Application of a dynamic nitrogen model to reduce nutrient pollution by dairy cows

2002 ◽  
Vol 2002 ◽  
pp. 106-106
Author(s):  
E. Kebreab ◽  
J.A.N. Mills ◽  
L.A. Crompton ◽  
J. France
Keyword(s):  
Mathematical Models ◽  
Environmental Pollution ◽  
Dairy Cows ◽  
Dairy Herds ◽  
Nutrient Pollution ◽  
Dairy Production ◽  
Biological Processes ◽  
Annual Output ◽  
N Utilization ◽  
N Pollution

Agriculture is one of the major sources of nitrogen (N) pollution. Dairy production causes losses of N in faeces and urine that contribute to environmental pollution with an estimated annual output of 320 kt N and 80 kt ammonia in the U.K. alone. Therefore, improving N utilization in dairy cows and especially reducing N output in excreta is desirable to reduce environmental N pollution, particularly as ammonia. Mathematical models have been used to predict potential N excretion from dairy cows. However, these models generally are empirical in nature, hence not process based and therefore there is a need to develop a model that can describe biological processes in the animal. The objective of the present study was to develop a dynamic N model to predict the amount and form of N excreted by dairy herds and seek to make appropriate recommendations that will reduce N excretion from dairy cows.

LIME AND DAIRY PRODUCTION

1982 ◽  
pp. 93-103
Author(s):  
N.A. Thomson
Keyword(s):  
Soil Moisture ◽  
Dairy Cows ◽  
Milk Production ◽  
Soil Ph ◽  
Dairy Production ◽  
Pasture Production ◽  
The Third ◽  
One Year ◽  
Plasma Magnesium

In a four year grazing trial with dairy cows the application of 5000 kg lime/ ha (applied in two applications of 2500 kg/ha in winter of the first two years) significantly increased annual pasture production in two of the four years and dairy production in one year. In three of the four years lime significantly increased pasture growth over summer/autumn with concurrent increases in milk production. In the last year of the trial lime had little effect on pasture growth but a relatively large increase in milkfat production resulted. A higher incidence of grass staggers was recorded on the limed farmlets in spring for each of the four years. In the second spring immediately following the second application of lime significant depressions in both pasture and plasma magnesium levels were recorded. By the third spring differences in plasma magnesium levels were negligible but small depressions in herbage magnesium resulting from lime continued to the end of the trial. Lime significantly raised soil pH, Ca and Mg levels but had no effect on either soil K or P. As pH levels of the unlimed paddocks were low (5.2-5.4) in each autumn and soil moisture levels were increased by liming, these factors may suggest possible causes for the seasonality of the pasture response to lime

Methodology of Research in Micropollutants – Heavy Metals

1982 ◽  
Vol 14 (12) ◽  
pp. 107-125 ◽  
Author(s):  
Roland Wollast
Keyword(s):  
Heavy Metals ◽  
Mathematical Models ◽  
Aqueous Phase ◽  
Suspended Matter ◽  
Solid Phase ◽  
Aquatic Organisms ◽  
Biological Processes ◽  
Particulate Phase ◽  
Sources Of Pollution ◽  
Adsorption Desorption

A comparison of the concentration of dissolved and of particulate heavy metals in the aquatic system indicates that these elements are strongly enriched in the suspended matter. The transfer between the aqueous phase and the solid phase may be due to dissolution-precipitation reactions, adsorption-desorption processes or biological processes. When these processes are identified, it is further possible to develop mathematical models which describe the behaviour of these elements. The enrichment of heavy metals in the particulate phase suspended or deposited and in aquatic organisms constitutes a powerful tool in order to evaluate sources of pollution.

