Seasonal fluxes of carbon monoxide from an intensively grazed grassland in Scotland.

Fluxes of carbon monoxide (CO) were measured using a fast-response quantum cascade laser absorption spectrometer and the eddy covariance method at a long-term intensively grazed grassland in southern Scotland. Measurements lasted 20 months from April 2016 to November 2017, during which normal agricultural activities continued. Observed fluxes followed a regular diurnal cycle, peaking at midday and returning to values near zero during the night, with occasional uptake observed. CO fluxes correlated well with the meteorological variables of solar radiation, soil temperature and soil moisture content. Using a general additive model (GAM) we were able to gap fill CO fluxes and estimate annual fluxes of 0.38 ±â€¯0.046 and 0.35 ±â€¯0.045 g C m-2 y-1g C m-2 y-1 for 2016 and 2017, respectively. If the CO fluxes reported in this study are representative of UK grasslands, then national annual emissions could be expected to be in the order of 61.91 (54.3-69.5) Gg, which equates to 3.8% (3.4-4.3%) of the current national inventory total.

Identifying gene targets for the metabolic engineering of lycopene biosynthesis in Escherichia coli.

The identification of genetic targets that are effective in bringing about a desired phenotype change is still an open problem. While random gene knockouts have yielded improved strains in certain cases, it is also important to seek the guidance of cell-wide stoichiometric constraints in identifying promising gene knockout targets. To investigate these issues, we undertook a genome-wide stoichiometric flux balance analysis as an aid in discovering putative genes impacting network properties and cellular phenotype. Specifically, we calculated metabolic fluxes such as to optimize growth and then scanned the genome for single and multiple gene knockouts that yield improved product yield while maintaining acceptable overall growth rate. For the particular case of lycopene biosynthesis in Escherichia coli, we identified such targets that we subsequently tested experimentally by constructing the corresponding single, double and triple gene knockouts. While such strains are suggested (by the stoichiometric calculations) to increase precursor availability, this beneficial effect may be further impacted by kinetic and regulatory effects not captured by the stoichiometric model. For the case of lycopene biosynthesis, the so identified knockout targets yielded a triple knockout construct that exhibited a nearly 40% increase over an engineered, high producing parental strain.

Relationships between reproduction traits, age and body weight at calving, and days dry in first lactation Ayrshires and Holsteins.

Individual cow test day records collected between December 1979 and June 1986 were used to calculate measures of reproductive performance, age and weight at calving, and days dry for 7824 Ayrshire and 79,755 Holstein cows in first lactation. Separate analyses by breed were carried out according to a multiple-trait mixed model. Sixty-two Ayrshire and 369 Holstein sires were treated as random in the analyses. Ayrshires were, on average, older and lighter at calving than Holsteins, but the breeds differed little in reproduction measures and days dry. Heritabilities of fertility traits, days to first breeding, days open, and services per conception were all less than .015 in the multi-trait analyses. With the exception of body weight, heritability estimates for the other traits were less than .05. Phenotypic correlations between traits were almost identical for the two breeds, and genetic correlations tended to be similar. Exceptions involved the trait days to first breeding and services per conception, but heritabilities of these traits were close to zero (p less than .008) in Ayrshires. Fertility traits were positively correlated genetically. Genetic correlations between days open and both age and body weight at calving were small. The genetic correlation between age and weight at calving was -.90 and -.68 in Ayrshires and Holsteins, respectively. Genetic correlations between days dry and all traits except body weight were moderate and positive.

Impact of the Higgins Nutrition Intervention Program on birth weight: a within-mother analysis.

A study was conducted to evaluate the impact of the Higgins Nutrition Intervention Program of individual nutritional assessment and rehabilitation on pregnancy outcome in a group of urban low-income women. Developed as an adjunct to routine prenatal care, the Higgins program utilizes an individualized approach to dietary treatment that combines an assessment of the risk profile for the presenting pregnancy with the application of specific nutritional rehabilitation allowances to compensate for the negative impact of diagnosed risks. This report presents results of analyses evaluating differences in birth outcomes between 552 sibling pairs; each mother had participated in the Higgins program during the pregnancy of the second-born, but not of the first-born, member of her pair. After adjustment for parity and sex, the intervention infants weighed an average of 107 gm more than their matched siblings at birth (p less than .01). The rate of low birth weight was 50% lower among the intervention infants than among their siblings (p less than .01); rates of intra-uterine growth retardation and perinatal mortality were also lower in the intervention group. The high risk of poor pregnancy outcome in this group of urban low-income women was reduced by the Higgins program.

