Effect of postpartum calcium supplementation on serum calcium and parathyroid hormone concentrations in multiparous Holstein cows.

Although postpartum Ca supplementation strategies are often employed to prevent subclinical hypocalcemia in dairy cows, these strategies have produced a mix of beneficial, neutral, and detrimental results when assessing milk yield and subsequent disease outcomes. Because the mechanisms underlying these differing results are unknown, our objectives were to determine how common postpartum Ca supplementation strategies affect blood Ca concentrations and parathyroid hormone (PTH). We conducted a randomized controlled trial with 74 multiparous dairy cows on a commercial dairy in central New York. Cows were assigned to 1 of 4 supplementation groups immediately after calving: (1) control (CON; no Ca supplementation, n = 15); (2) conventional oral Ca supplementation (BOL-C; 43 g of oral Ca bolus administered immediately after calving and 24 h later, n = 17); (3) delayed oral Ca supplementation (BOL-D; 43 g of oral Ca bolus administered 48 and 72 h after calving, n = 15); or (4) subcutaneous infusion (SQ; 500 mL of 23% Ca borogluconate infused subcutaneously once immediately after calving, n = 15). Blood samples were collected immediately after calving (0 h) and at 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 120, and 168 h postpartum for a total of 15 blood samples per cow. Cows were excluded if administered Ca, via any route, by farm employees or if they died or were sold within 96 h following parturition, which left 62 cows for analysis. Linear mixed models, accounting for repeated measures, were created to analyze changes in serum total Ca (tCa) and PTH over the first 168 h after parturition and assess differences between supplementation groups. Serum tCa and PTH concentrations were not different at the time of calving among supplementation groups. There was a supplementation group by hour postcalving interaction for mean tCa concentration in which SQ cows had reduced tCa concentrations from 32 to 64 h compared with CON cows, 32 to 96 h compared with BOL-C cows, and 40 to 64 h compared with BOL-D cows. Mean PTH concentration did not differ among supplementation groups across 168 h after enrollment and was 158.1 pmol/L (95% confidence interval [CI] = 148.2 to 168.0) for CON cows, 164.0 pmol/L (95% CI = 154.9 to 173.1) for BOL-C cows, 158.7 pmol/L (95% CI = 149.2 to 168.1) for BOL-D cows, and 153.2 pmol/L (95% CI = 143.6 to 162.8) for SQ cows. Our findings suggest that although serum tCa does not differ between cows that receive conventional or delayed oral Ca bolus supplementation at calving and cows that receive no supplemental Ca, subcutaneous infusion of Ca at calving reduces serum tCa for a substantial period between 32 and 64 h postsupplementation. However, as PTH concentrations did not differ among groups across 168 h postpartum, the mechanism by which tCa is reduced remains unclear.

Calcium dynamics and associated temporal patterns of milk constituents in early-lactation multiparous Holsteins.

