2007.00726.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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Abstract
We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two groups were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9·00 to 13·00; afternoon group (PM), from 12·00 to 16·00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0·01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16·7 v. 19·8% DM; P<0·01 and 26·8 v. 30·4 g/kg DM; P<0·01). Pasture dry matter intake (DMI) was significantly higher in the afternoon (0·82 v. 0·75 kg/d; P=0·026). Fat corrected milk production (FCM), milk fat and lactose content were not affected by treatment, whereas protein and titrable acidity (°SH) increased in the PM group (respectively 3·56 v. 3·42%; P=0·01; 3·55 v. 3·22°SH/50 ml; P=0·01). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0·037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1·02 v. 0·90, P=0·037; 0·71 v. 0·81% of total fatty acids, P=0·022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.
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Stoop WM, Bovenhuis H, van Arendonk JAM. Genetic Parameters for Milk Urea Nitrogen in Relation to Milk Production Traits. J Dairy Sci 2007; 90:1981-6. [PMID: 17369239 DOI: 10.3168/jds.2006-434] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim of this study was to estimate genetic parameters for test-day milk urea nitrogen (MUN) and its relationships with milk production traits. Three test-day morning milk samples were collected from 1,953 Holstein-Friesian heifers located on 398 commercial herds in The Netherlands. Each sample was analyzed for somatic cell count, net energy concentration, MUN, and the percentage of fat, protein, and lactose. Genetic parameters were estimated using an animal model with covariates for days in milk and age at first calving, fixed effects for season of calving and effect of test or proven bull, and random effects for herd-test day, animal, permanent environment, and error. Coefficient of variation for MUN was 33%. Estimated heritability for MUN was 0.14. Phenotypic correlation of MUN with each of the milk production traits was low. The genetic correlation was close to zero for MUN and lactose percentage (-0.09); was moderately positive for MUN and net energy concentration of milk (0.19), fat yield (0.41), protein yield (0.38), lactose yield (0.22), and milk yield (0.24), and percentage of fat (0.18), and percentage of protein (0.27); and was high for MUN and somatic cell score (0.85). Herd-test day explained 58% of the variation in MUN, which suggests that management adjustments at herd-level can reduce MUN. This study shows that it is possible to influence MUN by herd practice and by genetic selection.
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Affiliation(s)
- W M Stoop
- Animal Breeding and Genomics Centre, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
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Caraviello DZ, Weigel KA, Fricke PM, Wiltbank MC, Florent MJ, Cook NB, Nordlund KV, Zwald NR, Rawson CL. Survey of Management Practices on Reproductive Performance of Dairy Cattle on Large US Commercial Farms. J Dairy Sci 2006; 89:4723-35. [PMID: 17106104 DOI: 10.3168/jds.s0022-0302(06)72522-x] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A survey regarding general management, sire selection, reproductive management, inseminator training and technique, heat abatement, body condition scoring, facility design and grouping, nutrition, employee training and management, and animal health and bio-security was carried out from March to September of 2004 in 153 herds in the Alta Genetics (Watertown, WI) Advantage Progeny Testing Program. A total of 103 herds (67.3%) completed the survey. Herd size was 613 +/- 46 cows, with herds located in Wisconsin (26), California (12), New York (11), Minnesota (10), Michigan (7), Washington (6), Pennsylvania (6), Iowa (5), Idaho (5), Texas (4), Ohio (4), and other states (7). These farms sold 34.5 +/- 0.3 kg of milk/d per cow, with an annual culling rate of 34 +/- 1% and a calving interval of 13.8 +/- 0.1 mo. Cows were observed for estrus 2.8 +/- 0.3 times/d, for a duration of 27 +/- 4 min, but 78% of the respondents admitted that detection of estrus was not the employee's sole responsibility at that time. Managers tried to achieve pregnancy until 8.8 +/- 0.9 failed inseminations, 300 +/- 26 d postpartum, or milk yield <17.7 +/- 0.5 kg/d. Nonpregnant cows were culled at 326 +/- 36 d postpartum or milk yield <16.4 +/- 0.3 kg/ d. Mean durations of the voluntary waiting period were 52 +/- 1.3 and 53 +/- 1.4 d for primiparous and multiparous cows, respectively. Hormonal synchronization or timed artificial insemination programs were used in 87% of the herds, with 86% synchronizing first services, 77% resynchronizing repeat services, and 59% treating cystic, anestrous, or anovular cows. Finding good employees was identified as the greatest labor challenge, followed by training and supervising employees. Mastitis and hairy heel warts were noted as the greatest animal health concerns, followed by lameness, abortions, and death losses, whereas the greatest reproductive challenges were artificial insemination service rate, conception rate, twinning, and retained placenta or metritis. Results of this study can provide a useful benchmark or reference with regard to commonly used management practices on large commercial US dairy farms at the present time.