Hospital inpatient mortality. Is it a predictor of quality?

Various potential measures of quality of care are being used to differentiate hospitals. Last year, on the basis of diagnostic and demographic data, the Health Care Financing Administration identified hospitals in which the actual death rate differed from the predicted rate. We have developed a similar model. To understand why there are high-outlier hospitals (in which the actual death rate is above the predicted one) and low-outlier hospitals (in which the actual death rate is below the predicted one), we reviewed 378 medical records from 12 outlier hospitals treating patients with one of three conditions: cerebrovascular accident, myocardial infarction, and pneumonia. After adjustment for the severity of illness, the death rate in the high outliers exceeded that predicted from the severity of illness alone by 3 to 10 percent, and in the low outliers, the actual death rate fell short of the severity-adjusted predictions by 10 to 15 percent (P less than 0.01). Reviews of the process of care using 125 criteria revealed no differences between the high and low outliers. However, detailed reviews by physicians of the records of patients who died during hospitalization revealed a higher rate of preventable deaths in the high outliers than in the low outliers. For the three conditions studied, we project that 5.7 percent of a standard cohort of patients admitted to the high-outlier hospitals would have preventable deaths, as compared with 3.2 percent of patients admitted to the low-outlier hospitals (P less than 0.05). A meaningful comparison of hospital death rates requires adjustment for severity of illness. Our findings indicate that high-outlier hospitals care for sicker patients. However, these same hospitals or their medical staffs may also provide poorer care. Our results need confirmation before death-rate models can be used to screen hospitals.

Variation in milk protein concentrations associated with genetic polymorphism and environmental factors.

Concentrations of alpha s-casein, beta-casein, kappa-casein, beta-lactoglobulin, alpha-lactalbumin, serum albumin, and immunoglobulin in milk from 1888 Holstein cows were determined monthly over the lactation period. Cows were phenotyped for genetic variants of alpha s1-casein, beta-casein, kappa-casein, and beta-lactoglobulin. Least squares analyses showed variations in individual proteins due to parity number, month of test, stage of lactation, somatic cell count, fat content, milk yield, and phenotypes of cows for milk proteins. beta-Casein declined and serum proteins increased with advancing age of cows. Concentration of individual proteins decreased during the first 2 to 3 mo in lactation and then increased as lactation progressed. alpha s1-Casein variants significantly affected concentrations of alpha s-casein (BC greater than BB greater than AB) and beta-lactoglobulin (AB greater than BB greater than BC). Variant B for beta-casein is associated with lower alpha s-casein, beta-lactoglobulin, immunoglobulins, and higher beta-casein and alpha-lactalbumin concentrations than variant A1, A2, or A3. Milk from BB kappa-casein, and BB beta-lactoglobulin cows contained more alpha s-casein, kappa-casein, and less beta-lactoglobulin than milk from AA cows for the two proteins. Concentrations of all proteins were negatively correlated with milk production. Increased somatic cell counts were associated with lower beta-casein and higher concentrations of other proteins. Fat content of milk was positively correlated with the three casein fractions and beta-lactoglobulin.

Percentages of protein and nonprotein nitrogen with varying fat and somatic cells in bovine milk.