At the onset of lactation, calcium (Ca) homeostasis is challenged. For the transitioning dairy cow, inadequate responses to this challenge may result in subclinical hypocalcemia at some point in the postpartum period. It has been proposed that dynamics of blood Ca and the timing of subclinical hypocalcemia allow cows to be classified into 4 Ca dynamic groups by assessing serum total Ca concentrations (tCa) at 1 and 4 days in milk (DIM). These differing dynamics are associated with different risks of adverse health events and suboptimal production. Our prospective cohort study aimed to characterize the temporal patterns of milk constituents in cows with differing Ca dynamics to investigate the potential of Fourier-transform infrared spectroscopic (FTIR) analysis of milk as a diagnostic tool for identifying cows with unfavorable Ca dynamics. We sampled the blood of 343 multiparous Holsteins on a single dairy in Cayuga County, New York, at 1 and 4 DIM and classified these cows into Ca dynamic groups using threshold concentrations of tCa (1 DIM: tCa <1.98 mmol/L; 4 DIM: tCa <2.22 mmol/L) derived from receiver operating characteristic curve analysis based on epidemiologically relevant health and production outcomes. We also collected proportional milk samples from each of these cows from 3 to 10 DIM for FTIR analysis of milk constituents. Through this analysis we estimated the milk constituent levels of anhydrous lactose (g/100 g of milk and g/milking), true protein (g/100 g of milk and g/milking), fat (g/100 g of milk and g/milking), milk urea nitrogen (mg/100 g of milk), fatty acid (FA) groups including de novo, mixed origin, and preformed FA measured in grams/100 g of milk, by relative percentage, and grams/milking, as well as energy-related metabolites including ketone bodies and milk-predicted blood nonesterified FA. Individual milk constituents were compared among groups at each time point and over the entire sample period using linear regression models. Overall, we found differences among the constituent profiles of Ca dynamic groups at approximately every time point and over the entire sample period. The 2 at-risk groups of cows did not differ from each other at more than one time point for any constituent, however prominent differences existed between the milk of normocalcemic cows and the milk of the other Ca dynamic groups with respect to FA. Over the entire sample period, lactose and protein yield (g/milking) were lower in the milk of at-risk cows than in the milk of the other Ca dynamic groups. In addition, milk yield per milking followed patterns consistent with previous Ca dynamic group research. Though our use of a single farm does limit the general applicability of these findings, our conclusions provide evidence that FTIR may be a useful method for discriminating between cows with different Ca dynamics at time points that may be relevant in the optimization of management or development of clinical intervention strategies.

Patterns of Fourier-transform infrared estimated milk constituents in early lactation Holstein cows on a single New York State dairy.

Cows undergo immense physiological stress to produce milk during early lactation. Monitoring early lactation milk through Fourier-transform infrared (FTIR) spectroscopy might offer an understanding of which cows transition successfully. Daily patterns of milk constituents in early lactation have yet to be reported continuously, and the study objective was to initially describe these patterns for cows of varying parity groups from 3 through 10 d postpartum, piloted on a single dairy. We enrolled 1,024 Holstein cows from a commercial dairy farm in Cayuga County, New York, in an observational study, with a total of 306 parity 1 cows, 274 parity 2 cows, and 444 parity ≥3 cows. Cows were sampled once daily, Monday through Friday, via proportional milk samplers, and milk was stored at 4°C until analysis using FTIR. Estimated constituents included anhydrous lactose, true protein, and fat (g/100 g of milk); relative % (rel%) of total fatty acids (FA) and concentration (g/100 g of milk) of de novo, mixed, and preformed FA; individual fatty acids C16:0, C18:0, and C18:1 cis-9 (g/100 g of milk); milk urea nitrogen (MUN; mg/100 g of milk); and milk acetone (mACE), milk ß-hydroxybutyrate (mBHB), and milk-predicted blood nonesterified fatty acids (mpbNEFA) (all expressed in mmol/L). Differences between parity groups were assessed using repeated-measures ANOVA. Milk yield per milking differed over time between 3 and 10 DIM and averaged 8.7, 13.3, and 13.3 kg for parity 1, 2, and ≥3 cows, respectively. Parity differences were found for % anhydrous lactose, % fat, and preformed FA (g/100 g of milk). Parity differed across DIM for % true protein, de novo FA (rel% and g/100 g of milk), mixed FA (rel% and g/100 g of milk), preformed FA rel%, C16:0, C18:0, C18:1 cis-9, MUN, mACE, mBHB, and mpbNEFA. Parity 1 cows had less true protein and greater fat percentages than parity 2 and ≥3 cows (% true protein: 3.52, 3.76, 3.81; % fat: 5.55, 4.69, 4.95, for parity 1, 2, ≥3, respectively). De novo and mixed FA rel% were reduced and preformed FA rel% were increased in primiparous compared with parity 2 and ≥3 cows. The increase in preformed FA rel% in primiparous cows agreed with milk markers of energy deficit, such that mpbNEFA, mBHB, and mACE were greatest in parity 1 cows followed by parity ≥3 cows, with parity 2 cows having the lowest concentrations. When measuring milk constituents with FTIR, these results suggest it is critical to account for parity for the majority of estimated milk constituents. We acknowledge the limitation that this study was conducted on a single farm; however, if FTIR technology is to be used as a method of identifying cows maladapted to lactation, understanding variations in early lactation milk constituents is a crucial first step in the practical adoption of this technology.