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Affiliation(s)
- D Z Caraviello
- Department of Dairy Science, University of Wisconsin, Madison, WI 53706, USA
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Stein DR, Allen DT, Perry EB, Bruner JC, Gates KW, Rehberger TG, Mertz K, Jones D, Spicer LJ. Effects of feeding propionibacteria to dairy cows on milk yield, milk components, and reproduction. J Dairy Sci 2006; 89:111-25. [PMID: 16357273 DOI: 10.3168/jds.s0022-0302(06)72074-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Two weeks before parturition, 38 Holstein primiparous and multiparous cows were assigned to 1 of 3 treatment groups: control animals (n = 13) received regular total mixed rations (TMR), the low-dose group (n = 14) received the control TMR plus 6 x 10(10) cfu/cow of Propionibacterium strain P169 (P169), and the high-dose group (n = 11) received the control TMR plus 6 x 10(11) cfu/cow of P169 from -2 to 30 wk postpartum. Weekly milk samples were analyzed for percentage of milk fat, protein, lactose, and SNF, milk urea nitrogen, and somatic cell counts. Daily milk production expressed as 4% fat-corrected milk was affected by treatment and week x parity. High-dose and low-dose P169-treated cows exhibited 7.1 and 8.5% increases above controls in daily 4% fat-corrected milk, respectively. Treatment x parity and week significantly influenced percentage of milk fat, lactose, and protein, whereas treatment x parity and treatment x week influenced SNF. Ruminal propionate levels were influenced by treatment such that high-dose P169 cows had greater molar percentage of propionate than did low-dose P169 and control cows. Change in body weight postpartum was influenced by week x parity and treatment x parity such that high-dose and low-dose P169 multiparous cows exhibited a more rapid recovery of wk-1 body weight than did control multiparous cows. There was no treatment, parity, or interaction on days to first postpartum ovulation or on estrous behavior at 45 and 90 d postpartum. We concluded that P169 might have potential as an effective direct-fed microorganism to increase milk production in dairy cows.
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Affiliation(s)
- D R Stein
- Department of Animal Science, Oklahoma State University, Stillwater, 74078, USA
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Hammon DS, Holyoak GR, Dhiman TR. Association between blood plasma urea nitrogen levels and reproductive fluid urea nitrogen and ammonia concentrations in early lactation dairy cows. Anim Reprod Sci 2005; 86:195-204. [PMID: 15766800 DOI: 10.1016/j.anireprosci.2004.08.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2004] [Revised: 07/19/2004] [Accepted: 08/01/2004] [Indexed: 11/27/2022]
Abstract
Two experiments were conducted to study the relationship of blood plasma urea nitrogen (PUN) concentrations with NH3, urea nitrogen, K, Mg, P, Ca, and Na concentrations in fluid of preovulatory follicles (experiment 1) and the relationships of PUN concentration and stage of estrus cycle with ammonia and urea nitrogen concentrations in uterine fluids (experiment 2) in early lactation dairy cows. Mean PUN levels were used to distribute cows into two groups: cows with PUN>or=20 mg/dl (HPUN), and cows with PUN<20 mg/dl (LPUN). In experiment 1, blood and follicular fluids from preovulatory follicles of 38 early lactation dairy cows were collected on the day of estrus (day 0) 4h after feed was offered. Follicular fluid NH3 was higher (P<0.01) in HPUN cows (339.0 micromol/L+/-72.2) compared to LPUN cows (93.9 micromol/L+/-13.1). Follicular fluid urea N was higher (P<0.001) in HPUN cows (22.4 mg/dl+/-0.4) compared to LPUN cows (17.0 mg/dl+/-0.3). PUN and follicular fluid urea N were correlated (r2=0.86) within cows. In experiment 2, blood and uterine fluids were collected from 30 cows on day 0 and on day 7. Uterine fluid NH3 was higher (P=0.05) in HPUN cows (1562 micromol/L+/-202) than in LPUN cows (1082 micromol/L+/-202) on day 7, but not on day 0. Uterine fluid urea N was higher (P<0.001) in HPUN cows than in LPUN cows on day 0 (26.9 mg/dl+/-1.3 and 20.4 mg/dl+/-0.7) and day 7 (26.5 mg/dl+/-1.1 and 21.4 mg/dl+/-1.1). There was a correlation (r2=0.17) between PUN and uterine fluid urea N within cows. The results of this study indicate that high PUN concentrations were associated with elevated NH3 and urea N concentrations in the preovulatory follicular fluids on the day of estrus and in the uterine fluid during the luteal phase of the estrous cycle in early lactation dairy cows. Elevated NH3 or urea N concentrations in the reproductive fluids may contribute to reproductive inefficiency in dairy cows with elevated plasma urea nitrogen due to embryo toxicity.
