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Biomedical subjects

C F Nockels

Publications and source records attributed to C F Nockels.

At least 19 recordsLinked to original sources
PubMed1997

Zinc repletion with organic or inorganic forms of zinc and protein turnover in marginally zinc-deficient calves.

We conducted two experiments using marginally Zn-deficient (-Zn) calves to determine which supplemental chemical form of Zn would most rapidly reverse certain Zn deficiency signs and to determine whether a change in protein turnover had occurred in Zn deficiency. In Exp. 1, 40 crossbred beef heifers were allocated by BW to four groups. The control group received 23 mg Zn/kg diet DM from ZnSO4 supplemented to the -Zn diet (17 mg Zn/kg diet DM). The three other groups received the -Zn diet. After 21 d, based on a decreased (P < .05) feed efficiency, they were deemed -Zn. Cell-mediated immune (CMI) response to phytohemagglutinin (PHA) was reduced (P < .05) but plasma and liver Zn were unaffected in the -Zn calves. Zinc was repleted by feeding iso-Zn amounts (23 mg Zn/kg diet DM) from Zn lysine, Zn methionine, or ZnSO4. At 8 h after injection of PHA, control CMI response values were similar to Zn Methionine, and Zn lysine was lower (P < .05). In Exp. 2, 10 Holstein steers were allocated by BW to two groups. One group received the -Zn diet, and the other received the +Zn diet. Urine collections were obtained from both groups of calves when the -Zn calves showed a decrease (P < .05) in feed efficiency relative to the controls and when they were repleted with 23 mg Zn/kg diet DM from ZnSO4 and their feed efficiency had returned to that of the controls. Urinary 3-methylhistidine indicated that -Zn calves had less (P < .05) daily protein degradation than the controls. Refeeding Zn to the -Zn group did not change BW or daily protein degradation. Results indicated that a marginal Zn deficiency decreased fractional accretion rate, increased (P < .05) urine excretion, and tended to increase (P < .19) Na and decrease (P < .12) K concentrations in the urine.

Animals↗
PubMed1996

Vitamin E supplementation and stress affect tissue alpha-tocopherol content of beef heifers.

The effect of stress on tissue alpha-tocopherol was investigated in 16 crossbred heifers fed a corn/corn silage-based diet. For 28 d, eight heifers (379 +/- 10 kg BW) received a dietary supplement of 1,000 IU of dl-alpha-tocopheryl acetate, whereas the controls (375 +/- 10 kg BW) received no supplemental vitamin E. Tissue samples of plasma, red blood cells, liver, trapezius, and longissimus muscles and subcutaneous fat immediately dorsal to each muscle were taken on d 1 for determination of alpha-tocopherol concentration. On d 2 through 4 each heifer was restricted to 2.61 kg of grass hay and allowed water. On d 5, 6, and 7 no feed or water was given, 100 IU of ACTH and .0024 mg of epinephrine/kg BW were given every 8 h, and biopsies for alpha-tocopherol content were again taken on d 7. The stress reduced (P < .01) mean BW, increased (P < .01) serum cortisol, creatine kinase, and urea. After stress, supplemental vitamin E reduced (P < .13) the increase in creatine kinase relative to that in heifers not supplemented with vitamin E. Stress also increased (P < .04) serum Se in heifers fortified with the vitamin E. Alpha-tocopherol content of plasma, red blood cells, liver, and subcutaneous fat dorsal to the trapezius muscle was increased (P < .01) by supplemental vitamin E. The stress treatment reduced (P < .01) alpha-tocopherol content of plasma in those fed the vitamin E and increased it (P < .05) in the nonsupplemented vitamin E-deficient heifers. Stress also decreased red blood cell (P < .01) and liver (P < .05) alpha-tocopherol content in cattle supplemented with vitamin E. Tissue alpha-tocopherol concentrations were reduced by stress only when a diet adequate in vitamin E was fed. In addition, in most sampled tissues, stress did not affect alpha-tocopherol concentrations.

Adipose Tissue↗
PubMed1993

Stress induction affects copper and zinc balance in calves fed organic and inorganic copper and zinc sources.

