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The reaction mechanism of anti-PbO type CoSe in Li, Na, and K ion half cells is studied. Ex situ X-ray diffraction data is analyzed with the Rietveld method, in conjunction with discharge profiles and extended cycling data. These indicate that intercalation followed by a conversion reaction occur in all systems. For the case of Na, the intercalation reaction was associated with a contraction in the stacking axis lattice parameter, whereas Li and K exhibited expansion. Magnetic susceptibility versus temperature measurements of Li- and Na-intercalated CoSe samples produce unusual results, and several explanations are proposed, including the formation of a superconductive phase. Extended cycling experiments are also performed, and high initial capacities of 937, 657, and 972 mAh/g are observed for Li, Na, and K, respectively. However, all systems exhibit significantly lower second discharge capacities of 796, 530, and 515 mAh/g. The capacities continue to decline during extended cycling, with the systems exhibiting tenth cycle capacity fades of 52, 85, and 95% and Li half cells exhibit capacities over 150 mAh/g at 15 mA/g after 50 cycles. The capacity fade is likely attributable to volume changes and irreversibility associated with conversion and intercalation reactions. This work correlates electrochemical features to the structural evolution, magnetic properties, and reaction mechanisms.

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The metabolism of vitamin K was studied in 66 preruminant veal calves that were fed supplemental menadione sodium bisulfite complex or phylloquinone. Menadione sodium bisulfite complex was converted by intestinal microorganisms to menaquinone-4 and absorbed and stored in the liver as menaquinone-4. Phylloquinone was absorbed unchanged. Production of menaquinones 6, 7, 8, and 10 by intestinal microorganisms also was observed, but was not dependent upon dietary vitamin K. No difference was noted in prothrombin time among the groups. Intestinal microorganisms provide sufficient vitamin K to meet the physiological needs of calves fed milk replacers. Menaquinone-4 was the form of vitamin K used to meet the calf's requirement.

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Factors associated with bulk tank milk bacterial and somatic cell counts were investigated for one year on nine well managed dairies. Geometric mean total bacterial count among dairies was 4.4 × 103 colony cfu/ml. Geometric mean bulk tank milk somatic cell counts among herds was 265 × 103ml. Bacterial counts in bulk tank milk were correlated with rates of coliform and environmental streptococcal clinical mastitis cases. Rates of total clinical cases were also correlated with bulk tank milk somatic cell counts. Correlations were measured among bulk tank milk bacterial counts and gram-negative bacterial, coliform, Klebsiella species, and streptococcal counts in materials used to bed lactating cows. Total bacterial and staphylococcal bulk tank milk counts increased when synthetic rubber liners were used greater than 800 quarter milkings. Correlations measured indicated that monitoring bulk tank milk may be an effective means of detecting management changes in herds with low bacterial and milk somatic cell counts.

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Length, size, and interval between eating bouts were determined for four forages with two lactating dairy cows. The forages were low dry matter alfalfa haylage, high dry matter alfalfa haylage, alfalfa hay, and alfalfa pellets. Recordings were made for 96-h periods, and nibbling bouts were separated from meals according to the time and weight of eating bouts. Meal data were analyzed by a stepwise least squares analysis to determine the best model for characterizing feed intake data for lactating dairy cows. Initial meal size and lengths were not different; however, interval following the initial meal was longer on the alfalfa pellet diet. Spontaneous meals were similar in number and size for all diets; however, meal length was increased on the alfalfa hay diet. Total daily dry matter intakes were not different for the four diets. It is important to distinguish between nibbling and meals for effective analysis of intake, feeding behavior, and meal patterns.

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In order to partition indigestible N in heat-damaged forages into its various chemical fractions, alfalfa (41.1% dry matter), stored in an upright stave silo, was not sealed, and heating was promoted. Silage was labeled as unheated silage (temperature below 20 degrees C); 35 degrees C silage (temperature near 35 degrees C, 5220 degrees C d); and 60 degrees C silage (temperature near 60 degrees C, 10,800 degrees C d). Total amino acid content of 60 degrees C silage was lower and acid detergent insoluble amino acid content was higher than in 35 degrees C or unheated silages. Apparent N digestibilities, determined using lactating dairy cows, were 47.5, 48.4, and 63.6% for 60 degrees C, 35 degrees C, and unheated silages. Estimates of true N digestibility were 76, 76, and 90%; true digestibility coefficients for amino acid N were 86, 92, and 95%; and true digestion coefficients for nonamino acid N were 67, 45, and 69% for 60 degrees C, 35 degrees C, and unheated silages. Two possible causes for depressed N digestibility of 60 degrees C silage were 1) the ratio of poorly digested nonamino acid N to highly digested amino acid N was higher in 60 degrees C silage than in 35 degrees C or unheated silage, and 2) amino acid N in 60 degrees C silage was digested less than amino acid N in 35 degrees C or unheated silage. Reasons for low digestibility of N in 35 degrees C silage are less clear, but evidence suggests formation of indigestible N complexes in digesta.