CO2 enrichment influences yields of 'Florunner,' 'Georgia Red' and 'New Mexico' peanut cultivars.

Three peanut cultivars, 'Florunner,' 'Georgia Red,' and 'New Mexico,' were grown in reach-in chambers to determine response to CO2 enrichment. CO2 treatments were ambient (400 micromol mol-1) and 700 micromol mol-1. Growth chamber conditions included 700 micromol m-2 s-1 photosynthetic photon flux (PPF), 28/22C, 7O% RH, and 12/12 h photoperiod. Growth media consisted of a 1:1 mixture (v/v) of vermiculite and sterilized sand. Six 10 L pots of each cultivar were fertilized three times per week with 250 mL of nutrient solution containing additional Ca (10 mM) and NO3 (25 mM) and watered well. Beginning 21 days after planting (DAP) and every three weeks thereafter up to 84 days, the second leaf from the growing axis (main stem) was detached to determine CO2 effect on leaf area, specific leaf area (SLA) and dry weight. Plants were harvested 97 DAP, at which time total leaf area, leaf number, plant and root weights and pod production data were taken. Numbers of pods per plant, pod fresh and dry weights, fibrous root and plant dry weights were higher for all cultivars grown at 700 micromol mol-1 than at ambient CO2. Also, leaf area for all cultivars was larger with CO2 enrichment than at ambient. SLA tended to decline with time regardless of CO2 treatment. Percentage of total sound mature kernels (%TSMK) was similar for both treatments. Plants grown at 700 micromol mol-1 CO2 had slightly more immature pods and seeds at final harvest.

The safety profile of nefazodone.

Comprehensive review of safety data from approximately 3500 patients who received nefazodone in premarketing clinical trials demonstrates the drug to be very well tolerated, with a favorable side effect profile compared with other antidepressant drugs. Nefazodone treatment was associated with fewer side effects than were the control drugs. The incidence of side effects was generally low, and treatment discontinuations for adverse effects were less frequent with nefazodone than with imipramine and comparable with fluoxetine. No late-appearing side effects or toxicity emerged during the long-term treatment (1 year or longer) of several hundred patients. There were no drug-related fatalities and no evidence that nefazodone caused specific organ toxicity, although some cardiovascular side effects were noted (e.g., asymptomatic reduced systolic blood pressure, asymptomatic sinus bradycardia). Experience in 488 elderly patients treated with nefazodone yielded no evidence of increased susceptibility of older patients to nefazodone-associated adverse experiences, including those pertaining to the cardiovascular system. However, treatment should be initiated at a reduced dose in elderly patients because of reduced hepatic clearance of nefazodone in this age group. Final dose range may be similar in healthy younger and older patients. Although nefazodone may interact with some other medications (e.g., increases at steady state in AUC: alprazolam, twofold; triazolam, fourfold), drug-drug interactions involving patients have been clinically minor. On the basis of the inhibition of cytochrome P450 3A4 isoenzyme by nefazodone in vitro, coadministration of terfenadine or astemizole with nefazodone is contraindicated because nefazodone can increase the plasma levels of these two drugs. Extensive clinical experience provides substantial evidence that nefazodone is an extremely safe and effective treatment for depression, with important advantages over existing therapies. Therapeutic benefits include a low incidence of clinically troublesome side effects and lack of unwanted psychic activation, sexual dysfunction, weight change, and the cardiotoxicity of other antidepressants.

Ergonomics in the German Democratic Republic.

A survey of ergonomics in the German Democratic Republic (GDR) was conducted over approximately a two-month period starting in mid-May 1982. This study was sponsored by the International Research and Exchanges Board (IREX) located in New York City. IREX maintains scientific exchange agreements with Eastern European countries and the USSR. This survey is one of a series of similar studies conducted in Eastern Europe. Earlier countries surveyed were Romania (Seminara, 1975), Bulgaria (Seminara, 1976a, 1976b, 1982), the USSR (Seminara, 1977, 1979/80), Poland (Seminara, 1979a), Czechoslovakia (Seminara, 1979b), Hungary (Seminara, 1980), and Yugoslavia (Seminara, 1983).