This study determined whether Cu and Zn balance was affected by feeding either Zn methionine (ZnMet) + Cu lysine (CuLys) or Zn sulfate (ZnSO4) + Cu sulfate (CuSO4) before and after stressing calves. Eight Charolais crossbred steer calves weighting 167 +/- 5 kg were randomly assigned to two treatments in a crossover experimental design. The millet hay and soybean meal diet when supplemented with the inorganic salts provided 9.2 ppm of Cu and 36.6 ppm of Zn or when fortified with the metal complexes contained 10.5 ppm of Cu and 36.6 ppm of Zn. Gentled calves were fed their respective diets for 28 d before an 18-d mineral balance trial was conducted. Collection consisted of five periods: 1) a 5-d baseline period, 2) 3 d of no Cu and Zn supplement, 3) 3 d of stress consisting of feed and water restriction and ACTH (80 IU) injections i.m. every 8 h, 4) 3 d of refeeding with no Cu and Zn supplement, and 5) 4 d of Cu and Zn repletion. Calves fed CuLys had 53% greater apparent Cu absorption and increased Cu retention (P < .05) during repletion compared with calves fed CuSO4. The 18-d mean retention of Cu from CuLys was greater (P < .05) than that from CuSO4. No differences (P > .05) in apparent absorption or retention of Zn were found between Zn sources, although during the 18-d trial mean retention was 58% higher when ZnMet was fed. Urinary Cu and Zn excretion decreased (P < .01) during stress.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Effects of shipping, handling, adrenocorticotropic hormone, and epinephrine on alpha-tocopherol content of bovine blood.

In 2 studies, plasma, erythrocyte, and neutrophil alpha-tocopherol concentrations were monitored in beef cattle after shipping, handling, and sample collection. On the basis of alpha-tocopherol results, an additional 2 studies were designed to measure the effects of administration of adrenocorticotropic hormone (ACTH) and epinephrine on the alpha-tocopherol concentration in the aforementioned blood constituents and on creatine kinase (CK) activity in Holstein calves. In the first of these studies, 15 beef cattle that had recently arrived at the feedlot consumed feed supplemented daily with 1,000 IU of dl-alpha-tocopheryl acetate. Values for initial blood samples indicated that CK activity was high. Although plasma alpha-tocopherol concentration indicated that vitamin supplementation was adequate, RBC and neutrophil alpha-tocopherol values were generally nondetectable. After 4 weeks of supplementation, plasma alpha-tocopherol concentration increased (P < 0.05), and neutrophil and RBC alpha-tocopherol values became measurable in most of the cattle. In the second study, 6 beef heifers had decreased (P < 0.05) plasma, RBC, and neutrophil alpha-tocopherol values after multiple periods of handling and blood sample collection. In the third and fourth studies, 10 tamed Holstein heifer calves, 5 of which were administered ACTH and epinephrine to simulate stress effects on blood alpha-tocopherol concentrations and CK activity. In study 3, the vitamin E-adequate heifers had increased blood CK (P < 0.001) activity and cortisol (P < 0.01) concentration, and decreased (P < 0.05) neutrophil alpha-tocopherol concentration after hormone injections.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1992

Cattle blood plasma and red blood cell alpha-tocopherol levels in response to different chemical forms and routes of administration of vitamin E.

The chemical form and site of administration of vitamin E were assessed in cattle by measuring area under the time curve alpha-tocopherol levels in plasma and red blood cells (RBC). In Exp. 1, four groups of Holstein calves, 4 to 6 d old, received daily one of the following forms equivalent to 228 mg of alpha-tocopherol: D-alpha-tocopheryl acetate (DTA); DL-alpha-tocopheryl acetate (DLTA); D-alpha-tocopheryl polyethylene glycol 1,000 succinate (TPGS); and an experimental blend (EB) containing DTA and TPGS. A control group received no supplement. Temporal alpha-tocopherol responses were determined in blood samples collected for 35 d. Relative to controls whose plasma and RBC alpha-tocopherol levels remained unchanged, all supplementation increased (P less than .05) alpha-tocopherol levels in plasma and RBC in calves; the highest levels occurred in those that received either DTA or EB. In a second experiment, five Hereford steers with ruminal and duodenal cannulas were used in a crossover design to determine whether site of vitamin E administration affected plasma alpha-tocopherol levels. A single dose of 810 mg of DTA was placed daily into the rumen, and the same amount divided into five equal doses was given (into the duodenum) during a 12-h period. Plasma alpha-tocopherol levels were higher (P less than .05) when steers were ruminally dosed than when they were dosed duodenally. The results suggest that the alpha-tocopherol concentration of plasma and red blood cells in cattle depends on both the chemical form and on the site of administration.