Comparing the performance of Holstein and Friesian dairy cows on British dairy farms

2002 ◽  
Vol 2002 ◽  
pp. 18-18
Author(s):  
G. E. Pollott ◽  
J. D. Leaver
Keyword(s):  
Dairy Cows ◽  
Dairy Herd ◽  
Dairy Farms ◽  
Dairy Herds ◽  
The Uk ◽  
Friesian Cows

In recent years there has been an influx of Holstein genes into the UK dairy herd, largely achieved by a ‘grading up’ process using imported Holstein semen on Friesian cows. The research reported here investigates this process using performance records from UK dairy herds.

scholarly journals Exosomal Cargo May Hold the Key to Improving Reproductive Outcomes in Dairy Cows

2021 ◽  
Vol 22 (4) ◽  
pp. 2024
Author(s):  
Natalie Turner ◽  
Pevindu Abeysinghe ◽  
Pawel Sadowski ◽  
Murray D. Mitchell
Keyword(s):  
Mass Spectrometry ◽  
Dairy Cows ◽  
Bioactive Peptides ◽  
Cell Types ◽  
Dairy Herds ◽  
Dairy Farmers ◽  
Early Biomarkers ◽  
Health And Disease ◽  
Place Of Origin ◽  
Quantitative Profiling

The reproductive status of dairy cows remains a challenge for dairy farmers worldwide, with impaired fertility linked to a significant reduction in herd profitability, due in part to impaired immunity, increased metabolic pressure, and longer postpartum anestrous interval (PPAI). Exosomes are nanovesicles released from a variety of cell types and end up in circulation, and carry proteins, bioactive peptides, lipids, and nucleic acids specific to the place of origin. As such, their role in health and disease has been investigated in humans and animals. This review discusses research into exosomes in the context of reproduction in dairy herds and introduces recent advances in mass-spectrometry (MS) based proteomics that have a potential to advance quantitative profiling of exosomal protein cargo in a search for early biomarkers of cattle fertility.

scholarly journals RELATIONSHIP BETWEEN BLOOD METABOLIC PROFILES AND MILK YIELD ASSOCIATED WITH PARITY AND STAGE OF LACTATION IN CROSSBRED DAIRY COWS IN BANGLADESH

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
L Naher ◽  
M. A. Samad ◽  
S. H. M. F. Siddiki ◽  
M. T. Islam
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Metabolic Profile ◽  
Transition Period ◽  
Dairy Herds ◽  
Metabolic Profiles ◽  
Milk Samples ◽  
Stage Of Lactation ◽  
Lactating Dairy Cows ◽  
Calcium Phosphorus

Background: Cattle cross-breeding program has been launched throughout Bangladesh but this program has still focused mainly on biological rather than economic evaluation. Currently, 30000 dairy farms with mainly cross-bred cows are in operation throughout the country and this intensive dairy farming system with high milk yielding dairy cows is supposed to be associated with high incidence of sub-clinical nutritional and metabolic diseases. Objectives: The objective of this study was to detect the relationship between major blood metabolic profiles and milk yield associated with parity and stage of lactation in cross-bred dairy cows. Materials and Methods: Blood samples of 220 apparently healthy lactating cross-bred dairy cows (HF x L, n = 190; SH x L, n = 20 and JS x L, n = 10) of 10 dairy herds were collected for metabolic profile test (MPT) in Bangladesh during the period from July to November 2016. The major metabolic profiles which are associated with milk fever (calcium, phosphorus & magnesium) and ketosis (glucose) were considered in this study. These biochemical parameters were estimated to detect the influence of risk factors including herds, breeds, parities and lactation age of cross-bred lactating dairy cows by using the commercial kits in spectrophotometer method. Results: The evaluation of the biochemical constituents of 220 cross-bred lactating dairy cows revealed that 30% (n = 66) had hypocalcaemia and 20.45% (n = 45) had hypoglycemia. Significantly lower levels of average calcium (7.93 ± 0.36 mg/dl; p < 0.024) and glucose (43.44 ± 3.63 mg/dl; p < 0.0001) values were recorded in HF x L cross-bred dairy herd of BAUDF, Mymensingh in comparison to other investigated nine dairy herds. The highest milk yield was recorded at 7th parity (16 +- 0.91 liter / day) and 1st week of lactation (17.33 +- 1.09 liter / day) were associated with low mean calcium (8.09 +- 0.85 mg / dl; 6.68 +- 0.13 mg/dl) and glucose (36.45 +- 7.67 mg/dl; 32.31 +- 3.90 mg / dl) levels in comparison to the respective values of different parity and lactation weeks. Conclusions: A relationship between blood metabolic profiles and milk yield associated with herd, breed, parity and lactation stages was recorded in lactating crossbred dairy cows. The evaluation of blood metabolites at different stages of lactation cycle especially at transition period is required to detect the nutritional and metabolic health for optimum milk production and to achieve maximum reproductive potential of high yielding dairy cattle. The readily available milk samples could be used as a biological fluid to monitor the health and nutritional status of dairy cows by using mid-infrared (MIR) spectroscopy method to prevent sub-clinical metabolic disorders. Therefore, well developed laboratories with necessary equipment, test kits and reagent should be provided to perform MPT in both the blood and milk samples for practical uses. Keywords: Compton metabolic profile test, Metabolic profile, Lactating cross-bred cows, Calcium, Phosphorus, Magnesium, Glucose, Parity, Lactation stages