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Affiliation(s)
- D S Hammon
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322-4815, USA.
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Hojman D, Gips M, Ezra E. Association Between Live Body Weight and Milk Urea Concentration in Holstein Cows. J Dairy Sci 2005; 88:580-4. [PMID: 15653524 DOI: 10.3168/jds.s0022-0302(05)72721-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Use of milk urea (MU) concentration as a parameter for detection of nutritional imbalances requires identification and quantification of nutritional and nonnutritional factors that influence it. The objective of this study was to assess the relationship between live body weight (BW) and MU concentration in Holstein cows. Results for the test-day measurements at 7 dairy farms were obtained from the Israeli Dairy Herd Improvement Center and concomitant cow weights were registered in local computerized weighing systems. A total of 1996 cows and 25,485 records were studied. The overall unadjusted per-cow mean MU nitrogen concentration and BW were 15.3 mg/dL (SD = 3.8) and 593 kg (SD = 84), respectively. The linear association between BW and MU was negative and highly significant and the quadratic component of BW had a highly significant positive association with MU. There was a significant interaction between the association of MU and BW with lactation number. Sampling month, milk yield, milk fat percentage, and somatic cell count accounted for significant variation in MU. Predicted MU concentrations at different BW values were calculated for each parity group, by setting equations that included the estimates of the variables associated with MU and constant values (lactation averages) for the independent variables, with the exception of BW. Plotting of results showed exponential characteristics for the relationship between BW and predicted MU concentrations. At any of the considered BW, predicted MU concentrations were lower for first-parity cows. The trends and interactions found in the present study may contribute to improving accuracy of models designed to calculate urinary nitrogen excretion rates and normative milk urea concentrations.
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Affiliation(s)
- D Hojman
- Dairy Cattle Department-Extension Service, Ministry of Agriculture and Rural Development, Bet Dagan 50150, Israel.
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Kuterovac K, Balaš S, Gantner V, Jovanovac S, Dakić A. Evaluation of nutritional status of dairy cows based on milk analysis results. ITALIAN JOURNAL OF ANIMAL SCIENCE 2005. [DOI: 10.4081/ijas.2005.3s.33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Arieli A, Adin G, Bruckental I. The effect of protein intake on performance of cows in hot environmental temperatures. J Dairy Sci 2004; 87:620-9. [PMID: 15202646 DOI: 10.3168/jds.s0022-0302(04)73204-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Two trials were conducted with cows in commercial herds during midlactation to evaluate the effect of dietary crude protein (CP) concentration on the production, composition, and efficiency of milk production under hot ambient conditions. Cows were group-fed in trial 1, which was conducted in two herds, and were fed individually in trial 2. The respective average ambient temperature, relative humidity, and temperature-humidity index (THI) were 31 degrees C, 45%, and 78 in trial 1 and 27 degrees C, 70%, and 76 in trial 2. Cows were cooled by forced evaporative means six times daily in trial 1 and three times daily in trial 2. Dietary CP was 15.3 or 17.3% of dry matter (DM) in trial 1 and 15.1 or 16.7% of DM in trial 2. The respective ratios of rumen-degradable organic matter (RDOM) to rumen-degradable protein were 5.3 and 4.8 for the low CP (LP) and high CP (HP) diets. Average DM intake, milk yield, and milk fat and protein concentrations were 22 and 23 kg/d, 34 and 35 kg/d, 3.1 and 3.4%, and 3.2 and 3.1% in trials 1 and 2, respectively, and were similar among diets in both trials. The resultant calculated milk protein efficiency ratio and overall CP efficiency were 0.31 and 0.32 for the LP diets and 0.28 and 0.29 for the HP diets. In cows fed the LP diet, diet rumen ammonia was lower in trial 1, and milk urea N was lower in trial 2. The BW change was higher in trial 1, and tended to be higher in trial 2, with the LP diets. Changes in body condition score in trials 1 and 2 tended to be higher with the LP diets. It was concluded that a dietary CP content of 15.3% is adequate to maintain production in heat-exposed dairy cows producing 35 kg of milk/d, provided that the forced evaporative cooling and the ratio of RDOM to rumen-degradable protein is appropriate
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Affiliation(s)
- A Arieli
- The Hebrew University of Jerusalem, Faculty of Agricultural, Food, and Environmental Quality Sciences, Rehovot, Israel.