Administration, Oral↗
PubMed1991

The effects of stress, Escherichia coli, dietary ethylenediaminetetraacetic acid, and their interaction on tissue trace elements in chicks.

The present study determined effects of Escherichia coli infection, crowding stress, and EDTA supplementation on Cu, Fe, and Zn levels in the serum, liver, bursa of Fabricius, and spleen of chickens. Organ weights as a percentage of BW were affected by treatments prior to and after infection. Liver and spleen weights as a percentage of BW increased with infection but bursa weight decreased. One week of stress increased hepatic Cu, but 3 wk of EDTA ingestion increased serum Cu and serum, hepatic, bursal, and splenic Fe. These elemental changes resulting from EDTA may have predisposed the chicks to a higher mortality rate from E. coli compared with controls. Peak mortality occurred 2 days after infection, coincident with an increased serum Cu, decreased serum and bursal Fe and Zn, and increased hepatic and splenic Zn. At 7 days postinfection, recovering chicks experienced decreased hepatic Fe, elevated hepatic Zn, decreased bursal Cu, Fe, and Zn, and increased splenic Cu, Fe, and Zn. The current study demonstrates the interactive effects of EDTA, stress, and E. coli infection on serum and organ trace element concentration.

Animals↗
PubMed1990

Effects of transportation on early embryonic death in mares.

Incidence of early embryonic death (EED) and associated changes in serum cortisol, progesterone and plasma ascorbic acid (AA) in transported mares were investigated. Mares were transported for 472 km (9 h) during either d 16 to 22 (T-3 wk, n = 15) or d 32 to 38 (T-5 wk, n = 15) of gestation. Blood samples were drawn from control, nontransported mares (NT-3 wk, NT-5 wk, n = 24) and transported mares pre-trip, midtrip, and at 0, 12, 24, 48 and 72 h post-transport and daily for the next 2 wk. Incidence of EED between transported and nontransported mares was not different (P greater than .05). Serum cortisol in all transported mares increased (P less than .05) relative to pre-trip values at midtrip and 0 h post-transport. Relative to NT mares, serum cortisol was higher (P less than .05) at midtrip in T-3 wk mares and 0 h post-transport in T-5 wk mares. Serum progesterone in all T mares increased (P less than .05) at midtrip relative to pre-trip values and was higher (P less than .05) in T-3 wk mares than in NT-3 wk mares at midtrip and 0 h post-transport. Post-transport decreases (P less than .05) in concentrations of progesterone were observed in mares that aborted. Plasma AA in transported mares increased (P less than .05) at midtrip in T-5 wk mares and decreased (P less than .05) relative to pre-trip values at 24 and 48 h post-transport (T-3 wk and T-5 wk mares, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Endocrine and metabolic changes during altered growth rates in beef cattle.

Eight steers from a group of 14 were fed ad libitum from 240 to 510 kg live weight, gaining at 1.4 +/- .2 kg/d. The six other steers were diet-restricted and grew at .37 +/- .09 kg/d from 240 to 307 kg, prior to ad libitum realimentation on the same diet to a final weight of 510 kg. Blood samples taken during the growth phases from both treatments were analyzed for insulin-like growth factor-I (IGF-I), triiodothyronine (T3), thyroxine (T4), glucose (GLU), nonesterified fatty acids (NEFA), and blood urea nitrogen (BUN) and (or) growth hormone (GH). During restricted growth, mean serum concentrations of GH were elevated (45.6 vs 23.4 ng/ml; P less than .05), serum concentrations of IGF-I decreased (108 vs 167 ng/ml; P less than .05) compared with control steers with ad libitum access to feed. Levels of T4 and GLU also were lower (P less than .05) during restricted than during normal growth. During early realimentation, levels of GLU (P less than .05), IGF-I (P less than .01), T4 and BUN (P less than .01) increased. Levels of T3 remained unchanged, whereas concentration of NEFA declined (P less than .001). Blood urea nitrogen decreased during early realimentation despite a large increase in diet protein intake and in protein storage, suggesting an increased efficiency of nitrogen use for protein synthesis. During realimentation, IGF-I levels rose above those of control steers and remained higher at the final weight of 510 kg (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1988

The role of vitamins in modulating disease resistance.