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Some animals consuming hay treated with anhydrous ammonia have developed neurological signs including hyperexcitability, circling and convulsions. A series of experiments was conducted to identify tentatively the toxin and determine its mode of action. Three out of four sheep fed ammoniated orchardgrass hay (approximately 4% ammonia on a dry basis) developed convulsions. Two of the three sheep died within 18 h of the onset of signs. The concentrations of blood lactate and pyruvate were elevated in the symptomatic sheep (P less than .05). A proposed toxin, 4-methyl imidazole, did not induce the syndrome when 750 mg/d (approximately 10 times the dietary amount) were administered orally. Four out of five calves that received milk from cows fed ammoniated oat hay (approximately 5% ammonia on dry basis) displayed hyperexcitability and circling. Concentrations of blood lactate and pyruvate were also elevated in the calves. The crude alkaloid fraction of the toxic milk produced neurological signs similar to those of the calves when injected into mice. A fluorescent compound was found in the alkaloid fraction of toxic milk and ammoniated hay, but not in control milk or untreated hay. The fluorescent compound was quite labile; hence, characterization has been unsuccessful thus far.

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Selenium injections and oral vitamin E supplementation prepartum were related to: postpartum uterine involution (decrease in uterine size per unit time) and days to minimum uterine size in a 2 X 2 factorial design. Complete data were analyzed from 64 cows. Groups were selenium plus vitamin E, vitamin E, selenium, and control. Factors significantly affecting uterine size between 14 and 50 d postpartum were cow weight, days postpartum-linear, days postpartum-quadratic, day X metritis, and day X metritis X selenium treatment. Days to minimum uterine size were significantly less in cows with metritis and selenium treated when compared with cows with metritis and not selenium treated (32.9 vs. 35.8).

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Holstein steers were fed corn silage supplemented with either wet or dried brewers' grains to determine effects of heat drying commercial brewers' grains. Four rumen-fistulated steers were fed a 12.5% crude protein diet in a single reversal design experiment. Brewers' grains supplied 45% of the protein of the diet. Bacterial numbers, concentration of ciliated protozoa, and ammonia concentration in the rumen were higher, and rumen pH was lower, for steers fed wet brewers' grains. Concentrations of rumen volatile fatty acids were similar for both diets. Ruminal digestibility of dry matter decreased when wet versus dried brewers' grains were fed (56.9 versus 39.3%). The rate of dry matter passage from the rumen was faster with wet brewers' grains. In Experiment 2, 12 steers were in a 2 X 2 factorial design. Diets contained wet or dried brewers' grains supplemented at 22 or 40% of the diet dry matter (12.5 and 14.5% crude protein). Nitrogen retention was increased in steers fed the higher crude protein diet. Apparent digestible nitrogen, acid detergent fiber nitrogen, and nitrogen retention were higher with wet versus dried brewers' grains. Plasma essential and nonessential amino acids were also higher in steers fed wet brewers' grains. Alteration in microbial numbers, fermentation measurements, and nitrogen utilization were associated with more soluble nitrogen with wet (13.4%) versus dried (3.3%) brewers' grains.