Over 15 mo, 28,390 individual milk samples from 3,600 cows in 62 Quebec Holstein herds were analyzed for crude protein, true protein, nonprotein nitrogen, fat, and somatic cell counts. Unadjusted means with standard errors were 3.51% +/- .002, 3.31% +/- .002, 31.70 mg/100 ml +/- .12, 3.67% +/- .004, and 297,230 cells/ml +/- 4002. Nonprotein nitrogen as a percentage of total nitrogen was 5.57% +/- .02. Least squares analyses showed significant effects of herd, age of cow, month of test, stage of lactation, somatic cell count, and fat percentage on contents of crude protein, true protein, and ratio of nonprotein nitrogen to total nitrogen. Highly variable nonprotein nitrogen fraction content during different months of the year and various stages of lactation is responsible for changes of crude protein content whereas changes of crude protein for different ages of cows, fat, and somatic cells in milk are due to changes of true protein content. Automatic infrared instrument calibrated against crude protein standards can be used satisfactorily to measure crude protein in milk if variations are due to age of cow, fat, and somatic cell counts. However, the instrument becomes inaccurate for measuring large variation of crude protein caused by variability of nonprotein nitrogen due to season and stage of lactation.

Heritability of lactation cell count measures and their relationships with milk yield and composition in Ayrshire cows.

Lactation measures of somatic cell count were calculated from monthly test-day observations (transformed to a log scale) taken between February 1977 and February 1981 in Ayrshire cows in 115 herds enrolled in the Quebec Dairy Herd Analysis Service. Analyses were separate within three groups: 1137 first lactations, representing 37 sires; 1728 second and later lactations, representing 57 sires; and 2510 all lactations, representing 74 sires. Heritabilities of lactation measures were estimated from sire and error variances obtained by iterative minimum norm quadratic unbiased estimation. Heritabilities ranged from .09 to .16 in first lactations and averaged .09 for the group of second and later lactations and .07 for all lactations. Genetic correlations of lactation measures of cell count with milk, fat, protein yield, fat percent, and protein percent averaged .36, .68, .74, .38, and .45, in first lactations; -.97, -.27, -.56, .52, and .03 in second and later lactations; and -.50, -.54, -.73, .43, and .19 in all lactations. Respective average phenotypic correlations were low and negative for milk, fat, protein yield, and fat percent and low and positive for protein percent.

Effects of calving ease-calf survival on production and reproduction in Holsteins.

Data on 23,873 Holstein cows on official test of the Quebec Dairy Herd Analysis Service were analyzed for effects of calving ease-calf survival on cow productivity; data on 35,773 Holstein cows were analyzed for effects on culling and reproductive efficiency. Traits were milk, fat, and protein yields, percent fat and protein for 90-day and 305-day lactations, days from calving to first service and conception, percentage conception rate from first service, and services per conception. The effect of calving ease-calf survival on production traits was not significant in most cases except surgical calvings associated with stillbirth. For these the loss of 305-day production was approximately 300 to 500 kg milk, 8 to 17 kg fat, and 8 to 14 kg protein. Stillbirth in nonsurgical calvings was associated with lower production than when the calf survived; differences were 100 to 400 kg milk, 4 to 11.5 kg fat, and 2.5 to 13 kg protein. Age of cow and calving ease-calf survival significantly affected all measures of reproductive efficiency. Reproductive efficiency declined with advancing age. Effect of calving ease-calf survival tended to be more pronounced when calving was associated with stillbirth.

Association of genetic variants of casein and milk serum proteins with milk, fat, and protein production by dairy cattle.

Polyacrylamide gel electrophoresis methods were used to phenotype caseins for 2045 cows and milk serum proteins for 3870 cows distributed in 63 Quebec dairy herds. Frequencies were: alpha s1-casein A .003, alpha s1-casein B .970, alpha s1-casein C .027; beta-casein A1 .561, beta-casein A2 .421, beta-casein A3 .011, beta-casein B .007; kappa-casein A .744, kappa-casein B .256; beta-lactoglobulin A .387, beta-lactoglobulin B .613; alpha-lactalbumin B 1.00. Overall unadjusted means for 305-day production in first lactation were: 5530 +/- 26.6 kg, 197 +/- 1.0 kg, 172 +/- 1.0 kg, 3.58 +/- .009, 3.12 +/- .009 for milk yield, fat yield, protein yield, fat percentage, and protein percentage for 1687 cows for casein systems. Similar data for 2906 cows phenotyped for milk serum proteins were: 5412 +/- 20.6 kg, 193 +/- .8 kg, 170 +/- .7 kg, 3.57 +/- .007, and 3.13 +/- 007. Least squares analysis of variance showed that herd location, month of calving, age of cow at first calving, and protein variants had significant effects on production traits. alpha s1-Casein B and beta-casein A phenotypes were associated with higher milk, fat, and protein yields than other variants in the two casein systems. Milk from kappa-casein BB and beta-lactoglobulin AA phenotypes contained .13 and .05% more protein than the AA and BB phenotypes with the AB phenotype intermediate.