Development of mathematical models to predict calcium, magnesium and selenium excretion from lactating Holstein cows

2018 ◽  
Vol 58 (3) ◽  
pp. 489 ◽  
Author(s):  
K. Taylor ◽  
J. A. D. Ranga Niroshan Appuhamy ◽  
J. Dijkstra ◽  
E. Kebreab
Keyword(s):  
Mathematical Models ◽  
Dairy Cows ◽  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Meta Analysis ◽  
Model Development ◽  
Dietary Factors ◽  
Mineral Excretion ◽  
Lactating Dairy Cows

The aim of this study was to develop and evaluate mathematical models that predict mineral excretion, particularly calcium (Ca), magnesium (Mg) and selenium (Se), from lactating dairy cows. Mineral excretion can be affected by several dietary factors. A deficiency in Ca or Mg application to pasture, among other factors, can contribute to grass tetany or wheat pasture poisoning in cows, whereas an excess can cause runoff into water supplies. Manure application with high Se concentration can also result in runoff, causing the bioaccumulation of selenium in aquatic ecosystems, wetland habitats and estuaries, leading to toxic levels in fish. A database composed of studies relating to mineral utilisation in lactating dairy cows conducted after and including the year 2000 was compiled. A meta-analysis was conducted with the aim of creating multiple empirical equations to predict Ca, Mg and Se excretion from lactating dairy cows. Calcium intake, feed Ca content, milk yield, milk protein content and acid detergent fibre content in diet were positively and linearly related to Ca excretion. Dietary crude protein content and milk fat content were negatively related to Ca excretion. Magnesium intake, feed Mg content and milk yield were positively and linearly related to Mg excretion. Selenium content of diet and dry matter intake were linearly and positively related to Se excretion. Two sets of models were developed using or excluding the intake variable and both sets of models were evaluated with independent data originating from commercial herd or individual animals. In general, intake measurements improved prediction when evaluated with independent datasets (root mean square prediction error = 8% to 19% vs 14% to 26% of the average observed value). There were substantial mean biases, particularly those evaluated with data from a commercial farm, perhaps due to inaccurate feed intake measurements. Although there was generally good agreement between predicted and observed mineral excretion, model development and evaluation would benefit from an expanded database.

Escherichia coli O157 in Cull Dairy Cows on Farm and at Slaughter

1997 ◽  
Vol 60 (11) ◽  
pp. 1386-1387 ◽  
Author(s):  
DANIEL H. RICE ◽  
ERIC D. EBEL ◽  
DALE D. HANCOCK ◽  
THOMAS E. BESSER ◽  
DONALD E. HERRIOTT ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Cattle ◽  
Dairy Cows ◽  
Dairy Herds ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Cull Cows ◽  
On Farm

Cull dairy cattle both on the farm and at slaughter from herds in the states of Idaho, Oregon, and Washington were surveyed for Escherichia coli O157 by culturing fecal swab samples. A total of 205 cull cows from 19 dairy herds were sampled on the farm of origin; 7 (3.4%) tested positive for E. coli O157. A total of 103 cull cows from 15 dairy herds were sampled at slaughter; 4 (3.9%) were positive for E. coli O157. Eighty-nine cull cows were sampled both at the farm and at slaughter; 2 (2.2%) were positive in both locations, 3 (3.3%) only on the farm, and 2 (2.2%) only at the slaughter plant. Seven (7.9%) of the 89 cull cows tracked from farm to slaughter were positive in at least one location. This suggests a higher prevalence of E. coli O157 in cull dairy cattle than previously has been reported to occur in other ages and classes of cattle.