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The objective was to determine the efficacy of a blend of ammonium salts of the volatile fatty acids, isobutyric, 2-methylbutyric, isovaleric, and valeric as a supplement to diets for dairy cows. Treatments of 0 (control) or 120 (supplemented) g/cow of the blend were fed daily from approximately 3 wk prepartum through a complete lactation. Five trials were conducted concurrently with a total of 116 multiparous Holstein cows. Dietary ingredients or combinations of ingredients differed in each of the trials. Diets contained either 1) corn gluten meal and urea, 2) soybean meal, or 3) cottonseed meal as the primary grain source of crude protein. The forage portion of the diets contained corn silage in combination with one or more of the following: alfalfa hay, alfalfa haylage, or wheat silage. Cows fed the supplement produced more milk and fat-corrected milk than the control cows for the 305-d lactation on four of the five diets, resulting in an average increase of 1.7 kg/d or 7%. Feed intake of cows on the supplemented diet was generally similar or lower than intake of the control cows throughout lactation, indicating that increased milk yield was associated with improved feed utilization. Percent milk fat was similar for cows on the supplemented diet, but fat yield was higher. Percent milk protein was lower for supplemented cows, but protein yield was about the same for both treatments because of higher milk yield. Health and reproduction were similar for all cows.

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Following intravenous infusion with approximately 300 mg deuterium oxide per kg body weight, blood was drawn from lactating Holsteins (Trial 1, n = 4, and Trial 2, n = 5) at suitable intervals for up to 12 days while the cows were maintained on dietary regimens to which they were well adapted. Time results for deuterium oxide concentration in blood were described best by the three-compartment open model system, which showed that the central, shallow peripheral, and deep peripheral body water compartments contained 27.1, 25.0, and 23.2% body weight in trial 1 and 33.7, 27.1, and 19.9% body weight in trial 2. Total body water estimates averaged 75.3 and 80.7% body weight during trials 1 and 2. Estimates for biological half-life of water were 4.6 and 3.2 days and those for water turnover were 68.9 and 109.7 liters/day, respectively. The data fitted the two-compartment open model system when observations made prior to 25 min post-administration were excluded from the analyses, because the central and shallow peripheral compartments were apparently lumped into one. Blood sampling at 0.5, 1, and 1.5 days following infusion and thereafter at 1-day intervals was adequate for the estimates of the one compartment open model system. Estimates of total body water, water biological half-life, and water turnover were similar for the different models. It is concluded that the three-compartment open model provides greater detail and insight into the water dynamics of lactating dairy cows having regular access to food and water, whereas the two- and one-compartment open model systems provide good approximations only.

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Twenty-four wethers were fed fresh cut orchardgrass, fertilized so that the magnesium concentration in the forage varied, and six lactating dairy cows were fed a 60% concentrate diet supplemented so that the magnesium concentration in the diet varied. This was to evaluate relationships between intake of magnesium and fecal excretion of magnesium in ruminants. Linear and logarithmic equations were evaluated for sheep and dairy cows. Although there was little difference between equations in ability to predict apparent absorption of magnesium at normal intakes of magnesium, the logarithmic equation was more useful for predicting magnesium apparent absorption at extreme intakes of magnesium. Constants for logarithmic equations for sheep and cows were similar; therefore, the data were combined and a single equation was derived for both species on the same logarithmic scale. Apparent absorption of magnesium in ruminants may be a function of the amount of magnesium consumed per unit of digesta surface area exposed to the rumen wall.

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Body composition was studied in five animal groups (two 8-week-old calves, two 16-week-old calves, three Holsteins and three Jerseys in late lactation and two groups of cows each having a Holstein and a Jersey in early lactation). Each group was fed a different diet so as to effect wide variations in body composition. Body water volume and kinetics were estimated by deuterium oxide (D2O) dilution in trials lasting 10-12 days for each animal. The experimental animals were slaughtered at the end of the trials for direct chemical analyses of body components. The following prediction equations were derived from D2O measurements and direct chemical analyses (slaughter studies) in kilograms except energy, which is in megacalories: TBW = 1.501D0.898 (Sy.x = 0.285); P = 1.501 (D0.898 - 2.682T0.605); protein = 0.147P1.095 (Sy.x = 0.895); ash = 0.0381P1.057 (Sy.x = 0.298); fat = 0.00122P-2.769 LW4.275 (Sy.x = 0.342); energy = fat X 9.226 + protein X 5.926 where TBW = total body water, D = D2O space in kilograms, T = water turnover (L/day), P = predicted empty body water and LW = liveweight (kilograms). It was concluded that further studies are required, with more animals, to improve and/or verify the utility of the above equations.