Heritability of milk casein and genetic and phenotypic correlations with production traits.

Individual milk samples were obtained monthly from November 1979 to November 1981 from approximately 2,800 Holstein cows in 63 herds enrolled in the Quebec Dairy Herd Analysis Service. These milk samples were analyzed for fat, total protein, casein, and serum protein. After editing, the data comprised 2,813 lactations representing 109 sires. By approximate maximum likelihood procedures, the model included herd (absorbed), year-month, and parity fixed effects, and sire and error random effects. Lactation casein yield increased with advancing parity to parity five and then decreased slightly. Lactation casein percent and number (percent casein in protein) declined until parities four and three, respectively, and essentially remained constant thereafter. Lactation casein yield was high for lactations initiated during winter months as opposed to summer months. No seasonal trend was apparent for casein percent or number. Heritabilities for lactation casein yield, percent, and number were .11, .26, and .08. Genetic and phenotypic correlations of casein yield with milk, fat, and protein yields were large and positive. Genetic correlation of casein percent with milk yield was negative (-.76) but positive (.96) with protein percent. Genetic correlations involving casein number tended to be small.

Variability of test-day milk production and composition and relations of somatic cell counts with yield and compositional changes of bovine milk.

Between November 1979 and November 1981, 41,783 test-day observations were obtained from 63 Holstein herds in the province of Quebec. Measured were milk yield, percentages of fat, protein, casein, and serum protein, and somatic cell counts that had unadjusted means with standard errors 20.44 +/- .04 kg, 3.684 +/- .003%, 3.314 +/- 002%, 2.694 +/- .001, .669 +/- .001%, and 313625 +/- 3238/ml of milk. Casein as a percentage of total protein (casein number) was 79.35 +/- .015. Least squares analyses showed significant effects of herd, calendar month of test, age of sample at laboratory testing, stage of lactation, age of cow, and somatic cell counts on milk yield and composition. Milk yield was higher whereas percentages of fat and protein and somatic cell counts were lower in summer than in winter months. Somatic cells, fat, protein, and casein contents were high during early stages of lactation, reached a minimum at 2 mo in lactation, and rose gradually throughout the rest of the lactation. A comparison of younger cows (less than or equal to 2 yrs) with older one (greater than or equal to 6 yr) revealed that somatic cell counts increased from 166,000 to 507,000/ml of milk and casein number decreased from 80.14 to 78.88. Increase of somatic cell counts in milk was associated with increased protein content, which was mainly from the serum protein fraction as the casein fraction was not related with somatic cells.

Environmental influences on protein content and composition of bovine Milk.

A total of 24,405 individual milk samples from approximately 2,800 Holstein-Friesian cows in 63 dairy herds enrolled in the Quebec Dairy Herd Analysis Service program were analyzed monthly for protein, serum protein, casein, and somatic cell counts during 17 mo. Unadjusted means for protein, serum protein, and casein were 3.396% +/- .002, .687% +/- .001, and 2.708% +/- .002. Least squares analyses showed significant effects of calendar month of test, stage of lactation, age of cow, and somatic cell count on milk protein content and composition. Total protein, casein, and serum protein contents of milk showed a generally increasing trend from July to December. These components were highest during the first 10 days in lactation when means were 3.81%, 3.05%, and .76% and reached a minimum at 2 mo in lactation to give corresponding means of 3.08%, 2.46%, and .62%. The proportion of casein in milk protein decreased as cows became older. For every unit of increase in log somatic cell count there was an increase in protein content of 0.99%, mainly from change in the serum protein fraction. The same change in somatic cells would decrease ratio of casein to protein by 2.79%.