Many of the metabolic incursions resulting from stress and oxidative damage are detrimental to disease resistance. Vitamins A, E, and C and carotenoids are able to protect cells from free radical oxidation, reduce the detrimental effects of certain eicosanoids, and enhance humoral and cellular immune responses in disease. The regulation of cell differentiation by vitamin A in maintaining an epithelial barrier to pathogen entry and the differentiation of precursor cells to functional lymphocytes by 1,25-dihydroxycholecalciferol are essential to disease resistance. Nutritionists must redefine the levels of vitamins necessary to maximize health-supportive systems. The animal's metabolism must constantly be adjusting to its environmental stress or disease and may require increased vitamins.

Animals↗
PubMed1988

Differences in diagnostic test results and hematologic data between aged and young horses.

Hematologic data and results of diagnostic tests were compared between aged (greater than or equal to 20 years old) and young (less than or equal to 5 years old) horses to identify hematologic and metabolic changes associated with aging. Initial data were obtained from 8 aged and 6 young mares (group 1). Similar data were collected from a second group of aged (3 mares and 3 geldings) and young (1 mare and 5 geldings) horses (group 2). Dexamethasone suppression tests (DST) and necropsies were performed on 6 additional mares and mare 8 from group 1 (group 3). Complete blood counts and serum biochemical profiles were compared between young and aged horses of groups 1 and 2. Mean corpuscular volume was higher (P less than 0.05) in aged horses. Oral glucose tolerance and insulin response to orally administered glucose were measured in 13 aged horses (groups 1 and 2) and 6 young mares of group 1. In group 1, plasma ascorbic acid values were lower (P less than 0.05) in aged horses than in young horses maintained under the same conditions and feeding regimens. An apparent age-related hyperinsulinemic response to orally administered glucose identified in group-1 mares was probably a result of a high occurrence of subclinical hypophyseal and/or thyroid adenomas. Of 13 aged horses necropsied (groups 2 and 3), 10 had hypophyseal and/or thyroid adenomas that, in group 2, were consistently associated (P less than 0.05) with hyperinsulinemic responses to orally administered glucose. All horses in groups 2 and 3 were given a 24-hour DST.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1986

The influence of supplemental vitamins A and E on ovine humoral immune response.

These experiments determined if supplemental vitamins A and/or E would enhance ovine antibody responses. All-rac-alpha-tocopheryl acetate was fed to lambs approximately 6 months old (30 to 40 kg) at levels of 33 (controls), 121, 276, 396, and 476 mg/kg of feed (which are total vitamin E levels). Primary and secondary immunizations with 10 mg keyhole limpet hemocyanin (KLH) were given. A nonlinear dose response of serum antibody titers was observed and the 476 mg vitamin E/kg treatment significantly enhanced (P less than 0.05) the peak primary response over controls. Retinyl acetate fed at five levels ranging from 7000 (the control level) to 97,400 IU/kg feed failed to influence antibody production to 10 mg KLH of lambs about 6 months old (29 to 41 kg). There was no detectable response to an ovalbumin antigen (100 mg). Neonatal lambs were injected with retinyl palmitate or the carrier of the injected vitamin. These lambs failed to raise antibody titers to either of the antigens administered (10 mg KLH, 100 mg ovalbumin). This was apparently due to a neonatal period of immune paralysis to certain antigens. A preliminary study showed that no KLH-specific antibodies are detectable in lambs immunized earlier than 7 weeks of age. Lambs in this age range were utilized in the last trial in which four treatments were applied: 3000 mg oral vitamin E, 400,000 IU injected vitamin A, 4 ml of the injectable vitamin A carrier, or no treatment. Half of the animals in each of these groups were immunized with 15 mg KLH and 1 ml Brucella ovis bacterin and the other half served as nonimmunized controls. No significant differences in titers to KLH were observed. Lambs receiving 3000 mg vitamin E or the carrier produced secondary peak anti-B. ovis titers higher (P less than 0.05) than those of the untreated controls.