Remedial human factors engineering (Part 2).

The article concludes with comments on panel enhancement techniques, overlays, segmented panel enhancement approaches, factors in selecting between approaches, future modifications, durability, configuration control, cost and practical lessons learned. Part 1 was published in the December 1983 issue on pages 253-264.

Remedial human factors engineering - part 1.

Some generic problems have been observed in present-generation nuclear power plant control rooms. This paper presents an initial attempt to develop remedial solutions. In Part 1, enhancement methodology is discussed in general terms. Part 2 will explore detailed panel enhancement options as applied to a specific case history.

A survey of ergonomics in Yugoslavia.

The writer conducted a survey of ergonomics in Yugoslavia during the month of December 1982. This survey was made possible by the scientific exchange programme between the National Academy of Sciences of the USA and the Council of Academies of Yugoslavia. The writer met with engineers and scientists in academic, research and public health institutions to develop an overview of historical developments, the compostion of the ergonomics community, current research interests and methodologies, academic training programmes and future trends. The schedule of visits, which spanned four of the six Yugoslavian republics, is summarised in Table 1. The present study is a sequel to earlier surveys of ergonomics or human factors in Eastern Europe (Seminara, 1975; 1976; 1979a; 1979b; 1979/80; 1980; 1982; 1983).

Nuclear power plant maintainability.

In the mid-1970s a general awareness of human factors engineering deficiencies associated with power plant control rooms took shape and the Electric Power Research Institute (EPRI) awarded the Lockheed Corporation a contract to review the human factors aspects of five representative operational control rooms and their associated simulators. This investigation revealed a host of major and minor deficiencies that assumed unforeseen dimensions in the post- Three Mile Island accident period. In the course of examining operational problems (Seminara et al, 1976) and subsequently the methods for overcoming such problems (Seminara et al, 1979, 1980) indications surfaced that power plants were far from ideal in meeting the needs of maintenance personnel. Accordingly, EPRI sponsored an investigation of the human factors aspects of power plant maintainability (Seminara, 1981). This paper provides an overview of the maintainability problems and issues encountered in the course of reviewing five nuclear power plants.

Bulgarian ergonomics revisited.

In his earlier and more intensive review of ergonomics in Bulgaria, the author concluded that this discipline was highly developed and enjoyed strong government support. It was found that the network of ergonomics activities across national, regional, and local industrial plant levels was perhaps the most highly organised and comprehensive extension of ergonomics concerns of any country in the world. The brief revisit described in this report revealed that ergonomics continues to enjoy a very high measure of respectability. As also noted earlier, the field of ergonomics is still largely the province of physiologists and engineers. Some psychologists that are associated with design organisations are involved in ergonomics activities but, for the most part, psychologists deal primarily with more traditional topics that fall under the heading of industrial or work psychology.

Ergonomics in Hungary.

This report was made possible by a grant from the National Academy of Sciences. The NAS maintains an exchange programme with the USSR and Eastern European countries in order to stimulate the development of improved scientific relationships between East and West. The author participated in this exchange programme as an individual researcher and not as a representative of his employer, The Lockheed Missiles and Space Co.

Human factors in the USSR (Part 2).

In this second part of a survey of the human factors discipline which the author conducted in the USSR, work at four further centres is discussed and there are some comments on exhibitions of Russian products, together with general observations and conclusions. The first part of this report, which compares the Russian and American development, research interests, and academic programmes, appeared in the December 1979 issue.

Human factors in the USSR (Part 1).

A survey of the human factors discipline was conducted in the USSR. Interviews were conducted with prominent Russian scientists in research institutes, academic institutions and design organisations. This report describes the historical development of the field, current research interests and methodologies, academic programmes and the nature of this discipline as it has evolved in the USSR in comparison with the USA.

A survey of ergonomics in Czechoslovakia.

A survey of the historical development of ergonomics, and current research and training in this discipline, in Czechoslovakia. The report follows a series of visits to scientists in academic and research in institutions in the summer of 1978.