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The effect of selenium and vitamin E on concentrations of selenium and selenium-dependent glutathione peroxidase in tissues of dairy cows was studied. Selenium (5 mg/day) and vitamin E (2 g/day) were supplemented for 10 days in a 2 X 2 factorial arrangement. Selenium supplementation increased content of selenium in whole blood, plasma, ovary, and liver and increased activity of selenium-dependent glutathione peroxidase in liver. Activity of selenium-dependent glutathione peroxidase in follicular fluid was closely correlated with selenium-dependent glutathione peroxidase in plasma. Significant activity of selenium-dependent glutathione peroxidase was detected in luteal tissue of the ovary. Relationships were linear between content of selenium and selenium-dependent glutathione peroxidase in ovary, uterus, and adrenal tissues.

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Eleven nonlactating Holstein cows in late gestation were used to study the effect of dietary calcium concentration on apparent selenium absorption. Digestion trials with total collection helped to estimate apparent absorption of specific nutrients. Mean daily selenium intake ranged from 900 to 1700 micrograms per day. Regression analysis indicated apparent selenium absorption was maximum when dietary calcium was .8% of dry matter intake. Amounts of dietary calcium less or greater than .8% of dry matter intake reduced apparent selenium absorption. Dietary calcium quantitatively affected apparent selenium absorption in amounts of nutritional significance when selenium was provided from natural feedstuffs.

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Incidence of clinical mastitis and duration of clinical symptoms for complete lactations were evaluated for 80 cows randomly assigned to one of four groups: vitamin E supplemented- and selenium injected, selenium injected, vitamin E supplemented, and controls. Vitamin E supplementation and selenium injection were during the dry period. Log-linear analysis of incidence data revealed a significant 37% reduction of clinical mastitis by vitamin E. Incidence was not affected by selenium alone, nor was there any evidence for interaction of vitamin E with selenium on incidence. However, duration of clinical symptoms (calendar months clinical/quarter lactating) was reduced by 46% for the selenium group, 44% for the vitamin E group, and 62% for the vitamin E-selenium group as compared to controls. We conclude that dairy cow diets deficient of vitamin E may elevate incidence of clinical mastitis. Selenium deficiency may result in greater duration of clinical symptoms, and selenium may interact with vitamin E. Coliform bacteria and species of streptococcus other than Streptococcus agalactiae were isolated from 70% of the clinical cases.

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Two bottom unloading silos were filled with alternate loads of alfalfa (Medicago sativa L.) and ground shelled corn grain mix (1:5, grain:forage, wet basis) to determine effects of propionic acid added to supplemental corn on performance of lactating dairy cow consuming a complete ensiled diet. One silo received grain mix containing 1% propionic acid. Each of two groups of six lactating cows was fed one of the complete ensiled diets supplemented with high moisture corn, dried-shelled corn, or no supplemental corn for 4 mo. Cows that consumed the acid-treated diet produced less milk, fat, and protein than cows consuming the untreated diet. Supplemental high moisture corn and dried shelled corn increased milk and protein yields, and high moisture corn increased fat yields compared to the unsupplemented. Daily variation of the ratio of grain:forage indicated that alternate load additions of forage and grain resulted in poor mixing of ration components and may be related to some of the differences in performance.

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Selenium injections and oral vitamin E supplementation prepartum were related to incidence of retained placenta, metritis, and cystic ovaries in a 2 X 2 factorial experiment. Groups were: 1) selenium and vitamin E, 2) vitamin E, 3) selenium, and 4) control. Incidence of retained placenta was 17.5% in cows of groups 2, 3, and 4, whereas it was reduced to 0% in cows receiving both selenium and vitamin E. Incidence of metritis was 60% for cows injected with selenium and 84% for those not receiving selenium. Cystic ovaries were diagnosed in 19% of cows injected with selenium, and incidence was 47% for cows not treated with selenium. Supplementation of vitamin E was required in addition to selenium for prevention of retained placenta of cows fed stored ensiled forage, and prepartum selenium injections were effective for reducing the incidence of metritis and cystic ovaries during the early postpartum period.

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Total collection digestion trials were used to study selenium absorption and retention as related to selenium intake in nonlactating dairy cows. Relationship between selenium absorption and retention was linear over selenium intakes from 400 to 3100 micrograms/day. Regression analysis showed partial selenium absorption of 51% over total range of intake and 41% retention of dietary selenium intake. Also, negative selenium balances could occur when nonlactating cows are fed selenium-deficient diets without a supplemental source of selenium.

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