On-farm phosphorus budget: Model to predict yearly phosphorus contents in manure of dairy herds

2007 ◽  
Vol 87 (3) ◽  
pp. 407-411
Author(s):  
Isabelle Chaperon, Cynthia Ouellet ◽  
Vincent Girard ◽  
Younes Chorfi
Keyword(s):  
Dairy Cows ◽  
Soil Phosphorus ◽  
Reproductive Efficiency ◽  
Dairy Herds ◽  
Cow Manure ◽  
Phosphorus Budget ◽  
Budget Model ◽  
Dairy Animals ◽  
On Farm ◽  
The Relationship

In order to reduce soil phosphorus (P) saturation, it is essential to assess the amount of manure P on cultivated soil. The purpose of this study was to estimate yearly herd manure P outputs from production and feeding records with a model based on replacement and dairy animals. The model predicts manure P based on P ingested by dairy cows (kg yr-1), P secreted in milk (kg yr-1), P in calf at birth (kg yr-1), and the number of first-lactation cows. The relationship between first-lactation cows and heifers was established; there were 1.3 ± 0.05 heifers for each first-lactation cow. Manure P from heifers was then obtained by fitting the model to manure P accumulated in concrete pits of 12 farms, measured over two 6-mo periods at 1 yr intervals. The model added 10.6 ± 4.6 kg of P for each first-lactation cow to predict the yearly P output of 1.3 heifers. Ratios between P harvested as feed and P predicted in manure were calculated in 1133 herds. High ratios were obtained in herds with less customized concentrate (P < 0.001), more harvested grain and silage (P < 0.001) on farm and larger size of herd (P < 0.001) with more milk (P < 0.001) and lower calf production (P < 0.001). Decreasing purchased customized concentrates and increasing the amount of silage fed to animals are valid options to reduce non-point-source P pollution. Key words: Dairy herds, manure, phosphorus, model, reproductive efficiency

scholarly journals Antagonism in the carbon footprint between beef and dairy production systems

2015 ◽  
Vol 44 (5) ◽  
pp. 17-20
Author(s):  
MM Scholtz ◽  
J Du Toit ◽  
FWC Neser
Keyword(s):  
Dairy Cows ◽  
Carbon Footprint ◽  
Production Systems ◽  
Beef Cows ◽  
Dairy Farming ◽  
Feed Water ◽  
Dairy Production ◽  
Pasture Production ◽  
Total Mixed Ration ◽  
Cow Calf

Primary beef cattle farming in South Africa is largely extensive, whereas dairy farming is based on both total mixed ration and pasture production systems. Under natural rangeland conditions, decomposition of manure is aerobic, which produces carbon dioxide (CO2), part of which is absorbed by the regrowth of vegetation rather than released into the atmosphere, and water (H2O) as end products. Thus the cow releases methane (CH4) and the manure CO2. This is in contrast to intensive cow-calf systems in large parts of Europe and North America, where large quantities of manure are stockpiled and undergo anaerobic decomposition and produce CH4. Thus both the cow and the manure release CH4, which result in a higher carbon footprint than the extensive cow-calf systems. In dairy farming, increasing cow efficiency through intensive feeding (same kg milk output by fewer animals) can reduce farm CH4 production by up to 15%. In addition, when differences in productivity are accounted for, pasture systems require more resources (land, feed, water, etc.) per unit of milk produced and the carbon footprint is greater than that of intensive systems. This raises the question as to why the carbon footprint of intensive dairy cow production systems is less, but the carbon footprint of intensive beef cow-calf production systems is higher. The explanation lies in the differences in production levels. In the case of beef cows the weight of the intensive cows will be ± 30% higher than that of the extensive cows, and the weaning weight of their calves will also differ by ± 30%. In the case of dairy cows the weight of the intensive cows will be ± 20% higher, but their milk production will be ± 60% higher. The higher increase in production (milk) of intensive dairy cows, compared to the increase in production (calf weight) of intensive beef cows, explains the antagonism in the carbon footprint between different beef and dairy production systems. Unfortunately, carbon sequestration estimates have been neglected and thus the quantitative effects of these differences are not known.Keywords: Cow-calf production, methane, pasture production, production levels, total mixed ration

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