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Hojman D, Kroll O, Adin G, Gips M, Hanochi B, Ezra E. Relationships Between Milk Urea and Production, Nutrition, and Fertility Traits in Israeli Dairy Herds. J Dairy Sci 2004; 87:1001-11. [PMID: 15259235 DOI: 10.3168/jds.s0022-0302(04)73245-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objectives of this study were to identify and evaluate production and environmental factors that influence milk urea (MU) in Israeli dairy herds, to analyze the relationships between MU concentration and nutritional variables, and to examine a possible association between MU and pregnancy rate (PR). Production and environmental data were obtained from the Israeli Dairy Herd Improvement (DHI) Center (n = 1,279,600). Programmed total mixed rations (feeds and quantities) on milk-test day were collected from 42 dairy herds. Data on 36,073 cows that were inseminated close to milk-test day and pregnancy diagnosis results were obtained from the DHI data bank. Highly significant positive relationships were found between MU concentration and milk yield and fat percentage; relationships between MU and milk total protein percentage and somatic cell count were negative. Milk urea levels were higher during the summer months and were higher for adult cows. These levels increased as lactation progressed. Milk urea was positively associated with dietary levels of crude protein, ruminal digestible protein, and neutral detergent fiber contents; it was negatively associated with ration energy and nonstructural carbohydrate contents. Significant influences of specific feeds on MU were detected. A significant negative association was found between MU level and PR. Least squares means for PR for cows in the lowest and highest MU quartiles were 38.4 and 36.1%, respectively. Increasing levels of MU were negatively related to reproductive performance of dairy cows, but the risk of nonpregnancy caused by high levels of MU was lower than reported in previous studies.
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Affiliation(s)
- D Hojman
- Dairy Cattle Department-Extension Service, Ministry of Agriculture and Rural Development, Bet Dagan 50150 Israel.
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Johnson RG, Young AJ. The Association Between Milk Urea Nitrogen and DHI Production Variables in Western Commercial Dairy Herds. J Dairy Sci 2003; 86:3008-15. [PMID: 14507038 DOI: 10.3168/jds.s0022-0302(03)73899-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A retrospective observational study was conducted using data from Dairy Herd Improvement monthly tests to investigate the association between milk urea nitrogen (MUN) concentration and milk yield, milk protein, milk fat percentage, SCC, and parity for commercial Holstein and Jersey herds in Utah, Idaho, and Montana. Mean MUN for Holstein cows was 15.5 mg/ dl (5.5 mmol/L) MUN and 14.1 mg/dl (5.0 mmol/L) for Jersey cows. Mean MUN, categorized by 30-d increments of days in milk (DIM), paralleled changes in milk values and followed a curvilinear shape. For Holstein cows, concentrations of MUN were different among lactation groups 1, 2, and 3+ for the first 90 DIM for Holsteins. Overall, concentrations of MUN were lower during for the first 30 DIM compared with all other DIM categories for both Holstein and Jersey cows. Multivariate regression models of MUN by milk protein showed that as the milk protein percentage increased, MUN concentration decreased; however, models for Jersey cows showed that MUN did not decrease significantly until above 3.4% milk protein. Milk fat percentage also decreased as MUN increased, but by only 1 mg/dl MUN over the range of 2.2 to 5.8% milk fat. Somatic cell count showed a negative relationship with MUN. Holstein cows with milk protein percentage >3.2% had lower MUN compared with cows having milk protein <3.2% for milk yields from 27.3 to 54.5 kg/d and lower than cows having a milk protein <3.0% for milk yield of 54.5 to 63.6 kg/d. In Jersey cows, MUN concentrations were not different among milk protein percentage categorized by milk yield. This study found that MUN was inversely associated with milk protein percentage and paralleled change in milk yield over time.
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Affiliation(s)
- R G Johnson
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan 84322, USA
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Melendez P, Donovan A, Hernandez J, Bartolome J, Risco CA, Staples C, Thatcher WW. Milk, plasma, and blood urea nitrogen concentrations, dietary protein, and fertility in dairy cattle. J Am Vet Med Assoc 2003; 223:628-34. [PMID: 12959380 DOI: 10.2460/javma.2003.223.628] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Pedro Melendez
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA
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