Animals↗
PubMed1984

Hypothyroidism: an early sign of vitamin A deficiency in chickens.

The effect of a marginal vitamin A deficiency on thyroid function was investigated in chicks gaining weight. This study examined the hypothesis that hypothyroidism is one of the earliest manifestations of hypovitaminosis A in chicks. Day-old Leghorn cockerels were fed vitamin A-adequate and deficient diets. Blood vitamin A levels were reduced in the deficient chicks by 3 weeks of age. Body weight gains were less in the 5-, 6-, 7- and 8-week-old A-deficient chicks than in controls. Compared to controls, vitamin A-deficient chicks were characterized by thyroid follicle hypertrophy by 4 weeks, heavier thyroids as a percent of body weight at 5 weeks, less serum thyroxine (T4) at 7 weeks and lower serum triiodothyronine (T3) and T4 at 8 weeks. These results indicate that one of the earliest signs of vitamin A deficiency in chicks is hypothyroidism.

Animals↗
PubMed1981

Vitamin E and aspirin depress prostaglandins in protection of chickens against Escherichia coli infection.

The hypothesis was tested that vitamin E protects chickens from a lethal Escherichia coli infection by inhibiting the biosynthesis of prostaglandins, thereby activating humoral immunity and phagocytosis. When chickens were fed supplement vitamin E at the level of 300 mg/kg diet, which is six times the presently used dietary level, endogenous PGE1, PGE2, and PGF2 alpha levels decreased in the immunopoietic organs, bursa, and spleen. Antibody titers to E. coli lipopolysaccharide and phagocytosis increased at the same time. Infection slightly increased prostaglandin levels and vitamin E appeared to compensate for this increase. Aspirin, a known prostaglandin inhibitor acted synergistically with vitamin E in depressing endogenous PG levels in bursa and decreasing mortality from E. coli infection.

Animals↗
PubMed1979

Protective effects of supplemental vitamin E against infection.

Vitamin E supplementation (dl-alpha-tocopheryl acetate except where noted) in excess of requirement significantly increased humoral immune response or disease resistance. Mice immunized with sheep red blood cells or tetanus toxoid and fed the supplemental vitamin demonstrated increased plaque-forming cells (PFC) and hemagglutinin (HA) titers. A vitamin E deficiency resulted in decreased PFC and little IgG which was partially corrected by N,N-diphenyl-p-phenylenediamine but not as effectively as by vitamin E. Hens immunized with Brucella abortus and fed different levels of the vitamin produced chicks with increased passive immunity; a biphasic antibody response to the level of the vitamin fed was noted. Vitamin E fed to nonimmunized hens was found to significantly increase the primary immune response of their immunized chicks. Feeding dl-alpha-tocopheryl acetate to guinea pigs immunized with Venezuelan equine encephalomyelitis virus resulted in no increased immunity. Injecting this form of the vitamin resulted in severe tissue reaction. However, injecting dl-alpha-tocopheryl significantly improved hemagglutinin inhibition titers. Chicks and turkeys infected with Escherichia coli and fed supplemental vitamin E had reduced mortality and increased HA titers. Sheep fed vitamin E and challenged with Chlamydia had improved weight gains and no detectable Chlamydia.

Animals↗
PubMed1978

Maternal vitamin E alters passively acquired immunity of chicks.

Passively transferred antibody levels were significantly increased in plasma of two- and seven-day-old chicks when the dams were fed 150 and 450 p.p.m. vitamin E prior to immunization with Brucella abortus. However, if the hens were fed 90, 300 and 900 p.p.m. vitamin E before immunization, the chicks evidenced no increase in antibody titers relative to controls. This nonlinear antibody response by the reticulo-endothelial system to vitamin E confirms in Gallus domesticus similar results reported for other species.

Animals↗